corticosteroid receptors and unipolar depression


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(Updated 4/27/04)

[See also CRF and Unipolar Depression.]

Peeters F, Nicolson NA, Berkhof J.
Levels and variability of daily life cortisol secretion in major depression.
Psychiatry Res. 2004 Apr 15;126(1):1-13.
"Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is an important feature of major depressive disorder (MDD), but relatively little attention has been given to within-person variability of hormone secretion over time. Because most studies have been conducted in hospital settings, little information is available about naturally occurring patterns of cortisol secretion throughout the day in depressed outpatients. Multiple salivary cortisol samples were obtained over a 6-day period from 47 outpatients with MDD and 39 healthy controls in their everyday environment. We used multilevel regression analysis to estimate the effects of MDD and associated clinical characteristics on cortisol levels and intraindividual variability. Although more severe symptoms were associated with small elevations in cortisol levels, we found no clear evidence for hypercortisolism in the MDD group as a whole. However, cortisol output in MDD outpatients was less stable from sample to sample, as evidenced by a significantly lower autocorrelation than that observed in controls. Secretory patterns were particularly erratic in patients with more severe or recurrent episodes. Findings suggest that erratic cortisol secretion may be a more characteristic feature of HPA axis dysregulation in MDD than hypercortisolism, especially in outpatient populations." [Abstract]

Raison, Charles L., Miller, Andrew H.
When Not Enough Is Too Much: The Role of Insufficient Glucocorticoid Signaling in the Pathophysiology of Stress-Related Disorders
Am J Psychiatry 2003 160: 1554-1565
"OBJECTIVE: Previous theories have emphasized the role of excessive glucocorticoid activity in the pathology of chronic stress. Nevertheless, insufficient glucocorticoid signaling (resulting from decreased hormone bioavailability or reduced hormone sensitivity) may have equally devastating effects on bodily function. Such effects may be related in part to the role of glucocorticoids in restraining activation of the immune system and other components of the stress response, including the sympathetic nervous system (SNS) and corticotropin-releasing hormone (CRH). METHOD: The literature on neuroendocrine function and glucocorticoid-relevant pathologies in stress-related neuropsychiatric disorders, including posttraumatic stress disorder and major depression, was reviewed. RESULTS: Although not occurring together, both hypocortisolism and reduced responsiveness to glucocorticoids (as determined by dexamethasone challenge tests) were reliably found. Stress-related neuropsychiatric disorders were also associated with immune system activation/inflammation, high SNS tone, and CRH hypersecretion, which are all consistent with insufficient glucocorticoid-mediated regulation of stress hyperresponsiveness. Finally, antidepressants, a mainstay in the treatment of stress-related disorders, were regularly associated with evidence of enhanced glucocorticoid signaling. CONCLUSIONS: Neuroendocrine data provide evidence of insufficient glucocorticoid signaling in stress-related neuropsychiatric disorders. Impaired feedback regulation of relevant stress responses, especially immune activation/inflammation, may, in turn, contribute to stress-related pathology, including alterations in behavior, insulin sensitivity, bone metabolism, and acquired immune responses. From an evolutionary perspective, reduced glucocorticoid signaling, whether achieved at the level of the hormone or its receptor, may foster immune readiness and increase arousal. Emphasis on insufficient glucocorticoid signaling in stress-related pathology encourages development of therapeutic strategies to enhance glucocorticoid signaling pathways." [Abstract]


Pariante CM, Miller AH.
Glucocorticoid receptors in major depression: relevance to pathophysiology and treatment.
Biol Psychiatry 2001 Mar 1;49(5):391-404
"Hyperactivity of the hypothalamic--pituitary--adrenal (HPA) axis has been reliably observed in patients with major depression. One of the primary features of this HPA axis hyperactivity is reduced sensitivity to the inhibitory effects of the glucocorticoid dexamethasone on the production of adrenocorticotropic hormone and cortisol during the dexamethasone suppression test and, more recently, the dexamethasone--corticotropin-releasing hormone test. Because the effects of glucocorticoids are mediated by intracellular receptors including, most notably, the glucocorticoid receptor (GR), a number of studies have considered the possibility that the number and/or function of GRs are reduced in depressed patients. Moreover, whether antidepressants act by reversing these putative GR changes has been examined. The extant literature on GR receptors in major depression was reviewed along with studies examining the impact of antidepressants on the GR. The data support the hypothesis that the function of the GR is reduced in major depression in the absence of clear evidence of decreased GR expression. The data also indicate that some antidepressants have direct effects on the GR, leading to enhanced GR function and increased GR expression. Hypotheses regarding the mechanism of these receptor changes involve relevant second messenger pathways that regulate GR function. The findings indicate that the GR is an important molecular target in major depression. Further elucidation of the biochemical and molecular mechanisms involved in GR changes in major depression is an exciting frontier that will no doubt lead to new insights into the pathophysiology and treatment of affective disorders." [Abstract]

Webster MJ, Knable MB, O'Grady J, Orthmann J, Weickert CS.
Regional specificity of brain glucocorticoid receptor mRNA alterations in subjects with schizophrenia and mood disorders.
Mol Psychiatry 2002;7(9):985-94, 924
"Glucocorticoid receptors (GR) mediate the direct effects of glucocorticoids released in response to stress and the regulation of the hypothalamic-pituitary-adrenocortical (HPA) system through a negative feedback mechanism. Individuals with major mental illness, who often exhibit hypercortisolemia, may have down-regulated levels of GR mRNA. In situ hybridization for GR mRNA was performed on post-mortem specimens from patients suffering from depression, bipolar disorder, schizophrenia and from normal controls (n = 15 per group). In frontal cortex, GR mRNA levels were decreased in layers III-VI in the subjects with depression and schizophrenia. In inferior temporal cortex, GR mRNA levels were decreased in layer IV in all three diagnostic groups. In the entorhinal cortex, GR mRNA levels were decreased in layers III and VI in the bipolar group. In hippocampus, GR mRNA levels were reduced in the dentate gyrus, CA(4), CA(3) and CA(1) in the schizophrenia group. In the subiculum, GR mRNA levels were reduced in the bipolar group. These results suggest that GR dysregulation occurs in all three major psychiatric illnesses with variability according to anatomical site. The severity and heterogeneity of this reduction may underlie some of the clinical heterogeneity seen in these disorders." [Abstract]

Kling MA, Whitfield HJ Jr, Brandt HA, Demitrack MA, Kalogeras K, Geracioti TD, Perini GI, Calabrese JR, Chrousos GP, Gold PW.
Effects of glucocorticoid antagonism with RU 486 on pituitary-adrenal function in patients with major depression: time-dependent enhancement of plasma ACTH secretion.
Psychopharmacol Bull 1989;25(3):466-72
"Data from our group and others suggest that pituitary-adrenal activation in major depression reflects a defect at or above the hypothalamus which results in the hypersecretion of corticotropin-releasing hormone (CRH); some have suggested, however, that elevated indices of cortisol secretion and lack of suppressibility to dexamethasone may be a manifestation of a primary defect in glucocorticoid receptor activation. We report here a study of early morning pituitary-adrenal responses to the glucocorticoid antagonist RU 486 in patients with major depression and healthy volunteers. Previous data suggested that the response to RU 486 could represent an index of endogenous CRH secretory activity. RU 486 produced a robust increase in plasma corticotropin (ACTH) and cortisol secretion in both control subjects and depressed patients. In the controls, however, the increase was confined to the last 2 hours of sampling (6 to 8 am), whereas in the depressed patients the increase occurred throughout the sampling period (3 to 8 am). The ACTH response in the depressed patients exceeded that in the controls during most of the sampling period, including a significant (p less than .005) increase between 3 and 4:30 am. These results are compatible with the idea that hypercortisolism in major depression represents an alteration in the overall set point for hypothalamic CRH secretion rather than a primary alteration at the level of the glucocorticoid receptor." [Abstract]

Holsboer F.
Stress, hypercortisolism and corticosteroid receptors in depression: implications for therapy.
J Affect Disord 2001 Jan;62(1-2):77-91
"Clinical and preclinical studies have gathered substantial evidence that alterations of the stress hormone system play a major, causal role in the development of depression. In this review article, a summary of studies sustaining that view is given and data are presented which demonstrate that depression is associated with an impairment of corticosteroid receptor function that gives rise to an excessive release of neurohormones to which a number of signs and symptoms characteristic of depression can be attributed. The studies referred to in the following unanimously support the concept of an antidepressant mechanism of action that exerts its effects beyond the cell membrane receptors of biogenic amines and particularly includes the improvement of corticosteroid receptor function. When activated by ligands, corticosteroid receptors act as transcription factors in correspondence with numerous other transcription factors already known to be activated by antidepressants. Furthermore, the potential of drugs that interfere more directly with stress hormone regulation, such as corticosteroid receptor antagonists and corticotropin-releasing hormone receptor antagonists, is discussed." [Abstract]

Holsboer F.
The corticosteroid receptor hypothesis of depression.
Neuropsychopharmacology 2000 Nov;23(5):477-501
"Signs and symptoms that are characteristic for depression include changes in the setpoint of the hypothalamic-pituitary-adrenocortical (HPA) system, which in the majority of these patients result in altered regulation of corticotropin (ACTH) and cortisol secretory activity. More refined analysis of the HPA system revealed that corticosteroid receptor (CR) signaling is impaired in major depression, resulting among other changes, in increased production and secretion of corticotropin-releasing hormone (CRH, also frequently abbreviated CRF) in various brain regions postulated to be involved in the causality of depression. This article summarizes the clinical and preclinical data, supporting the concept that impaired CR signaling is a key mechanism in the pathogenesis of depression. Mouse genetics, allowing for selective inactivation of genes relevant for HPA regulation and molecular pharmacology, dissecting the intracellular cascade of CR signaling, are the most promising future research fields, suited for identifying genes predisposing to depression. Focusing on these two research lines may also allow to gain insight into understanding how current antidepressants work and further, how more specific targets for future antidepressant drugs can be identified." [Abstract]

Hugin-Flores ME, Steimer T, Schulz P, Vallotton MB, Aubert ML.
Chronic corticotropin-releasing hormone and vasopressin regulate corticosteroid receptors in rat hippocampus and anterior pituitary.
Brain Res 2003 Jun 27;976(2):159-170
"Corticotropin-releasing hormone (CRH) and vasopressin (AVP) participate in the endocrine, autonomic, immunological and behavioral response to stress. CRH and AVP receptors are found in hippocampus and anterior pituitary, where mineralocorticoid (MR) and glucocorticoid (GR) receptors are abundant. We investigated the possible influence of CRH and AVP on the regulation of MR and GR in both tissues. CRH, AVP, or their antagonists were administered to adrenalectomized rats substituted with corticosterone, to avoid interference with adrenal secretion. Repeated i.c.v. oCRH injections (10 &mgr;g) for 5 days significantly decreased MR and GR mRNA in hippocampus and MR mRNA in anterior pituitary. AVP significantly increased both corticosteroid receptor mRNAs, as repeated i.c.v. injections (5 &mgr;g) for 5 days in hippocampus, and as continuous i.c.v. infusion (10 ng/h/5 days) in anterior pituitary. The i.c.v. infusion of 5 or 10 &mgr;g/day of the alpha-helical CRH antagonist during intermittent restraint stress (5 days), induced a significant decrease in hippocampal MR binding. In anterior pituitary, 5 &mgr;g/day significantly decreased MR binding, while 10 &mgr;g/day significantly increased GR binding. Under the same conditions of stress, the infusion of 15 &mgr;g/day of the vasopressin V1a/1b receptor antagonist [dP Tyr (Me)(2)AVP] significantly increased MR and GR binding in hippocampus and anterior pituitary; 5 &mgr;g/day significantly decreased pituitary MR binding. Our results show that CRH and AVP regulate MR and GR in hippocampus and anterior pituitary. This reveals another important function of CRH and AVP, which could be relevant to understand stress adaptation and the pathophysiology of stress-related disorders like major depression." [Abstract]


van Haarst AD, Oitzl MS, Workel JO, de Kloet ER.
Chronic brain glucocorticoid receptor blockade enhances the rise in circadian and stress-induced pituitary-adrenal activity.
Endocrinology 1996 Nov;137(11):4935-43
"This study examined the hypothesis that experimentally induced corticosteroid resistance in the brain would lead to adaptations in the activity of the hypothalamic-pituitary-adrenal (HPA) axis similar to the endocrine features of the endogenous resistance accompanying the pathogenesis of depression. For this purpose, the glucocorticoid antagonist RU 38486 (aGC) was infused intracerebroventricularly (i.c.v.) (100 ng/h) via Alzet minipumps for several days. During this chronic receptor blockade, parameters for basal and stress-induced HPA activity were measured in a longitudinal study design. Chronic i.c.v. infusion of the aGC did not affect basal morning levels of ACTH and corticosterone. During the afternoon phase of the circadian cycle, the aGC caused gradual and sequential changes in the HPA axis. After aGC infusion, the circadian rise of ACTH levels was enhanced in the afternoon of day 1, but was normal on subsequent days. For corticosterone, basal afternoon levels towards the diurnal peak were increased at days 1, 3, and 4 in aGC-treated rats. On day 2, in contrast, corticosterone levels did not differ from vehicle-infused controls. Paraventricular CRH messenger RNA, as measured at day 4, was not altered by aGC treatment. After 10 days of aGC treatment, the adrenal weight was increased, and the sensitivity of adrenocortical cells in vitro to ACTH was enhanced. Corticosteroid receptor binding in vitro in hippocampus, hypothalamus, and pituitary was not different between the aGC and vehicle-treated rats. In a second series of experiments, the HPA responsiveness to the stress of a novel environment at day 2 in the morning was increased after chronic aGC infusion, at a time basal hormone levels were not affected. The data show that 1) chronic i.c.v. infusion of aGC readily enhances the amplitude of circadian corticosterone changes, presumably by increasing the adrenocortical sensitivity to ACTH; 2) chronic aGC-treated animals show an enhanced ACTH and corticosterone response to stress, which is delayed in termination; 3) corticosteroid receptor expression, basal CRH messenger RNA, and ACTH levels are not altered after prolonged chronic aGC treatment. It is concluded that, over a period of a few days, aGC-induced corticosteroid resistance triggers a sequelae of pituitary-adrenal adaptations ultimately resulting in hypercorticism. Paradoxically, however, this hypercorticism develops because of increased peak levels of corticosteroid hormone rather than through elevated trough levels as is commonly observed during depressive illness." [Abstract]

Dijkstra, Ivar, Tilders, Fred J. H., Aguilera, Greti, Kiss, Alexander, Rabadan-Diehl, Cristina, Barden, Nicholas, Karanth, Sharada, Holsboer, Florian, Reul, Johannes M. H. M.
Reduced Activity of Hypothalamic Corticotropin-Releasing Hormone Neurons in Transgenic Mice with Impaired Glucocorticoid Receptor Function
J. Neurosci. 1998 18: 3909-3918
"Loss of central glucocorticoid receptor (GR) function is thought to be involved in the development of neuroendocrine and psychiatric disorders associated with corticotropin-releasing hormone (CRH) hyperactivity. The possible causal relationship between defective GR function and altered activity of CRH neurons was studied in transgenic mice (TG) expressing antisense RNA against GR. Immunocytochemical studies showed significant reductions in CRH immunoreactive neurons in the paraventricular nucleus (PVN) and in CRH and vasopressin (AVP) stores in the external zone of the median eminence. Concomitantly, stimulus-evoked CRH secretion from mediobasal hypothalami of TG mice in vitro was reduced significantly. However, CRH mRNA levels in the PVN of TG mice were marginally lower than those in wild-type (WT) mice. 125I-CRH binding autoradiography revealed no differences between WT and TG animals in any of the brain regions that were studied. Basal plasma corticosterone (cort) levels and 125I-CRH binding, CRH-R1 mRNA, POMC mRNA, and POMC hnRNA levels in the anterior pituitary gland were similar in WT and TG mice. Intraperitoneal injection of interleukin-1beta (IL-1beta) increased plasma cort levels, CRH mRNA in the PVN, and anterior pituitary POMC hnRNA similarly in WT and TG mice. The injection of saline significantly reduced anterior pituitary CRH-R1 mRNA levels in WT mice, but not in TG mice, whereas IL-1beta produced a decrease in these mRNA levels in both strains. The data show that long-term GR dysfunction can be associated with reduced activity of CRH neurons in the PVN and decreased sensitivity of pituitary CRH-R1 mRNA to stimulus-induced downregulation. Moreover, the hypothalamic changes observed in this model suggest that impaired GR function, at least if present since early embryonic life, does not necessarily result in CRH hyperexpression characteristics of disorders such as major depression." [Full Text]

Sharada Karanth, Astrid C. E. Linthorst, Günther K. Stalla, Nicholas Barden, Florian Holsboer, and Johannes M. H. M. Reul
Hypothalamic-Pituitary-Adrenocortical Axis Changes in a Transgenic Mouse with Impaired Glucocorticoid Receptor Function
Endocrinology 138: 3476-3485
"Recently, a transgenic mouse with impaired glucocorticoid receptor (GR) function was created to serve as an animal model for the study of neuroendocrine changes occurring in stress-related disorders, such as major depression. Here, we investigated the hypothalamic-pituitary-adrenocortical (HPA) axis changes in these transgenic mice. There were no significant differences between basal early morning plasma ACTH and corticosterone levels in normal and transgenic mice. When animals were exposed to a mild stressor, an enhanced response in plasma ACTH was observed in the transgenic mice, whereas plasma corticosterone responses were not different. In view of these differences in plasma ACTH and corticosterone responses, we directed our studies toward the regulation of ACTH secretion on the hypothalamic-hypophyseal level in vitro. Therefore, an in vitro model, the pituitary-hypothalamic complex (PHc) was developed and its ACTH release profile was compared with that of the pituitary (PI) alone. The basal ACTH release by PHc and PI from normal and transgenic mice was similar. Regardless of the strain under study, the basal ACTH release by PI was significantly lower than the release by PHc. Stimulation of tissues with either high K+ (56 mM) or CRH (10 or 20 nM) produced an enhanced ACTH release from both PHc and PI, whereas the response in PI was larger than that in PHC. Moreover, the responses to these stimuli were markedly enhanced in tissues from transgenic mice. In tissues of normal mice, corticosterone inhibited both basal and CRH-stimulated ACTH release more potently in PHc than in PI. Furthermore, the feedback capacity of corticosterone to restrain both basal and CRH-stimulated ACTH release was highly impaired in tissues of transgenic mice, whereas the feedback in PHc appeared to be more affected than that in the PI of these animals.

In conclusion, the in vitro data on PHc and PI revealed intrahypothalamic mechanisms operating 1) to fine-tune stimulus-evoked ACTH responses; and 2) to facilitate the negative feedback action of glucocorticoids. Moreover, in the transgenic tissues, the impaired GR function was found to cause augmented stimulus-evoked ACTH responses and an impaired glucocorticoid feedback efficacy which appeared to be mainly defective at the hypothalamic level. Thus, in the transgenic mice with life-long central GR dysfunction we found impaired negative feedback combined with "normal" (i.e. noncompensated) in vivo plasma corticosterone responses. This is a condition with potentially grave pathophysiological consequences and, therefore, this transgenic animal may be regarded as a valuable model for the study of functional glucocorticoid insufficiency at the central nervous system level." [Full Text]

Heuser I.
Anna-Monika-Prize paper. The hypothalamic-pituitary-adrenal system in depression.
Pharmacopsychiatry 1998 Jan;31(1):10-3
"Patients with depression frequently have symptom clusters which point strongly to involvement of the hypothalamic-pituitary-adrenal (HPA) system as a relay station between neurocircuitries in the brain and peripheral hormone and autonomic nervous function. It has been proposed that this increased, state-dependent hyperactivity of the HPA-system in depression is probably initiated and/or maintained by the combination of enhanced central production of CRH and desensitization of the binary, glucocorticoid receptor binding system in the hippocampus, which is the central regulator of HPA system activity. In a first series of studies a refined neuroendocrine test to probe the integrity of HPA system status--the combined dexamethasone suppression/CRH challenge (DEX/CRH) test--was developed and the differential effects of aging and depressed psychopathology on DEX/CRH test outcome were described. In a second set of studies, the chronological relationship between improvement of psychopathology in depressed patients treated with antidepressants and normalization of the disturbed HPA system function in these patients was further elucidated. Given the evidence from animal studies, we conclude that antidepressants induce an up-regulation of hippocampal glucocorticoid receptor mRNA concentration, thus amplifying the negative feedback effect of glucocorticoids. This then results in the normalization of DEX/CRH test results observed in the depressed patients in our study. We further conclude that dampening of HPA system hyperactivity in depression by means of antidepressants is a conditio sine qua non for successful improvement of psychopathology." [Abstract]

Montkowski A, Barden N, Wotjak C, Stec I, Ganster J, Meaney M, Engelmann M, Reul JM, Landgraf R, Holsboer F.
Long-term antidepressant treatment reduces behavioural deficits in transgenic mice with impaired glucocorticoid receptor function.
J Neuroendocrinol 1995 Nov;7(11):841-5
"Impaired cognitive function and enhanced activity of the hypothalamic-pituitary-adrenocortical system are among the cardinal symptoms of major depression in humans that resolve after successful antidepressant treatment. We used a transgenic mouse model expressing antisense RNA complementary to that of glucocorticoid receptor (GR) mRNA to test the hypothesis that reduced GR function can cause these clinical disturbances. The transgenic mice show profound behavioural changes in a number of animal tests that are indicative of cognitive impairment. These mice also have elevated plasma corticotropin concentrations in response to stress. After long-term treatment with moclobemide, a reversible inhibitor of monoamine oxidase type A that acts clinically as an antidepressant, both the behavioural deficits and the hormonal alterations disappeared. These observations suggest that a transgenic mouse with GR dysfunction may be a useful model for investigation of drug effects on the cognitive and neuroendocrine aspects of depression." [Abstract]

Pepin MC, Pothier F, Barden N.
Antidepressant drug action in a transgenic mouse model of the endocrine changes seen in depression.
Mol Pharmacol 1992 Dec;42(6):991-5
"We have created transgenic mouse lines with impaired glucocorticoid receptor function by expression of a type II glucocorticoid receptor antisense RNA in brain tissues. These animals have endocrinological characteristics similar to those seen in depression, including a hyperactive hypothalamic-pituitary-adrenal axis as indicated by elevated plasma corticosterone and adrenocorticotropin hormone levels. Treatment of transgenic animals with the tricyclic antidepressant desipramine increased hypothalamic glucocorticoid receptor mRNA concentration and dexamethasone-binding activity while decreasing plasma adrenocorticotropin hormone concentration and corticosterone levels. These results support the hypothesis that antidepressants exert action on the hypothalamic-pituitary-adrenal axis through modulation of glucocorticoid receptor gene expression." [Abstract]

Barden N.
Regulation of corticosteroid receptor gene expression in depression and antidepressant action.
J Psychiatry Neurosci 1999 Jan;24(1):25-39
"OBJECTIVE: Major alterations of the hypothalamic-pituitary-adrenocortical (HPA) system are often seen in patients with depression, and can be reversed by successful antidepressant therapy. Persuasive evidence points to the involvement of a dysfunctional glucocorticoid receptor system in these changes. The authors developed a transgenic mouse to determine the mechanism for these changes. DESIGN: In vivo and in vitro animal experiments. ANIMALS: Transgenic mice expressing glucocorticoid receptor antisense RNA and control mice. INTERVENTIONS: In vivo: hormone assays and dexamethasone suppression tests; in vitro: cell transfection, chloramphenicol acetyl transferase assay, Northern blot analysis, binding assays of cytosolic receptor. OUTCOME MEASURES: Indicators of depressive disorder in transgenic mice, effect of antidepressant therapy on dexamethasone binding in transgenic mouse hippocampus, mouse behaviour, and glucocorticoid receptor activity. RESULTS: Transgenic mice showed no suppression of corticosterone with a dose of 2 mg per 100 g body weight dexamethasone. Treatment with amitriptyline reduced levels of corticotropin and corticosterone, increased glucocorticoid receptor mRNA concentrations and glucocorticoid binding capacity of several brain areas, and reversed behavioural changes. In vitro experiments also showed that desipramine increased glucocorticoid receptor mRNA. CONCLUSION: These transgenic mice have numerous neuroendocrine characteristics of human depression as well as altered behaviour. Many of these neuroendocrinologic and behavioural characteristics are reversed by antidepressants. The antidepressant-induced increase in glucocorticoid receptor activity may render the HPA axis more sensitive to glucocorticoid feedback. This new insight into antidepressant drug action suggests a novel approach to the development of new antidepressant drugs." [Abstract]


Okugawa G, Omori K, Suzukawa J, Fujiseki Y, Kinoshita T, Inagaki C.
Long-term treatment with antidepressants increases glucocorticoid receptor binding and gene expression in cultured rat hippocampal neurones.
J Neuroendocrinol 1999 Nov;11(11):887-95
"Since the glucocorticoid receptor (GR) and/or mineralocorticoid receptor (MR) in the hippocampus have been implicated in cortisol feedback of the hypothalamus-pituitary-adrenal (HPA) axis, abnormalities in those receptors might underlie the hyperactivity of the HPA axis described in patients with major depression. Animal studies have shown that long-term in-vivo treatment with antidepressants up-regulates hippocampal GR and/or MR, but it is not clear whether this up-regulation is evoked through a direct action of antidepressants on these receptors. We therefore examined the direct effects of long-term antidepressant treatment on GR binding and the levels of GR messenger RNA (mRNA) in primary cultures of rat hippocampal neurones. The time course of the effects of the tricyclic antidepressants desipramine and amitriptyline on GR binding, as assessed by [3H]dexamethasone binding using RU 28362, a specific agonist for GR, showed a biphasic mode of stimulation: desipramine significantly increased the GR binding with 2-day exposure by 36% over that in controls and by 99% and 60% with 10- and 14-day exposures, respectively. Amitriptyline also led to a significant increase in GR binding, with peaks at 2 (by 60%) and 14 days of exposure (by 60%). The effects of 14-day treatment with desipramine required at least the first 4-day exposure, and the first 10-day exposure was required for the full effect. Northern blot analysis demonstrated that the GR mRNA level was significantly increased by 14-day treatment with desipramine (+142% over control), amitriptyline (+108%), mianserin (+124%), paroxetine (+42%) and sulpiride (+92%), but not with haloperidol. Immunocytochemistry for GR revealed that 2- or 14-day treatment with desipramine significantly increased the number of GR-positive cells with dominant immunoreactivity in the nuclei of granule cell-like neurones or in perikarya of pyramidal cell- and granule cell-like neurones. These findings suggest that tricyclic antidepressants directly increase hippocampal GR by short-term (2-day) and long-term (14-day) exposure, and that the increase by long-term exposure is evoked commonly with different classes of antidepressants through transcriptional up-regulation of GR expression." [Abstract]

Brady LS, Gold PW, Herkenham M, Lynn AB, Whitfield HJ Jr.
The antidepressants fluoxetine, idazoxan and phenelzine alter corticotropin-releasing hormone and tyrosine hydroxylase mRNA levels in rat brain: therapeutic implications.
Brain Res 1992 Feb 14;572(1-2):117-25
"Various classes of antidepressant drugs with distinct pharmacologic actions are differentially effective in the treatment of classic melancholic depression--characterized by pathological hyperarousal and atypical depression--associated with lethargy, hypersomnia, and hyperphagia. All antidepressant agents exert their therapeutic efficacy only after prolonged administration. In situ hybridization histochemistry was used to examine in rats the effects of short-term (2 weeks) and long-term (8 weeks) administration of 3 different classes of activating antidepressant drugs which tend to be preferentially effective in treating atypical depressions, on the expression of central nervous system genes thought to be dysregulated in major depression. Daily administration (5 mg/kg, i.p.) of the selective 5-hydroxytryptophan (5-HT) reuptake inhibitor fluoxetine, the selective alpha 2-adrenergic receptor antagonist idazoxan, and the nonspecific monoamine oxidase A and B inhibitor phenelzine increased tyrosine hydroxylase mRNA levels by 70-150% in the locus coeruleus after 2 weeks of drug and by 71-115% after 8 weeks. The 3 drugs decreased corticotropin-releasing hormone mRNA levels by 30-48% in the paraventricular nucleus of the hypothalamus. The decreases occurred at 8 weeks but not at 2 weeks. No consistent change in steroid hormone receptor mRNA levels was seen in the hippocampus with the 3 drugs, but fluoxetine and idazoxan increased the level of mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) mRNA, respectively, after 8 weeks of drug administration. Proopiomelanocortin (POMC) mRNA levels in the anterior pituitary and plasma adrenocorticotropic-hormone (ACTH) levels were not altered after 2 or 8 weeks of drug treatment." [Abstract]

Brady LS, Whitfield HJ Jr, Fox RJ, Gold PW, Herkenham M.
Long-term antidepressant administration alters corticotropin-releasing hormone, tyrosine hydroxylase, and mineralocorticoid receptor gene expression in rat brain. Therapeutic implications.
J Clin Invest 1991 Mar;87(3):831-7
"Imipramine is the prototypic tricyclic antidepressant utilized in the treatment of major depression and exerts its therapeutic efficacy only after prolonged administration. We report a study of the effects of short-term (2 wk) and long-term (8 wk) administration of imipramine on the expression of central nervous system genes among those thought to be dysregulated in imipramine-responsive major depression. As assessed by in situ hybridization, 8 wk of daily imipramine treatment (5 mg/kg, i.p.) in rats decreased corticotropin-releasing hormone (CRH) mRNA levels by 37% in the paraventricular nucleus (PVN) of the hypothalamus and decreased tyrosine hydroxylase (TH) mRNA levels by 40% in the locus coeruleus (LC). These changes were associated with a 70% increase in mRNA levels of the hippocampal mineralocorticoid receptor (MR, type I) that is thought to play an important role in mediating the negative feedback effects of low levels of steroids on the hypothalamic-pituitary-adrenal (HPA) axis. Imipramine also decreased proopiomelanocortin (POMC) mRNA levels by 38% and glucocorticoid receptor (GR, type II) mRNA levels by 51% in the anterior pituitary. With the exception of a 20% decrease in TH mRNA in the LC after 2 wk of imipramine administration, none of these changes in gene expression were evident as a consequence of short-term administration of the drug. In the light of data that major depression is associated with an activation of brain CRH and LC-NE systems, the time-dependent effect of long-term imipramine administration on decreasing the gene expression of CRH in the hypothalamus and TH in the LC may be relevant to the therapeutic efficacy of this agent in depression." [Abstract]

Okuyama-Tamura M, Mikuni M, Kojima I.
Modulation of the human glucocorticoid receptor function by antidepressive compounds.
Neurosci Lett 2003 May 22;342(3):206-10
"Hyperactivity of the hypothalamic-pituitary-adrenal axis is associated with depression. We investigated the effect of various types of antidepressant agents in vitro on the function of glucocorticoid receptor (GR). Desipramine, clomiplamine, fluoxetine, milnacipran and clorgyline all induced rapid and sustained translocation of GR into the nucleus of human lymphocytes. In contrast, major and minor tranquilizers, lithium and verapamil, a blocker of membrane steroid transporter, were without effect. These antidepressants did not affect GR-mediated transcription by themselves, but significantly inhibited dexamethasone-induced transcription. These results indicate that structurally different antidepressants induce translocation of GR and inhibit GR-mediated transcription." [Abstract]

Carmine M. Pariante, Andrew Makoff, Simon Lovestone, Susan Feroli, Alexandra Heyden, Andrew H. Miller, and Robert W. Kerwin
Antidepressants enhance glucocorticoid receptor function in vitro by modulating the membrane steroid transporters
Br J Pharmacol 2001 134: 1335-1343
"1. Previous data demonstrate that the tricyclic antidepressant, desipramine, induces glucocorticoid receptor (GR) translocation from the cytoplasm to the nucleus in L929 cells and increases dexamethasone-induced GR-mediated gene transcription in L929 cells stably transfected with the mouse mammary tumour virus-chloramphenicol acetyltransferase (MMTV-CAT) reporter gene (LMCAT cells) (Pariante et al., 1997). 2. To extend these findings, the present study has investigated the effects of 24 h coincubation of LMCAT cells with dexamethasone and amitriptyline, clomipramine, paroxetine, citalopram or fluoxetine. 3. All antidepressants, except fluoxetine, enhanced GR-mediated gene transcription, with clomipramine having the greatest effect (10 fold increase). Twenty-four hours coincubation of cells with desipramine, clomipramine or paroxetine, also enhanced GR function in the presence of cortisol, but not of corticosterone. 4. It is proposed that these effects are due to the antidepressants inhibiting the L929 membrane steroid transporter, which actively extrudes dexamethasone and cortisol from the cell, but not corticosterone. This is further confirmed by the fact that clomipramine failed to enhance GR-mediated gene transcription in the presence of dexamethasone when the membrane steroid transporter was blocked by verapamil. 5. The membrane steroid transporters that regulate access of glucocorticoids to the brain in vivo, like the multiple drug resistance p-glycoprotein, could be a fundamental target for antidepressant action." [Abstract]

Rossby SP, Nalepa I, Huang M, Perrin C, Burt AM, Schmidt DE, Gillespie DD, Sulser F.
Norepinephrine-independent regulation of GRII mRNA in vivo by a tricyclic antidepressant.
Brain Res 1995 Jul 31;687(1-2):79-82
"Desipramine (DMI), a tricyclic antidepressant drug used in the treatment of depression, has been shown to increase steady-state levels of glucocorticoid receptor type II (GRII) mRNA in vitro and in vivo. To determine whether this effect is secondary to norepinephrine (NE) reuptake inhibition i.e., increases in synaptic NE induced by DMI, GRII mRNA levels were assayed in rat hippocampus following neurotoxic lesioning of NE neurons with DSP4. Chronic DMI treatment significantly increased GRII mRNA levels to the same degree in lesioned and non-lesioned animals. In contrast to DMI, the non-tricyclic antidepressant fluoxetine had no effect on GRII mRNA. These results provide evidence which demonstrates that a tricyclic antidepressant can regulate steady-state mRNA levels in vivo by a mechanism which is independent of its effects on synaptic monoamine levels." [Abstract]

Pariante, Carmine M., Pearce, Bradley D., Pisell, Tracy L., Owens, Michael J., Miller, Andrew H.
Steroid-Independent Translocation of the Glucocorticoid Receptor by the Antidepressant Desipramine
Mol Pharmacol 1997 52: 571-581
"The glucocorticoid receptor (GR) is a ligand-regulated transcription factor that in its unactivated form resides primarily in the cytoplasm. After being bound by steroid, the GR undergoes a conformational change and translocates to the nucleus, where it influences gene transcription. Because the GR mediates negative feedback exerted by circulating glucocorticoid hormones on the hypothalamic-pituitary-adrenal (HPA) axis, it has been hypothesized that abnormalities in GR expression and/or function may underlie the HPA axis hyperactivity described in patients with major depression. In further support of this hypothesis, animal studies have shown that long term in vivo treatment with antidepressants enhances glucocorticoid feedback inhibition, possibly through a direct effect on the GR. To examine this latter possibility, we evaluated translocation of the GR from the cytoplasm to the nucleus after 24-hr in vitro treatment of L929 cells (mouse fibroblasts) with the tricyclic antidepressant desipramine (0.1-10 microM) in the presence or absence of the synthetic steroid dexamethasone. In addition, GR-mediated gene transcription was measured with the use of L929 cells stably transfected with the mouse mammary tumor virus-chloramphenicol acetyltransferase reporter gene. Desipramine was found to (i) induce GR translocation from the cytoplasm to the nucleus in the absence of steroids (with no effect alone on GR-mediated gene transcription) and (ii) potentiate dexamethasone-induced GR translocation and dexamethasone-induced GR-mediated gene transcription. Treatment with desipramine for 24-96 hr had no effect on the expression of GR protein as measured by cytosolic radioligand receptor binding. We suggest that one important aspect of the effects of antidepressants in vivo may be to facilitate GR-mediated feedback inhibition on the HPA axis, by facilitating GR translocation and function, and thereby reverse glucocorticoid hypersecretion in depression." [Full Text]

Hatzinger M.
Neuropeptides and the hypothalamic-pituitary-adrenocortical (HPA) system: review of recent research strategies in depression.
World J Biol Psychiatry 2000 Apr;1(2):105-11
"Depressed patients show a variety of alterations in hypothalamic-pituitary-adrenocortical (HPA) system regulation which is reflected by increased pituitary-adrenocortical hormone secretion at baseline and a number of aberrant neuroendocrine function tests. The latter include the combined dexamethasone (DEX) suppression/corticotropin-releasing hormone (CRH) challenge test, in which CRH was able to override DEX induced suppression of ACTH and cortisol secretion. Whereas the abnormal HPA activation in these patients improved in parallel with clinical remission, persistent HPA dysregulation was associated with an increased risk of relapse. Moreover, healthy subjects at high genetic risk for depression also showed this phenomenon as a trait marker. In consequence, it has been concluded that HPA alteration and developmen as well as course of depression may be causally related. As evidenced from clinical and preclinical studies, underlying mechanisms of these abnormalities involve impairment of central corticosteroid receptor function which leads to enhanced activity of hypothalamic neurons synthesising and releasing vasopressin and CRH. These neuropeptides mediate not only neuroendocrine but also behavioural effects. Recent research provided evidence that CRH can induce depression-like symptoms in animals and that these signs are mediated through the CRH1 receptor subtype. Hence, therapeutical application of new compounds acting more specifically on the HPA system such as CRH1 receptor antagonists appear to be a promising approach for future treatment options of depression. In conclusion, research in neuroendocrinology provided new insights into the underlying pathophysiology of depression and, in consequence, may lead to the development of new therapeutic tools." [Abstract]

Muller M, Holsboer F, Keck ME.
Genetic modification of corticosteroid receptor signalling: novel insights into pathophysiology and treatment strategies of human affective disorders.
Neuropeptides 2002 Apr-Jun;36(2-3):117-31
"Every disturbance of the body, either real or imagined, evokes a stress response. Essential to this stress response is the activation of the hypothalamic-pituitary-adrenocortical (HPA) system, finally resulting in the release of glucocorticoid hormones from the adrenal cortex. Glucocorticoid hormones, in turn, feed back to this system by central activation of two types of corticosteroid receptors: the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR) which markedly differ in their neuroanatomical distribution and ligand affinity. Whereas a brief period of controllable stress, experienced with general arousal and excitement, can be a challenge and might thus be beneficial, chronically elevated levels of circulating corticosteroids are believed to enhance vulnerability to a variety of diseases, including affective disorders. Corticosteroids are known to influence emotions and cognitive processes, such as learning and memory. In addition, corticosteroids play extremely important roles in modulating fear and anxiety-related behaviour. The mechanisms by which corticosteroids exert their effects on behaviour are often indirect, by modulating particular sets of neurons or neurotransmitter systems. In addition, the timing of corticosteroid increase (before, during or after exposure to a stressor) determines whether and how behaviour is affected.The cumulative evidence makes a strong case implicating corticosteroid receptor dysfunction in the pathogenesis of affective disorders. Although definitive controlled trials remain to be conducted, there is evidence indicating that cortisol-lowering or corticosteroid receptor antagonist treatments may be of clinical benefit in selected individuals with major depression. A more detailed knowledge of the GR signalling pathways therefore opens up the possibility to specifically target GR function.In recent years, refined molecular technologies and the generation of genetically engineered mice (e.g. "conventional" and "conditional" knock-outs) have allowed to specifically target individual genes involved in corticosteroid receptor signalling and stress hormone regulation. Given the fundamental role of corticosteroid receptors in hippocampal integrity and mental performance during aging and psychiatric disorders, the identification and detailed characterization of these molecular pathways will ultimately lead to the development of novel neuropharmacological intervention strategies." [Abstract]


Barden N.
Modulation of glucocorticoid receptor gene expression by antidepressant drugs.
Pharmacopsychiatry 1996 Jan;29(1):12-22
"Through expression of a glucocorticoid receptor (GR) antisense RNA in brain, we have produced transgenic mice with an hyperactive hypothalamic-pituitary-adrenocortical (HPA) system similar to that seen in depressed patients. This model supports the hypothesis that disturbed corticosteroid receptor regulation could be the primary factor responsible for both the CRH/AVP hyperdrive that leads to increased activity of the HPA system, and the premature escape from the cortisol suppressant action of dexamethasone seen in affective disorders. Although normalisation of the hyperactive HPA system occurs during successful antidepressant therapy of depressive illness, these improvements do not correlate with changes in monoaminergic neurotransmitter systems, suggesting that unknown mechanisms of action may be operative. Work from my laboratory was the first to show that different types of antidepressants increased glucocorticoid receptor (GR) mRNA. We found increased GR mRNA levels irrespective of the preferential inhibitory action of antidepressant on the monoamine neurotransmitter re-uptake and showed increased GR gene transcription in antidepressant-treated mouse fibroblast cells that do not possess monoamine re-uptake mechanisms. We measured changes in glucocorticoid response in cells transfected with a glucocorticoid-sensitive reporter plasmid (MMTV-CAT) and observed increased glucocorticoid-stimulated CAT activity when the cells were treated with antidepressant. A different chimaeric gene construct consisting of a fragment of the GR gene promoter region fused to the CAT gene allowed more direct measurement of antidepressant action and increased CAT activity was also seen when cells transfected with this construct were treated with antidepressant. Finally, GR mRNA concentration and glucocorticoid binding activity were increased in brain tissues of animals chronically treated with antidepressant. The time course of antidepressant actions on corticosteroid receptors coincides with their long-term actions on HPA system activity and follows closely that of clinical improvement of depression. This suggests that antidepressant-induced changes in brain corticosteroid receptors may underlie the observed simultaneous decrease in circulating ACTH and corticosterone levels and the decreased adrenal size. Some of these effects may be mediated through CRH since, in antidepressant-treated transgenic mice hypothalamic CRH mRNA levels were decreased. From this work we have formulated the hypothesis that a primary action of antidepressants could be the stimulation of corticosteroid receptor gene expression that renders the HPA system more susceptible to feedback inhibition by cortisol. The resultant decrease in HPA system activity could induce secondary changes in glucocorticoid-sensitive gene expression and lead to redressment of neurotransmitter imbalance. This work opens up a completely new insight into antidepressant drug action and suggests a line of approach to the development of new drugs by focusing on this action." [Abstract]

Post A, Ohl F, Almeida OF, Binder EB, Rucker M, Welt S, Binder E, Holsboer F, Sillaber I.
Identification of molecules potentially involved in mediating the in vivo actions of the corticotropin-releasing hormone receptor 1 antagonist, NBI30775 (R121919).
Psychopharmacology (Berl). 2005 Jan 29; [Epub ahead of print]
RATIONALE: The neuropeptide corticotropin-releasing hormone (CRH) plays a central role in the regulation of the hypothalamo-pituitary-adrenocortical (HPA) axis. The view that CRH hypersecretion underlies anxiety and mood disorders was recently supported by preclinical and clinical data obtained after application of the CRH receptor (CRH-R1) antagonist NBI30775 (R121919). Despite its therapeutic efficacy, there is only little information about its mechanisms of action on cellular and molecular targets. OBJECTIVE: To identify some of the intracellular substrates mediating the actions of NBI30775 after its acute administration in a stress-independent animal model. RESULTS: Of the different doses of NBI30775 tested (0.5, 1, 5 and 30 mg/kg), the 1-mg/kg dose proved behaviorally active insofar that it reduced anxiety-like behavior in mice under basal conditions. Subsequent analysis of brain tissues revealed NBI30775-induced increases in the nuclear translocation of glucocorticoid receptors (GR) and BAG-1, an upregulation of mRNA transcripts encoding GR, mineralocorticoid receptors (MR) and CRH-R1, and a suppression of the DNA-binding activity of the transcription factor AP-1. These changes were significant at a dose of 1 mg/kg of NBI30775. CONCLUSION: NBI30775 reduces levels of anxiety in mice (under basal conditions) with a steep dose-response curve. Molecules such as GR, MR, BAG-1 and AP-1 have been identified as some of the drug's intracellular targets; interestingly, changes in these molecules have also been seen in response to conventional antidepressants, showing that structurally and mechanistically unrelated anxiolytic and antidepressant drugs can influence common downstream pathways. [Abstract]

Modell S, Yassouridis A, Huber J, Holsboer F.
Corticosteroid receptor function is decreased in depressed patients.
Neuroendocrinology 1997 Mar;65(3):216-22
"Decreased feedback control of the hypothalamic-pituitary-adrenocortical (HPA) system as revealed by the combined dexamethasone and corticotropin-releasing hormone (DEX-CRH) test has been documented in the vast majority of patients with affective disorders. This finding was interpreted as a failure at the level of the glucocorticoid receptor (GR)-mediated feedback action, which apparently fails to restrain HPA activity in the presence of elevated plasma corticosteroid levels. To test this hypothesis we conducted the DEX/CRH test using increasing doses of DEX in order to establish a dose-response relationship. We used three different DEX doses (0.75, 1.5, 3.0 mg) in three groups of depressed patients and controls. As expected, increasing DEX doses were associated with decreasing amounts of adrenocorticotropin (ACTH) and cortisol being released after CRH injection. However, dose-response curves for both plasma ACTH and cortisol concentrations were shifted to higher area under the curve (AUC) values among patients compared to controls. Pretreatment with 0.75 and 1.5 mg DEX produced significantly higher AUC values for both plasma ACTH and cortisol values among patients. These differences became less obvious with the higher DEX doses, indicating that the dose of 1.5 mg used in the majority of clinical studies so far is well suited to differentiate between healthy controls and patients. The reported data here are consistent with the hypothesis that an altered GR capacity or function underlies the exaggerated HPA activity in depression." [Abstract]

Michael Deuschle, Ulrich Schweiger, Bettina Weber, Ulrike Gotthardt, Andreas Körner, Jurgen Schmider, Harald Standhardt, Claas-Hinrich Lammers, and Isabella Heuser
Diurnal Activity and Pulsatility of the Hypothalamus-Pituitary-Adrenal System in Male Depressed Patients and Healthy Controls
J. Clin. Endocrinol. Metab. 82: 234-238
"There is only sparse and ambiguous information about circadian and pulsatile secretion features of the hypothalamus-pituitary-adrenocortical system in depression. We studied 15 severely depressed (Hamilton Depression Scale 30.4 +/- 6.7) male patients (age 22-72 yr; mean, 47.7 +/- 14.8) and 22 age-matched male controls (age 23-85 yr; mean, 53.1 +/- 18.2). Twenty-four-hour blood sampling from 0800-0800 h with 30-min sampling intervals was performed; from 1800-2400 h, blood was drawn every 10 min. Multivariate analysis of covariance, with the covariate being age, revealed mean 24-h cortisol (315.9 +/- 58.5 vs. 188.2 +/- 27.3 nmol/L) and mean ACTH (7.82 +/- 1.94 vs. 5.79 +/- 1.28 pmol/L) to be significantly increased in depressed patients. The frequency of cortisol (2.6 +/- 0.7 vs. 1.3 +/- 1.0 pulses/6 h) and ACTH (2.6 +/- 1.6 vs. 1.6 +/- 1.4 pulses/6 h) pulses during the evening were higher in patients compared to controls. The flattened circadian cortisol variation and reduced time of quiescence of cortisol secretory activity (140 +/- 116 vs. 305 +/- 184 min) in patients suggest disturbances of circadian functions. We conclude that increased hypothalamus-pituitary-adrenocortical activity in depression is related to a greater frequency of episodic hormone release, and we hypothesize that the observed circadian changes might be partly due to altered mineralocorticoid and glucocorticoid receptor capacity and function." [Full Text]

Calfa G, Kademian S, Ceschin D, Vega G, Rabinovich GA, Volosin M.
Characterization and functional significance of glucocorticoid receptors in patients with major depression: modulation by antidepressant treatment.
Psychoneuroendocrinology. 2003 Jul; 28(5): 687-701.
"Hyperactivity of the hypothalamic pituitary adrenal (HPA) axis in patients with major depression is one of the most consistent findings in biological psychiatry. Experimental data support the idea that glucocorticoid-mediated feedback via glucocorticoid receptors (GR) is impaired in major depression. The aim of the present work was to assess the putative changes in GR density of peripheral blood mononuclear cells (PBMCs) in a group of patients with major depression and to determine modulation of these GR sites by antidepressant treatment. In addition, susceptibility of PBMCs to glucocorticoid effects was also studied using a functional end-point analysis in vitro, such as cortisol inhibition of mitogen-induced lymphocyte proliferation. Cortisol levels were also measured before and after dexamethasone suppression test (DST). The results showed a decrease in GR density in depressed patients compared with healthy subjects, mainly in those patients that showed basal cortisol levels in the upper normal range and were refractory to DST. Regarding the functional significance of this variation, two representative groups emerged from our study: a) free-medication patients with GR function comparable to healthy controls, and b) patients showing diminished GR activity. These results suggest a lack of relationship between GR density and cortisol-induced inhibition of lymphocyte proliferation. Patients treated with different antidepressant drugs showed a marked increase in the number of GR sites per cell compared to non-treated. Interestingly, this increase was even higher than in normal subjects. Hence, restoration of GR density after an efficient antidepressant treatment could be an index of an effective modulatory action of drugs on GR expression and highlights the possibility that GR levels might be used as markers of a successful treatment." [Abstract]

Yehuda R, Boisoneau D, Mason JW, Giller EL.
Glucocorticoid receptor number and cortisol excretion in mood, anxiety, and psychotic disorders.
Biol Psychiatry 1993 Jul 1-15;34(1-2):18-25
"In the present study, we measured cytosolic lymphocyte glucocorticoid receptor and 24-hour urinary cortisol excretion in patients with major depressive disorder, bipolar mania, posttraumatic stress disorder, panic disorder, and schizophrenia. Patients with major depression had the smallest, and posttraumatic stress disordered patients the largest, mean number of glucocorticoid receptors per cell compared to patients in the other groups. Bipolar manic and panic patients did not differ from each other in regard to the number of lymphocyte glucocorticoid receptors. Bipolar manic and panic patients did have significantly more glucocorticoid receptors/cell than schizophrenic patients. The mean 24-hour urinary cortisol excretion was significantly higher in patients with major depression and bipolar mania than in those in the other diagnostic groups. Lymphocyte glucocorticoid receptor number and cortisol excretion tended to be inversely related, when the entire sample was considered as a whole, but this effect did not reach statistical significance. It is concluded that lymphocyte glucocorticoid receptors may be modulated by multiple influences, not just ambient cortisol levels. These preliminary data suggest that the assessment of lymphocyte glucocorticoid receptor number in tandem with cortisol levels may provide a more meaningful estimate of hypothalamic-pituitary-adrenal axis activity than is achieved using cortisol alone." [Abstract]

Rupprecht R, Kornhuber J, Wodarz N, Lugauer J, Gobel C, Riederer P, Beckmann H.
Lymphocyte glucocorticoid receptor binding during depression and after clinical recovery.
J Affect Disord 1991 May-Jun;22(1-2):31-5
"Lymphocyte glucocorticoid receptor binding parameters were studied in 15 severely depressed patients during depression and after clinical recovery, and in 15 healthy controls. There was no difference in glucocorticoid receptor number or affinity between depressed patients and recovered or control subjects. Afternoon ACTH and cortisol concentrations did not differ significantly between the three groups. No relationship could be established between glucocorticoid receptor binding and antidepressant medication. These data support the view of an impaired ligand-induced plasticity of glucocorticoid receptor regulation rather than the hypothesis of decreased glucocorticoid receptor numbers during depression." [Abstract]

Whalley LJ, Borthwick N, Copolov D, Dick H, Christie JE, Fink G.
Glucocorticoid receptors and depression.
Br Med J (Clin Res Ed) 1986 Mar 29;292(6524):859-61
"The number of glucocorticoid receptor sites in lymphocytes was estimated and plasma cortisol concentrations measured in 17 depressed patients, 12 patients with chronic schizophrenia, and 31 healthy control subjects. The number of receptor sites was significantly lower in the depressed patients than in either the controls or the patients with chronic schizophrenia, but there were no differences between the groups in the dissociation constants of the glucocorticoid receptors or the plasma cortisol concentrations. When two control subjects were studied intensively over 28 hours a slight diurnal variation in the number of glucocorticoid receptors was detected. The lower numbers of glucocorticoid receptors in the lymphocytes of depressed patients may explain why such patients, who often have hypercortisolaemia, do not show the clinical features of excess production of cortisol." [Abstract]

Gormley GJ, Lowy MT, Reder AT, Hospelhorn VD, Antel JP, Meltzer HY.
Glucocorticoid receptors in depression: relationship to the dexamethasone suppression test.
Am J Psychiatry 1985 Nov;142(11):1278-84
"Cytoplasmic glucocorticoid receptor content wa quantitated in lymphocytes from unmedicated depressed patients and control subjects before and after a standardized dexamethasone suppression test. Depressed patients (N = 11) had significantly lower (32%) basal cytoplasmic glucocorticoid receptor content than the control group (N = 14). Suppression of serum cortisol (5.0 micrograms/dl or less) in both control and depressed subjects (N = 16) following dexamethasone (1 mg) was associated with a decrease in lymphocyte cytoplasmic glucocorticoid receptor number, whereas no such change occurred in cortisol nonsuppressors (N = 9). Changes in receptor concentration were positively correlated with postdexamethasone serum cortisol levels and with the inhibitory effect of dexamethasone on mitogen-induced lymphocyte proliferation." [Abstract]

Wassef A, Smith EM, Rose RM, Gardner R, Nguyen H, Meyer WJ.
Mononuclear leukocyte glucocorticoid receptor binding characteristics and down-regulation in major depression.
Psychoneuroendocrinology 1990;15(1):59-68
"Some patients with major depressive disorder (MDD) have elevated plasma cortisol concentrations and show failure to suppress cortisol secretion upon administration of dexamethasone (DEX), yet they do not have Cushingoid features. To study whether this represents glucocorticoid (GC) resistance, [3H]-DEX-binding assays were used to measure, in vitro, the GC receptor affinity (1/Kd) and number (Bmax) in mononuclear leukocytes of 11 MDD patients and 15 control subjects. No receptor abnormalities were detected in the MDD group; thus any cellular defect leading to a lack of responsiveness to GC in the MDD patients, if present, probably lies beyond the initial receptor binding. DEX (1.0 mg orally) was administered to study in vivo GC receptor down-regulation. Compared to the control group, fewer depressed subjects down-regulated Bmax after DEX. By paired t-test, Bmax decreased significantly in the control group but not in the depressed group. Receptor number on the control day did not correlate significantly with the degree of receptor down-regulation, severity of depression or cortisol concentrations across all the subjects. These results do not lend support to previous reports suggesting that GC resistance in MDD results from a GC receptor-binding abnormality, and they emphasize the importance of considering receptor studies in the context of GC-mediated cell processes in order to identify the exact cellular defect(s) leading to GC resistance." [Abstract]

McQUADE, RICHARD, YOUNG, ALLAN H. Y.
Future therapeutic targets in mood disorders: the glucocorticoid receptor
Br J Psychiatry 2000 177: 390-395
"BACKGROUND: The hypercortisolaemia and dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis associated with mood disorders have been attributed to a breakdown in the glucocorticoid-receptor-mediated negative feedback mechanism regulating HPA activity. Reinstating normal feedback may be therapeutic in mood disorders. AIMS: To review the evidence for the involvement of the glucocorticoid receptor in the pathogenesis and treatment of mood disorders. METHOD: Medline and hand searches were carried out, selecting literature relevant to psychiatrists and psychopharmacologists. RESULTS: A dysfunction in glucocorticoid receptors is integral to the HPA abnormalities of mood disorders. Antidepressant and mood-stabilising drugs can up-regulate glucocorticoid receptors, restoring glucocorticoid function. Preliminary clinical studies targeting the glucocorticoid receptor are encouraging. CONCLUSIONS: Drugs designed specifically to up-regulate glucocorticoid receptors may be integral to future strategies in treating mood disorders." [Full Text]

Wolkowitz, Owen M., Reus, Victor I.
Treatment of Depression With Antiglucocorticoid Drugs
Psychosom Med 1999 61: 698-711
"OBJECTIVE: The theoretical and empirical rationales for the potential therapeutic use of antiglucocorticoid agents in the treatment of depression are reviewed. METHOD: Individual case reports, case series, open-label, and double-blind, controlled trials of the usage of cortisol-lowering treatments in Cushing's syndrome and major depression are evaluated and critiqued. RESULTS: In each of the 28 reports of antiglucocorticoid treatment of Cushing's syndrome, antidepressant effects were noted in some patients; the largest two series document a response rate of 70% to 73%. Full response, however, was at times erratic and delayed. Across the 11 studies of antiglucocorticoid treatment of major depression, some degree of antidepressant response was noted in 67% to 77% of patients. Antidepressant or antiobsessional effects of antiglucocorticoid augmentation of other psychotropic medications have also been noted in small studies of patients with treatment-resistant depression, obsessive-compulsive disorder, and schizoaffective disorder or schizophrenia. CONCLUSIONS: These promising results with antiglucocorticoid treatment must be interpreted cautiously because of the small sample sizes and heterogeneity of the studies reviewed, the bias favoring publication of positive results, and the open-label nature of most of the studies. Although definitive controlled trials remain to be conducted, there is a consistent body of evidence indicating that cortisol-lowering treatments may be of clinical benefit in select individuals with major depression and other hypercortisolemic conditions." [Full Text]

Lowy MT, Reder AT, Gormley GJ, Meltzer HY.
Comparison of in vivo and in vitro glucocorticoid sensitivity in depression: relationship to the dexamethasone suppression test.
Biol Psychiatry 1988 Oct;24(6):619-30
"The effect of in vivo (1 mg) and in vitro (10(-7)-10(-10) M) dexamethasone administration on mitogen-induced lymphocyte proliferation was examined in drug-free depressed patients, nondepressed psychiatric patients, as well as normal controls, and was related to the results of a standard overnight Dexamethasone Suppression Test (DST). The effect of oral dexamethasone administration was also examined for its effect on lymphocyte cytosolic glucocorticoid receptor content. Oral dexamethasone administration significantly decreased both phytohemagglutinin (PHA) and concanavalin A (Con-A) induced lymphocyte proliferation, as well as glucocorticoid receptor number in suppressors, whereas dexamethasone failed to decrease these responses in nonsuppressors. Nonsuppressors had significantly lower serum dexamethasone levels compared to suppressors at both 8:00 AM and 4:00 PM. However, when differences in serum dexamethasone levels were covaried out, there were still significant differences between suppressors and nonsuppressors on the dexamethasone-induced mitogen changes, but the changes in glucocorticoid receptor content were no longer significant. In vitro incubation of lymphocytes with dexamethasone produced a dose-related decrease in mitogenesis, which was not different between the depressed and nondepressed groups. However, at physiologically relevant concentrations of dexamethasone (10(-9)-10(-10) M), nonsuppressors as compared to suppressors were more resistant to the immunosuppressive effects of in vitro dexamethasone on the Con-A response. The inhibitory effect of in vitro dexamethasone on Con-A-stimulated lymphocytes was positively correlated with basal 4:00 PM cortisol values. In conclusion, in vitro techniques are useful probes to assess glucocorticoid sensitivity in depression. The present results also further support the hypothesis that glucocorticoid insensitivity is associated with DST nonsuppression." [Abstract]

Cole MA, Kim PJ, Kalman BA, Spencer RL.
Dexamethasone suppression of corticosteroid secretion: evaluation of the site of action by receptor measures and functional studies.
Psychoneuroendocrinology 2000 Feb;25(2):151-67
"A dose of dexamethasone was determined in rats (50 micrograms/kg s.c.) that suppressed the corticosterone response to restraint stress by 80%. Corticosteroid receptor occupancy estimates found that the 50 micrograms/kg s.c. dose of dexamethasone had no significant effect on available glucocorticoid receptor (GR) or mineralocorticoid receptor (MR) binding in brain regions (hypothalamus, hippocampus and cortex); on the other hand dexamethasone produced a selective and significant decrease in available GR in peripheral tissues (pituitary and spleen). Functional studies showed that the 50 micrograms/kg s.c. dose of dexamethasone completely blocked the effects of corticotropin-releasing hormone (CRH; 0.3-3.0 micrograms/kg i.p.) on corticosterone secretion, but did not inhibit the corticosterone response to an adrenocorticotropin hormone (ACTH; 2.5 I.U./kg i.p.) challenge. These studies indicate that this dose of dexamethasone exerts its inhibitory effects on the HPA axis primarily by acting at GR in the pituitary. The plasma dexamethasone levels produced by this dose of dexamethasone are similar to those present in humans the afternoon after an oral dexamethasone suppression test (DST), a time at which many depressed patients escape from dexamethasone suppression. These results support and extend other studies which suggest that the DST provides a direct test of the effects of increased GR activation in the pituitary on ACTH and cortisol secretion." [Abstract]

Meyer U, van Kampen M, Isovich E, Flugge G, Fuchs E.
Chronic psychosocial stress regulates the expression of both GR and MR mRNA in the hippocampal formation of tree shrews.
Hippocampus 2001;11(3):329-36
"A persistent hyperactivity of the hypothalamic-pituitary-adrenal axis and thus elevated glucocorticoid levels are main neuroendocrine features of depressive symptomatology in humans. The broad range of effects that are set off by glucocorticoids is mediated by glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs), which themselves are subject to autoregulation. In order to investigate the impact of long-lasting psychological stress on corticosteroid receptor mRNA expression in the hippocampal formation, we employed the psychosocial stress paradigm in male tree shrews (Tupaia belangeri). By in situ hybridization studies and semiquantitative evaluation of stress-induced changes of GR and MR mRNA expression at the single-cell level, brain tissue from subordinate animals which were exposed to 27 days (1 h/day) of social confrontation was compared to that of nonstressed animals. Four weeks of stress exposure resulted in a downregulation of GR mRNA in the dentate gyrus and hippocampal subfields CA1 and CA3 of subordinate male tree shrews compared to controls. The MR mRNA content in these subfields of the anterior hippocampus was also clearly reduced. On the contrary, in a more posterior location on the longitudinal axis of the tree shrew hippocampus, the MR message was increased in subfields CA1 and CA3 and in the dentate gyrus. These results suggest a relevance of the stress-induced regulation of both corticosteroid receptor subtype mRNAs in a naturalistic challenging situation. Moreover, the differential regulation of MR mRNA along the rostrocaudal axis of the hippocampus adds another feature to the heterogenous composition of this structure." [Abstract]

Mizoguchi K, Ishige A, Aburada M, Tabira T.
Chronic stress attenuates glucocorticoid negative feedback: involvement of the prefrontal cortex and hippocampus.
Neuroscience. 2003; 119(3): 887-97.
"Disruption of the glucocorticoid negative feedback system is observed in approximate one half of human depressives, and a similar condition is induced in animals by chronic stress. This disruption is thought to involve down-regulation of glucocorticoid receptors (GRs) in the feedback sites of the brain. However, the responsible site of the brain has not been well elucidated. Here we examined the effects of chronic stress induced by water immersion and restraint (2 h/day) for 4 weeks followed by recovery for 10 days on the GR levels in the prefrontal cortex (PFC), hippocampus, and hypothalamus of rats using a Western immunoblot technique. In the PFC, the cytosolic GR levels were decreased, but the nuclear GR levels were not changed. In the hippocampus, the levels of cytosolic and nuclear GRs were increased. However, there were no marked changes in the GR levels in the hypothalamus. The changes in the cytosolic GR levels were confirmed at the mRNA level by an in situ hybridization technique. We next examined the suppressive effects of dexamethasone (DEX) infusions into these regions on the circulating corticosterone levels. When DEX was infused into the PFC or hippocampus of the chronically stressed rats, the suppressive response to DEX was abolished, but the response was normal in the hypothalamus. In addition, when DEX was injected systemically to the chronically stressed rats, the suppressive response to DEX was significantly attenuated. These results suggest that the abnormal changes in GRs in the higher centers of the hypothalamo-pituitary-adrenal axis are involved in the chronic stress-induced attenuation of the feedback. Since dysfunction of the PFC or hippocampus is implicated in the pathogenesis of depression, the present findings would help to understand the mechanisms underlying the disrupted feedback system and its relation to brain dysfunction in depression." [Abstract]

Xing GQ, Russell S, Webster MJ, Post RM.
Decreased expression of mineralocorticoid receptor mRNA in the prefrontal cortex in schizophrenia and bipolar disorder.
Int J Neuropsychopharmacol. 2004 Mar;:1-11. [Epub ahead of print]
"Abnormal prefrontal cortical activity, activation of the hypothalamicpituitaryadrenal (HPA) axis, and deficits in slow-wave sleep (SWS) have been extensively reported in patients with affective disorders and schizophrenia, yet the underlying pathophysiological mechanisms have not been completely elucidated. Mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) are two nuclear hormone receptors of primary importance in the control of stress-related and circadian HPA activity. A recent study showed that blocking brain MR activity not only enhances CRF-induced ACTH and cortisol release, but also significantly reduces SWS in humans. We hypothesized that the expression of MR would be deficient in the prefrontal cortex of patients with schizophrenia and affective disorders. The MR mRNA expression in the post-mortem prefrontal cortex of patients with major depression (MD), bipolar (BP), and schizophrenic (SZ) disorders and non-psychiatric controls (n=15 for each patient group, and n=14 for controls) was determined by in-situ hybridization. In the dorsolateral prefrontal cortex Brodmanns area 9 (BA 9), MR mRNA was significantly lower (p0.05) in all laminae (IVI) in BP, and in laminae I, III, IV and VI in SZ than in the controls. MR mRNA in BA 9 was negatively correlated with the duration of psychiatric illnesses. In BA 46, MR mRNA was not significantly different among groups, but was positively correlated with brain pH. These results provide the first evidence of deficient prefrontal MR mRNA expression in BP and SZ. Whether these findings may be linked to the abnormal prefrontal function, HPA axis activation, or the deficits in SWS found in these major psychiatric illnesses remains to be further explored." [Abstract]

Blom JM, Tascedda F, Carra S, Ferraguti C, Barden N, Brunello N.
Altered regulation of CREB by chronic antidepressant administration in the brain of transgenic mice with impaired glucocorticoid receptor function.
Neuropsychopharmacology 2002 May;26(5):605-14
"Various effects of antidepressant drugs on gene transcription have been described and altered gene expression has been proposed as being a common biological basis underlying depressive illness. One target for the common action of antidepressants is a modifying effect on the regulation of postreceptor pathways and genes related to the cAMP cascade. Recent studies have demonstrated that long-term antidepressant treatment resulted in sustained activation of the cyclic adenosine 3',5'-monophosphate system and in increased expression of the transcription factor cAMP response element binding protein (CREB). A transgenic animal model of depression with impaired glucocorticoid receptor function was used to investigate the effect of chronic antidepressant treatments on CREB expression in different brain areas. Wild-type and transgenic mice received one administration of saline, desipramine, or fluoxetine, daily for 21 days. The effects of antidepressants on CREB mRNA were analyzed using a sensitive RNase protection assay. Antidepressant treatment resulted in a neuroanatomically and animal specific expression pattern of CREB. Our findings suggest that life-long central glucocorticoid receptor dysfunction results in an altered sensitivity with respect to the effects of antidepressants on the expression of CREB." [Abstract]

Paskitti ME, McCreary BJ, Herman JP.
Stress regulation of adrenocorticosteroid receptor gene transcription and mRNA expression in rat hippocampus: time-course analysis.
Brain Res Mol Brain Res 2000 Sep 15;80(2):142-52
"Neuronal glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) proteins mediate the transcriptional effects of circulating glucocorticoids. These receptors bind the same DNA response element, yet mediate quite different cellular functions. The present study tests the hypothesis that acute and chronic stress, which cause increases in glucocorticoids sufficient to bind the GR, will regulate expression of the GR and MR genes in the hippocampal formation. Analysis of MR gene transcription using an intronic MR probe revealed a transient 50% decrease in MR hnRNA in CA1, CA3 and dentate gyrus at 60-120 min post-stress, consistent with glucocorticoid down-regulation of the MR gene. However, no changes were seen in full-length MR mRNA at any post-stress time point. In contrast, GR hnRNA was not affected by acute stress, but GR mRNA was decreased 120 min post stress in all hippocampal subregions. Chronic stress exposure down-regulated GR mRNA in CA3 only; effects were first evident 7 days post stress and persisted for the entire stress time-course (28 days). There was no evidence for down-regulation of GR hnRNA or MR hnRNA/mRNA at any point in the chronic stress regimen. The transient decrease in MR hnRNA in the absence of mRNA changes suggests increased MR mRNA stability. In contrast, acute stress decreases the availability of GR mRNA without demonstrably affecting transcription, suggesting reduced GR mRNA stability. The results suggest that acute stress alters GR mRNA expression by largely post-transcriptional mechanisms. However, elevations in basal corticosterone secretion seen following chronic stress are not sufficient to markedly down-regulate GR/MR expression in a long-term fashion." [Abstract]

Sheng Z, Yanai A, Fujinaga R, Kawano J, Tanaka M, Watanabe Y, Shinoda K.
Gonadal and adrenal effects on the glucocorticoid receptor in the rat hippocampus, with special reference to regulation by estrogen from an immunohistochemical view-point.
Neurosci Res. 2003 Jun; 46(2): 205-18.
"Focusing on the hippocampal CA1 region, effects of peripheral gonadal and adrenal steroids on the glucocorticoid receptor (GR) were immunohistochemically evaluated in male and female adult rat brains after adrenalectomy (ADX), gonadectomy (GDX), and administration of estradiol (E2) and/or corticosterone (CS). In ADXed male rats, the hippocampal nuclear GR decreased and turned back to the cytoplasm, whereas in females, nuclear localization persisted even after ADX. In GDX+ADXed female rats, the GR was dispersedly translocated from the nucleus to the cytoplasm as well as in GDX+ADXed males. The dispersed cytoplasmic GR was again translocated into the nucleus by administration of CS. In addition, administration of a small dose of E2 for 4-13 days was found to sufficiently recover the nuclear location of GR in GDX+ADXed rat brains, whereas medium-to-large doses could not do this. Also, a longer administration more strongly enhances the nuclear GR location and expression. The present study provided strong immunohistochemical evidence that the sexually dimorphic effects of ADX on hippocampal GR are attributable to gonadal hormones, and that E2 is implicated in the effects in inversely-dose- and directly-duration-dependent manner. Taken together, intriguing gonadal and adrenal crosstalk is considered to play some important role in regulating hippocampal GR morphology and to have a possibly crucial influence on stress-related disorders such as depression." [Abstract]

Miller AH, Pariante CM, Pearce BD.
Effects of cytokines on glucocorticoid receptor expression and function. Glucocorticoid resistance and relevance to depression.
Adv Exp Med Biol 1999;461:107-16
"Our data indicate that the proinflammatory cytokine, IL-1alpha inhibits GR translocation and hormone-induced GR-mediated gene transcription, and, in conjunction with previous in vivo and in vitro studies, can be interpreted to suggest that cytokines have the capacity to contribute to glucocorticoid resistance and thus the pathophysiology of depression. In addition, data from our mouse viral studies in glucocorticoid deficient animals demonstrate that endogenous glucocorticoids modulate a delicate balance between viral defense and cytokine toxicity. Finally, the antidepressant, DMI, has been found to enhance GR translocation and GR-mediated gene transcription and thus may provide a useful strategy for adjusting neuroendocrine setpoints in vivo. Taken together, these findings suggest that factors which modulate glucocorticoid action (e.g. cytokines and antidepressants) will be relevant contributors to disease expression including behavioral toxicity and sickness behavior." [Abstract]

Carmine M. Pariante, Bradley D. Pearce, Tracy L. Pisell, Carmen I. Sanchez, Cecilia Po, Cindy Su, and Andrew H. Miller
The Proinflammatory Cytokine, Interleukin-1, Reduces Glucocorticoid Receptor Translocation and Function
Endocrinology 140: 4359-4366 [Full Text]

Young EA, Lopez JF, Murphy-Weinberg V, Watson SJ, Akil H.
Mineralocorticoid receptor function in major depression.
Arch Gen Psychiatry. 2003 Jan; 60(1): 24-8.
"BACKGROUND: Negative feedback regulation of the hypothalamic-pituitary-adrenal axis occurs through a dual-receptor system of mineralocorticoid receptors (MR) and glucocorticoid receptors (GR). Their affinity for cortisol and their distribution in the brain differ. Studies using an MR antagonist have demonstrated that MR is active throughout the circadian rhythm. Because major depression is accompanied by increased glucocorticoid secretion and insensitivity to glucocorticoid feedback, and because glucocorticoids are capable of down-regulating MR and GR, we expected that major depression would be accompanied by decreased MR activity. METHODS: To test this hypothesis, we administered spironolactone, an MR antagonist, to individuals with major depression and matched control subjects and assessed levels of corticotropin and cortisol secretion in response to this acute challenge. Studies were conducted in the morning, the time of peak activation of the hypothalamic-pituitary-adrenal axis. All patients were currently depressed and free of all medications. All controls were free of all psychiatric diagnoses and of all medications. RESULTS: Spironolactone treatment resulted in a significant increase in cortisol secretion levels in both groups. Depressed patients demonstrated higher cortisol secretion levels than control subjects. In addition, depressed patients demonstrated a different pattern of increase in cortisol secretion levels after spironolactone administration. Furthermore, a significant effect of spironolactone treatment on corticotropin secretion levels can be observed in depressed patients, whereas controls show no such effect. CONCLUSIONS: Despite high baseline cortisol levels, patients with major depression show high functional activity of the MR system. Paired with the body of evidence regarding decreased sensitivity to GR agonists, these data suggest an imbalance in the MR/GR ratio. The balance of MR and GR is known to affect brain serotonin systems and may play an etiologic role in serotonin receptor changes observed in patients with major depression." [Abstract]

Bremner JD, Vythilingam M, Vermetten E, Anderson G, Newcomer JW, Charney DS.
Effects of glucocorticoids on declarative memory function in major depression.
Biol Psychiatry. 2004 Apr 15;55(8):811-5.
"BACKGROUND: Major depression has been associated with hypercortisolemia in a subset of patients with depression. Administration of exogenous cortisol and other glucocorticoids to healthy human subjects has been observed to result in a transient impairment in verbal declarative memory function. The purpose of this study was to assess the effects of the glucocorticoid, dexamethasone, on verbal declarative memory function in patients with untreated unipolar major depressive disorder (MDD). METHODS: Fifty two men and women with (n = 28) and without (n = 24) MDD received placebo or dexamethasone (1 mg and 2 mg on 2 successive days) in a double-blind, randomized fashion. Declarative memory was assessed with paragraph recall at baseline (day 1) and day 3. RESULTS: There was a significant interaction between diagnosis and drug (dexamethasone vs. placebo) on paragraph recall. In the healthy subjects, memory improved from baseline to day 3 with placebo and was unchanged with dexamethasone, whereas in MDD patients memory function showed a pattern of decreasing with placebo and improving with dexamethasone from baseline to day 3. CONCLUSIONS: These findings are consistent with an altered sensitivity of declarative memory function in MDD to regulation by glucocorticoids. Possible explanations of the findings include alterations in glucocorticoid receptors in the hippocampus or other brain regions mediating declarative memory, or differential sensitivity to dexamethasone-induced reductions in cortisol, in patients with MDD." [Abstract]



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Recent Corticosteroid Receptor and Depression Research

1) Tanke MA, Bosker FJ, Gladkevich AV, Medema HM, den Boer JA, Korf J
Lymphocyte glucocorticoid receptor resistance and depressive symptoms severity: A preliminary report.
Prog Neuropsychopharmacol Biol Psychiatry. 2008 Jul 1;32(5):1298-301.
OBJECTIVE: Assessment of the temporal interrelationship of neuropsychiatric parameters requires technologies allowing frequent biological measurements. We propose glucocorticoid receptor (GR) function of lymphocytes to assess the temporal relationship between glucocorticoid resistance and the course of major depressive disorder. METHOD: Dexamethasone suppression of lymphocyte proliferation was in vitro assessed via 5-bromo-2' deoxyuridine (BrdU) incorporation in DNA. Optimal conditions were determined using blood of healthy volunteers. Thereafter the relation between depression severity (Hamilton Depression Rating Scale, HDRS, scores), lymphocyte proliferation and morning cortisol levels in blood was studied in thirteen depressed patients, mostly with a history of treatment resistance. RESULTS: Recovery from depression was not directly associated with changes in lymphocyte glucocorticoid resistance. However, a negative correlation was observed between HDRS and BrdU incorporation and a positive correlation between morning cortisol and BrdU incorporation. No significant correlation was found between cortisol and HDRS. Regression analyses showed that HDRS was related to both suppression of BrdU incorporation (beta -0.508, p<0.001) and cortisol levels (beta 0.364, p=0.001) in a highly significant model (F(2,60)=14,244, p<0.001) Except for one case, such relation could not be found within patients. CONCLUSION: Our preliminary results suggest a mutual relation between lymphocyte GR function, morning cortisol levels and MDD symptom severity. A direct relation between glucocorticoids resistance and recovery may not exist, but glucocorticoid resistance might attenuate or prevent recovery. It is clear that additional studies using larger and more homogenous groups of MDD patients are required to support our findings. [PubMed Citation] [Order full text from Infotrieve]


2) Bhagwagar Z, Cowen PJ
'It's not over when it's over': persistent neurobiological abnormalities in recovered depressed patients.
Psychol Med. 2008 Mar;38(3):307-13.
The tendency of major depression to recur is a leading problem in clinical management and is responsible for much of the illness burden. Until recently, biological studies of depression have focused on the mechanisms involved in acute illness but there are now many data to suggest that neurobiological abnormalities persist when depressed patients are clinically recovered and withdrawn from medication. These abnormalities encompass a number of neurochemical and neuropsychological mechanisms that could be relevant to recurrence, including changes in the availability of serotonin (5-hydroxytryptamine, 5-HT) receptor subtypes, decreases in cortical gamma-aminobutyric acid (GABA), increases in cortisol secretion and negative biases in the processing of emotional information. Studies of groups at high risk of depression before illness onset will help to clarify which biological abnormalities precede the development of depression and which are the product of recurrent illness. Ultimately this work should lead to a better understanding of the neurobiology of vulnerability to depression and more innovative approaches to primary and secondary prevention. [PubMed Citation] [Order full text from Infotrieve]


3) Carvalho LA, Juruena MF, Papadopoulos AS, Poon L, Kerwin R, Cleare AJ, Pariante CM
Clomipramine In Vitro Reduces Glucocorticoid Receptor Function in Healthy Subjects but not in Patients with Major Depression.
Neuropsychopharmacology. 2008 Mar 26;
Previously, we have shown that in vitro antidepressants modulate glucocorticoid receptor (GR) function and expression, and have suggested that these effects could be relevant for the mechanism of action of antidepressants. To further clarify the interaction between antidepressants and glucocorticoids, we evaluated the in vitro effect of the tricyclic antidepressant, clomipramine (CMI), on the GR function in 15 treatment-resistant depressed inpatients and 28 healthy controls. Diluted whole-blood cells were incubated for 24 h in the presence or absence of CMI (10 muM). Glucocorticoid function was measured by glucocorticoid inhibition of lypopolysaccharide (LPS)-stimulated interleukin-6 (IL-6) levels. The results show that glucocorticoids (dexamethasone, prednisolone, cortisol and corticosterone) caused a concentration-dependent inhibition of LPS-stimulated IL-6 levels. In healthy controls, CMI decreased glucocorticoid inhibition of LPS-stimulated IL-6 levels, while this effect was not present in depressed patients. Therefore, depressed patients, who were clinically treatment resistant, also showed a lack of effect of the antidepressant in vitro. Upcoming studies shall test whether assessing the effects of antidepressants in vitro on GR function could predict future treatment response in a clinical setting.Neuropsychopharmacology advance online publication, 26 March 2008; doi:10.1038/npp.2008.44. [PubMed Citation] [Order full text from Infotrieve]


4) Zobel A, Jessen F, von Widdern O, Schuhmacher A, Höfels S, Metten M, Rietschel M, Scheef L, Block W, Becker T, Schild HH, Maier W, Schwab SG
Unipolar depression and hippocampal volume: Impact of DNA sequence variants of the glucocorticoid receptor gene.
Am J Med Genet B Neuropsychiatr Genet. 2008 Feb 19;
Glucocorticoid receptor (GR) plays a major role in regulation of the hypothalamic-pituitary-adrenocortical (HPA) system; HPA dysregulation represents the most consistent biological pattern of depression. Multiple functional polymorphisms are known for the GR gene, which might influence the development of unipolar depression. Previous studies reported associations to some variants in this gene but not consistently so. We investigated seven genetic polymorphisms in the GR gene (NR3C1) located in the putative promoter, exon 2 and intron 2 region. Study populations were 322 German inpatients with recurrent unipolar depression, and 298 German controls recruited from the general population. The relationships between intermediate phenotypes (hippocampal and amygdala volumes) and NR3C1 DNA sequence variants were additionally explored in a subpopulation of patients. We found association between the diagnosis of depression and DNA sequence variants in intron 2 as well as in the 5' region of the NR3C1 gene but not for the previously studied exon 2 and putative promoter variants (global test after control of multiple testing, P = 0.02). In patients, diagnosis-related alleles were also associated to hippocampal volume reduction and amygdala volume variation. Unipolar depression is associated with DNA variants of the NR3C1 gene in our population. Neurobiological underpinnings of depression as volumetric reductions of the hippocampus may also be mediated by variants in this gene. (c) 2008 Wiley-Liss, Inc. [PubMed Citation] [Order full text from Infotrieve]


5) Watanuki T, Funato H, Uchida S, Matsubara T, Kobayashi A, Wakabayashi Y, Otsuki K, Nishida A, Watanabe Y
Increased expression of splicing factor SRp20 mRNA in bipolar disorder patients.
J Affect Disord. 2008 Feb 15;
BACKGROUND: Variations and defects in alternative splicing are well known to be associated with a variety of human diseases and the stress response. We previously reported a decrease in glucocorticoid receptor (GR) alpha, but not GRbeta in mood disorder patients, suggesting an aberrant alternative splicing mechanism. To examine whether altered RNA splicing may underlie the pathophysiology of mood disorder, we evaluated the expression of a variety of SR protein splicing factors, a family of proteins indispensable for proper alternative splicing, in mood disorder patients. METHODS: We used quantitative real-time PCR to measure expressions of SRp20, SRp30c, SC35, SRp40, SRp46, SRp54, SRp55, SRp75, ASF/SF2, and 9G8 mRNA in peripheral white blood cells of 33 mood disorder patients during a depressive episode. In addition, the expressions of SRp20 and SC35 mRNA were quantified for 78 mood disorder patients in a remissive state, and 32 the first-degree relatives of these mood disorder patients. RESULT: A significant correlation was observed between SRp30c and the GRbeta/GRalpha ratio in control subjects, but not in mood disorder patients. Increased expression of SRp20 but not SRp30c mRNA was observed in bipolar disorder patients in both the depressive and remissive states. Major depressive disorder patients did not show any significant change in mRNA levels of SR proteins. LIMITATION: Subjects were Japanese adults. Patient treatment was not standardized. CONCLUSIONS: These results suggest that aberrant alternative splicing machinery caused by increased SRp20 mRNA expression would be associated with the pathophysiology of bipolar disorder. [PubMed Citation] [Order full text from Infotrieve]


6) Krishnamurthy P, Romagni P, Torvik S, Gold PW, Charney DS, Detera-Wadleigh S, Cizza G
Glucocorticoid receptor gene polymorphisms in premenopausal women with major depression.
Horm Metab Res. 2008 Mar;40(3):194-8.
Glucocorticoid receptor gene polymorphisms are associated with glucocorticoid hypersensitivity and visceral obesity. Perturbations in HPA axis sensitivity to glucocorticoids implicated in the pathogenesis of major depression may result from functional alterations in the glucocorticoid receptor gene. We 1) examined the prevalence of genotype distribution of specific polymorphisms of the glucocorticoid receptor gene (Bcl1, N363S, rs33388, rs33389) in a subset of women from the P.O.W.E.R. Study (which enrolled 21- to 45-year-old premenopausal women with major depression and healthy controls) and 2) explored whether such polymorphisms were associated with visceral obesity and insulin resistance. Women with major depression had a higher body mass index, a higher waist:hip ratio, and more body fat than did controls. No differences were observed in plasma and urinary cortisol or in insulin sensitivity. The G/G genotype of the Bcl1 polymorphism was significantly more common (p<0.03) in women with major depression (n=52) than in controls (n=29). In addition, GG homozygotes (depressed n=10; controls n=2) had higher waist:hip ratios than did non-GG carriers (p<0.02). N363S, rs33388, and rs33389 polymorphisms were not different between groups. In conclusion, premenopausal women with both major depression and the GG genotype of the Bcl1 polymorphism had greater abdominal obesity compared with non-GG carriers. [PubMed Citation] [Order full text from Infotrieve]


7) Willour VL, Chen H, Toolan J, Belmonte P, Cutler DJ, Goes FS, Zandi PP, Lee RS, Mackinnon DF, Mondimore FM, Schweizer B, Depaulo JR, Gershon ES, McMahon FJ, Potash JB
Family-based association of FKBP5 in bipolar disorder.
Mol Psychiatry. 2008 Jan 8;
The FKBP5 gene product forms part of a complex with the glucocorticoid receptor and can modulate cortisol-binding affinity. Variations in the gene have been associated with increased recurrence of depression and with rapid response to antidepressant treatment. We sought to determine whether common FKBP5 variants confer risk for bipolar disorder. We genotyped seven tag single-nucleotide polymorphisms (SNPs) in FKBP5, plus two SNPs previously associated with illness, in 317 families with 554 bipolar offspring, derived primarily from two studies. Single marker and haplotypic analyses were carried out with FBAT and EATDT employing the standard bipolar phenotype. Association analyses were also conducted using 11 disease-related variables as covariates. Under an additive genetic model, rs4713902 showed significant overtransmission of the major allele (P=0.0001), which was consistent across the two sample sets (P=0.004 and 0.006). rs7757037 showed evidence of association that was strongest under the dominant model (P=0.001). This result was consistent across the two datasets (P=0.017 and 0.019). The dominant model yielded modest evidence for association (P<0.05) for three additional markers. Covariate-based analyses suggested that genetic variation within FKBP5 may influence attempted suicide and number of depressive episodes in bipolar subjects. Our results are consistent with the well-established relationship between the hypothalamic-pituitary-adrenal (HPA) axis, which mediates the stress response through regulation of cortisol, and mood disorders. Ongoing whole-genome association studies in bipolar disorder and major depression should further clarify the role of FKBP5 and other HPA genes in these illnesses.Molecular Psychiatry advance online publication, 8 January 2008; doi:10.1038/sj.mp.4002141. [PubMed Citation] [Order full text from Infotrieve]


8) Kumamaru E, Numakawa T, Adachi N, Yagasaki Y, Izumi A, Niyaz M, Kudo M, Kunugi H
Glucocorticoid prevents brain-derived neurotrophic factor-mediated maturation of synaptic function in developing hippocampal neurons through reduction in the activity of mitogen-activated protein kinase.
Mol Endocrinol. 2008 Mar;22(3):546-58.
An increased level of glucocorticoid may be related to the pathophysiology of depressive disorder. The involvement of brain-derived neurotrophic factor (BDNF) in the antidepressive effect has also been suggested; however, the possible influence of glucocorticoid on the action of BDNF in the developing central nervous system has not been elucidated. In this study, we investigated the effect of glucocorticoid (dexamethasone, DEX) on synaptic maturation and function enhanced by BDNF in early developing hippocampal neurons. In the immature stage, BDNF increased the outgrowth of dendrites and the expression of synaptic proteins including glutamate receptors and presynaptic proteins. Pretreatment with DEX significantly inhibited the BDNF-dependent up-regulation of both dendritic outgrowth and synaptic proteins. In the more mature stage, the BDNF-reinforced postsynaptic Ca(2+) influx was decreased by DEX. BDNF-enhanced presynaptic glutamate release was also suppressed. RU486, a glucocorticoid receptor antagonist, canceled the DEX-dependent blocking effect on the action of BDNF. After down-regulation of glucocorticoid receptor by small interfering RNA application, no inhibitory effect of DEX on the BDNF-increased synaptic proteins was observed. Interestingly, the BDNF-activated MAPK/ERK pathway, which is an essential intracellular signaling pathway for the BDNF-increased synaptic proteins, was reduced by DEX. These results suggest that BDNF-mediated synaptic maturation is disturbed after neurons are exposed to high-level glucocorticoid in their development stage. [PubMed Citation] [Order full text from Infotrieve]


9) Thomson F, Craighead M
Innovative approaches for the treatment of depression: targeting the HPA axis.
Neurochem Res. 2008 Apr;33(4):691-707.
Altered activity of the hypothalamic pituitary adrenal (HPA) axis is one of the most commonly observed neuroendocrine abnormalities in patients suffering from major depressive disorder (MDD). Altered cortisol secretion can be found in as many as 80% of depressed patients. This observation has led to intensive clinical and preclinical research aiming to better understand the molecular mechanisms which underlie the alteration of the HPA axis responsiveness in depressive illness. Dysfunctional glucocorticoid receptor (GR) mediated negative feedback regulation of cortisol levels and changes in arginine vasopressin (AVP)/vasopressin V1b receptor and corticotrophin-releasing factor/CRF1 receptor regulation of adrenocotricotrophin (ACTH) release have all been implicated in over-activity of the HPA axis. Agents that intervene with the mechanisms involved in (dys)regulation of cortisol synthesis and release are under investigation as possible therapeutic agents. The current status of some of these approaches is described in this review. [PubMed Citation] [Order full text from Infotrieve]


10) Drevets WC, Thase ME, Moses-Kolko EL, Price J, Frank E, Kupfer DJ, Mathis C
Serotonin-1A receptor imaging in recurrent depression: replication and literature review.
Nucl Med Biol. 2007 Oct;34(7):865-77.
INTRODUCTION: Serotonin-1A receptor (5-HT1AR) function appears to be decreased in major depressive disorder (MDD) based on physiological responses to 5-HT1AR agonists in vivo and to 5-HT1AR binding in brain tissues postmortem or antemortem. We have previously assessed 5-HT1AR binding potential (BP) in depression using positron emission tomography (PET) and [carbonyl-(11)C]WAY-100635, and we have demonstrated reduced 5-HT1AR BP in the mesiotemporal cortex (MTC) and raphe in depressives with primary recurrent familial mood disorders (n=12) versus controls (n=8) [Drevets WC, Frank E, Price JC, Kupfer DJ, Holt D, Greer PJ, Huang Y, Gautier C, Mathis C. PET imaging of serotonin 1A receptor binding in depression. Biol Psychiatry 1999;46(10):1375-87]. These findings were replicated by some, but not other, studies performed in depressed samples that were more generally selected using criteria for MDD. In the current study, we attempted to replicate our previous findings in an independent sample of subjects selected according to the criteria for primary recurrent depression applied in our prior study. METHODS: Using PET and [carbonyl-(11)C]WAY-100635, 5-HT1AR BP was assessed in 16 depressed subjects and 8 healthy controls. RESULTS: Mean 5-HT1AR BP was reduced by 26% in the MTC (P<.005) and by 43% in the raphe (P<.001) in depressives versus controls. CONCLUSIONS: These data replicate our original findings, which showed that BP was reduced by 27% in the MTC (P<.025) and by 42% in the raphe (P<.02) in depression. The magnitudes of these reductions in 5-HT1AR binding were similar to those found postmortem in 5-HT1AR mRNA concentrations in the hippocampus in MDD [López JF, Chalmers DT, Little KY, Watson SJ. Regulation of serotonin 1A, glucocorticoid, and mineralocorticoid receptor in rat and human hippocampus: implications for neurobiology of depression. Biol Psychiatry 1998;43:547-73] and in 5-HT1AR-binding capacity in the raphe in depressed suicide victims [Arango V, Underwood MD, Boldrini M, Tamir H, Kassir SA, Hsiung S, Chen JJ, Mann JJ. Serotonin 1A receptors, serotonin transporter binding and serotonin transporter mRNA expression in the brainstem of depressed suicide victims. Neuropsychopharmacology 2001;25(6):892-903]. There exists disagreement within the literature, however, regarding the presence and direction of 5-HT1AR-binding abnormalities in depression, which may be explained in some cases by differences in anatomical location (e.g., [Stockmeier CA, Shapiro LA, Dilley GE, Kolli TN, Friedman L, Rajkowska G. Increase in serotonin-1A autoreceptors in the midbrain of suicide victims with major depression--postmortem evidence for decreased serotonin activity. J Neurosci 1998;18(18):7394-401]) and in other cases by pathophysiological heterogeneity within MDD (e.g., some depressives hypersecrete cortisol, which would be expected to down-regulate 5-HT1AR expression [López JF, Chalmers DT, Little KY, Watson SJ. Regulation of serotonin 1A, glucocorticoid, and mineralocorticoid receptor in rat and human hippocampus: implications for neurobiology of depression. Biol Psychiatry 1998;43:547-73]). Antidepressant drug treatment does not alter these abnormalities in 5-HT1AR binding [Sargent PA, Kjaer KH, Bench CJ, Rabiner EA, Messa C, Meyer J, Gunn RN, Grasby PM, Cowen PJ. Brain serotonin1A receptor binding measured by positron emission tomography with [11C]WAY-100635: effects of depression and antidepressant treatment. Arch Gen Psychiatry 2000;57(2):174-80; Moses-Kolko EL, Price JC, Thase ME, Meltzer CC, Kupfer DJ, Mathis CA, Bogers WD, Berman SR, Houck PR, Schneider TN, Drevets WC. Measurement of 5-HT1A receptor binding in depressed adults before and after antidepressant drug treatment using positron emission tomography and [11C]WAY-100635. Synapse 2007;61(7):523-30] but may compensate for blunted 5-HT1AR function by increasing post-synaptic 5-HT1AR transmission [Chaput Y, de Montigny C, Blier P. Presynaptic and postsynaptic modifications of the serotonin system by long-term administration of antidepressant treatments. An in vivo electrophysiologic study in the rat. Neuropsychopharmacology 1991;5(4):219-29]. [PubMed Citation] [Order full text from Infotrieve]


11) Gourley SL, Wu FJ, Kiraly DD, Ploski JE, Kedves AT, Duman RS, Taylor JR
Regionally specific regulation of ERK MAP kinase in a model of antidepressant-sensitive chronic depression.
Biol Psychiatry. 2008 Feb 15;63(4):353-9.
BACKGROUND: Elevated phosphorylation of neurotrophin-regulated transcription factors, such as cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB), in the hippocampus has been proposed as a common mediator of antidepressant (ADT) efficacy in otherwise naive rodents. The intracellular factors by which ADTs and glucocorticoids, causal factors in depression, regulate depression-like behavior remain unclear, but extracellular signal-regulated kinase 1/2 (ERK1/2), upstream of CREB, is a likely candidate. METHODS: We explored the long-term consequences of glucocorticoid exposure and subsequent ADT treatment in a novel model of chronic depression. Motivated behaviors, immobility during tail suspension, and ERK1/2, known to be required for behavioral response to ADTs, were quantified. RESULTS: Chronic corticosterone (CORT) increased immobility, decreased responding in an operant conditioning task of motivation, and selectively reduced phosphorylated ERK1/2 (pERK1/2) in the dentate gyrus. Behavioral and biochemical measures were restored to baseline by amitriptyline (AMI) treatment. Corticosterone regulated pERK1/2 on a time course that paralleled increases in heat shock proteins associated with depression and decreased tyrosine kinase receptor B (trkB) phosphorylation. Chronic AMI also produced regionally dissociable effects on pERK1/2 in CA1/CA3, amygdala, and striatum, but not prefrontal cortex. CONCLUSIONS: Antidepressant efficacy in a motivational task and behavioral despair assay are associated with altered limbic pERK1/2, including restored pERK1/2 in the dentate gyrus after stress-related insult. [Free Full Text] [PubMed Citation] [Order full text from Infotrieve]


12) Groenink L, Dirks A, Verdouw PM, de Graaff M, Peeters BW, Millan MJ, Olivier B
CRF1 not glucocorticoid receptors mediate prepulse inhibition deficits in mice overexpressing CRF.
Biol Psychiatry. 2008 Feb 15;63(4):360-8.
BACKGROUND: Both corticotropin-releasing factor (CRF) and glucocorticoid receptors (GR) are implicated in the psychotic symptoms of psychiatric disorders. Correspondingly, it is of interest to determine their respective involvement in the sensorimotor gating deficits displayed by transgenic mice overexpressing CRF. These mice reveal lifelong elevations of CRF and corticosterone levels. METHODS: Effects of the GR antagonists ORG34517 (5-45 mg/kg by mouth [PO]) and mifepristone (5-45 mg/kg PO) and the CRF(1) receptor antagonists CP154,526 (20-80 mg/kg intraperitoneally [IP]) and DMP695 (2.5-40.0 mg/kg IP) on prepulse inhibition (PPI) of the acoustic startle response were studied in mice overexpressing CRF and in their wild-type littermates. In addition, PPI was measured in both genotypes 2 weeks after adrenalectomy with or without exogenous corticosterone administration via subcutaneous pellet implant (20 mg corticosterone). RESULTS: ORG34517 and mifepristone did not influence perturbation of PPI in mice overexpressing CRF; reducing corticosterone levels by adrenalectomy likewise did not improve PPI. Further, elevation in corticosterone levels by pellet implantation did not disrupt PPI in wild-type mice. Conversely, both CRF(1) receptor antagonists, CP154,526 (40-80 mg/kg IP) and DMP695 (40 mg/kg IP), significantly restored PPI in CRF-overexpressing mice. CONCLUSIONS: Sustained overactivation of CRF(1) receptors rather than excessive GR receptor stimulation underlies impaired sensorimotor gating in CRF-overexpressing mice. CRF(1) receptors thus may play a role in the expression of psychotic features in stress-related psychiatric disorders. [PubMed Citation] [Order full text from Infotrieve]


13) Machado-Vieira R, Soares JC
[Treatment-resistant mood disorders]
Rev Bras Psiquiatr. 2007 Oct;29 Suppl 2:S48-54.
OBJECTIVE AND METHOD: Mood disorders are the most prevalent psychiatric disorders. Despite new insights and advances on the neurobiological basis and therapeutic approaches for bipolar disorders and recurrent depression, elevated prevalence of recurrence, persistent sub-syndromal symptoms and treatment resistance are challenging aspects and need to be urgently addressed. The objective of this literature review is to evaluate the current concepts of treatment resistance and refractoriness in mood disorders. RESULTS: Genetic factors, misdiagnosis, use of inappropriate pharmacological approaches, non-compliance and biological/psychosocial stressors account for dysfunctions in mood regulation, thus increasing the prevalence of refractory mood disorders. Regarding available treatments, the use of effective doses during an adequate period followed by augmentation with a second and/or third agent, and finally switching to other agent are steps frequently necessary to optimize efficacy. However, in the treatment-resistant paradigm, drugs mimicking standard strategies, which target preferentially the monoaminergic system, can present reduced therapeutic effects. Thus, the search for new effective treatments for mood disorders is critical to decreasing the overall morbidity secondary to treatment resistance. CONCLUSION: Emerging strategies targeting brain plasticity pathways or 'plasticity enhancers', including antiglutamatergic drugs, glucocorticoid receptor antagonists and neuropeptides, have been considered promising therapeutic options for difficult-to-treat mood disorders. [Free Full Text] [PubMed Citation] [Order full text from Infotrieve]


14) Bremner JD, McCaffery P
The neurobiology of retinoic acid in affective disorders.
Prog Neuropsychopharmacol Biol Psychiatry. 2008 Feb 15;32(2):315-31.
Current models of affective disorders implicate alterations in norepinephrine, serotonin, dopamine, and CRF/cortisol; however treatments targeted at these neurotransmitters or hormones have led to imperfect resolution of symptoms, suggesting that the neurobiology of affective disorders is incompletely understood. Until now retinoids have not been considered as possible contributors to affective disorders. Retinoids represent a family of compounds derived from vitamin A that perform a large number of functions, many via the vitamin A product, retinoic acid. This signaling molecule binds to specific retinoic acid receptors in the brain which, like the glucocorticoid and thyroid hormone receptors, are part of the nuclear receptor superfamily and regulate gene transcription. Research in the field of retinoic acid in the CNS has focused on the developing brain, in part stimulated by the observation that isotretinoin (13-cis retinoic acid), an isomer of retinoic acid used in the treatment of acne, is highly teratogenic for the CNS. More recent work has suggested that retinoic acid may influence the adult brain; animal studies indicated that the administration of isotretinoin is associated with alterations in behavior as well as inhibition of neurogenesis in the hippocampus. Clinical evidence for an association between retinoids and depression includes case reports in the literature, studies of health care databases, and other sources. A preliminary PET study in human subjects showed that isotretinoin was associated with a decrease in orbitofrontal metabolism. Several studies have shown that the molecular components required for retinoic acid signaling are expressed in the adult brain; the overlap of brain areas implicated in retinoic acid function and stress and depression suggest that retinoids could play a role in affective disorders. This report reviews the evidence in this area and describes several systems that may be targets of retinoic acid and which contribute to the pathophysiology of depression. [PubMed Citation] [Order full text from Infotrieve]


15) Goshen I, Kreisel T, Ben-Menachem-Zidon O, Licht T, Weidenfeld J, Ben-Hur T, Yirmiya R
Brain interleukin-1 mediates chronic stress-induced depression in mice via adrenocortical activation and hippocampal neurogenesis suppression.
Mol Psychiatry. 2008 Jul;13(7):717-28.
Several lines of evidence implicate the pro-inflammatory cytokine interleukin-1 (IL-1) in the etiology and pathophysiology of major depression. To explore the role of IL-1 in chronic stress-induced depression and some of its underlying biological mechanisms, we used the chronic mild stress (CMS) model of depression. Mice subjected to CMS for 5 weeks exhibited depressive-like symptoms, including decreased sucrose preference, reduced social exploration and adrenocortical activation, concomitantly with increased IL-1 beta levels in the hippocampus. In contrast, mice with deletion of the IL-1 receptor type I (IL-1rKO) or mice with transgenic, brain-restricted overexpression of IL-1 receptor antagonist did not display CMS-induced behavioral or neuroendocrine changes. Similarly, whereas in wild-type (WT) mice CMS significantly reduced hippocampal neurogenesis, measured by incorporation of bromodeoxyuridine (BrdU) and by doublecortin immunohistochemistry, no such decrease was observed IL-1rKO mice. The blunting of the adrenocortical activation in IL-1rKO mice may play a causal role in their resistance to depression, because removal of endogenous glucocorticoids by adrenalectomy also abolished the depressive-like effects of CMS, whereas chronic administration of corticosterone for 4 weeks produced depressive symptoms and reduced neurogenesis in both WT and IL-1rKO mice. The effects of CMS on both behavioral depression and neurogenesis could be mimicked by exogenous subcutaneous administration of IL-1 beta via osmotic minipumps for 4 weeks. These findings indicate that elevation in brain IL-1 levels, which characterizes many medical conditions, is both necessary and sufficient for producing the high incidence of depression found in these conditions. Thus, procedures aimed at reducing brain IL-1 levels may have potent antidepressive actions. [PubMed Citation] [Order full text from Infotrieve]


16) McIntyre RS, Soczynska JK, Woldeyohannes HO, Lewis GF, Leiter LA, MacQueen GM, Miranda A, Fulgosi D, Konarski JZ, Kennedy SH
Thiazolidinediones: novel treatments for cognitive deficits in mood disorders?
Expert Opin Pharmacother. 2007 Aug;8(11):1615-28.
The aim of this review is to provide a rationale for evaluating thiazolidinediones (TZDs) as putative treatments for cognitive deficits in individuals with mood disorders. A MedLine search of all English-language articles published between January 1966 and August 2006 was conducted. The search terms were: the non-proprietary names of TZDs (e.g., rosiglitazone and pioglitazone), peroxisome proliferator-activated receptor, cognition, neuroprotection, inflammation, oxidative stress, cellular metabolism and excitotoxicity cross-referenced with the individual names of mood (e.g., major depressive disorder and bipolar disorder) and dementing disorders (e.g., Alzheimer's disease) as defined in the Diagnostic and Statistical Manual of Mental Disorders third edition, revised/fourth edition, text revision (DSM-III-R/IV-TR). The search was augmented with a manual review of article reference lists. Articles selected for review were based on adequacy of sample size, the use of standardized experimental procedures, validated assessment measures and overall manuscript quality. Contemporary pathophysiologic models of mood disorders emphasize alterations in neuronal plasticity, metabolism and cytoarchitecture with associated regional abnormalities in neuronal (and glial) density and morphology. These abnormalities are hypothesized to subserve cognitive deficits and other clinical features of mood disorders. TZDs may attenuate, abrogate and/or reverse the neurotoxic effects of depressive illness by means of disparate mechanisms, notably insulin signaling, anti-inflammation, glucocorticoid activity and cellular metabolism. Extant data provide the basis for formulating a hypothesis that TZDs may be salutary for cognitive deficits and several aspects of somatic health (e.g., cardiovascular disease) associated with mood disorders. [PubMed Citation] [Order full text from Infotrieve]


17) McIntyre RS, Soczynska JK, Woldeyohannes HO, Alsuwaidan M, Konarski JZ
A preclinical and clinical rationale for quetiapine in mood syndromes.
Expert Opin Pharmacother. 2007 Jun;8(9):1211-9.
The main objective of this review is to discuss results from preclinical studies that aim to elucidate the putative mechanistic basis of the antidepressant action of quetiapine. Results from pivotal, randomized clinical trials in bipolar depression are also briefly reviewed. The authors conducted a PubMed search of all English-language articles published between January 1990 and December 2006. The key search term was quetiapine paired with: serotonin, dopamine, noradrenaline, glutamate, gamma-aminobutyric acid, signal transduction, neurogenesis, oxidative stress, glucocorticoid, antidepressant, major depressive disorder, bipolar disorder and randomized controlled trial. The search was augmented with a manual review of relevant article reference lists. Articles selected for review were based on author consensus, adequacy of sample size, the use of standardized experimental procedures, validated assessment measures and overall manuscript quality. Quetiapine enhances central serotonergic neurotransmission via its high affinity for serotonergic receptors (e.g., 5-HT2A receptor antagonism and partial agonistic activity at the 5-HT1A receptor). Activation of the 5HT1A receptor results in an increase in prefrontal cortex dopaminergic neurotransmission. Affinity for the alpha2-adrenoceptor mediates a relative increase in extracellular noradrenergic release in the prefrontal cortex. Emerging evidence indicates that quetiapine's principal, active, human plasma metabolite, N-desalkyl quetiapine, has high affinity for, and is a potent inhibitor of, the noradrenergic transporter. This latter finding is a point of commonality with other conventional antidepressant agents and may differentiate quetiapine from other atypical antipsychotics. Activity at other intracellular targets (e.g., signal transduction pathways and nerve growth transcription factors), neurotransmitters, inflammatory and oxidative stress networks, and endocrine systems may also mediate the antidepressant effects of quetiapine. The in vitro pharmacodynamic profile of quetiapine is predictive of antidepressant activity in mood syndromes. Available clinical evidence has established quetiapine as an effective monotherapy in bipolar depression. [PubMed Citation] [Order full text from Infotrieve]


18) Himmerich H, Zimmermann P, Ising M, Kloiber S, Lucae S, Kunzel HE, Binder EB, Holsboer F, Uhr M
Changes in the hypothalamic-pituitary-adrenal axis and leptin levels during antidepressant treatment.
Neuropsychobiology. 2007;55(1):28-35.
BACKGROUND: In depressed patients, overstimulation of the hypothalamo-pituitary-adrenocortical (HPA) system, probably caused by glucocorticoid receptor resistance, is the most consistent neurobiological finding. Glucocorticoids themselves are reported to increase leptin synthesis and secretion in humans. METHODS: We examined alterations in plasma levels of leptin as well as changes in the HPA system function using the combined dexamethasone/corticotropin-releasing hormone (dex/CRH) test on admission and at discharge in 74 depressed inpatients. RESULTS: Mean leptin concentration did not change significantly between admission and discharge. However, changes in ACTH response and partial cortisol response to the combined dex/CRH test between admission and discharge were significantly correlated with leptin levels at discharge. CONCLUSIONS: Leptin levels at discharge rise as the HPA axis normalizes. These findings may be explained by an improvement in glucocorticoid receptor sensitivity among depressed patients during antidepressant therapy and a consecutively increased influence of glucocorticoids on leptin levels via the glucocorticoid receptor. [PubMed Citation] [Order full text from Infotrieve]


19) Wu LM, Han H, Wang QN, Hou HL, Tong H, Yan XB, Zhou JN
Mifepristone repairs region-dependent alteration of synapsin I in hippocampus in rat model of depression.
Neuropsychopharmacology. 2007 Dec;32(12):2500-10.
Clinical investigations present much evidence that the glucocorticoid receptor (GR) antagonist mifepristone leads to a rapid amelioration of depression. The molecular mechanisms of mifepristone involved in the treatment of depression are not fully understood. Depression is associated with hippocampal plasticity, for which increased excitatory amino acid (EAA) release in CA3 induced by chronic stress is responsible, and glucocorticoids have a permissive role and act synergistically with EAAs in producing neuronal damage. Moreover, glucocorticoids increase synapsin I, which has a key role in the release of neurotransmitter, including EAAs. Hereby, we hypothesize that major depression involves synapsin I alteration and that mifepristone blocks this alteration. In the present study, we observed both the expression of hippocampal synapsin I and depression-associated behavior in a rat model of depression induced by chronic unpredictable mild stress (CUMS). The result showed that a region-dependent synapsin I alteration occurs in the rat hippocampus after 21 days of CUMS, that is, it increases in dentate gyrus (DG)/CA3 and decreases in the CA1 region. Correlation analysis indicated that the decrease of synapsin I in CA1 is highly correlated with the increase in the DG/CA3 subfield. Simultaneously, the region-dependent alteration of synapsin I is correlated with depression-associated behaviors. Both the alteration of synapsin I and the depression-associated behavior were rapidly restored after treatment with mifepristone for 1 week. The result suggests that the molecular mechanism underlying the treatment of depression with mifepristone is associated with the rapid repair of the synaptic alteration. [PubMed Citation] [Order full text from Infotrieve]


20) Rozeboom AM, Akil H, Seasholtz AF
Mineralocorticoid receptor overexpression in forebrain decreases anxiety-like behavior and alters the stress response in mice.
Proc Natl Acad Sci U S A. 2007 Mar 13;104(11):4688-93.
Although numerous stress-related molecules have been implicated in vulnerability to psychiatric illness, especially major depression and anxiety disorders, the role of the brain mineralocorticoid receptor (MR) in stress, depression, and affective function is not well defined. MR is a steroid hormone receptor that detects circulating glucocorticoids with high affinity and has been primarily implicated in controlling their basal level and circadian rhythm. To specifically address the role of MR in hypothalamic-pituitary-adrenal axis activity and anxiety-related behaviors, we generated transgenic mice with increased levels of MR in the forebrain (MRov mice) by using the forebrain-specific calcium/calmodulin-dependent protein kinase II alpha promoter to direct expression of MR cDNA. A mild but chronic elevation in forebrain MR results in decreased anxiety-like behavior in both male and female transgenic mice. Female MRov mice also exhibit a moderate suppression of the corticosterone response to restraint stress. Increased forebrain MR expression alters the expression of two genes associated with stress and anxiety, leading to a decrease in the hippocampal glucocorticoid receptor (GR) and an increase in serotonin receptor 5HT-1a, consistent with the decreased anxiety phenotype. These data suggest that the functions of forebrain MR may overlap with GR in hypothalamic-pituitary-adrenal axis regulation, but they dissociate significantly from GR in the modulation of affective responses, with GR overexpression increasing anxiety-like behavior and MR overexpression dampening it. These findings point to the importance of the MR:GR ratio in the control of emotional reactivity. [Free Full Text] [PubMed Citation] [Order full text from Infotrieve]