Pharmacological and nonpharmacological factors influencing hypothalamic-pituitary-adrenocortical axis reactivity in acutely depressed psychiatric in-patients, measured by the Dex-CRH test

Sex-specific cortisol levels in bipolar disorder and schizophrenia during mental challenge--relationship to clinical characteristics and medication

OBJECTIVE

Our objective was to examine the cortisol release during a mental challenge in severe mental disorders versus healthy controls (HC), analyzing effects of sex, clinical characteristics and medication, and comparing Bipolar Disorder (BD) to Schizophrenia (SCZ).

METHODS

Patients with BD and SCZ (n=151) were recruited from a catchment area. HC (n=98) were randomly selected from the same area. Salivary samples were collected before and after a mental challenge and cortisol levels determined.

RESULTS

During the challenge there was an interaction between group and sex (P = 0.015) with male patients having a blunted cortisol release compared to male HC (P = 0.037). Cortisol change did not differ significantly between BD and SCZ. In all patients, the cortisol change correlated with number of psychotic episodes (r = -0.23, P = 0.025), and in females patients, with number of depressive episodes (r = -0.33, P = 0.015). Patients using antidepressants had a greater cortisol release during challenge than those not using antidepressants (P = 0.043).

CONCLUSIONS

Male patients with severe mental disorders seem to have a uniform abnormal cortisol release during mental challenges which associates with clinical course, and with beneficial effects of antidepressants.

Glucocorticoids as predictors of treatment response in depression

INTRODUCTION

Glucocorticoids and the stress hormone system have been implicated in the pathophysiology of depression and in the mechanism of action of antidepressant response. Many studies have investigated this system in an effort to predict response to antidepressant treatment. The purpose of this review is to evaluate the evidence for using glucocorticoid-related measures for personalized treatment of depression.

METHODS

We conducted a MEDLINE search from 1966 through 2010 and examined English-language studies reporting on the use of endocrine challenge tests and genetic polymorphisms in genes regulating the stress hormone system as predictors of antidepressant response.

RESULTS

While measures of glucocorticoid levels using endocrine tests, as well polymorphisms in genes regulating the stress hormone system, show associations with response to antidepressant treatment, these measures will need to be combined with other variables, including clinical information and other biological measures, to realize the goal of highly predictive and clinically relevant biomarkers.

DISCUSSION

The glucocorticoid system is potentially of great use in predicting antidepressant response. New combinations of biomarkers including these measures should be tested to develop clinically relevant predictors.

Reliability of hypothalamic-pituitary-adrenal axis assessment methods for use in population-based studies

Population-based studies have been hampered in exploring hypothalamic-pituitary-adrenal axis (HPA) activity as a potential explanatory link between stress-related and metabolic disorders due to their lack of incorporation of reliable measures of chronic cortisol exposure. The purpose of this review is to summarize current literature on the reliability of HPA axis measures and to discuss the feasibility of performing them in population-based studies. We identified articles through PubMed using search terms related to cortisol, HPA axis, adrenal imaging, and reliability. The diurnal salivary cortisol curve (generated from multiple salivary samples from awakening to midnight) and 11 p.m. salivary cortisol had the highest between-visit reliabilities (r = 0.63-0.84 and 0.78, respectively). The cortisol awakening response and dexamethasone-suppressed cortisol had the next highest between-visit reliabilities (r = 0.33-0.67 and 0.42-0.66, respectively). Based on our own data, the inter-reader reliability (r(s)) of adrenal gland volume from non-contrast CT was 0.67-0.71 for the left and 0.47-0.70 for the right adrenal glands. While a single 8 a.m. salivary cortisol is one of the easiest measures to perform, it had the lowest between-visit reliability (R = 0.18-0.47). Based on the current literature, use of sampling multiple salivary cortisol measures across the diurnal curve (with awakening cortisol), dexamethasone-suppressed cortisol, and adrenal gland volume are measures of HPA axis tone with similar between-visit reliabilities which likely reflect chronic cortisol burden and are feasible to perform in population-based studies.

C-reactive protein polymorphisms are associated with the cortisol awakening response in basal conditions in human subjects

Cortisol affects the acute-phase response, but it is unknown whether C-reactive protein (CRP), an acute-phase reactant, also affects hypothalamus?pituitary?adrenal axis activity. In the present study, associations were explored between CRP haplotypes with plasma CRP concentrations and basal salivary cortisol level. We included 266 physically healthy Caucasian subjects (103 females and 163 males) aged between 18 and 65 years of whom 94 had a psychiatric disorder in a genetic association study. Six tag single-nucleotide polymorphisms capturing the common genetic variation of the CRP gene were genotyped (i.e. rs2808628, rs2808630, rs1205, rs1800947, rs1417938, and rs3091244) to yield common CRP haplotypes. Plasma CRP concentrations, the salivary cortisol awakening response (CAR) (0, 30, 45, and 60?min after awakening), and the diurnal cortisol decline (11:00, 15:00, 19:00, and 23:00 h) were assessed for 2 days. rs2808628, rs1205, rs1417938, and rs3091244 showed expected associations not only with CRP concentrations, but also with salivary cortisol levels during the CAR. Five well-characterized CRP haplotypes were arranged in ascending order according to increasing CRP levels. There was an inverse linear association between CRP haplotypes and cortisol levels during the CAR, but no association with the diurnal cortisol decline. Hence, genetic variants in the CRP gene that are associated with lifetime plasma CRP levels were also associated with salivary cortisol levels after awakening, in basal, non-inflammatory conditions.

Do stress hormones connect environmental effects with behavior in the forced swim test?

Forced swim test (FST) is a widely used test for antidepressant development. Depression is a stress related disease, as hormones of the stress-axis can modify mood. However it is not clear, how the appearance of depressive-like behavior (floating) in FST is connected with changes in the stress-hormone levels. We hypothesized, that different manipulations would alter the behavior through changes in stress-hormone levels. First the effect of environmental alterations was studied. Increasing water-temperature enhanced floating time together with a decrease in adrenocorticotropin levels. During the dark phase of the day rats spent more time with floating independently from the actual lighting. Neither the phase nor the actual lighting had significant effect on adrenocorticotropin concentrations with higher corticosterone levels during the dark phase. At greater water depth rats float less but the size of animals had no effect. Water depth did not influence adrenocorticotropin and corticosterone responses, but the size of the rats significantly affected both factors. Secondly, administration of imipramine reduced floating and adrenocorticotropin level without affecting corticosterone. Despite the known connection between depression and stress we did not find a correlation between floating behavior and hormone levels. As an alternative mechanism imipramine-induced heart rate and core body temperature decrease was found by telemetric approach. This study is the first summary in rats examining the effect of wide range of environmental alterations during FST. It seems likely that both brain monoamines and stress-axis take part in the development of depression, but these pathways are regulated independently.

Relationships between psychological distress, coping styles, and HPA axis reactivity in healthy adults

Psychological distress and coping styles have been suggested to relate to altered function in the hypothalamic-pituitary-adrenal (HPA) axis, although there remains much to be understood about their relationships. High and low cortisol levels (or reactivity) both represent HPA axis dysfunction, with accumulated evidence suggesting that they are linked to different types of psychopathology. The dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test has been extensively used to identify HPA axis abnormalities in various psychiatric conditions including mood disorders; however, the possible associations of psychological distress and coping styles with HPA axis function have not been well documented using this test. Here, we examined the relationships of HPA axis reactivity as measured by the DEX/CRH test with subjectively perceived psychological distress and coping styles, both of which were assessed with self-report questionnaires, in 121 healthy volunteers. Subjects were divided into three groups by the cortisol suppression pattern, namely the incomplete-suppressors (DST-Cortisol ≥ 5 μg/dL or DEX/CRH-Cortisol ≥ 5 μg/dL), moderate-suppressors (DST-Cortisol < 5 μg/dL and 1 μg/dL ≤ DEX/CRH -Cortisol < 5 μg/dL), and enhanced-suppressors (DST-Cortisol < 5 μg/dL and DEX/CRH-Cortisol < 1 μg/dL). The enhanced-suppressors showed significantly higher scores in obsessive-compulsive, interpersonal sensitivity and anxiety symptoms and significantly more frequent use of avoidant coping strategy, compared to the other two groups. These results point to the important role of enhanced suppression of cortisol, or blunted cortisol reactivity, in non-clinical psychopathology such as avoidant coping strategy and greater psychological distress.

Atypical depression is more common than melancholic in fibromyalgia: an observational cohort study

BACKGROUND

It has been postulated that atypical and melancholic depression subtypes exist in depressed fibromyalgia (FM) patients, yet no study has empirically tested this hypothesis. The purpose of this study is to determine whether major depressive disorder (MDD) with atypical features and MDD with melancholic features occurs in a FM sample and to describe their demographic, clinical and diagnostic characteristics.

METHODS

An observational cohort study using a descriptive cross-sectional design recruited a convenience sample of 76 outpatients with FM from an academic rheumatology clinic and a community mental health practice. Diagnoses of FM were confirmed using the 1990 ACR classification guidelines. Diagnoses of MDD and diagnostic subtypes were determined using the DSM-IV-TR criteria. Clinical characteristics were measured using the Fibromyalgia Impact Questionnaire, Structured Interview Guide for the Hamilton Depression Rating Scale with Atypical Depression Supplement and other standardized instruments. Odds ratios were computed on subtype-specific diagnostic criteria. Correlations assessed associations between subtype diagnoses and diagnostic criteria.

RESULTS

Of the 76 subjects with FM, 11.8% (n = 9) were euthymic, 52.6% (n = 40) met diagnostic criteria for MDD with atypical features and 35.6% (n = 27) for MDD with melancholic features. Groups did not differ on demographic characteristics except for gender (p = 0.01). The non-depressed and atypical groups trended toward having a longer duration of FM symptoms (18.05 yrs. +/- 12.83; 20.36 yrs. +/- 15.07) compared to the melancholic group (14.11 yrs. +/- 8.82; p = 0.09). The two depressed groups experienced greater severity on all clinical features compared to the non-depressed group. The atypical group did not differ clinically from the melancholic group except the latter experienced greater depression severity (p = 0.001). The atypical group demonstrated the highest prevalence and correlations with atypical-specific diagnostic criteria: (e.g., weight gain/ increased appetite: OR = 3.5, p = 0.02), as did the melancholic group for melancholic-specific criteria: (e.g., anhedonia: OR = 20, p < 0.001).

CONCLUSION

Depressed fibromyalgia patients commonly experience both atypical and melancholic depressive features; however, in this study, atypical depression was 1.5 times more common than melancholic depression. This finding may have significant research and clinical implications.

Gender-specific association of galanin polymorphisms with HPA-axis dysregulation, symptom severity, and antidepressant treatment response

Galanin (GAL) is an estrogen-inducible neuropeptide, highly expressed in brain regions reported to be involved in regulation of mood and anxiety. GAL possibly has a direct modulatory effect on hypothalamic-pituitary-adrenal (HPA)-axis regulation. Recent data from pharmacological and genetic studies indicate a significant function of GAL in stress-related disorders. By using a tag SNP approach covering the locus encoding preprogalanin (PPGAL), earlier findings of female-specific associations of polymorphisms in this locus with panic disorder were expanded to a larger sample of 268 outpatients with anxiety disorders (ADs). Within a larger sample of 541 inpatients with major depressive disorder (MDD), we then tested associations of one PPGAL tag SNP with specific depression symptom clusters and HPA-axis activity assessed by the combined dexamethasone-suppression/CRH-stimulation test both at inpatient admission and discharge (n=298). Gender specificity as well as dependence of the association on levels of circulating estrogens was analyzed. Genotyping revealed high linkage disequilibrium in the promoter area of the PPGAL gene, which includes several estrogen-response elements. Confirming earlier results, rs948854, tagging this promoter region, was associated with more severe anxiety pathology in female AD patients, but not in males. In premenopausal female MDD patients, the same allele of rs948854 was associated with more severe vegetative but not cognitive depressive symptoms at discharge and worse treatment response on antidepressant medication. Furthermore, this allele was associated with higher HPA-axis activity at admission. No significant case-control associations could be observed. However, because of power limitations of both patient samples, small effects cannot be excluded. The reported associations in independent samples of AD and MDD support an estrogen-dependent function of GAL in pathophysiology of anxiety and depression, affecting response to antidepressant treatment.

Higher overcommitment to work is associated with higher plasma cortisol but not ACTH responses in the combined dexamethasone/CRH test in apparently healthy men and women

BACKGROUND

Overcommitment (OC) is a pattern of excessive striving that has been associated with alterations in the hypothalamus-pituitary-adrenal (HPA) system. To investigate whether overcommitment is associated with alterations in HPA system function we measured cortisol and adrenocorticotropin (ACTH) release in response to the combined dexamethasone/CRH test.

METHODS

We recruited 92 men and 108 women of a wide range of OC scores including the minimum (6) and maximum (24) of possible OC scores (mean+/-SEM: 13.25+/-.27). We repeatedly measured plasma cortisol and ACTH levels in the combined dexamethasone/CRH test after injection of 100mul CRH preceded by administration of 1.5mg dexamethasone the night before. Moreover, we assessed depressive symptoms (Beck Depression Inventory, BDI) and work stress (effort-reward-imbalance, ERI).

RESULTS

Independent of age and gender, higher OC was associated with higher repeated cortisol (interaction time-by-OC: p=.014, f=.15) but not ACTH (p=.22) secretion in the combined dexamethasone/CRH test. Similarly, higher cortisol (beta=.16, p=.029, R(2)=.02) but not ACTH (p=.47) increase following CRH injection was predicted by higher OC. Depressive symptoms (BDI score) and work stress scores (effort-reward-ratio) did not relate to neuroendocrine responses to the dexamethasone/CRH test. Controlling for depressive symptoms and work stress scores in addition to age and gender did not change results. OC was not associated with ACTH or cortisol pre-test levels.

DISCUSSION

Whereas OC was not associated with alterations in negative feedback sensitivity after dexamethasone administration, our findings indicate that with increasing OC scores, a higher reactivity of the adrenal cortex together with a normal reactivity of the pituitary is observed following subsequent stimulation by CRH injection.

Acute HPA axis response to naltrexone differs in female vs. male smokers

BACKGROUND

Both opioid antagonist administration and cigarette smoking acutely increase hypothalamic-pituitary-adrenal (HPA) axis activity as measured by adrenocorticotropic hormone (ACTH) and cortisol levels. However, male and female smokers may differ in their response to the opioid antagonist naltrexone, which may be partially mediated by sex differences in HPA axis function. Smokers, as a group, have frequently been shown to have HPA axis dysfunction, which may have relevance to the course and maintenance of nicotine dependence. The purpose of this study was to examine possible sex differences in HPA axis function by comparing stress-hormone response to naltrexone within healthy male and female smokers. Additionally, exploratory analyses compared the combined effects of naltrexone and cigarette smoking on hormonal responsivity between the sexes.

METHOD

Thirty-eight healthy smokers (22 men) were tested in two separate morning sessions after 12h of smoking abstinence. For women, self-reports of menstrual cycle information were obtained prior to each session (date of last menstruation, cycle length, reproductive phase, etc.). Each participant received 50mg naltrexone or placebo capsule (in random order) and plasma levels of ACTH and cortisol were assessed at regular intervals for several hours. A subgroup of 12 participants underwent a similar, additional session in which they smoked a single cigarette three hours after naltrexone administration.

RESULTS

Naltrexone significantly increased ACTH and cortisol levels in women, but not men (DrugxSexxTime, p<0.05). A post hoc analysis suggested that women at an estimated 'high estrogen' phase had a greater cortisol response (DrugxEstrogen level, p<0.05) than those at an estimated 'low estrogen' phase. Exploratory analyses showed that smoking a single cigarette potentiated naltrexone-induced increases in ACTH (p<0.05) and cortisol (p<0.01) in all participants.

CONCLUSION

The findings support the hypothesis that women are more sensitive to opioid antagonism at the level of the HPA axis. Although further studies are needed to examine mechanisms underlying these responses, both results may have clinical implications for the use of naltrexone as a treatment for nicotine dependence.

Histories of major depression and premenstrual dysphoric disorder: Evidence for phenotypic differences

This study examined unique versus shared stress and pain-related phenotypes associated with premenstrual dysphoric disorder (PMDD) and prior major depressive disorder (MDD). Sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA)-axis measures were assessed at rest and during mental stress, as well as sensitivity to cold pressor and tourniquet ischemic pain tasks in four groups of women: (1) non-PMDD with no prior MDD (N=18); (2) non-PMDD with prior MDD (N=9); (3) PMDD with no prior MDD (N=17); (4) PMDD with prior MDD (N=10). PMDD women showed blunted SNS responses to stress compared to non-PMDD women, irrespective of prior MDD; while women with prior MDD showed exaggerated diastolic blood pressure responses to stress versus never depressed women, irrespective of PMDD. However, only in women with histories of MDD did PMDD women have lower cortisol concentrations than non-PMDD women, and only in non-PMDD women was MDD associated with reduced cold pressor pain sensitivity. These results suggest both unique phenotypic differences between women with PMDD and those with a history of MDD, but also indicate that histories of MDD may have special relevance for PMDD.

Polymorphisms in GRIK4, HTR2A, and FKBP5 show interactive effects in predicting remission to antidepressant treatment

Single-nucleotide polymorphisms (SNPs) in the FKBP5, GRIK4, and HTR2A genes have been shown to be associated with response to citalopram treatment in the STAR(*)D sample, but only associations with FKBP5 have so far been tested in the Munich Antidepressant Response Signature (MARS) project. Response and remission of depressive symptoms after 5 weeks of antidepressant treatment were tested against 82 GRIK4 and 37 HTR2A SNPs. Association analysis was conducted in about 300 depressed patients from the MARS project, 10% of whom had bipolar disorder. The most predictive SNPs from these two genes and rs1360780 in FKBP5 were then genotyped in a total of 387 German depressed in-patients to analyze potential additive and interactive effects of these variants. We could not replicate previous findings of the Sequenced Treatment Alternatives to Relieve Depression (STAR(*)D) study in our sample. Although not statistically significant, the effect for the best GRIK4 SNP of STAR(*)D (rs1954787, p=0.076, p(corrected)=0.98) seemed to be in the same direction. On the other hand, the nominally significant association with the top HTR2A SNPs of STAR(*)D (rs7997012, allelic, p=0.043, p(corrected)=0.62) was with the opposite risk allele. The GRIK4 SNP (rs12800734, genotypic, p=0.0019, p(corrected)=0.12) and the HTR2A SNP (rs17288723, genotypic, p=0.0011, p(corrected)=0.02), which showed the strongest association with remission in our sample, had not been reported previously. Associations across all genetic markers within the GRIK4 (genotypic, p=0.022) or HTR2A (genotypic, p=0.012) locus using the Fisher's product method (FPM) were also significant. In all 374 patients, the best predictive model included a main effect for GRIK4 rs12800734 and two significant interactions between GRIK4 rs12800734 and FKBP5 rs1360780, and GRIK4 rs12800734 and HTR2A rs17288723. This three SNP model explained 13.1% of the variance for remission after 5 weeks (p=0.00051 for the model). Analyzing a sub-sample of 194 patients, plasma ACTH (p=0.002) and cortisol (p=0.021) responses of rs12800734 GG (GRIK4) carriers, who also showed favorable treatment response, were significantly lower in the second combined dexamethasone (dex)/corticotrophin-releasing hormone (CRH) test before discharge compared with the other two genotype groups. Despite large differences in ethnicity and design compared with the STAR(*)D study, our results from the MARS study further support both independent and interactive involvement of GRIK4, HTR2A and FKBP5 in antidepressant treatment response.

Investigation of 17 candidate genes for personality traits confirms effects of the HTR2A gene on novelty seeking

Genes involved in serotonergic and dopaminergic neurotransmission have been hypothesized to affect different aspects of personality, but findings from genetic association studies did not provide conclusive results so far. In previous studies, however, only one or a few polymorphisms within single genes were investigated neglecting the possibility that the genetic associations might be more complex comprising several genes or gene regions. To overcome this limitation, we performed an extended genetic association study analyzing 17 serotonergic (SLC6A4, HTR1A, HTR1B, HTR2A, HTR2C, HTR3A, HTR6, MAOA, TPH1, TPH2) and dopaminergic genes (SLC6A3, DRD2, DRD3, DRD4, COMT, MAOA, TH, DBH), which have been previously reported to be implicated with personality traits. One hundred and ninety-five single nucleotide polymorphisms (SNPs) within these genes were genotyped with the Illumina BeadChip technology (HumanHap300, Human-1) in a sample of 366 mentally healthy Caucasians. Additionally, we tried to replicate our results in an independent sample of further 335 Caucasians. Personality traits in both samples were assessed with the German version of Cloninger's Tridimensional Personality Questionnaire. From 30 SNPs showing associations at a nominal level of significance, two intronic SNPs, rs2770296 and rs927544, both located in the HTR2A gene, withstood correction for multiple testing. These SNPs were associated with the personality trait novelty seeking. The effect of rs927544 could be replicated for the novelty seeking subscale extravagance, and the same SNP was also associated with extravagance in the combined samples. Our results show that HTR2A polymorphisms modulate facets of novelty seeking behaviour in healthy adults suggesting that serotonergic neurotransmission is involved in this phenotype.

The influence of psychiatric comorbidity on the dexamethasone/CRH test in major depression

BACKGROUND

The outcome of the dexamethasone/corticotropin-releasing-hormone (DEX/CRH) test in depressed patients is heterogeneous. The present study investigated whether comorbidity of anxiety or somatoform disorders might be an explaining factor for this finding.

METHODS

The DEX/CRH test was administered in 36 pure major depressive outpatients, 18 major depressive outpatients with a comorbid anxiety and/or somatoform disorder, and 43 healthy controls. Patients were free of psychotropic medication. Group differences in responsivity to the DEX/CRH test were analysed.

RESULTS

Depressive patients with comorbidity showed a significant lower cortisol response compared to pure depressive patients (p = 0.04) and controls (p = 0.003). Group differences between MDD patients with and without comorbidity in cortisol responses disappeared after adjustment for post-DEX cortisol concentrations (p = 0.34).

CONCLUSIONS

An enhanced suppression of cortisol to 1.5 mg DEX is present in a subgroup of depressed patients with psychiatric comorbidity. Distinct hypothalamic-pituitary-adrenal (HPA) axis dysfunctions are revealed when comorbidity is taken into account.

Assessing the neuroendocrine stress response in the functional neuroimaging context

Neural regulation of stress responses, and the feedback of stress hormones to the brain, reflect complex brain-body interactions that may underlie the effects of psychological stress on health. Elucidating the brain circuitry involved in the cortical control of limbic-hypothalamic-pituitary-adrenal axis, and the cortical "targets" of cortisol that in turn modulates brain function, requires careful assessment of glucocorticoid hormones, in the context of the neuroimaging paradigms. Here we discuss approaches for assessment of endocrine function in the context of neuroimaging, including methods of blood and saliva specimen collection, and methods for drug/hormone administration. We also briefly discuss important temporal considerations, including appropriate timing of sample collections for hormones with different time-courses of activation (e.g. ACTH vs. cortisol), the pharmacokinetics of both endogenous hormones and administered agents, and circadian considerations. These are crucial to experimental designs of rhythmic hormonal systems and multiple feedback loops. We briefly address psychological/behavioral 'activation' paradigms used for inducing endogenous LHPA axis responses within or in proximity to scanner, as well as strategies for administration of exogenous hormones or secretagogues. Finally, we discuss some of the analytical issues in terms of hormone responses (e.g. response and area under curve, diurnal variability) and strategies for linking measured levels of peripheral humoral factor to brain activity (e.g. hormone responses as between-subject regressors of BOLD activations, hormone levels as within-subject regressors in analyses of covariance of brain activity over time, etc.).

Outcome in delusional depression comparing trimipramine monotherapy with a combination of amitriptyline and haloperidol--a double-blind multicenter trial

BACKGROUND

Patients with delusional depression are difficult to treat. The atypical antidepressant trimipramine was effective in a previous 4-week open label pilot study in patients with this disorder. The major neurobiological effect of trimipramine is the inhibition of the hypothalamic-pituitary-adrenocortical (HPA) system. In delusional depression HPA overactivity is more distinct than in other subtypes of depression. HPA suppression is thought to contribute to the action of trimipramine.

METHODS

In a double-blind, randomized, placebo controlled multicenter trial we compared the effects of trimipramine monotherapy versus a combination of amitriptyline and haloperidol. Dosage was increased stepwise from 100mg up to 400mg trimipramine and from 100mg up to 200mg amitriptyline combined with 2mg up to 7.5mg haloperidol. The average dose of trimipramine was higher than that of amitriptyline throughout the trial. During sixth week mean dosage (+/-standard deviation) were 356.1+/-61.2mg trimipramine, 184.0+/-23.6 mg amitriptyline and 6.3+/-1.8 mg haloperidol. During six weeks psychometric assessments were performed weekly. For HPA monitoring a dexamethasone/corticotropin-releasing hormone (Dex/CRH) test was performed before active medication and at the end of treatment. Additionally tolerability was monitored by ECG, EEG assessment of extrapyramidal symptoms and akathisia, clinical laboratory routine and recording of blood pressure and heart rate. Adverse events were documented.

RESULTS

94 patients were enclosed into the study. The per protocol sample consisted of 33 patients of the trimipramine group and of 24 patients of the amitriptyline/haloperidol group. The decrease of the Hamilton depression (HAMD) score (24 items) showed non-inferiority of trimipramine compared to amitriptyline/haloperidol. Twenty-eight patients (84.84%) in the trimipramine arm and 17 patients (70.83%) in the amitriptyline/haloperidol arm were responders (HAMD <or=50%). Remission (HAMD<8) was found in 18 (54.55%) patients after trimipramine and in 11 (45.83%) patients after amitriptyline/haloperidol. No significant differences were found concerning response and remission. The cortisol and ACTH response in the Dex/CRH test decreased between days 1 and 42 in both groups. Serious side effects were not reported.

CONCLUSION

In all, trimipramine monotherapy appears to be an effective treatment in delusional depression.

Prednisolone suppression test in depression: prospective study of the role of HPA axis dysfunction in treatment resistance

BACKGROUND

People with severe depressive illness have raised levels of cortisol and reduced glucocorticoid receptor function.

AIMS

To obtain a physiological assessment of hypothalamic-pituitary-adrenal (HPA) axis feedback status in an in-patient sample with depression and to relate this to prospectively determined severe treatment resistance.

METHOD

The prednisolone suppression test was administered to 45 in-patients with depression assessed as resistant to two or more antidepressants and to 46 controls, prior to intensive multimodal in-patient treatment.

RESULTS

The patient group had higher cortisol levels than controls, although the percentage suppression of cortisol output after prednisolone in comparison with placebo did not differ. Non-response to in-patient treatment was predicted by a more dysfunctional HPA axis (higher cortisol levels post-prednisolone and lower percentage suppression).

CONCLUSIONS

In patients with severe depression, HPA axis activity is reset at a higher level, although feedback remains intact. However, prospectively determined severe treatment resistance is associated with an impaired feedback response to combined glucocorticoid and mineralocorticoid receptor activation by prednisolone.

Suppressive effect of mirtazapine on the HPA system in acutely depressed women seems to be transient and not related to antidepressant action

Impaired regulation of the hypothalamus-pituitary-adrenocortical (HPA) system is a consistent finding among patients with depression, which can be most sensitively detected with the combined dexamethasone (dex)/corticotrophin releasing hormone (CRH) test. The majority of patients with acute depression shows an exaggerated plasma corticotrophin (ACTH) and cortisol response to this test that normalizes gradually during successful antidepressant therapy. In contrast, persistently high HPA-responses to this challenge are prognostically less favorable. It has been recently questioned, whether this observation applies also to treatment with the atypical antidepressant mirtazapine, as patients treated with this drug showed a distinct attenuation of the endocrine response to the dex/CRH test already after 1 week of treatment. In the present study, we investigated whether the attenuating effect of mirtazapine on the HPA system is an acute pharmacological reaction disappearing after physiological adaptation or whether this effect is related to the antidepressant action of the drug. We examined plasma ACTH and cortisol responses to the dex/CRH test in acutely depressed inpatients treated either with mirtazapine (n=55) or a monoamine reuptake inhibitor (n=105) according to doctor's choice and compared the test results with healthy controls (n=40). Patients treated with monoamine reuptake inhibitors received either selective serotonin reuptake inhibitors (SSRI), tricyclic antidepressants (TCA) or the combined serotonin and noradrenalin reuptake inhibitor venlafaxine. We found increased plasma ACTH and cortisol responses to the dex/CRH test in depressed patients compared with healthy controls, but also significantly (p=.017) attenuated plasma cortisol secretion in the mirtazapine group compared to the group of monoamine reuptake inhibitor treated patients. This effect was not significant in male patients. Furthermore this effect was independent of the psychopathological state, but depended on treatment duration. Patient treatment with mirtazapine for up to 7 days resulted in dex/CRH test outcome that was indistinguishable from controls. This effect, however waned as it was not observable in patients treated for a longer period. These results suggest that short-term administration of mirtazapine has immediate but only transient suppressive effects on the HPA system predominantly in women. Our results confirm that dex/CRH tests can be used as predictors of clinical course also under mirtazapine treatment.

Polymorphisms in the angiotensin-converting enzyme gene region predict coping styles in healthy adults and depressed patients

Dispositional coping styles are important moderators of the stress reaction and are altered in stress-related disorders like cardiovascular diseases and affective disorders. Heritability studies suggest a considerable genetic contribution to the interindividual variability in coping styles. Since the angiotensin-converting enzyme (ACE) gene has been described to be associated with the vulnerability for stress-related disorders and with altered stress hormone regulation, we investigated the ACE gene as potential candidate gene for coping styles. Five hundred forty one mentally healthy subjects and 194 patients suffering from depression participating in the Munich Antidepressant Response Signature (MARS) project were examined. Coping styles were assessed with a self-report questionnaire (German Stress Coping Questionnaire SVF78) measuring the individual coping style pattern in response to stressful situations. We genotyped 15 single nucleotide polymorphisms (SNPs) and the insertion/Deletion (I/D)-polymorphism in the ACE gene region and investigated their associations with coping styles. In healthy subjects, the highest association was observed between rs8066276, an intronic SNP of the ACE gene, and the coping factor Distraction. A further intronic SNP rs4305, not in linkage disequilibrium with rs8066276, showed an association with Devaluation/Defense. All associated copying styles can be categorized as potentially stress reducing factors (positive coping). Both SNPs were also found to be associated with positive coping styles in the patient sample; rs8066276 was associated with Devaluation/Defense, and rs4305 showed associations with Control. These results suggest that the ACE gene is involved in the development of coping strategies.

Why do we respond so differently? Reviewing determinants of human salivary cortisol responses to challenge

Stress and stress-related health impairments are major problems in human life and elucidating the biological pathways linking stress and disease is of substantial importance. However, the identification of mechanisms underlying a dysregulation of major components of the stress response system is, particularly in humans, a very challenging task. Salivary cortisol responses to diverse acute challenge paradigms show large intra- and interindividual variability. In order to uncover mechanisms mediating stress-related disorders and to potentially develop new therapeutic strategies, an extensive phenotyping of HPA axis stress responses is essential. Such a research agenda depends on substantial knowledge of moderating and intervening variables that affect cortisol responses to different stressors and stimuli. The aim of this report is, therefore, to provide a comprehensive summary of important determinants of, in particular, human salivary cortisol responses to different kinds of laboratory stimuli including acute psychosocial stress as well as pharmacological provocation procedures. This overview demonstrates the role of age and gender, endogenous and exogenous sex steroid levels, pregnancy, lactation and breast-feeding, smoking, coffee and alcohol consumption as well as dietary energy supply in salivary cortisol responses to acute stress. Furthermore, it briefly summarizes current knowledge of the role of genetic factors and methodological issues in terms of habituation to repeated psychosocial stress exposures and time of testing as well as psychological factors, that have been shown to be associated with salivary cortisol responses like early life experiences, social factors, psychological interventions, personality as well as acute subjective-psychological stress responses and finally states of chronic stress and psychopathology.

HPA-axis regulation at in-patient admission is associated with antidepressant therapy outcome in male but not in female depressed patients

A concatenation of data implicates a hyperactivity of the hypothalamus pituitary adrenal (HPA)-axis in the pathogenesis of depression and its normalization as a necessary predecessor of clinical response to antidepressant drugs. In addition, regulation of the HPA-axis has been shown to be dependent on sex hormones. We therefore investigated gender differences in HPA-axis regulation in depression and its normalization during remission of clinical symptoms. We used the combined dexamethasone suppression/CRH stimulation (Dex-CRH) test to evaluate the degree of HPA-axis dysregulation in 194 in-patients with unipolar depression from the Munich Antidepressant Response Signature (MARS) study at both admission and discharge. The Hamilton Depression (HAM-D) Rating Scale was used to monitor clinical response to antidepressant treatment. For both genders, we observed a normalization of HPA-axis dysregulation in remitters but not in non-remitters, both after 5 weeks of treatment and at discharge. The pattern of HPA-axis normalization with remission of depressive symptoms, however, showed gender-specific differences. In male patients, remission after 5 weeks of in-patient treatment was associated with a significantly higher cortisol response in the Dex-CRH test at admission. In female patients, 5-week remitters and non-remitters had a comparable cortisol response at admission. Cortisol response at admission was not correlated with gonadal steroid levels at this time point and the results were similar for pre-menopausal women vs. post-menopausal women. Gender-associated biological characteristics, likely independent of circulating gonadal steroids, thus seem to influence HPA-axis regulation in depression. In male patients, a single measure of HPA-axis dysregulation at admission may serve as a predictor of response to antidepressant treatment in addition to the previously reported repeated measure of the Dex-CRH test.

The glutamatergic system and its relation to the clinical effect of therapeutic-sleep deprivation in depression - an MR spectroscopy study

Rapid improvement of depressive symptoms occurs after the administration of the NMDA antagonist ketamine. Ketamine administration is accompanied by an increase in GLX (sum-peak of glutamate, glutamine (GLN) and GABA) and GLN in the brain, as measured by magnetic-resonance (MR) spectroscopy. In healthy subjects, we observed an increase in GLX and GLN levels after total sleep deprivation (TSD), which has a rapid antidepressant effects. We examined, if an increase in GLX or GLN is related to the therapeutic effect of TSD. We examined 13 patients with major depression by means of proton MR spectroscopy (field strength: 1.5T) before and after 24h of TSD. Two anatomical areas (dorsolateral prefrontal cortex (DLPC) and parieto-occipital cortex (POC)) were studied. In the DLPC TSD did not change GLX or its elements, whereas the total creatine and choline signal increased marginally. No change could be observed in the POC. For further exploration we took gender and the presence of vegetative characteristics of melancholic depression into account, i.e. the presence of early morning awakening, appetite and weight loss was taken into account, to define vegetative melancholia (VM). TSD led to an increase in GLX and GLN in the DLPC only of male patients. In patients with VM an increase in GLN occurred in this area. The low field strength limits the accuracy for GLX and GLN estimates. Despite the exploratory nature of the study, it nevertheless supports earlier data on the importance of glutamatergic neurotransmission and furthermore of gender and/or vegetative features in depression.

Clinical characteristics and treatment outcome in a representative sample of depressed inpatients - findings from the Munich Antidepressant Response Signature (MARS) project

Depression is a common and often difficult-to-treat clinical condition with a high rate of patients showing insufficient treatment response and persistence of symptoms. We report the characteristics of a representative sample of depressed inpatients participating in the Munich Antidepressant Response Signature (MARS) project. Eight hundred and forty-two inpatients admitted to a psychiatric hospital for treatment of a major depressive episode, recurrent or bipolar depression were thoroughly characterized with respect to demographic factors, clinical history, and the degree of HPA-axis dysregulation evaluated by means of combined dex/CRH tests, and the predictive value of these factors for treatment outcome is investigated. 80.8% of patients responded to treatment (i.e., improvement in symptom severity of at least 50%) and 57.9% reached remission (i.e., near absence of residual depressive symptoms) at discharge after a mean treatment period of 11.8 weeks. Regression analysis identified early partial response (within 2 weeks) as the most important positive predictor for achieving remission. Previous ineffective treatment trials in the current episode and presence of a migration background are potent negative predictors for treatment outcome. In addition, remitters were characterized by a more pronounced normalization of an initially dysregulated HPA-axis. We could show that a large majority of inpatients suffering from depression benefits from antidepressant treatment during hospitalization. However, a considerable number of patients failed to achieve remission. We demonstrated that this subgroup can be characterized by a set of demographic, clinical and neuroendocrine variables allowing to predict unfavorable outcome at an early stage of treatment.

Combined dexamethasone/corticotropin-releasing factor test in chronic fatigue syndrome

BACKGROUND

Studies of hypothalamic-pituitary-adrenal (HPA) axis function in chronic fatigue syndrome (CFS) point to hypofunction, although there are negative reports. Suggested mechanisms include a reduced hypothalamic or supra-hypothalamic stimulus to the HPA axis and enhanced sensitivity to the negative feedback of glucocorticoids. The aim of the current study was to investigate HPA axis function in CFS with the dexamethasone/corticotropin-releasing factor (Dex/CRF) test, in analogy with research in affective disorders.

METHOD

Thirty-four well-characterized female CFS patients and 25 healthy control subjects participated in the low-dose Dex/CRF test. Current major depressive episode was an exclusion criterion. History of early-life stress (ELS) was assessed with the Structured Trauma Interview.

RESULTS

Salivary cortisol responses after 0.5 mg Dex were lower in CFS patients than in controls (before 100 microg CRF, p=0.038; after 100 microg CRF, p=0.015). A secondary analysis revealed an influence of early-life stress and of oestrogen intake. After removal of the 10 participants who were taking an oral oestrogen, patients without a history of ELS showed lower cortisol responses than patients with ELS and controls (before CRF, p=0.005; after CRF, p=0.008).

CONCLUSIONS

CFS is globally associated with reduced cortisol responses in the combined low-dose Dex/CRF test, but this effect is only clearly present in CFS patients without a history of ELS. This study provides further support for an enhanced glucocorticoid negative feedback and/or a reduced central HPA axis drive in CFS. Furthermore, it demonstrates that ELS is an important variable to consider in CFS research.

A combined dexamethasone/corticotropin-releasing hormone test in patients with chronic PTSD--first preliminary results

BACKGROUND

Reports about alterations of hypothalamic-pituitary-adrenocortical (HPA) function in patients with chronic posttraumatic stress disorder (PTSD) are inconsistent and controversial. More refined laboratory tests and subgrouping of PTSD patients might help to decrease variance of findings.

METHODS

14 subjects with chronic PTSD and 14 healthy controls were examined between 13:00 and 17:00 using a modified combined dexamethasone/CRH test (0.5 mg dexamethasone at 23:00, 100 microg CRH at 15:00). Plasma adenocorticotropic hormone (ACTH), cortisol and blood pressure were measured every 15 min from 14:45 until 17:00.

RESULTS

No significant differences between patients and controls were found in the analyses of ACTH and cortisol levels, but a significantly elevated systolic and diastolic blood pressure in PTSD. Severity of depressive symptoms had no influence. However, explorative analyses showed that patients with a history of childhood traumatization had significantly higher post-dexamethasone-ACTH levels and a significantly lower diastolic blood pressure in comparison to patients without early trauma.

CONCLUSIONS

In this first pilot study in a typical clinical sample of patients with chronic PTSD we found effects of severe adverse events in childhood on HPA axis regulation. Maybe, childhood traumatization could influence HPA axis findings in PTSD. Further research is needed, especially dose-response studies with different doses of dexamethasone in dexamethasone/CRH tests in PTSD.

Relationships of DEX/CRH and GHRH test results to the outcome of depression--preliminary results suggest the GHRH test may predict relapse after discharge

To explore and compare hypothalamic-pituitary-somatotropic (HPS) axis function and hypothalamic-pituitary-adrenocortical (HPA) axis function in depression, the dexamethasone (DEX)/CRH test and growth hormone releasing hormone (GHRH) test were prospectively performed on patients with depression at the time of admission and discharge. The patients who relapsed within six months after discharge exhibited significantly lower growth hormone (GH) responses to GHRH at the time of discharge than those who did not relapse. There were no significant correlations between GH response to GHRH and the results of DEX/CRH tests after controlling for age, sex, and body mass index. The findings of this study suggest that results of the GHRH test may be a predictor of future relapse in patients with depression.

Social support and enhanced suppression of adrenocorticotropic hormone and cortisol responses to hypothalamic-pituitary-adrenal function and thyrotropin-releasing hormone tests in patients with major depressive disorder

The results of the thyrotropin-releasing hormone (TRH) stimulation test and the combined dexamethasone/corticotropin-releasing hormone (DEX/CRH) test are believed to correlate with social support status in patients with major depressive disorder. We studied 41 consecutive patients hospitalized for major depressive disorder and tested their responses to DEX/CRH and TRH on hospital days 4-7. DeltaMAX TSH and DeltaMAX cortisol were measured. Multiple regression analysis found that social support questionnaire (SSQ-A) and SSQ-B scores were significantly related to DeltaMAX cortisol and DeltaMAX TSH, respectively, at the time of admission. Social support might contribute partially to the TRH and DEX/CRH test results in patients with major depressive disorder.

Longitudinal neuroendocrine changes assessed by dexamethasone/CRH and growth hormone releasing hormone tests in psychotic depression

Although psychotic depression has been reported to exhibit a greater degree of dysregulation of hypothalamic-pituitary-adrenocortical (HPA) function than non-psychotic depression, little is known concerning hypothalamic-pituitary-somatotropic (HPS) function in psychotic depression and how neuroendocrine function changes after treatment. To investigate the longitudinal changes in HPA and HPS system function in psychotic depression, we performed repeated dexamethasone/corticotropin releasing hormone (DEX/CRH) tests and growth hormone (GH) releasing hormone (GHRH) tests in inpatients with major depressive disorder. The psychotic depression group exhibited greater elevation of ACTH responses to the DEX/CRH test and stronger decreases in GH responses to the GHRH test than the non-psychotic depression group at admission. At discharge, the neuroendocrine responses to the DEX/CRH test of the psychotic depression group were still stronger than those of the non-psychotic depression group, though there were no significant differences in severity of depression between the groups. There were significant longitudinal changes in neuroendocrine responses to the DEX/CRH test between admission and discharge. The psychotic depression group exhibited increased GH responses to GHRH at discharge compared with those at admission, whereas no significant longitudinal change in GH response was found in the non-psychotic depression group. Consequently, there were no significant differences in GH responses to GHRH between the psychotic and non-psychotic depression groups at discharge. The results of GHRH test showed no significant relationships with severity of depression except psychotic features and the results of the DEX/CRH test. Our findings suggest that the HPS axis may be associated with psychotic features rather than general severity of depression. Further longitudinal studies are needed to clarify the role of HPS function in psychotic depression and whether sustained dysregulation of HPA function in psychotic depression is associated with a poor outcome after discharge.

HPA axis and sleep: identifying subtypes of major depression

It is increasingly acknowledged that the diagnosis of major depression encompasses patients who do not necessarily share the same disease biology. Though the diagnostic criteria allow the specification of different subtypes, e.g. melancholic and atypical features, a consensus still has to be reached with regard to the clinical symptoms that clearly delineate these subtypes. Beside clinical characteristics, biological markers may help to further improve identification of biologically distinct endophenotypes and, ultimately, to devise more specific treatment strategies. Alterations of the hypothalamus-pituitary-adrenal (HPA) axis and sleep architecture are not only commonly observed in patients with major depression, but the nature and extent of these alterations can help to identify distinct subtypes. Thus, a HPA overdrive, due to enhanced secretion of corticotropin-releasing hormone (CRH) and an impaired negative feedback via glucocorticoid receptors, seems to be most consistently observed in patients with melancholic features. These patients also show the clearest sleep-electroencephalogram (EEG) alterations, including disrupted sleep, low amounts of slow wave sleep (SWS), a short rapid eye movement (REM) latency and a high REM density. In contrast, patients with atypical features are characterized by reduced activity of the HPA axis and ascending noradrenergic neurons in the locus coeruleus. Though sleep-EEG alterations have been less thoroughly examined in these patients, there are data to suggest that SWS is not reduced and that REM sleep parameters are not consistently altered. While the atypical and melancholic subtypes of major depression may represent the extremes of a spectrum, the distinct clinical features provide an opportunity to further explore biological markers, as well as environmental factors, contributing to these clinical phenotypes. Moreover, dysregulations of the HPA axis and sleep-EEG alterations can also be induced in rodents, thereby allowing alignment of critical biological aspects of a human disease subtype with an animal model. Such "Translational Research" efforts should help to develop targeted therapies for distinct patient populations.

Neurobiological factors linking personality traits and major depression

OBJECTIVE

To examine the neurobiological basis of personality and depression.

METHOD

We examined preclinical and clinical studies related to neuroanatomy, neuroendocrine, molecular, and genetic alterations in depressed patients. We considered whether common neurobiological factors might be shared between personality and depression.

RESULTS

Preclinical studies provide insights into the neurobiological mechanisms underlying the pathophysiology of depression including neuroendocrine alterations in hypothalamic-pituitary-adrenal (HPA) function, neuroanatomical alterations in key brain regions, and alterations in neurotrophin and serotonergic signalling systems. Clinical studies show similar alterations in depressed patients. Evidence suggests that neuroendocrine alterations in HPA function may contribute to personality traits. Brain regions implicated in depression, including the hippocampus and the anterior cingulate cortex, might play a role in personality. Key molecules implicated in depression have been extensively studied with reference to personality traits, particularly neuroticism. To date, physiological measures (serum and positron emission tomography) provide the strongest evidence implicating brain-derived neurotrophic factor and serotonin in personality, while genetic evidence is less convincing.

CONCLUSIONS

A neurobiological link exists between personality and depression; however, more work is needed to provide an understanding of the nature of this relation and to link this work with clinical studies examining the influence of personality factors on depression.

The antidepressant desipramine requires the ABCB1 (Mdr1)-type p-glycoprotein to upregulate the glucocorticoid receptor in mice

The mechanisms by which antidepressants regulate the hypothalamic-pituitary-adrenal (HPA) axis are still unknown. The ABCB1-type multiple drug resistance (MDR) p-glycoprotein (PGP) regulates the HPA axis by limiting the access of glucocorticoids to the brain in mice and humans. Previous work in cell cultures has found that antidepressants enhance glucocorticoid receptor (GR) function in vitro by inhibiting MDR PGP, and therefore by increasing the intracellular concentration of glucocorticoids-but this model has never been tested directly in animals. Here, the tricyclic antidepressant, desipramine (20 mg/kg/day, i.p., for seven days), was administered to abcb1ab MDR PGP knockout mice (congenic on the FVB/N background strain) and to FVB/N controls. The hippocampal mRNA expression of GR, mineralocorticoid receptor (MR), MDR (Mdr1a) PGP, and 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) were measured, together with plasma corticosterone levels. In FVB/N controls, desipramine induced a significant upregulation of GR mRNA in the CA1 region (+31%; p=0.045); in contrast, in abcb1ab (-/-) mice, desipramine induced a significant downregulation of GR mRNA in the CA1 region (-45%; p=0.004). MR mRNA expression was unaltered. Desipramine decreased corticosterone levels in both FVB/N controls and in abcb1ab (-/-) mice, but in abcb1ab (-/-) mice the effects were smaller. Specifically, in FVB/N controls (but not in abcb1ab (-/-) mice), desipramine reduced corticosterone levels not only compared with saline-treated mice but also compared with the 'physiological' levels of untreated mice (-39%; p=0.05). Finally, desipramine reduced Mdr1a mRNA expression across all hippocampus areas (-9 to -23%), but had no effect on 11beta-HSD1 mRNA expression. These data support the notion that the MDR PGP is one of the molecular targets through which antidepressants regulate the HPA axis.

Changes in the hypothalamic-pituitary-adrenal axis and leptin levels during antidepressant treatment

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.

Persistent cognitive impairment in depression: the role of psychopathology and altered hypothalamic-pituitary-adrenocortical (HPA) system regulation

BACKGROUND

Dysregulation of the hypothalamic-pituitary-adrenocortical (HPA) system and cognitive impairment are consistent findings in depression. This study examines the associations between HPA system regulation, cognitive functioning, and psychopathology in depressed inpatients on admission and at discharge.

METHODS

The HPA system dysregulation was evaluated with the dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test. Cognitive assessment included speed of information processing, divided and selective attention, as well as short-term and working memory. Psychopathology was evaluated with the Hamilton Rating Scale for Depression (HAMD). Data from 75 depressed inpatients are reported, 51 (68%) of them achieved remission.

RESULTS

Despite a significant reduction of depressive symptoms between admission and discharge, a high rate of patients remained cognitively impaired. Selective attention improved significantly in remitters and nonremitters, while speed of information processing increased only in remitters. The cortisol response to the DEX/CRH test decreased significantly only in remitters, which was uncorrelated with cognitive performance. In nonremitters, severity of depression was significantly correlated with information processing time while improvement in short-term memory was negatively associated with the cortisol response at discharge.

CONCLUSIONS

Our data support the assumption that psychopathological symptoms and the HPA system dysregulation can be dissociated in their impact on cognitive functioning in depressed patients.

Overweight and obesity affect treatment response in major depression

BACKGROUND

Epidemiologic and clinical studies suggest comorbidity between major depressive disorder (MDD) and obesity. To elucidate the impact of weight on the course of depression beyond comorbidity, we investigated psychopathology, attention, neuroendocrinology, weight change, and treatment response in MDD patients, depending on their weight.

METHODS

Four hundred eight inpatients with MDD participated in the Munich Antidepressant Response Signature Study, designed to discover biomarkers and genotypes that are predictive for clinical outcome. Psychopathology and anthropometric parameters were monitored weekly in 230 patients. In subsamples, combined dexamethasone-corticotropin-releasing hormone and attention tests were conducted at admission and discharge. One thousand twenty-nine diagnosed matched controls served for morphometric comparisons.

RESULTS

Patients with MDD had a significantly higher body mass index (BMI) compared with healthy controls. Patients with high BMI (> or =25) showed a significantly slower clinical response, less improvement in neuroendocrinology and attention, and less weight gain than did patients with normal BMI (18.5 < or = BMI < 25) during antidepressant treatment.

CONCLUSIONS

Our findings suggest that overweight and obesity characterize a subgroup of MDD patients with unfavorable treatment outcome.

Combined dexamethasone/corticotropin releasing hormone test predicts treatment response in major depression - a potential biomarker?

BACKGROUND

Exaggerated corticotropin (ACTH) and cortisol response to the combined dexamethasone (DEX)/corticotropin releasing hormone (CRH) test, indicating impaired regulation of the hypothalamus-pituitary-adrenocortical (HPA) system, is frequently observed in depression. In the present study, we examined whether change in HPA system function during the first weeks of hospitalization predicts response to antidepressant treatment in major depression and thus constitutes a potential biomarker.

METHODS

We conducted the DEX/CRH test in 50 inpatients suffering from severe major depression, once after study inclusion and a second time 2 to 3 weeks later while under continuous antidepressant treatment.

RESULTS

We found increased ACTH and cortisol responses to the first DEX/CRH test compared with healthy control subjects. In the second DEX/CRH test 2 to 3 weeks later, 36 of the 50 patients showed an attenuated cortisol response, while 14 patients did not display improvement or exhibited even aggravation of the altered HPA system function. Improved HPA system regulation in the second DEX/CRH test was associated with beneficial treatment response after 5 weeks and a higher remission rate at the end of hospitalization.

CONCLUSIONS

The results suggest that change in HPA system regulation assessed with repeated DEX/CRH tests is a potential biomarker that may predict clinical outcome at follow-up. There is consensus that the drug development process could be improved, once reliable biomarkers become available that help to allow a judgement regarding the efficacy of a novel drug candidate. The combined DEX/CRH test seems to be a promising candidate for such a biomarker.

A four-step approach for developing diagnostic tests in psychiatry

A four-step approach for developing diagnostic tests in psychiatry is proposed. Step 1, a biological variable is observed to be deviant from healthy controls in a particular patient population. The demonstration of test retest reliability of the finding using blinding procedures is an essential component of this early step. Step 2, is the demonstration of potential clinical usefulness of the specific finding. The two most important objectives at this step are demonstration of difference between the target patient population and appropriate control groups (these should be groups of patients with diagnoses that commonly appear on the differential diagnostic lists of the target disorder). Estimation of the effect size of the finding could be a reasonable guide to which findings should be considered good candidates for Step 3 studies. During Step 3 the performance characteristics of the test should be established. Specifically, the sensitivity, specificity, positive and negative predictive values of the biological marker should be examined. Step 4 defines the clinical application of the test and helps standardize the technique used in large and multicenter clinical trials. Multicenter trials should pave the road towards standardization of laboratory procedures used to conduct the test, as well as providing data regarding cost effectiveness and impact on both short-term and long-term clinical outcomes.

The DEX/CRH neuroendocrine test and the prediction of depressive relapse in remitted depressed outpatients

Hypothalamo-pituitary-adrenal (HPA) system dysfunction is the most characteristic biological alteration found in a majority of depressed patients. Accumulating evidence suggests that the combined dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test is highly sensitive to detect HPA system abnormalities. The aim of this study was to evaluate whether the DEX/CRH test has a predictive value for the risk of depressive relapse in outpatients who are in clinical remission from a major depressive episode. Thirty-eight depressed outpatients (23 women, 15 men) in remission (MADRS score < or =8) underwent the DEX/CRH test and were followed up for 12 months regarding the occurrence of a new depressive episode. In parallel we recruited 24 controls (13 men and 11 women). The main result is a statistically significant difference concerning the delta and AUC numbers for cortisol plasmatic values between the group of patients who relapsed during the 1-year follow-up and control subjects, but not between the group of patients with prolonged remission and controls. These results suggest that in outpatients who are in clinical remission from a major depressive episode, high delta and AUC values in the DEX/CRH test compared to controls subjects can be associated with a higher risk of relapse.

Dopaminergic function in depressed patients with affective flattening or with impulsivity: [18F]fluoro-L-dopa positron emission tomography study with voxel-based analysis

A decreased striatal presynaptic dopaminergic function has been reported in depressed patients with affective flattening and psychomotor retardation, using (18)F-fluorodopa positron emission tomography and regions-of-interest. The present study aimed to investigate regional ;[(18)F]dopa uptake in mesolimbic and mesocortical dopaminergic projections with the hypothesis that there should be a decrease in mesolimbic [(18)F]dopa uptake associated with affective flattening and psychomotor retardation. [(18)F]Dopa-positron emission tomography and anatomical magnetic resonance imaging datasets from 12 screened depressed patients with either marked affective flattening and psychomotor retardation (n=6) or with marked impulsivity (n=6), and from eight healthy subjects, were analyzed using a voxel-based approach. Regional differences in [(18)F]dopa uptake rate constant (K(i)) values between the healthy group and the two depression subgroups were compared using both statistical parametric mapping and cluster-based regions-of-interest. Patients with affective flattening and psychomotor retardation had [(18)F]dopa K(i) decreases in the left caudate, bilateral putamen and nucleus accumbens, left parahippocampus and dorsal brainstem. Impulsive depressives had [(18)F]dopa K(i) decreases in the anterior cingulate and hypothalamus, and an increase in the right parahippocampal gyrus. These findings support distinct regional dysfunctions of monoamines depending on the depressive symptomatology.

Dysregulation of the hypothalamic-pituitary-adrenal axis in postpartum depression

Postpartum depression (PPD) affects at least 10% to 15% of postpartum women, including more than 600,000 American mothers in 2003 alone. Dramatic changes in the hypothalamic-pituitary-adrenal (HPA) system in the transition from pregnancy to postpartum coupled with research on the psychobiology of depression provided the foundation for this study. The purpose of this study was to compare the reactivity and regulation of the HPA axis components, adrenocorticotropic hormone (ACTH) and cortisol, in depressed and nondepressed postpartum women. A comparative, longitudinal study design was used with 22 normal, healthy, nondepressed pregnant women. Physiologic and postpartum depression data were collected at 6 and 12 weeks postpartum at a university clinical research center. Maximal treadmill exercise stimulated plasma ACTH and serum cortisol levels which were measured before, during, and after 20 min of exercise. Postpartum depression was measured with the Postpartum Depression Screening Scale. Lag within-subject ACTH levels predicting cortisol regression slopes were significantly different between the depressed and nondepressed groups at both 6 and 12 weeks. The depressed group showed no relationship between their ACTH and cortisol levels, with higher ACTH and lower cortisol levels when compared with the nondepressed group. The expected regulated relationship with cortisol levels rising in response to rising ACTH levels was found in the non-depressed group. These findings indicate that the HPA axis was dysregulated in the depressed group, but regulated in the nondepressed group at 6 and 12 weeks postpartum. This pattern of higher ACTH levels to stimulate less cortisol is similar to patterns found in women with early life stresses.

Different responses to dexamethasone and prednisolone in the same depressed patients

RATIONALE

Patients with major depression show hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, but the mechanisms underlying this abnormality are still unclear.

OBJECTIVES

We have compared two synthetic glucorticoids, dexamethasone and prednisolone, in their ability to suppress the hypothalamic-pituitary-adrenal (HPA) axis in depressed patients. Dexamethasone probes glucocorticoid receptor (GR) function, while prednisolone probes both GR and mineralocorticoid receptor (MR) function.

MATERIALS AND METHODS

We used a single-blind, repeated-measure design. We administered placebo, prednisolone (5 mg) or dexamethasone (0.5 mg), at 22:00, to 18 severe, treatment-resistant depressed inpatients (15 of them with a history of childhood trauma) and 14 healthy volunteers. On the following days, we collected salivary cortisol from 9:00 to 22:00.

RESULTS

Depressed patients had higher salivary cortisol levels compared with controls, at baseline and after both prednisolone and dexamethasone (p<0.001). Consistent with previous studies, depressed inpatients showed impaired suppression by dexamethasone: based on the analysis of the areas under the curve (AUCs), suppression by dexamethasone (0.5 mg) was -85% in controls vs -46% in depressed patients (p=0.018). However, the same depressed patients showed normal suppression by prednisolone (5 mg): suppression was -41% in controls and -36% in depressed patients (p=0.6).

CONCLUSIONS

We suggest that the additional effects of prednisolone on the MR explain the different responses to these glucocorticoids in the same depressed patients.

Regulation of the hypothalamic-pituitary-adrenocortical system in patients with panic disorder

Anxiety and depressive disorders are among the most common psychiatric disorders with a high number of hospital admissions and a lifetime prevalence of up to 25%. So far, the pathophysiological mechanisms for anxiety disorders remain to be found. Preclinical studies suggest that changes in hypothalamic-pituitary-adrenocortical (HPA) system function are causally related to the expression of anxiety-related behavior. The findings on HPA system function in patients with anxiety disorders are, however, heterogeneous. Both hypo- and hyperresponsiveness of HPA response in various anxiety disorders under different experimental conditions were found. In order to characterize putative case/control differences in HPA system function, we performed a Dex-CRH test, a widely used test to pick up changes in HPA system regulation with high sensitivity, in 30 patients with panic disorder, 35 patients with major depressive episode and in 30 controls individually matched for ethnicity, age and gender. The results indicate a similar dysregulation of the HPA system response in the Dex-CRH test in both patient groups. This finding further underlines the hypothesis that both, depression and panic disorder, share impaired HPA system regulation, supporting the notion that the impairment is involved in the pathophysiology of these clinical conditions. However, differences in the suppression effects and psychopathological correlation patterns between depressed and panic patients suggest different biological mechanisms of HPA system dysregulation in both disorders.

Polymorphisms in the angiotensin-converting enzyme gene are associated with unipolar depression, ACE activity and hypercortisolism

Angiotensin-converting enzyme (ACE) is assumed to influence the activity of the hypothalamic-pituitary-adrenocortical (HPA) system, which shows hyperactivity in the majority of patients with major depression. The ACE gene, known to be associated with cardiovascular disorders, which in turn are accompanied with an increased susceptibility for depression, is therefore a promising candidate gene for affective disorders. We investigated the genetic association between 35 single-nucleotide polymorphisms (SNPs) and an insertion/deletion (I/D)-polymorphism in the ACE gene and the susceptibility for unipolar major depression together with the genetic association with ACE serum activity and functional parameters of the HPA system. Two independent case/control samples with a total of 843 unrelated unipolar depressed patients and 1479 healthy controls were investigated. A case/control sample was screened to detect genetic associations with unipolar major depression. In addition, a replication sample was used to confirm the detected associations and to further investigate functional consequences of the genetic variants associated with depression. In the screening sample, two SNPs within the ACE gene were significantly associated with unipolar major depression. The association with unipolar major depression of one SNP (rs4291) located in the promoter region of the ACE gene was confirmed in our replication sample. The T-allele of this SNP was associated with depression and depressed T-allele carriers showed higher ACE serum activity and HPA-axis hyperactivity. Variants of the ACE gene such as SNP rs4291 are suggested susceptibility factors for unipolar major depression. We could show that SNP rs4291 influences ACE activity and HPA-axis hyperactivity and might therefore represent a common pathophysiologic link for unipolar depression and cardiovascular disease.

Neuroendocrine, cognitive and structural imaging characteristics of women on longterm sickleave with job stress-induced depression

BACKGROUND

A recent increase in long-term sick leave (LTSL) in Sweden affects mostly women in the public sector. Depression-related diagnoses account for most of the increase, and work-related stress has been implicated.

METHODS

We examined dexamethasone/corticotropin-releasing hormone (dex/CRH) test responses, magnetic resonance imaging measures of prefrontocortical and hippocampal volumes, and cognitive performance in 29 female subjects fulfilling three core criteria: 1) LTSL > 90 days; 2) unipolar depression or maladaptive stress reaction with depressed mood; 3) job-related stress given as a reason for disability. This group was compared with 28 healthy matched controls.

RESULTS

The cortisol response to CRH differed markedly between the two groups (p = .002), with a dampened response in patients. This difference remained after removing subjects on antidepressant drugs (p = .006) or smokers (p = .003). Neither hippocampal nor prefrontocortical volumes differed. Performance on hippocampus-dependent declarative memory tests did not differ between groups, but the LTSL group had impaired working memory.

CONCLUSIONS

Our most salient finding is an attenuated dex-CRH response in patients on LTSL due to job-stress related depression. This is opposite to what has been described in major depression. It remains to be established whether this impairment is the end result of prolonged stress exposure, or a pre-existing susceptibility factor.

Time course of hypothalamic-pituitary-adrenocortical axis activity during treatment with reboxetine and mirtazapine in depressed patients

RATIONALE

In healthy subjects, cortisol and ACTH secretion are acutely stimulated by reboxetine and inhibited by mirtazapine. However, it was not investigated so far whether reboxetine and mirtazapine may also differ in their impact on hypothalamic-pituitary-adrenocortical (HPA) axis activity in depressed patients and whether these effects are related to clinical outcome.

OBJECTIVES

In the present study, we investigated the impact of 5-week treatment with reboxetine or mirtazapine on the combined dexamethasone suppression/corticotropin releasing hormone (DEX/CRH) test results in depressed patients.

METHODS

Forty drug-free patients suffering from a major depressive episode (Diagnostic and Statistical Manual of Mental Disorders-IV criteria) were treated with either reboxetine (8 mg/day; n=20) or mirtazapine (45 mg/day; n=20) for 5 weeks. Before, after 1 and 5 weeks of therapy, the DEX/CRH test was performed and cortisol and ACTH concentrations were measured.

RESULTS

During reboxetine treatment, a gradual and significant reduction in HPA axis activity as measured by the DEX/CRH test was seen, which was most pronounced after 5 weeks of treatment. In contrast, mirtazapine significantly reduced the cortisol and ACTH concentrations during the DEX/CRH test within 1 week. However, after 5 weeks of mirtazapine treatment, the cortisol and ACTH responses to the DEX/CRH test partially increased again both in responders and nonresponders.

CONCLUSIONS

This is the first study demonstrating differential effects of various antidepressants on the time course of serial DEX/CRH test results in depressed patients.

The circadian basis of winter depression

The following test of the circadian phase-shift hypothesis for patients with winter depression (seasonal affective disorder, or SAD) uses low-dose melatonin administration in the morning or afternoon/evening to induce phase delays or phase advances, respectively, without causing sleepiness. Correlations between depression ratings and circadian phase revealed a therapeutic window for optimal alignment of circadian rhythms that also appears to be useful for phase-typing SAD patients for the purpose of administering treatment at the correct time. These analyses also provide estimates of the circadian component of SAD that may apply to the antidepressant mechanism of action of appropriately timed bright light exposure, the treatment of choice. SAD may be the first psychiatric disorder in which a physiological marker correlates with symptom severity before, and in the course of, treatment in the same patients. The findings support the phase-shift hypothesis for SAD, as well as suggest a way to assess the circadian component of other psychiatric, sleep, and chronobiologic disorders.

The anti-apoptotic, glucocorticoid receptor cochaperone protein BAG-1 is a long-term target for the actions of mood stabilizers

Increasing data suggest that impairments of cellular plasticity/resilience underlie the pathophysiology of bipolar disorder. A series of microarray studies with validating criteria have recently revealed a common, novel target for the long-term actions of the structurally highly dissimilar mood stabilizers lithium and valproate: BAG-1 [BCL-2 (B-cell CLL/lymphoma 2)-associated athanogene]. Because BAG-1 attenuates glucocorticoid receptor (GR) nuclear translocation, activates ERK (extracellular signal-regulated kinase) MAP (mitogen-activated protein) kinases, and potentiates anti-apoptotic functions of BCL-2, extensive additional studies were undertaken. Chronic administration of both agents at therapeutic doses increased the expression of BAG-1 in rat hippocampus. Furthermore, these findings were validated at the protein level, and the effects were seen in a time frame consistent with therapeutic effects and were specific for mood stabilizers. Functional studies showed that either lithium or valproate, at therapeutically relevant levels, inhibited dexamethasone-induced GR nuclear translocation and inhibited GR transcriptional activity. Furthermore, small interfering RNA studies showed that these inhibitory effects on GR activity were mediated, at least in part, through BAG-1. The observation that BAG-1 inhibits glucocorticoid activation suggests that mood stabilizers may counteract the deleterious effects of hypercortisolemia seen in bipolar disorder by upregulating BAG-1. Additionally, these studies suggest that regulation of GR-mediated plasticity may play a role in the treatment of bipolar disorder and raise the possibility that agents affecting BAG-1 more directly may represent novel therapies for this devastating illness.

Regulation of Synaptic Transmission by CRF Receptors

Corticotropin-releasing factor (CRF or CRH) and its family of related peptides have long been recognized as hypothalamic-pituitary-adrenal (HPA) axis peptides that function to regulate the release of other hormones, e.g., ACTH. In addition, CRF acts outside the HPA axis not as a hormone, but as a regulator of synaptic transmission, pre- and post-synaptically, within specific CNS neuronal circuits. Synaptic transmission within the nervous system is today understood to be a more complex process compared to the concepts associated with the term 'synapse' introduced by Sherrington in 1897. Based on more than a century of progress with modern cellular and molecular experimental techniques, prior definitions and functions of synaptic molecules and their receptors need to be reconsidered (see Glossary and Fig. 1), especially in light of the important roles for CRF, its family of peptides and other potential endogenous regulators of neurotransmission, e.g., vasopressin, NPY, etc. (see Glossary). In addition, the property of 'constitutive activity' which is associated with G-protein coupled receptors (GPCRs) provides a persistent tonic mechanism to fine-tune synaptic transmission during both acute and chronic information transfer. We have applied the term 'regulator', adapted from the hormone literature, to CRF, as an example of a specific endogenous substance that functions to facilitate or depress the actions of neuromodulators on fast and slow synaptic responses. As such, synaptic neuroregulators provide a basic substrate to prime or initiate silently plastic processes underlying neurotransmitter-mediated information transfer at CNS synapses. Here we review the role of CRF to regulate CNS synaptic transmission and also suggest how under a variety of allostatic changes, e.g., associated with normal plasticity, or adaptations resulting from mental disorders, the synaptic regulatory role for CRF may be 'switched' in its polarity and/or magnitude in order to provide a coping mechanism to deal with daily and life-long stressors. Thus, a prominent role we assign to non-HPA axis CRF, its family of peptides, and their receptors, is to maintain both acute and chronic synaptic stability.

Assessment of the dexamethasone/CRH test as a state-dependent marker for hypothalamic-pituitary-adrenal (HPA) axis abnormalities in major depressive episode: a Multicenter Study

There is compelling evidence for the involvement of hypothalamic-pituitary-adrenal (HPA) axis abnormalities in depression. Growing evidence has suggested that the combined dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test is highly sensitive to detect HPA axis abnormalities. We organized a multicenter study to assess the DEX/CRH test as a state-dependent marker for major depressive episode in the Japanese population. We conducted the DEX/CRH test in 61 inpatients with major depressive episode (Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV)) and 57 healthy subjects. In all, 35 patients were repeatedly assessed with the DEX/CRH test on admission and before discharge. The possible relationships between clinical variables and the DEX/CRH test were also examined. Significantly enhanced pituitary-adrenocortical responses to the DEX/CRH test were observed in patients on admission compared with controls. Such abnormalities in patients were significantly reduced after treatment, particularly in those who underwent electroconvulsive therapy (ECT) in addition to pharmacotherapy. Age and female gender were associated with enhanced hormonal responses to the DEX/CRH test. Severity of depression correlated with DEX/CRH test results, although this was explained, at least in part, by a positive correlation between age and severity in our patients. Medication per se was unrelated to DEX/CRH test results. These results suggest that the DEX/CRH test is a sensitive state-dependent marker to monitor HPA axis abnormalities in major depressive episode during treatment. Restoration from HPA axis abnormalities occurred with clinical responses to treatment, particularly in depressed patients who underwent ECT.