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

Biomarker-Guided Tailored Therapy in Major Depression

This chapter provides a comprehensive examination of a broad range of biomarkers used for the diagnosis and prediction of treatment outcomes in major depressive disorder (MDD). Genetic, epigenetic, serum, cerebrospinal fluid (CSF), and neuroimaging biomarkers are analyzed in depth, as well as the integration of new technologies such as digital phenotyping and machine learning. The intricate interplay between biological and psychological elements is emphasized as essential for tailoring MDD management strategies. In addition, the evolving link between psychotherapy and biomarkers is explored to uncover potential associations that shed light on treatment response. This analysis underscores the importance of individualized approaches in the treatment of MDD that integrate advanced biological insights into clinical practice to improve patient outcomes.

Heterogeneity in major depressive disorder: The need for biomarker-based personalized treatments

Major Depressive Disorder (MDD) or depression is a pathological mental condition affecting millions of people worldwide. Identification of objective biological markers of depression can provide for a better diagnostic and intervention criteria; ultimately aiding to reduce its socioeconomic health burden. This review provides a comprehensive insight into the major biomarker candidates that have been implicated in depression neurobiology. The key biomarker categories are covered across all the "omics" levels. At the epigenomic level, DNA-methylation, non-coding RNA and histone-modifications have been discussed in relation to depression. The proteomics system shows great promise with inflammatory markers as well as growth factors and neurobiological alterations within the endocannabinoid system. Characteristic lipids implicated in depression together with the endocrine system are reviewed under the metabolomics section. The chapter also examines the novel biomarkers for depression that have been proposed by studies in the microbiome. Depression affects individuals differentially and explicit biomarkers identified by robust research criteria may pave the way for better diagnosis, intervention, treatment, and prediction of treatment response.

Ex vivo glucocorticoid receptor-mediated IL-10 response predicts the course of depression severity

Directly measuring hypothalamic pituitary adrenal (HPA) axis function, an important player in affective disorders, is intensive and invasive. A crucial component of this system, the activity of the glucocorticoid receptor (GR), can be assessed ex vivo instead. Here, we investigated GR sensitivity in patients with major depressive disorder (MDD) to determine its predictive potential. Psychometric data and blood samples were collected from patients experiencing a major depressive episode (MDE, n = 87), healthy control subjects (n = 49), and patients with remitted MDD (n = 31) at baseline and (for patients) after median 20 days of follow-up after treatment as usual. Blood cells were stimulated ex vivo with lipopolysaccharide and the effect was suppressed by increasing dexamethasone (DEX) concentrations. The resultant cytokine secretion profile (for IL-6, IL-10, and TNF-α) was considered indicative of GR activity. Higher baseline scores of the Montgomery–Åsberg Depression Rating Scale (MADRS) were associated with a stronger decrease of logIC IL-6 (indicating an increase of GR sensitivity). Higher baseline logEC IL-10 (indicating a lower GR sensitivity) and a stronger reduction of logEC IL-10 (indicating a stronger increase in GR sensitivity) were associated with a stronger decrease in the MADRS score. Patients with remitted MDD showed higher logIC TNF-α values (indicating lower GR sensitivity) in comparison to patients with a current MDD at baseline and follow-up. Initially low GR sensitivity measured ex vivo in peripheral blood cells that increases over the course of treatment could serve as a predictive marker for stronger improvement in depression severity.

Peripheral Markers of Depression

Major Depressive Disorder (MDD) is a leading cause of disability worldwide, creating a high medical and socioeconomic burden. There is a growing interest in the biological underpinnings of depression, which are reflected by altered levels of biological markers. Among others, enhanced inflammation has been reported in MDD, as reflected by increased concentrations of inflammatory markers-C-reactive protein, interleukin-6, tumor necrosis factor-α and soluble interleukin-2 receptor. Oxidative and nitrosative stress also plays a role in the pathophysiology of MDD. Notably, increased levels of lipid peroxidation markers are characteristic of MDD. Dysregulation of the stress axis, along with increased cortisol levels, have also been reported in MDD. Alterations in growth factors, with a significant decrease in brain-derived neurotrophic factor and an increase in fibroblast growth factor-2 and insulin-like growth factor-1 concentrations have also been found in MDD. Finally, kynurenine metabolites, increased glutamate and decreased total cholesterol also hold promise as reliable biomarkers for MDD. Research in the field of MDD biomarkers is hindered by insufficient understanding of MDD etiopathogenesis, substantial heterogeneity of the disorder, common co-morbidities and low specificity of biomarkers. The construction of biomarker panels and their evaluation with use of new technologies may have the potential to overcome the above mentioned obstacles.

Prospective biomarkers of major depressive disorder: a systematic review and meta-analysis

Leading biological hypotheses propose that biological changes may underlie major depressive disorder onset and relapse/recurrence. Here, we investigate if there is prospective evidence for biomarkers derived from leading theories. We focus on neuroimaging, gastrointestinal factors, immunology, neurotrophic factors, neurotransmitters, hormones, and oxidative stress. Searches were performed in Pubmed, Embase and PsychInfo for articles published up to 06/2019. References and citations of included articles were screened to identify additional articles. Inclusion criteria were having an MDD diagnosis as outcome, a biomarker as predictor, and prospective design search terms were formulated accordingly. PRISMA guidelines were applied. Meta-analyses were performed using a random effect model when three or more comparable studies were identified, using a random effect model. Our search resulted in 67,464 articles, of which 75 prospective articles were identified on: Neuroimaging (N = 24), Gastrointestinal factors (N = 1), Immunology (N = 8), Neurotrophic (N = 2), Neurotransmitters (N = 1), Hormones (N = 39), Oxidative stress (N = 1). Meta-analyses on brain volumes and immunology markers were not significant. Only cortisol (N = 19, OR = 1.294, p = 0.024) showed a predictive effect on onset/relapse/recurrence of MDD, but not on time until MDD onset/relapse/recurrence. However, this effect disappeared when studies including participants with a baseline clinical diagnosis were removed from the analyses. Other studies were too heterogeneous to compare. Thus, there is a lack of evidence for leading biological theories for onset and maintenance of depression. Only cortisol was identified as potential predictor for MDD, but results are influenced by the disease state. High-quality (prospective) studies on MDD are needed to disentangle the etiology and maintenance of MDD.

Esketamine and rapastinel, but not imipramine, have antidepressant-like effect in a treatment-resistant animal model of depression

OBJECTIVES

Treatment-resistance to antidepressants is a major problem in the pharmacotherapy of major depressive disorder (MDD). Unfortunately, only a few animal models are suitable for studying treatment-resistant depression, among them repeated treatment with Adrenocorticotropic hormone (ACTH) appears to be useful to mimic treatment-resistance to monoaminergic antidepressants. Therefore, the present work aimed to investigate the effectiveness of s-ketamine and rapastinel (formerly GLYX13), modulators of the glutamatergic N-methyl-D-aspartate receptor in ACTH-treated animals.

METHODS

Naïve male Sprague Dawley rats were subjected to repeated subcutaneous injections with ACTH (100 µg/0.1 ml/rat/day) for 14 days and drug treatment on the test day (open field and forced swim test) with imipramine, s-ketamine or rapastinel. In addition, assessment of plasma levels of corticosterone and ACTH was carried out.

RESULTS

We found that rats repeatedly treated with ACTH for 14 days responded to single injections with s-ketamine (15 mg/kg) and rapastinel (10 mg/kg), but failed to respond to imipramine (15 mg/kg). In the plasma, the levels of corticosterone and ACTH were increased after 14 days of daily treatment with ACTH, independently of the treatment.

CONCLUSION

The present data confirm development of a resistance to treatment following chronic ACTH administration. In addition, the study confirms the possible effectiveness of s-ketamine and rapastinel as treatment options in treatment-resistant depression. Moreover, it highlights the importance of the glutamatergic system in the neurobiology of depression. Further studies are necessary to evaluate how repeated treatment with ACTH leads to a depressed condition resistant to monoaminergic antidepressants.

Suggested Biomarkers for Major Depressive Disorder

Currently, the diagnosis of major depressive disorder (MDD) mainly relies on clinical examination and subjective evaluation of depressive symptoms. There is no non-invasive, quantitative test available today for the diagnosis of MDD. In MDD, exploration of biomarkers will be helpful in diagnosing the disorder as well as in choosing a treatment, and predicting the treatment response. In this article, it is aimed to review the findings of suggested biomarkers such as growth factors, cytokines and other inflammatory markers, oxidative stress markers, endocrine markers, energy balance hormones, genetic and epigenetic features, and neuroimaging in MDD and to evaluate how these findings contribute to the pathophysiology of MDD, the prediction of treatment response, severity of the disorder, and identification of subtypes. Among these, the findings related to the brain-derived neurotrophic factor, the hypothalamo-pituitary-adrenal axis, cytokines, and neuroimaging may be strong candidates for being biomarkers MDD, and may provide critical information in understanding biological etiology of depression. Although the findings are not sufficient yet, we think that the results of epigenetic studies will also provide very important contributions to the biomarker research in MDD. The availability of biomarkers in MDD will be an advancement that will facilitate the diagnosis of the disorder, treatment choices in the early stages, and prediction of the course of the disorder.

How to measure glucocorticoid receptor's sensitivity in patients with stress-related psychiatric disorders

Stress is a state of derailed homeostasis and a main environmental risk factor for psychiatric diseases. Chronic or uncontrollable stress may lead to a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which is a common feature of stress-related psychiatric disorders. One of the key mechanisms underlying a disturbed HPA axis is an impaired function of the glucocorticoid receptor (GR) with an enhanced or reduced feedback sensitivity for glucocorticoids and subsequently altered concentrations of peripheral cortisol. GR function is regulated by a multiprotein complex including the different expression of the hsp90 co-chaperone FK 506 binding protein 51 (FKBP5) that may be genetically determined or acquired in response to stressful stimuli. Specific patterns of a dysregulation of the HPA axis and GR function are found in different stress-related psychiatric entities e.g. major depression, job-related exhaustion or posttraumatic stress disorder. GR challenge tests like the dexamethasone-suppression test (DST), the dexamethasone-corticotropin-releasing hormone (dex-CRH) test or most recently the analysis of the dexamethasone-induced gene expression are employed to sensitively measure HPA axis activity in these disorders. They provide information for a stratification of phenotypic similar but neurobiological diverse psychiatric disorders. In this review we present a synopsis of GR challenge tests with a focus on the application of the DST, the CRH test and the dex-CRH test as well as the dexamethasone-induced gene expression in stress-related psychiatric entities.

Cortisol response patterns in depressed women and their healthy daughters at risk: Comparison with healthy women and their daughters

A dysfunctional hypothalamic pituitary adrenal (HPA) axis is widely accepted as a significant pathophysiological aspect of Major Depressive Disorder (MDD). Despite studies suggesting that a dysfunctional HPA axis might be present before the clinical syndrome becomes apparent, the functioning of the HPA axis in high-risk populations has not been well defined. The aim of the present study was to investigate the HPA axis functioning of mothers suffering from MDD and their healthy daughters compared to age- and sex-matched healthy controls. This design allowed a comparison of HPA axis functional differences among daughter and mother groups. HPA axis function was evaluated with a modified dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, which was performed after obtaining the diurnal adrenocorticotropic hormone (ACTH) and cortisol values at 8:00, 16:00, and 23:00 h. We found that MDD mothers and their daughters had low morning cortisol and the MDD mothers additionally had low-morning ACTH compared with controls. Dexamethasone suppressed both cortisol and ACTH in all groups and subsequent HPA axis stimulation by CRH-evoked a lower cortisol response but a higher ACTH response among subjects with MDD mothers. Although high-risk daughters had comparable cortisol levels after CRH infusion, the AUC for ACTH was greater than those of controls. These patterns of results suggest that multiple level HPA dysfunctions are present in both MDD patients and their high-risk carrying daughters. However, insufficient cortisol secretion was only present in MDD mothers, while the daughters could compensate cortisol levels during CRH challenge.

Behavioral effects and CRF expression in brain structures of high- and low-anxiety rats after chronic restraint stress

The aim of our study was to investigate the influence of chronic restraint stress (5 weeks, 3h/day) on behavior and central corticotropin-releasing factor (CRF) expression in rats selected for high (HR) and low anxiety (LR). The conditioned freezing response was used as a discriminating variable. Moreover, we assessed the influence of acute restraint on CRF expression in the brain in HR and LR rats. We found that chronic restraint induced symptoms of anhedonia (decreased consumption of 1% sucrose solution) in HR rats. In addition, HR restraint rats showed an increased learned helplessness behavior (immobility time in the Porsolt test) as well as neophobia in the open field test vs. LR restraint and HR control rats. These behavioral changes were accompanied by a decreased expression of CRF in the paraventricular nucleus of the hypothalamus (pPVN) and the dentate gyrus of the hippocampus (DG) compared to the HR control and LR restraint rat groups, respectively. The acute restraint condition increased the expression of CRF in the pPVN of HR rats compared to the HR control group, and enhanced the expression of CRF in the CA1 area and DG of LR restraint animals compared to the HR restraint and LR control rats, respectively. The present results indicate that chronic restraint stress in high anxiety rats attenuated CRF expression in the pPVN and DG, which was probably due to detrimental actions on the hippocampus-hypothalamus-pituitary-adrenal gland feedback mechanism, thus modulating the stress response and inducing anhedonia and depressive-like symptoms.

Vulnerability for new episodes in recurrent major depressive disorder: protocol for the longitudinal DELTA-neuroimaging cohort study

INTRODUCTION

Major depressive disorder (MDD) is widely prevalent and severely disabling, mainly due to its recurrent nature. A better understanding of the mechanisms underlying MDD-recurrence may help to identify high-risk patients and to improve the preventive treatment they need. MDD-recurrence has been considered from various levels of perspective including symptomatology, affective neuropsychology, brain circuitry and endocrinology/metabolism. However, MDD-recurrence understanding is limited, because these perspectives have been studied mainly in isolation, cross-sectionally in depressed patients. Therefore, we aim at improving MDD-recurrence understanding by studying these four selected perspectives in combination and prospectively during remission.

METHODS AND ANALYSIS

In a cohort design, we will include 60 remitted, unipolar, unmedicated, recurrent MDD-participants (35-65 years) with ≥ 2 MDD-episodes. At baseline, we will compare the MDD-participants with 40 matched controls. Subsequently, we will follow-up the MDD-participants for 2.5 years while monitoring recurrences. We will invite participants with a recurrence to repeat baseline measurements, together with matched remitted MDD-participants. Measurements include questionnaires, sad mood-induction, lifestyle/diet, 3 T structural (T1-weighted and diffusion tensor imaging) and blood-oxygen-level-dependent functional MRI (fMRI) and MR-spectroscopy. fMRI focusses on resting state, reward/aversive-related learning and emotion regulation. With affective neuropsychological tasks we will test emotional processing. Moreover, we will assess endocrinology (salivary hypothalamic-pituitary-adrenal-axis cortisol and dehydroepiandrosterone-sulfate) and metabolism (metabolomics including polyunsaturated fatty acids), and store blood for, for example, inflammation analyses, genomics and proteomics. Finally, we will perform repeated momentary daily assessments using experience sampling methods at baseline. We will integrate measures to test: (1) differences between MDD-participants and controls; (2) associations of baseline measures with retro/prospective recurrence-rates; and (3) repeated measures changes during follow-up recurrence. This data set will allow us to study different predictors of recurrence in combination.

ETHICS AND DISSEMINATION

The local ethics committee approved this study (AMC-METC-Nr.:11/050). We will submit results for publication in peer-reviewed journals and presentation at (inter)national scientific meetings.

TRIAL REGISTRATION NUMBER

NTR3768.

Early life trauma, depression and the glucocorticoid receptor gene--an epigenetic perspective

BACKGROUND

Hopes to identify genetic susceptibility loci accounting for the heritability seen in unipolar depression have not been fully realized. Family history remains the 'gold standard' for both risk stratification and prognosis in complex phenotypes such as depression. Meanwhile, the physiological mechanisms underlying life-event triggers for depression remain opaque. Epigenetics, comprising heritable changes in gene expression other than alterations of the nucleotide sequence, may offer a way to deepen our understanding of the aetiology and pathophysiology of unipolar depression and optimize treatments. A heuristic target for exploring the relevance of epigenetic changes in unipolar depression is the hypothalamic-pituitary-adrenal (HPA) axis. The glucocorticoid receptor (GR) gene (NR3C1) has been found to be susceptible to epigenetic modification, specifically DNA methylation, in the context of environmental stress such as early life trauma, which is an established risk for depression later in life.

METHOD

In this paper we discuss the progress that has been made by studies that have investigated the relationship between depression, early trauma, the HPA axis and the NR3C1 gene. Difficulties with the design of these studies are also explored.

RESULTS

Future efforts will need to comprehensively address epigenetic natural histories at the population, tissue, cell and gene levels. The complex interactions between the epigenome, genome and environment, as well as ongoing nosological difficulties, also pose significant challenges.

CONCLUSIONS

The work that has been done so far is nevertheless encouraging and suggests potential mechanistic and biomarker roles for differential DNA methylation patterns in NR3C1 as well as novel therapeutic targets.

Cushing Disease Presenting as Primary Psychiatric Illness: A Case Report and Literature Review

We report the case of a woman with long-standing refractory depression and psychotic features who was eventually diagnosed with Cushing disease. After surgical treatment of a pituitary adenoma, she experienced gradual psychiatric recovery and was eventually able to discontinue all psychotropic medication. We review the psychiatric components of Cushing disease, implications of psychiatric illnesses for the treatment and prognosis of Cushing disease, and potential pathophysiological mechanisms linking glucocorticoid excess to psychiatric illness.

Biochemical markers subtyping major depressive disorder

The pathophysiology of major depressive disorder (MDD) remains elusive, and there is no established biochemical marker used in the daily clinical setting. This situation may result in part from the heterogeneity of MDD, which might include heterogeneous subgroups with different biological mechanisms. In this review, we discuss three promising biological systems/markers to potentially subtype MDD: the dopamine system, the hypothalamic-pituitary-adrenal axis, and chronic inflammatory markers. Several lines of evidence suggest that a facet of MDD is a dopamine agonist-responsive subtype. Focusing on the hypothalamic-pituitary-adrenal axis, depressive spectrum disorders show hypercortisolism to hypocortisolism, which could be detected by hormonal challenge tests, such as the dexamethasone/corticotrophin-releasing hormone test. Finally, accumulating evidence suggests that at least some MDD patients show characteristics similar to those of chronic inflammatory diseases, including neuroinflammatory markers and reduced tryptophan due to the increased activation of the tryptophan-kynurenine pathway. Future studies should examine the inter-relations between these systems/markers to subtype and integrate the pathophysiology of MDD.

Depression history as a moderator of relations between cortisol and shame responses to social-evaluative threat in young adults

Changes in cortisol and shame are commonly elicited by psychosocial stressors involving social-evaluative threat. According to social self preservation theory, this coordinated psychobiological response is adaptive. Individuals with a history of depression, however, may exhibit diminished cortisol reactivity to acute stressors, which could interfere with coordinated cortisol and shame responses. The present study examined temporal relations between cortisol and shame responses to a psychosocial stress task in young adults who varied in their history of depression (56 remitted-depressed, 46 never-depressed). Lagged effects multilevel models revealed that depression history moderated relations between cortisol levels and shame ratings 25-55min later. The pattern of these interactions was similar: whereas higher cortisol levels predicted increases in shame in never-depressed individuals, cortisol levels were unrelated to shame responses in remitted-depressed individuals. Findings suggest a dissociation between cortisol and shame responses to stress in individuals with a history of depression.

Glucocorticoid and mineralocorticoid receptor polymorphisms and recurrence of major depressive disorder

OBJECTIVE

Previous research found that variants of the glucocorticoid receptor (GR) (9β, ER22/23EK, BclI, TthIIIl, NR3C1-1 and N363S) and mineralocorticoid receptor (MR) gene polymorphism (-2 C/G and I180V) are associated with both glucocorticoid (GC) sensitivity and major depressive disorder (MDD). There are no data which investigated prospectively whether these variants are associated with recurrence of MDD.

METHODS

Data were derived from the Netherlands Study of Depression and Anxiety (NESDA) which used the Composite International Diagnostic Interview (CIDI) to determine MDD. Polymorphisms in the GR and MR gene were determined and haplotypes were characterized. We analyzed in retrospect whether recurrent MDD (n=951) in comparison with first onset MDD (n=919) was associated with polymorphisms in the GR and MR gene. Furthermore, we analyzed prospectively for 4 years the time to recurrence among 683 subjects with a remitted MDD diagnosis. Time to recurrence of MDD was assessed using the CIDI and a life chart interview. Additionally, we analyzed interactions of the investigated polymorphisms with childhood trauma and recent negative life events.

RESULTS

GR and MR gene polymorphisms and derived haplotypes were not associated with recurrence of depression in both retrospective and prospective analyses. In addition, no consistent interactions between GR and MR polymorphisms and childhood trauma or life events were found.

CONCLUSION

This study did not find consistent associations between GR and MR gene polymorphisms, interactions between GR and MR haplotypes and stressful conditions and recurrence of MDD.

Increased cortisol awakening response was associated with time to recurrence of major depressive disorder

INTRODUCTION

Although HPA-axis activity has been studied extensively in relation to depression, there is no consensus whether HPA-axis parameters predicts major depressive disorder (MDD) recurrence. We investigated whether HPA-axis parameters (cortisol awakening response (CAR), the dexamethasone suppression test (DST) and evening cortisol) predict time to recurrence in remitted subjects with a history of MDD and whether childhood trauma and life events interact with HPA-axis parameters in increasing the risk for recurrence.

METHOD

Data were derived from 549 subjects with a lifetime diagnosis of MDD in remission for at least six months preceding the baseline assessment of the Netherlands Study of Depression and Anxiety (NESDA). Subjects were followed up with two interviews over the course of four years to assess recurrence. DSM-IV based diagnostic interviews were used to assess time to recurrence of MDD. Seven salivary cortisol samples collected at baseline with information on CAR, evening cortisol and the DST. Hazard ratios were calculated using Cox regression analysis, adjusted for covariates.

RESULTS

A higher CAR was associated with time to recurrence of MDD (HR=1.03, 95%CI 1.003-1.060, p=0.03) whereas evening cortisol and DST were not. No interactions between HPA-axis parameters and stress-related factors were found.

CONCLUSIONS

Our data support previous studies reporting that subjects with a higher CAR are more vulnerable to recurrence of MDD.

Cortisol reactivity to experimentally manipulated psychosocial stress in young adults at varied risk for depression

This study examined cortisol and affective reactivity to a psychosocial stress task in 102 young adults who varied in risk for depression (56 remitted depressed, 46 never depressed). Participants were randomly assigned to either a stress (i.e., social-evaluative threat) or control (i.e., no social-evaluative threat) condition. For never-depressed individuals, cortisol responses were significantly greater in the stress compared to the control condition. Moreover, cortisol responses were significantly greater for never-depressed than remitted-depressed individuals in the stress condition. For individuals with a history of depression, cortisol responses did not differ significantly between the stress and control conditions. Negative affective reactivity also was higher for never depressed, but not remitted depressed, individuals in the stress compared to the control condition. Moreover, cortisol responses were inversely related to negative affect during the recovery phase in both stress and control conditions. Findings indicate the lack of a robust cortisol response to social evaluation stress among remitted-depressed individuals as compared to that of never-depressed controls. Future studies should investigate unique and interactive links between these hypothalamic-pituitary-adrenal and affective reactivity alterations and risk for subsequent depressive episodes.

Nonhuman primate models of depression: effects of early experience and stress

Depression causes significant morbidity in the human population. The Diathesis-Stress/Two-Hit model of depression hypothesizes that stress interacts with underlying (probably genetic) predispositions to produce a central nervous system that is primed to express psychopathology when confronted with stressful experiences later in life. Nonhuman primate (NHP) studies have been extensively utilized to test this model. NHPs are especially useful for studying effects of early experience, because many aspects of NHP infancy are similar to humans, whereas development occurs at an accelerated rate and therefore allows for more rapid assessment of experimental variables. In addition, the ability to manipulate putative risk factors, including introducing experimental stress during development, allows inference of causality not possible with human studies. This manuscript reviews experimental paradigms that have been utilized to model early adverse experience in NHPs, including peer-rearing, maternal separation, and variable foraging. It also provides examples of how this model has been used to investigate the effects of early experience on later neurobiology, physiology, and behavior associated with depression. We conclude that the NHP offers an excellent model to research mechanisms contributing to the Diathesis-Stress/Two-Hit model of depression.

Pretreatment cortisol levels predict posttreatment outcomes among older adults with depression in cognitive behavioral therapy

Previous studies suggest that individuals with elevated levels of cortisol (the "stress hormone") could be particularly resistant to treatment for depression. However, most of these studies have been conducted in the context of antidepressant medications, and no study has examined pretreatment cortisol levels as a predictor of treatment outcomes among older adults with depression in cognitive-behavioral therapy (CBT), despite the relevance of this population for such a research question. The current study includes 54 older adults with depression who provided salivary cortisol samples at baseline and completed measures of depression at pretreatment and posttreatment, following a 12-week course of CBT. Structural equation modeling results suggest that those with higher daily outputs of cortisol and flatter diurnal slopes were less likely to benefit from CBT-a finding which if replicated could have important implications for clinical practice and future research.

Salivary cortisol levels and the 2-year course of depressive and anxiety disorders

INTRODUCTION

Depression and anxiety disorders have been associated with hyperactivity of the hypothalamic-pituitary adrenal (HPA) axis. However, lower cortisol levels have also been observed in depressed patients. Whether cortisol level predicts the course of these disorders has not been examined in detail. We examined whether salivary cortisol indicators predict the 2-year course of depression and anxiety disorders.

METHODS

Longitudinal data are obtained from 837 participants of the Netherlands Study of Depression and Anxiety, with a DSM-IV based depressive and/or anxiety disorder at baseline. At baseline, seven saliva samples were obtained, including the 1-h cortisol awakening response, evening cortisol level and a 0.5mg dexamethasone suppression test. At follow-up, DSM-IV based diagnostic interviews and Life Chart Interview integrating diagnostic and symptom trajectories over 2 years were administered to determine an unfavorable course.

RESULTS

41.5% of the respondents had a 2-year unfavorable course trajectory without remission longer than 3 months. Adjusted analyses showed that a lower awakening response was associated with an unfavorable course (RR=0.83, p=0.03). No associations were found between evening cortisol or cortisol suppression after dexamethasone ingestion and an unfavorable course trajectory.

CONCLUSIONS

Among patients with depressive or anxiety disorders, a lower cortisol awakening response - which may be indicative of underlying exhaustion of the HPA axis - predicted an unfavorable course trajectory.

Study protocol for the randomised controlled trial: antiglucocorticoid augmentation of anti-Depressants in Depression (The ADD Study)

BACKGROUND

Some patients with depression do not respond to first and second line conventional antidepressants and are therefore characterised as suffering from treatment refractory depression (TRD). On-going psychosocial stress and dysfunction of the hypothalamic-pituitary-adrenal axis are both associated with an attenuated clinical response to antidepressants. Preclinical data shows that co-administration of corticosteroids leads to a reduction in the ability of selective serotonin reuptake inhibitors to increase forebrain 5-hydroxytryptamine, while co-administration of antiglucocorticoids has the opposite effect. A Cochrane review suggests that antiglucocorticoid augmentation of antidepressants may be effective in treating TRD and includes a pilot study of the cortisol synthesis inhibitor, metyrapone. The Antiglucocorticoid augmentation of anti-Depressants in Depression (The ADD Study) is a multicentre randomised placebo controlled trial of metyrapone augmentation of serotonergic antidepressants in a large population of patients with TRD in the UK National Health Service.

METHODS/DESIGN

Patients with moderate to severe treatment refractory Major Depression aged 18 to 65 will be randomised to metyrapone 500 mg twice daily or placebo for three weeks, in addition to on-going conventional serotonergic antidepressants. The primary outcome will be improvement in Montgomery-Åsberg Depression Rating Scale score five weeks after randomisation (i.e. two weeks after trial medication discontinuation). Secondary outcomes will include the degree of persistence of treatment effect for up to 6 months, improvements in quality of life and also safety and tolerability of metyrapone. The ADD Study will also include a range of sub-studies investigating the potential mechanism of action of metyrapone.

DISCUSSION

Strengths of the ADD study include broad inclusion criteria meaning that the sample will be representative of patients with TRD treated within the UK National Health Service, longer follow up, which to our knowledge is longer than any previous study of antiglucocorticoid treatments in depression, and the range of mechanistic investigations being carried out. The data set acquired will be a rich resource for a range of research questions relating to both refractory depression and the use of antiglucocorticoid treatments.

TRIAL REGISTRATION

Current Controlled Trials: ISRCTN45338259; EudraCT Number: 2009-015165-31.

The DEX/CRH test for major depression: a potentially useful diagnostic test

The dexamethasone/corticotropin-releasing hormone (DEX/CRH) test has been proposed as a potential diagnostic test for major depressive disorder (MDD). A previously proposed four-step approach assesses the stage of development for a biological finding into a clinically useful diagnostic test. Using this approach, we evaluated the progress of the DEX/CRH test using meta-analysis as a part of step 1. A literature review identified 15 studies of the DEX/CRH test in patients with MDD and healthy controls. Meta-analysis estimated the effect size, heterogeneity, and confidence intervals using random effects models. Studies consistent with any step of the four-step approach were identified, and their characteristics were presented. Eleven studies reported significantly higher cortisol levels with the DEX/CRH test in patients with MDD, compared with the healthy controls (step 1). Eight eligible studies were included in meta-analysis, and had an effect size of 1.34 (95% confidence interval: 0.70-1.97). Most studies were step-1 studies (comparison of patients and healthy controls), and no step-4 studies (multicenter trials) were found. This review emphasizes that despite appearing as a promising test, the DEX/CRH has not been adequately studied for the required stages of development into a clinically useful laboratory test. Particularly, additional step-3 and step-4 studies are necessary.

CRF test in melancholic depressive patients with partial versus complete relapses: a 2-year follow-up study

BACKGROUND

Patients with depressive disorders present abnormalities in the hypothalamic pituitary adrenal (HPA) axis. The effects of a partial relapse with regard to HPA axis has not been studied so far.

AIM

To assess whether patients with partial relapse have a different neuroendocrine profile compared with those with complete relapse and with those without relapse over a 2-year follow-up.

METHODS

The adrenocorticotropin hormone (ACTH) and cortisol responses to corticotrophin releasing factor (CRF) stimulation was assessed in 62 outpatients diagnosed with unipolar depressive disorder with melancholic features according to DSM-IV. Twenty-three healthy controls were included in the study for comparison. Monthly follow-up visits were performed over a 2-year period after remission; partial and complete relapses were established using the Hamilton Depression Rating Scale (HDRS) and according to Frank's criteria. Fifty-four patients completed the study. A comparative statistical analysis was performed.

RESULTS

Stratifying the net area under cortisol curve (NAUCC) (µg/ml/min) at three levels-< 150, 150-350 and ≤ 350-significant differences appear between the three depressive groups of patients (non-relapsers, partial relapsers and complete relapsers). Particularly, there are more patients with a NAUCC ≤ 350 who show partial or complete relapses than patients with a NAUCC ≤ 350 who do not relapse (P ≤ 0.05).

CONCLUSIONS

Our results show an increasingly altered HPA axis in those depressive patients with complete or partial relapses compared with those who did not relapse or with healthy controls, but there are not differences in HPA axis between partial and complete relapsers.

Metyrapone in treatment-resistant depression

Depression affects a significant proportion of the population, with 1-year and lifetime prevalence of 3-5% and 10-30% respectively. Full remission is achieved in only a third of patients following treatment with first-line antidepressant. There is a need for novel treatments for treatment-resistant depression (TRD). Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been described in patients with depression. There is persistent rise in the levels of cortisol (end product of the HPA axis) and impairment of the negative feedback inhibition mechanism of the HPA axis. Dysregulation of the HPA axis has been found to be linked to nonresponse to antidepressants and relapse following successful treatment. The efficacy of pharmacological agents that intervene with the mechanisms involved in dysregulation of cortisol synthesis and release are being explored in depression, particularly in TRD. Studies have been carried out with these drugs as augmenting agents for antidepressants or as monotherapy. The strongest evidence has come from studies using metyrapone, a cortisol synthesis inhibitor, and this has been described in detail in this review. The most robust evidence for its antidepressant efficacy in depression comes from a double-blind, randomized, placebo-controlled study of augmentation of serotonergic antidepressants with metyrapone. A 3-week augmentation of serotonergic antidepressants with 1 g metyrapone daily was shown to be superior to placebo in reducing the Montgomery-Asberg Depression Rating Scale by 50%, 5 weeks following initiation of treatment. The mechanism of the antidepressant action of metyrapone is not clear but the evidence for various potential mechanisms is discussed.

Predictors of remission in depression to individual and combined treatments (PReDICT): study protocol for a randomized controlled trial

BACKGROUND

Limited controlled data exist to guide treatment choices for clinicians caring for patients with major depressive disorder (MDD). Although many putative predictors of treatment response have been reported, most were identified through retrospective analyses of existing datasets and very few have been replicated in a manner that can impact clinical practice. One major confound in previous studies examining predictors of treatment response is the patient's treatment history, which may affect both the predictor of interest and treatment outcomes. Moreover, prior treatment history provides an important source of selection bias, thereby limiting generalizability. Consequently, we initiated a randomized clinical trial designed to identify factors that moderate response to three treatments for MDD among patients never treated previously for the condition.

METHODS/DESIGN

Treatment-naïve adults aged 18 to 65 years with moderate-to-severe, non-psychotic MDD are randomized equally to one of three 12-week treatment arms: (1) cognitive behavior therapy (CBT, 16 sessions); (2) duloxetine (30-60 mg/d); or (3) escitalopram (10-20 mg/d). Prior to randomization, patients undergo multiple assessments, including resting state functional magnetic resonance imaging (fMRI), immune markers, DNA and gene expression products, and dexamethasone-corticotropin-releasing hormone (Dex/CRH) testing. Prior to or shortly after randomization, patients also complete a comprehensive personality assessment. Repeat assessment of the biological measures (fMRI, immune markers, and gene expression products) occurs at an early time-point in treatment, and upon completion of 12-week treatment, when a second Dex/CRH test is also conducted. Patients remitting by the end of this acute treatment phase are then eligible to enter a 21-month follow-up phase, with quarterly visits to monitor for recurrence. Non-remitters are offered augmentation treatment for a second 12-week course of treatment, during which they receive a combination of CBT and antidepressant medication. Predictors of the primary outcome, remission, will be identified for overall and treatment-specific effects, and a statistical model incorporating multiple predictors will be developed to predict outcomes.

DISCUSSION

The PReDICT study's evaluation of biological, psychological, and clinical factors that may differentially impact treatment outcomes represents a sizeable step toward developing personalized treatments for MDD. Identified predictors should help guide the selection of initial treatments, and identify those patients most vulnerable to recurrence, who thus warrant maintenance or combination treatments to achieve and maintain wellness.

Longitudinal hypothalamic-pituitary-adrenal axis trait and state effects in recurrent depression

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA)-axis hyperactivity has been observed in (recurrent) major depressive disorder (MDD), although inconsistently and mainly cross-sectional. Longitudinal studies clarifying state-trait issues are lacking. We aimed to determine whether HPA-axis (hyper)activity in recurrent MDD is: (I) reflecting a persistent trait; (II) influenced by depressive state; (III) associated with stress or previous episodes; (IV) associated with recurrence; and (V) influenced by cognitive therapy.

METHODS

We included 187 remitted highly recurrent MDD-patients (mean number of previous episodes: 6.3), participating in a randomized-controlled-trial investigating the preventive effect of additional cognitive therapy on recurrence. In an add-on two-staged patient-control and prospective-cohort design, we first cross-sectionally compared patients' salivary morning and evening cortisol concentrations with 72 age- and sex-matched controls, and subsequently longitudinally followed-up the patients with repeated measures after three months and two years.

RESULTS

Patients had higher cortisol concentrations than controls (p<.001), which did not change by MDD-episodes during follow-up. HPA-axis activity had no relation with daily hassles or childhood life events. Cortisol concentrations were lower in patients with more previous episodes (p=.047), but not associated with recurrence(s) during follow-up. Finally, randomly assigned cognitive therapy at study-entry enhanced cortisol declines over the day throughout the two-year follow-up (p=.052).

CONCLUSIONS

Our results indicate that remitted recurrent MDD-patients have a persistent trait of increased cortisol concentrations, irrespective of stress. In combination with our finding that patients' cortisol concentrations do not change during new MDD-episodes (and thus not represent epiphenomenal or state-effects), our results support that hypercortisolemia fulfills the state-independence criterion for an endophenotype for recurrent depression.

Neurobiological correlates of illness progression in the recurrent affective disorders

Some clinical aspects of affective illness progression, such as episode-, stress-, and substance-induced sensitization, have been well documented in the literature, but others have received less attention. These include cognitive deficits, treatment-refractoriness, and neurobiological correlates of illness progression, which are the primary focus of this paper. We review the evidence that cognitive dysfunction, treatment resistance, medical comorbidities, and neurobiological abnormalities increase as a function of the number of prior episodes or duration of illness in the recurrent unipolar and bipolar disorders. Substantial evidence supports the view that cognitive dysfunction and vulnerability to a diagnosis of dementia in old age increases as a function of number of prior mood episodes as does non-response to many therapeutic interventions as well as naturalistic treatment. Neurobiological abnormalities that correlate with the number of mood episodes or duration of illness include: anatomical, functional, and biochemical deficits in the prefrontal cortex and hippocampus, as well as amygdala hyperactivity and cortisol hyper-secretion. Some neurotrophic factors and inflammatory markers may also change with greater illness burden. Causality cannot be inferred from these correlative relationships. Nonetheless, given the potentially grave consequences of episode recurrence and progression for morbidity and treatment non-responsiveness, it is clinically wise to assume episodes are causing some of the progressive cognitive and neurobiological abnormalities. As such, earlier and more sustained long-term prophylaxis to attempt to reduce these adverse outcomes is indicated.

Decision making under stress: a selective review

Many decisions must be made under stress, and many decision situations elicit stress responses themselves. Thus, stress and decision making are intricately connected, not only on the behavioral level, but also on the neural level, i.e., the brain regions that underlie intact decision making are regions that are sensitive to stress-induced changes. The purpose of this review is to summarize the findings from studies that investigated the impact of stress on decision making. The review includes those studies that examined decision making under stress in humans and were published between 1985 and October 2011. The reviewed studies were found using PubMed and PsycInfo searches. The review focuses on studies that have examined the influence of acutely induced laboratory stress on decision making and that measured both decision-making performance and stress responses. Additionally, some studies that investigated decision making under naturally occurring stress levels and decision-making abilities in patients who suffer from stress-related disorders are described. The results from the studies that were included in the review support the assumption that stress affects decision making. If stress confers an advantage or disadvantage in terms of outcome depends on the specific task or situation. The results also emphasize the role of mediating and moderating variables. The results are discussed with respect to underlying psychological and neural mechanisms, implications for everyday decision making and future research directions.

Impact of citalopram on the HPA system. A study of the combined DEX/CRH test in 30 unipolar depressed patients

BACKGROUND

Dysregulation of the hypothalamic-pituitary-adrenocortical (HPA) system is one of the best replicated pathophysiological findings in depression. However, studies on the influence of treatment on the HPA system have partly yielded inconsistent results.

OBJECTIVE

To assess the effects of citalopram monotherapy on the HPA system of mainly drug naïve patients with major depression by means of the combined DEX/CRH test.

METHODS

The DEX/CRH test was conducted twice in 30 patients (25 drug naïve for the index episode) with major depression (single episode or unipolar recurrent; SCID I- and II-confirmed): directly before the start of a citalopram monotherapy (day 0) and four weeks thereafter (day 28).

RESULTS

Twenty-three patients responded (≥50% reduction in the HDRS(21)-score), and 17 of them also reached criteria of remission (HDRS ≤ 7). Baseline (dexamethasone-suppressed) and CRH-stimulated ACTH concentrations significantly decreased from day 0 to day 28. CRH-stimulated cortisol concentrations also fell, although not significantly, but baseline cortisol concentrations exhibited a significant increase from day 0 to day 28.

CONCLUSIONS

The blunting of the ACTH response in the DEX/CRH test under citalopram is in line with what has been observed in most studies with antidepressants. However, the partial rise in cortisol concentrations indicates an increase in the sensitivity of the adrenal cortex to ACTH. State-dependent alterations in the volume and the ACTH responsiveness of the adrenal gland have repeatedly been reported in depressed subjects, which indicates the possibility that SSRIs such as citalopram might exhibit a direct or indirect effect on the adrenal cortex.

Interaction of FKBP5 gene variants and adverse life events in predicting depression onset: results from a 10-year prospective community study

OBJECTIVE

The binding protein FKBP5 is an important modulator of the function of the glucocorticoid receptor, the main receptor of the stress hormone system. This turns the FKBP5 gene into a key candidate for gene-environment interactions, which are considered critical for pathogenesis of stress-related disorders. The authors explored gene-environment interactions between FKBP5 gene variants and adverse life events in predicting the first occurrence of a major depressive episode.

METHOD

The analyses were based on 884 Caucasians in a 10-year prospective community study. At baseline, they were 14-24 years old and did not fulfill criteria for a major depressive episode. The DSM-IV-based Munich Composite International Diagnostic Interview was used to assess adverse life events preceding baseline and major depressive episodes during follow-up. On the basis of previous findings, five single-nucleotide polymorphisms (SNPs) within the FKBP5 gene were selected for genotyping.

RESULTS

While the authors did not observe genetic main effects, they found interactions between the five SNPs and traumatic (but not separation) events, with the strongest effect for severe trauma. The effect of trauma on incident major depressive episodes was evident among subjects homozygous for the minor alleles but not subjects with other genotypes. The findings were replicated in the U.K. Environmental Risk Longitudinal Twin Study.

CONCLUSIONS

These hypothesis-driven results suggest that an interaction between FKBP5 genotype and trauma is involved in the onset of depression. Subjects homozygous for the minor alleles of the investigated FKBP5 SNPs seem to be particularly sensitive to effects of trauma exposure in terms of triggering depression onset.

Poor sleep is associated with exaggerated cortisol response to the combined dexamethasone/CRH test in a non-clinical population

Although sleep disturbance has been shown to be associated with psychological distress and the hypothalamic-pituitary-adrenal (HPA) axis function, the simultaneous relationship between sleep, distress and HPA axis function is less clear. Here we examined the relationship between sleep quality as assessed with the Pittsburgh Sleep Quality Index, psychological distress as assessed with the Hopkins Symptom Checklist, and cortisol responses to the dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test in 139 non-clinical volunteers. Poor sleep was significantly correlated with greater cortisol response to the combined DEX/CRH challenge, but not with the cortisol level just before CRH challenge. When subjects were divided into three groups based on the suppression pattern of cortisol (i.e., incomplete-, moderate-, and enhanced-suppressors), poor sleep was significantly associated with the incomplete suppression in women while no significant association was found between sleep and the enhanced suppression. The association between poor sleep and exaggerated cortisol response to the CRH challenge became more clear in the regression analysis where the confounding effect of psychological distress was taken into consideration. These results indicate that poor sleep would be associated with exaggerated cortisol reactivity. The observed association of poor sleep with reactive cortisol indices to the CRH challenge, but not with the cortisol level after DEX administration alone, might add to the well-established evidence demonstrating the role of CRH in the regulation of sleep. Our findings further suggest that the mediation model would work better than the bivariate approach in investigating the relationship between sleep, distress and HPA axis reactivity.

Discrimination between patients with melancholic depression and healthy controls: comparison between 24-h cortisol profiles, the DST and the Dex/CRH test

Diurnal (24-h) cortisol profiles were compared to DST and Dex/CRH test outcomes with regard to their discriminative power in depressive disorder. With regard to several statistical measures (effect sizes, area under the curve) we found 24-h cortisol profiles to better discriminate between healthy controls and inpatients with the melancholic subtype of depression compared to the DST and Dex/CRH test. In search of a shortened time interval we found the 2-h time window 1000-1200 h of the cortisol profile to be the one with the highest sensitivity (83.3%) and specificity (87.9%). The specificity of the DST was 93.3% and somewhat higher than that of the cortisol profiles and the Dex/CRH test (87.9% and 78.8.%, respectively). However, the sensitivity of the DST was very low (30.8%), in fact similar to that of the Dex/CRH test (30.8%), but much lower than that of the 1000-1200 h interval (83.3%). The assessment of cortisol in plasma is an easy to perform, cost-saving method for the evaluation of the HPA system activity, which may have a series of clinical and scientific implications for the depressive disorder.

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.

Tolerability of the dexamethasone-corticotropin releasing hormone test in major depressive disorder

BACKGROUND

The dexamethasone-corticotropin releasing hormone (Dex-CRH) test may differentially predict which depressed patients will respond to antidepressant medication. However, a comprehensive analysis of the safety of this test in psychiatric patients has not previously been performed.

METHODS

We conducted a pooled analysis of depressed patients in four clinical studies. Observed and subjectively reported side-effects in 454 patients were collected for 90 minutes following CRH administration. Pre-test electrocardiograms were available in 250 patients to assess cardiac safety. Descriptive statistics were performed to evaluate these safety data.

RESULTS

Eight-six (18.9%) subjects experienced no side-effects from the procedure. The mean number of side-effects per subject was 1.4±1.0. The most frequent adverse events were: flushing (n=216, 47.6%), feeling of warmth (144, 31.7%), hyperpnea/tachypnea (108, 23.8%), palpitations (37, 8.1%), and tachycardia (28, 6.2%). Side-effects were consistently mild and brief in duration. There were no serious adverse events.

CONCLUSION

The Dex-CRH test produces a mild, predictable side-effect profile, characterized by flushing, feelings of warmth, hyperpnea/tachypnea, palpitations, and tachycardia. These results provide reassurance that the Dex-CRH test is well tolerated in psychiatric patients.

The cortisol awakening response in patients remitted from depression

An impressive number of data has been accumulated on dysfunctions of the hypothalamo-pituitary-adrenal (HPA) axis and cortisol hypersecretion in depression. To assess the dynamic HPA functioning, the cortisol awakening response (CAR) is an easily accessible and reliable approach. Some data suggest that elevated CAR in depressed patients has trait-like characteristics. Therefore we investigated whether patients in remission from a depressive episode have elevated CAR compared to control subjects. CAR of thirty-eight patients in remission from depression (11 men, 27 women, age range 24-66) and 52 control participants were analyzed (18 men, 34 women, age range 24-63). All patients had experienced ≥3 previous depressive episodes and were off psychotropic medication since at least 3 months. Saliva samples were collected only once, at home, either on weekend or weekday at 0, 15, 30, 45 and 60 min post-awakening. The area under the curve (AUC) above minimum cortisol concentration displayed large interindividual variability (6.4-fold in remitted patients and 8.1-fold in controls, based on 80% range). Investigation of possible variability factors showed that percent explained variance increased from 3.9% when group was considered alone to 8.8%, 12.3% and 19.2% after adjusting for significant effects of weekday vs. weekend, wake-up time and sleep duration, respectively. According to the latter model, AUC was estimated to be 51% higher in remitted patients than in controls (p = 0.007), while a 21% AUC decrease was associated with a 1-h longer sleep duration (p<0.001). In future studies, detection of between-group differences might benefit from adjusting for sleep duration and other possible confounders.

Interface between hypothalamic-pituitary-adrenal axis and brain-derived neurotrophic factor in depression

Although the pathophysiology of depressive disorder remains elusive, two hypothetical frameworks seem to be promising: the involvement of hypothalamic pituitary-adrenal (HPA) axis abnormalities and brain-derived neurotrophic factor (BDNF) in the pathogenesis and in the mechanism of action of antidepressant treatments. In this review, we focused on research based on these two frameworks in relation to depression and related conditions and tried to formulate an integrated theory of the disorder. Hormonal challenge tests, such as the dexamethasone/corticotropin-releasing hormone test, have revealed elevated HPA activity (hypercortisolism) in at least a portion of patients with depression, although growing evidence has suggested that abnormally low HPA axis (hypocortisolism) has also been implicated in a variety of stress-related conditions. Several lines of evidence from postmortem studies, animal studies, blood levels, and genetic studies have suggested that BDNF is involved in the pathogenesis of depression and in the mechanism of action of biological treatments for depression. Considerable evidence has suggested that stress reduces the expression of BDNF and that antidepressant treatments increase it. Moreover, the glucocorticoid receptor interacts with the specific receptor of BDNF, TrkB, and excessive glucocorticoid interferes with BDNF signaling. Altered BDNF function is involved in the structural changes and possibly impaired neurogenesis in the brain of depressed patients. Based on these findings, an integrated schema of the pathological and recovery processes of depression is illustrated.

Depression relapse prophylaxis with Mindfulness-Based Cognitive Therapy: replication and extension in the Swiss health care system

BACKGROUND

Mindfulness-Based Cognitive Therapy (MBCT) is a group intervention that integrates elements of Cognitive Behavioural Therapy (CBT) with components of mindfulness training to prevent depressive relapse. The efficacy of MBCT compared to Treatment As Usual (TAU), shown in two randomized controlled trials indicates a significant decrease in 1-year relapse rates for patients with at least three past depressive episodes. The present study is the first independent replication trial comparing MBCT+TAU to TAU alone across both language and culture (Swiss health care system).

METHODS

Sixty unmedicated patients in remission from recurrent depression (>or=3 episodes) were randomly assigned to MBCT+TAU or TAU. Relapse rate and time to relapse were measured over a 60 week observation period. The frequency of mindfulness practices during the study was also evaluated.

RESULTS

Over a 14-month prospective follow-up period, time to relapse was significantly longer with MBCT+TAU than TAU alone (median 204 and 69 days, respectively), although both groups relapsed at similar rates. Analyses of homework adherence revealed that following treatment termination, the frequency of brief and informal mindfulness practice remained unchanged over 14 months, whereas the use of longer formal meditation decreased over time.

LIMITATIONS

Relapse monitoring was 14months in duration and prospective reporting of mindfulness practice would have yielded more precise frequency estimates compared to the retrospective methods we utilized.

CONCLUSIONS

Further studies are required to determine which patient characteristics, beyond the number of past depressive episodes, may predict differential benefits from this therapeutic approach.

Neuropsychological functioning in health and mood disorder: Modulation by glucocorticoids and their receptors

Numerous studies have shown that disturbances in hypothalamic-pituitary-adrenal (HPA) axis function and consequent hypercortisolaemia occur in a significant proportion of patients with mood disorders. This dysfunction has been proposed to be an exacerbating factor of depressive symptoms and may predict symptomatic relapse. Glucocorticoids are also known to have a specific role in learning and memory processes. In this review we present a brief overview of the relationship between HPA axis dysfunction and neuropsychological impairment in mood disorders and the specific links between glucocorticoids and cognition in health and illness states. Finally we examine the neuropsychological effects of drugs that specifically target glucocorticoid receptor function.

Dex/CRH test cortisol response in outpatients with major depression and matched healthy controls

BACKGROUND

The dexamethasone/corticotropin releasing hormone (Dex/CRH) test has been proposed as a potential tool for identifying endophenotypes relevant to mood disorders. An exaggerated cortisol response to the test during major depressive episodes has been demonstrated for inpatients with melancholic or psychotic features. A diminished hormone response has been observed in chronically depressed outpatients.

METHODS

Following a battery of self-report and interview assessments, 68 adults completed the Dex/CRH test. Thirty-four met structured interview criteria for current major depressive disorder and 34 age- and sex-matched control subjects had no current or lifetime DSM-IV depressive disorder. Effect of diagnosis on cortisol response to the Dex/CRH test was examined in a repeated measures general linear model.

RESULTS

The matched groups were equivalent with regard to childhood adversity. Cortisol response to the Dex/CRH test among subjects with current MDD was not significantly different from that seen in matched healthy controls. Independent of diagnosis, an exploratory analysis showed a trend-level association between maltreatment history and diminished cortisol response; no interactive effects with depression diagnosis were detected.

CONCLUSIONS

The results do not support the hypothesis that elevated cortisol response to the Dex/CRH test represents a marker for major depressive episodes.

Prediction of relapse in melancholic depressive patients in a 2-year follow-up study with corticotropin releasing factor test

PURPOSE

To study the power of CRF stimulation test to predict relapse in a sample of melancholic depressive patients in depressed phase, followed-up over a two-year period from the moment they achieved complete remission of depressive symptoms.

METHODS

Fifty-one outpatients diagnosed with unipolar depressive disorder with melancholic features according to DSM-IV were assessed with the CRF test. The Structured Clinical Interview for DSM-IV (SCID-IV) was used for diagnosis. Monthly follow-up visits were held over a two-year period after remission; relapse was established using HDRS according to Frank's criteria [Frank E, Prien RF, Jarret RB, Keller MB, Kupfer DJ, Lavori PW, et al. Conceptualization and rationale for consensus definitions of terms in major depressive disorder: remission, recovery, relapse, and recurrence. Arch Gen Psychiatry 1991;48:851-5]. Forty-three patients completed the study. Non-controlled antidepressant treatment protocols were used. Predictive statistical analysis was performed through logistic regression.

FINDINGS

The final predictive model included three variables: net area under cortisol curve (NAUCC), previous suicide attempt, and stress during follow-up. Sensitivity was of 89%, and specificity was of 92%. NAUCC has shown a predictive power of 80%, with an optimal cut-off point of 251.24 microg/ml/min.

CONCLUSIONS

Cortisol is the hormone of the HPA axis which shows the highest power to predict relapse. NAUCC is the most relevant variable. The complete predictive model is a complex combination of biological, clinical and psychoenvironmental variables (NAUCC, previous suicide attempts, and stress during follow-up). Further studies with better control of the psychoenvironmental variables are required to obtain more precise neuroendocrine findings.

The combined dexamethasone/CRH Test (DEX/CRH test) and prediction of acute treatment response in major depression

Background

In this study the predictive value of the combined dexamethasone/CRH test (DEX/CRH test) for acute antidepressant response was investigated.

Methodology/Principal Findings

In 114 depressed inpatients suffering from unipolar or bipolar depression (sample 1) the DEX/CRH test was performed at admission and shortly before discharge. During their stay in the hospital patients received different antidepressant treatment regimens. At admission, the rate of nonsuppression (basal cortisol levels >75.3 nmol/l) was 24.6% and was not related to the later therapeutic response. Moreover, 45 out of 114 (39.5%) patients showed an enhancement of HPA axis function at discharge in spite of clinical improvement. In a second sample, 40 depressed patients were treated either with reboxetine or mirtazapine for 5 weeks. The DEX/CRH test was performed before, after 1 week, and after 5 weeks of pharmacotherapy. Attenuation of HPA axis activity after 1 week was associated with a more pronounced alleviation of depressive symptoms after 5-week mirtazapine treatment, whereas downregulation of HPA system activity after 5 weeks was related to clinical response to reboxetine. However, early improvement of HPA axis dysregulation was not necessarily followed by a beneficial treatment outcome.

Conclusions/Significance

Taken together, performance of a single DEX/CRH test does not predict the therapeutic response. The best predictor for response seems to be an early attenuation of HPA axis activity within 1 or 2 weeks. However, early improvement of HPA system dysfunction is not a sufficient condition for a favourable response. Since a substantial part of depressive patients display a persistence of HPA axis hyperactivity at discharge, downregulation of HPA system function is not a necessary condition for acute clinical improvement either. Our data underline the importance of HPA axis dysregulation for treatment outcome in major depression, although restoration of HPA system dysfunction seems to be neither a necessary nor a sufficient determinant for acute treatment response.

Estrogen impairs glucocorticoid dependent negative feedback on the hypothalamic-pituitary-adrenal axis via estrogen receptor alpha within the hypothalamus

Numerous studies have established a link between individuals with affective disorders and a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, most notably characterized by a reduced sensitivity to glucocorticoid negative (-) feedback. Furthermore there is a sex difference in the etiology of mood disorders with incidence in females being two to three times that of males, an association that may be a result of the influence of estradiol (E2) on HPA axis function. In these studies, we have examined the effect of E2 on glucocorticoid-mediated HPA axis (-) feedback during both the diurnal peak and the stress-induced rise in corticosterone (CORT). Young adult female Sprague-Dawley (SD) rats were ovariectomized (OVX) and 1 week later treated subcutaneous (s.c.) with oil or estradiol benzoate (EB) for 4 days. On the 4th day of treatment, animals were injected with a single dose of dexamethasone (DEX), or vehicle. EB treatment significantly increased the evening elevation in CORT and the stress-induced rise in CORT. In contrast, DEX treatment reduced the diurnal and stress induced rise in CORT and adrenocorticotropic hormone (ACTH), and this reduction was not apparent following co-treatment with EB. To determine a potential site of E2's action, female SD rats were OVX and 1 week later, wax pellets containing E2, the estrogen receptor beta (ERbeta) agonist diarylpropionitrile (DPN), or the estrogen receptor alpha (ERalpha) agonist propylpyrazoletriol (PPT), was implanted bilaterally and dorsal to the paraventricular nucleus of the hypothalamus (PVN). Seven days later, animals were injected s.c. with a single dose of DEX, or vehicle to test for glucocorticoid-dependent (-) feedback. Results show that E2 and PPT increased, while DPN decreased the diurnal peak and stress-induced CORT and ACTH levels as compared to controls. Furthermore, E2 and PPT impaired the ability of DEX to inhibit both the diurnal and the stress-induced rise in CORT and ACTH, whereas DPN had no effect. Neuronal activation was measured by c-fos mRNA expression within the PVN following restraint. E2 and PPT increased c-fos mRNA, and impaired the normal DEX suppression of neuronal activation in the PVN. Taken together, these data indicate that estradiol causes a dysregulation of HPA axis (-) feedback as evidenced by the inability of DEX to suppress diurnal and stress-induced CORT and ACTH secretion. Additionally, the ability of E2 to inhibit glucocorticoid (-) feedback occurs specifically via ERalpha acting at the level of the PVN.

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.

Persistent depressive state after chronic stress in rats is accompanied by HPA axis dysregulation and reduced prefrontal dopaminergic neurotransmission

Exposure to stress is thought to play an important role in the etiology of depression. Dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis characterized by glucocorticoid negative feedback resistance is frequently observed in human depressives. Additionally, dysfunctions of the dopaminergic and serotonergic systems in the prefrontal cortex (PFC) are thought to be involved in the development of a depressive state. In rats, chronic stress induces a behaviorally depressive state, concomitant with dysregulation of the HPA axis and reductions in dopaminergic and serotonergic transmissions in the PFC. Considering that dysregulation of the HPA axis is associated with relapse and persistency of depression, it is possible that the chronic stress-induced depressive state persists during long-term rest after its exposure. In the present study, we examined this possibility in rats and found that the behaviorally depressive state in the rotarod test, negative feedback resistance in the dexamethasone suppression test, and a decrease in the extracellular concentration of dopamine but not serotonin in the PFC persisted for 3 months following a 4-week stress session. These results suggest that dysregulation of the HPA system and reduced dopaminergic transmission in the PFC underlies persistent behavioral depression following chronic stress.