Normalization of the dexamethasone suppression test at discharge from hospital. Its prognostic value

Cortisol and the Dexamethasone Suppression Test as a Biomarker for Melancholic Depression: A Narrative Review

The dexamethasone suppression test (DST) assesses the functionality of the HPA axis and can be regarded as the first potential biomarker in psychiatry. In 1981, a group of researchers at the University of Michigan published a groundbreaking paper regarding its use for diagnosing melancholic depression, reporting a diagnostic sensitivity of 67% and a specificity of 95%. While this study generated much enthusiasm and high expectations in the field of biological psychiatry, subsequent studies produced equivocal results, leading to the test being rejected by the American Psychiatric Association. The scientific reasons leading to the rise and fall of the DST are assessed in this review, suggestions are provided as to how the original test can be improved, and its potential applications in clinical psychiatry are discussed. An improved, standardized, and validated version of the DST would be a biologically meaningful and useful biomarker in psychiatry, providing a tool for clinicians caring for depressed patients in the areas of diagnosis, treatment, and prognosis, and predicting the risk of suicide. Additionally, such a test could be a crucial part in the generation of biologically homogenous patient cohorts, necessary for the successful development of new psychotropic medications.

Assessment of Contributing Factors and Treatment Practices for Therapeutic Efficacy and Drug-Related Problems in Suicidal Psychotic Patients

Suicide, a deliberate act of self-harm with the intention to die, is an emerging health concern but, unfortunately, the most under-researched subject in Pakistan, especially in Khyber Pukhtunkhwa (KPK). In this study, we aimed to identify risk factors that can be associated with suicidal behavior (SB) and to evaluate the prevailing treatment practices for therapeutic efficacy and drug-related problems (DRPs) in psychotic patients among the local population of KPK. A prospective, multicenter study was conducted for suicidal cases admitted to the study centers by randomized sampling. Socio-demographics and data on suicidal behavior were assessed using the Columbia-Suicide Severity Rating Scale (C-SSRS), socioeconomic condition by Kuppuswamy socioeconomic scale (KSES) and treatment adherence by Morisky Medication-Taking Adherence Scale (MMAS-4). Drug-related problems and the therapeutic efficacy of prevailing treatment practices were assessed at baseline and follow-up after 3 months of treatment provided. Regarding suicidality (N = 128), females reported more ideations (63.1%), while males witnessed more suicidal behavior (66.6%, p < 0.001). Suicide attempters were mostly married (55.6%, p < 0.002); highly educated (53.9%, p = 0.004); dissatisfied with their life and had a previous history (p < 0.5) of suicide attempt (SA) (20.6%), self-injurious behavior (SIB) (39.7%) and interrupted (IA) or aborted attempts (AA) (22.2%). A greater improvement was observed in patients receiving combination therapy (p = 0.001) than pharmacotherapy (p = 0.006) or psychotherapy (p = 0.183), alone. DRPs were also detected, including drug-selection problems (17.88%), dose-related problems (20.64%), potential drug−drug interactions (24.31%), adverse drug reactions (11.46%) and other problems like inadequate education and counseling (21.55%). Furthermore, it was also found that psychotic patients with suicidal ideations (SI) were significantly (p = 0.01) more adherent to the treatment as compared to those with suicidal attempts. We concluded that suicide attempters differed significantly from patients with suicidal ideations in psychotic patients and presented with peculiar characteristics regarding socio-demographic factors. A combination of therapies and adherence to the treatment provided better outcomes, and targeted interventions are warranted to address drug-related problems.

Biological risk factors for suicidal behaviors: a meta-analysis

Prior studies have proposed a wide range of potential biological risk factors for future suicidal behaviors. Although strong evidence exists for biological correlates of suicidal behaviors, it remains unclear if these correlates are also risk factors for suicidal behaviors. We performed a meta-analysis to integrate the existing literature on biological risk factors for suicidal behaviors and to determine their statistical significance. We conducted a systematic search of PubMed, PsycInfo and Google Scholar for studies that used a biological factor to predict either suicide attempt or death by suicide. Inclusion criteria included studies with at least one longitudinal analysis using a biological factor to predict either of these outcomes in any population through 2015. From an initial screen of 2541 studies we identified 94 cases. Random effects models were used for both meta-analyses and meta-regression. The combined effect of biological factors produced statistically significant but relatively weak prediction of suicide attempts (weighted mean odds ratio (wOR)=1.41; CI: 1.09-1.81) and suicide death (wOR=1.28; CI: 1.13-1.45). After accounting for publication bias, prediction was nonsignificant for both suicide attempts and suicide death. Only two factors remained significant after accounting for publication bias-cytokines (wOR=2.87; CI: 1.40-5.93) and low levels of fish oil nutrients (wOR=1.09; CI: 1.01-1.19). Our meta-analysis revealed that currently known biological factors are weak predictors of future suicidal behaviors. This conclusion should be interpreted within the context of the limitations of the existing literature, including long follow-up intervals and a lack of tests of interactions with other risk factors. Future studies addressing these limitations may more effectively test for potential biological risk factors.

Biological basis of suicide and suicidal behavior

OBJECTIVE

Suicide is a major public health concern as each year 30000 people die by suicide in the USA alone. In the teenage population, it is the second leading cause of death. There have been extensive studies of psychosocial factors associated with suicide and suicidal behavior. However, very little is known about the neurobiology of suicide. Recent research has provided some understanding of the neurobiology of suicide, which is the topic of this review.

METHODS

Neurobiology of suicide has been studied using peripheral tissues such as platelets, lymphocytes, and cerebrospinal fluid obtained from suicidal patients or from the postmortem brains of suicide victims.

RESULTS

These studies have provided encouraging information with regard to the neurobiology of suicide. They show an abnormality of the serotonergic mechanism, such as increased serotonin receptor subtypes and decreased serotonin metabolites (e.g. 5-hydroxyindoleacetic acid). These studies also suggest abnormalities of receptor-linked signaling mechanisms such as phosphoinositide and adenylyl cyclase. Other biological systems that appear to be dysregulated in suicide involve the hypothalamic-pituitary-adrenal axis, and neurotrophins and neurotrophin receptors. More recently, several studies have also indicated abnormalities of neuroimmune functions in suicide.

CONCLUSIONS

Some encouraging information emerged from the present review, primarily related to some of the neurobiological mechanisms mentioned above. It is hoped that neurobiological studies may eventually result in the identification of appropriate biomarkers for suicidal behavior as well as appropriate therapeutic targets for its treatment.

The hypothalamic-pituitary-adrenal axis and serotonin abnormalities: a selective overview for the implications of suicide prevention

Suicidal behavior and mood disorders are one of the world's largest public health problems. The biological vulnerability for these problems includes genetic factors involved in the regulation of the serotonergic system and stress system. The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system that regulates the body's response to stress and has complex interactions with brain serotonergic, noradrenergic and dopaminergic systems. Corticotropin-releasing hormone and vasopressin act synergistically to stimulate the secretion of ACTH that stimulates the biosynthesis of corticosteroids such as cortisol from cholesterol. Cortisol is a major stress hormone and has effects on many tissues, including on mineralocorticoid receptors and glucocorticoid receptors in the brain. Glucocorticoids produce behavioral changes, and one important target of glucocorticoids is the hypothalamus, which is a major controlling center of the HPA axis. Stress plays a major role in the various pathophysiological processes associated with mood disorders and suicidal behavior. Serotonergic dysfunction is a well-established substrate for mood disorders and suicidal behavior. Corticosteroids may play an important role in the relationship between stress, mood changes and perhaps suicidal behavior by interacting with 5-HT1A receptors. Abnormalities in the HPA axis in response to increased levels of stress are found to be associated with a dysregulation in the serotonergic system, both in subjects with mood disorders and those who engage in suicidal behavior. HPA over-activity may be a good predictor of mood disorders and perhaps suicidal behavior via abnormalities in the serotonergic system.

What can post-mortem studies tell us about the pathoetiology of suicide?

Suicide is a major public health concern; however, its neurobiology is unclear. Post-mortem brain tissue obtained from suicide victims and normal controls offers a useful method for studying the neurobiology of suicide. Despite several limitations, these studies have offered important leads in the neurobiology of suicide. In this article, we discuss some important findings resulting from these studies, focusing on serotonergic mechanisms, signal transduction systems, neuroendocrine studies and immune function abnormalities in suicide. These studies suggest that abnormalities of certain receptor subtypes, components of signaling systems such as protein kinase C and protein kinase A, transcription factors such as cyclic AMP response element-binding protein and neurotrophins may play an important role in the pathophysiology of suicide. These studies also suggest abnormalities of hypothalamic-pituitary-adrenal axis system components, feedback mechanisms and cytokines, which are chemical mediators of the immune functions. Post-mortem brain tissue offers an opportunity for future studies, such as genetic and epigenetic studies.

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.

HPA axis hyperactivity as suicide predictor in elderly mood disorder inpatients

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis function is associated with suicidal behaviour and age-associated alterations in HPA axis functioning may render elderly individuals more susceptible to HPA dysregulation related to mood disorders. Research on HPA axis function in suicide prediction in elderly mood disorder patients is sparse. The study sample consisted of 99 depressed elderly inpatients 65 years of age or older admitted to the department of Psychiatry at the Karolinska University Hospital between 1980 and 2000. The hypothesis was that elderly mood disorder inpatients who fail to suppress cortisol in the dexamethasone suppression test (DST) are at higher risk of suicide. The DST non-suppression distinguished between suicides and survivors in elderly depressed inpatients and the suicide attempt at the index episode was a strong predictor for suicide. Additionally, the DST non-suppression showed higher specificity and predictive value in the suicide attempter group. Due to age-associated alterations in HPA axis functioning, the optimal cut-off for DST non-suppression in suicide prediction may be higher in elderly mood disorder inpatients. These data demonstrate the importance of attempted suicide and DST non-suppression as predictors of suicide risk in late-life depression and suggest the use for neuroendocrine testing of HPA axis functioning as a complementary tool in suicide prevention.

ROC analysis of dexamethasone suppression test threshold in suicide prediction after attempted suicide

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis function is associated with suicidal behavior. In suicide attempters with mood disorder, the non-suppressor status in the dexamethasone suppression test (DST) is associated with suicide indicating that HPA-axis hyperactivity is a biological risk factor for suicide and may be a useful predictor. The threshold of 5 microg/dl for cortisol levels measured at 08:00 a.m. or 4:00 p.m. following dexamethasone at 11:00 p.m. to define the DTS nonsuppression was derived as being optimal for the separation of melancholia and nonmelancholic conditions rather than the prediction of suicide. A different threshold may offer a better identification of suicide. The aim of this study was to find the optimal threshold level of post DST plasma cortisol at 4 p.m. for suicide prediction using receiver operating characteristics (ROC) analysis. A cohort of 106 depressed inpatients with an index suicide attempt admitted to the department of Psychiatry at the Karolinska University Hospital between 1980 and 2000, were submitted to DST and followed up for causes of death. During the follow-up (mean 17 years), 25 suicides (24%) were identified. The ROC analysis revealed that a lower threshold of 3.3 microg/dl for the nonsuppressor status predicted 17 of 25 suicides (sensitivity of 68%) compared with 15 of 25 suicides (sensitivity 60%) with a conventional threshold of 5 microg/dl at 4:00 p.m. In male suicide attempters the lower threshold for pathological DST result (3.3 microg/dl) changed the Odds ratio from 6.7 till 18. In female suicide attempters a higher threshold (7.3 microg/dl) optimised the value of DST as a biological test for suicide prediction indicating a gender difference.

Neuroendocrinological mechanisms of actions of antidepressant drugs

Noradrenaline or serotonin (5-HT) reuptake-inhibiting antidepressants such as reboxetine or citalopram acutely stimulate cortisol and adrenocorticotrophic hormone (ACTH) secretion in healthy volunteers, whereas mirtazapine acutely inhibits the ACTH and cortisol release, probably due to its antagonism at central 5-HT(2) and/or H(1) receptors. These differential effects of antidepressants on cortisol and ACTH secretion in healthy subjects after single administration are also reflected by their different time course in the down-regulation of hypothalamic-pituitary-adrenocortical (HPA) axis hyperactivity in depressed patients as assessed by serial dexamethasone (DEX)/corticotrophin-releasing hormone (CRH) tests: Reuptake-inhibiting antidepressants such as reboxetine gradually normalise HPA axis hyperactivity in depressed patients during several weeks of treatment via up-regulation of mineralocorticoid and glucocorticoid receptor function and by step-by-step restoration of the disturbed feedback control. By contrast, mirtazapine markedly reduces HPA axis activity in depressed patients within 1 week, but there is a partial re-enhancement of HPA hormone secretion after several weeks of therapy. In all studies performed to date, the short-term effects of daily treatment with antidepressants on the DEX/CRH test results are comparable in responders and nonresponders. Moreover, a reduction in HPA axis activity is not necessarily followed by a favourable clinical response and some depressed patients keep on showing nonsuppression in the DEX/CRH test despite clinical improvement. Therefore, the importance of HPA axis dysregulation for the short-term efficacy of antidepressants continues to be a matter of debate. However, there are convincing data suggesting that persisting nonsuppression in the DEX/CRH test despite clinical remission predicts an enhanced risk for relapse of depressive symptomatology with respect to the medium- and long-term outcome.

A review of prospective studies of biologic predictors of suicidal behavior in mood disorders

Predicting suicide is difficult due to the low base rate, even in high-risk groups, and the multi-causal nature of suicidal behavior. Clinical predictors have shown low specificity. Retrospective and cross-sectional studies have identified a number of biologic anomalies associated with suicide and suicide attempt. Prospective studies provide estimates of the predictive utility of biologic measures. Here we review prospective studies of suicidal behavior and serotonergic, noradrenergic, dopaminergic and hypothalamic-pituitary-adrenocortical axis function in mood disorders. The most promising biologic predictors are low CSF 5-HIAA and HPA axis dysfunction as demonstrated by dexamethasone non-suppression that are each associated with about 4.5 fold greater risk of suicide.

The dexamethasone suppression test as a predictor of suicidal behavior in unipolar depression

BACKGROUND

Non-suppression on the dexamethasone suppression test (DST) in unipolar depression has been found to be associated with completed suicide, with less consistent data for attempted suicide and hospitalizations for suicidality. The purpose of this study was to examine DST non-suppression as a predictor of these three aspects of suicidal behavior.

METHODS

Records were reviewed for 101 patients who met criteria for major depressive disorder and/or dysthymic disorder and had a DST performed. All patients were treated naturalistically and were followed for an average of 2 years. DST suppressors and non-suppressors were compared with respect to three outcomes: (1) completed suicide; (2) attempted suicide; and (3) hospitalizations for suicidality.

RESULTS

DST non-suppressors were significantly more likely to have completed suicide or be hospitalized for suicidality than DST suppressors, with a non-significant trend for attempts. Total suicidal events were also significantly more frequent in the non-suppressor group.

LIMITATIONS

Axis II diagnoses and severity of illness were not assessed. Knowledge of DST results may have influenced the decision to hospitalize patients.

CONCLUSIONS

DST non-suppression identifies unipolar depressed patients with a higher risk for future suicide completion or hospitalization for suicidality. Performance of DST upon initiation of treatment may be a useful adjunct in identifying suicidal risk.

Sleep deprivation and hypothalamic-pituitary-adrenal (HPA) axis activity in depressed patients

In the present study we investigated HPA axis activity in depressed patients treated with partial sleep deprivation (PSD) in order to identify endocrinological characteristics related to PSD responsiveness. Thirty-three drug-free patients (14 men, 19 women) suffering from major depression according to DSM-IV criteria were treated with PSD. Response to PSD was defined as a reduction of at least 30% according to the 6-item version of the Hamilton Depression Scale (6-HAMD). Subsequently, the combined dexamethasone-suppression/CRH-stimulation test (DEX/CRH test) was performed. Patients were pretreated with 1.5 mg dexamethasone (DEX) at 23:00 h and challenged with 100 microg corticotropin-releasing hormone (CRH) the following day. Postdexamethasone cortisol concentrations (before CRH administration) served as parameters for the DST status (dexamethasone suppression test). The cortisol stimulation after CRH was used as measurement for the DEX/CRH test status. Of the depressive patients, 54.5% (18 out of 33) responded to PSD. DST suppressors (postdexamethasone cortisol levels < 15 ng/ml) showed a significantly greater reduction in 6-HAMD scores after PSD than DST nonsuppressors. Furthermore, a significant negative correlation between postdexamethasone cortisol levels and reduction in 6-HAMD scores after PSD could be established. However, there was no relationship between the cortisol stimulation following CRH challenge and response to PSD. Although the combined DEX/CRH challenge test is a more sensitive marker for HPA axis dysregulation in depression than the standard DST, the negative feedback of the HPA system reflected by the DST status is apparently more closely associated with response to partial sleep deprivation in major depressive disorder.

Relapse of depression after ECT: a review

Relapse of severe depression after successful treatment with electroconvulsive therapy (ECT) continues to be a major problem. We review the literature on relapse after ECT and factors that predict relapse. Early studies showed that the relapse rate was approximately 50% without follow-up treatment and that the majority of these relapses occurred in the first 6 months. More recent studies have found even higher rates in delusional depression and possibly in "double depression." Studies of biological markers as predictors of relapse were examined. Six of nine studies of the dexamethasone suppression test and one study of cortisol hypersecretion show that post-ECT nonsuppressors are at higher risk; although insensitive for diagnostic purposes, this test may be useful, when persistently abnormal, as a predictor of relapse. Studies of the thyrotropin-releasing hormone stimulation test and shortened rapid eye movement sleep latency are inconclusive. Medication resistance pre-ECT has been shown to predict relapse in two studies and highlights the need for more aggressive and effective treatment in this group. Further research into the prediction and prevention of depressive relapse after ECT is needed, and the field anxiously awaits current trials comparing ECT with combination lithium and nortriptyline.

Patterns of DST positivity in remitted affective disorders

BACKGROUND

While the Dexamethasone Suppression Test (DST) has been extensively used in cross-sectional observations of patients with major affective disorders, studies have tended to ignore the longitudinal application of the DST in patients stabilized on long-term prophylactic medication.

METHODS

Monthly DST's were performed on 19 patients, 16 with bipolar disorder and 3 with recurrent major depression. All cases had an excellent response to lithium treatment, and family history positive for bipolar disorder. The average duration of observation was 4 years.

RESULTS

All patients remained clinically stable throughout the period of observation. Eleven patients showed intermittent DST positivity ranging from 10% to 60% of tests, and 2 patients exhibited no positivity. Six patients had fewer than 10% positive DST's. Females showed significantly higher positivity than males. The frequency of positivity did not correlate with current age, age of illness onset, duration of illness, duration of lithium treatment, or season. The risk of primary affective disorders in first-degree relatives was also unrelated to the frequency of positivity.

CONCLUSIONS

While the highly selected and small sample population limits generalizability, our observations suggest that clinically sufficient lithium prophylaxis does not automatically prevent intermittent HPA dysregulation. We hope that a better understanding of this phenomenon will offer new approaches to the long-term management of mood disorders.

Adrenal weight and morphology in victims of completed suicide

Several lines of evidence have implicated hypothalamic-pituitary-adrenal (HPA) axis dysfunction in major depression and suicidal behavior. In the present study, the weight and morphology of postmortem adrenal glands were compared between suicide victims and sudden death, nonpsychiatric controls. The mean adrenal weight of the combined left and right glands was significantly higher in the suicide group; this difference was accounted for specifically by increases in left adrenal weight of suicides compared with the control group. There was a positive correlation between adrenal weight and total cortical thickness in both left and right glands, providing direct evidence that increased adrenal weight in suicide victims is due to cortical hypertrophy. The finding of left-right adrenal weight asymmetry in suicides is consistent with the hypothesis of abnormal lateralized input from higher control centers of the HPA axis.

Hypothalamic-pituitary-adrenal axis activity and 1-year outcome in depression

The relationships of longitudinal biological measures to longer-term outcome in depressed patients have not been well explored. This study was designed to investigate whether in a sample of depressed patients: (a) symptomatic and functional outcome at 1 year was significantly different in psychotic major depressed (PMD) patients as compared with nonpsychotic major depressed (NPMD) patients and (b) high urinary or plasma cortisol levels at baseline or 1 year were associated with poorer outcomes at 1 year. Forty-two depressed patients (9 psychotic, 33 nonpsychotic) were evaluated at baseline and at 1 year using a battery of clinical ratings and measures of cortisol. A group of normal, healthy control subjects were similarly evaluated at baseline. At 1-year follow-up, PMD patients did not differ from NPMD patients in their Hamilton Depression Rating Scale (HDRS) and Brief Psychiatric Rating Scale scores (BPRS), but PMD patients demonstrated significantly poorer social and occupational functioning. Significant correlations were observed (n = 18) between higher levels of urinary and plasma cortisol at 1 year and poorer social and occupational functioning at 1 year, independent of the degree of residual depression. In contrast, baseline measures of urinary and plasma cortisol did not predict social and occupational functioning at 1 year.

State specificity of DST abnormalities in geriatric depression

Pre-treatment and posttreatment dexamethasone suppression test (DST) results in physically healthy elderly major depressives without dementia demonstrated an association between treatment and DST normalization. Sixty percent of subjects were nonsuppressors at baseline compared to 17% after intensive treatment. DST results normalized in 75% of initial nonsuppressors; none of the initial suppressors converted to nonsuppression. A strong correlation between clinical improvement and decreases in afternoon cortisol levels was identified. Initial suppression status did not influence this association. There was a nonsignificant trend for very high (> 15 micrograms/dl) afternoon cortisol levels to be associated with delusional depression. The advantage of using continuous rather than categorical measures to assess the relationship between reversal of depression and DST results is discussed.

Multiplicity of depressive episodes: phenomenological and neuroendocrine correlates

Sixty-four patients with a Research Diagnostic Criteria (RDC) diagnosis of major depressive disorder were categorized into three groups based on their number of depressive episodes (DE): Gr I (1 DE), n = 16, Gr II (2-4 DE), n = 25; and Gr III (5 or more DE), n = 23. All patients were nonsuppressors after 1 mg dexamethasone suppression test (DST) prior to the start of treatment. Patients were monitored during the course of their treatment using serial Hamilton Depression scores and post-DST plasma cortisol levels. A proportionately equal number of patients in the three groups had a favorable outcome, i.e., the number of depressive episodes did not predict recovery. Despite favorable clinical outcome, patients with higher numbers of depressive episodes had significantly higher post-DST plasma cortisol levels that were above the suppressive range (greater than 5 micrograms/dl). Patients with a higher number of depressive episodes had a significantly shorter duration of index episode and were younger at first depressive episode than patients in the other two groups. These results, however, were confounded with polarity, with a higher number of bipolars in Gr III than in the other two groups. Results are discussed in light of phenomenological and psychoendocrine findings of earlier studies.

The dexamethasone suppression test and completed suicide

The present study was undertaken to further explore the relationship between the dexamethasone suppression test (DST) and suicide. Depressed inpatients who had undergone the DST at index admission and later committed suicide (n = 13) were matched for age, gender, diagnosis, and type of DST (1 mg, 2 mg) with depressed inpatients from the same hospital and study time period to form 2 groups: a suicide attempter group (n = 25) and a nonattempter group (n = 28). The suicide completers group had significantly higher 1600 postdexamethasone cortisol levels than the suicide attempters group and a significantly higher 1600 rate of DST nonsuppression compared with the suicide attempter + nonattempter combined group. Although the rate of DST nonsuppression did not differ between the suicide attempter and nonattempter groups, serious attempters had significantly higher 1600 cortisol levels and a statistically higher proportion of patients who completed suicide than nonserious attempters.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistent cortisol non-suppression after clinical recovery predicts symptomatic relapse in unipolar depression

We assessed the length and the quality of remission of 13 unipolar endogenous depressed patients, DST non-suppressors before treatment, in a 2-year prospective study. During this period, we recorded stressful life events. Persistent dexamethasone non-suppression, after treatment and complete clinical recovery, correlated highly with early clinical relapse. All six non-normalizers but only one normalizer were rehospitalized within the following 2 years for a major depressive relapse. Persistent DST non-suppression was unrelated to any impact of drug discontinuation, the occurrence of stressful life events or the length of illness-free intervals in the patient's prior course of illness. Persistent DST non-suppression appears to have significant prognostic value.

Psychoneuroendocrine research in depression. I. Hormone levels of different neuroendocrine axes and the dexamethasone suppression test

Psychoneuroendocrinology is of major importance in the biological research of depression. Most studies have focussed on the regulation of the hypothalamic-pituitary-adrenal (HPA) axis but other endocrine systems such as the hypothalamic-pituitary-thyroid (HPT), hypothalamic-pituitary-somatotropic (HPS), and the hypothalamic-pituitary-gonadal (HPG) axis have also been shown to be involved in the psychobiology of depression. There are close interrelations between various endocrine axes which possibly are affected during depressive illness. A variety of neuroendocrine abnormalities has been detected in depressive disorder but the pathophysiology of these derangements remains still unclear. Although the currently used neuroendocrine tests are not of diagnostic validity they may help to clarify the pathophysiological significance of the complex regulatory mechanisms of different neuroendocrine axes in affective disorders. Neuroendocrine regulation is determined both by peripheral and central mechanisms which both have to be adequately considered as well as potent interactions between various endocrine systems in further neuroendocrine depression research.

The predictive power of the salivary cortisol dexamethasone suppression test for three-year outcome in major depressive illness

Seventy patients satisfying DSM-III and Research Diagnostic Criteria for major depression were given a salivary cortisol dexamethasone suppression test, with samples collected at 0700 h, 1500 h and 2300 h after dexamethasone. The patients were classified as nonsuppressors (mean post-dexamethasone salivary cortisol concentration greater than or equal to 2.0 ng/ml, N = 27) and suppressors (mean post-dexamethasone salivary cortisol concentration less than 2.0 ng/ml, N = 43). At 3-yr follow-up there was no difference in illness outcome as assessed by the life table method or by the length of rehospitalisation for several periods after the index episode. In multiple regression and discriminant function analyses, with outcome as the dependent variable (readmitted within 1 yr, readmitted between 1 and 3 yr, not readmitted), the mean post-dexamethasone salivary cortisol concentration was not significantly predictive of outcome.

Biology of depression

Research over the past three decades has led to a greater understanding of the biologic basis of depression. Observations that certain medications could improve or worsen mood led to the development of hypotheses describing the possible role of specific neurotransmitters in the brain in depression. Modifications of these original hypotheses focused on altered receptor function, failures in the regulation of neurotransmitter systems, and interactions of the monoamines with cholinergic systems. Strategies using endocrinologic measurements in the evaluation of the depressed patient have provided researchers with new clues regarding disordered neuroendocrine function in depression and clinicians with new tests to aid in diagnosis and management. Moreover, the development of standardized sleep EEG methodology has proven useful for the identification of characteristic sleep abnormalities in depression. Although there are many methodologic and clinical problems still to be resolved, the use of biological markers in the assessment of the depressed patient is increasing, and is likely to be of significant importance in the future. Finally, recent advances in molecular genetics hold promise for further advances in our understanding of the inheritance and biochemistry of depression.

Monitoring of antidepressant response to ECT with polysomnographic recordings and the dexamethasone suppression test

Ten patients treated with electroconvulsive therapy (ECT) only were followed with serial sleep polysomnographic recordings and dexamethasone suppression tests (DSTs). Both biological correlates of depression showed improvement with ECT. The use of serial sleep measures and serial DSTs in monitoring the clinical response to ECT is discussed.

Prediction of outcome in depressed patients by weekly monitoring with the dexamethasone suppression test

Forty-three depressed patients in hospital were studied with weekly dexamethasone suppression tests (DSTs) and were followed as out-patients for at least three months after discharge. The detection rate of patients with LHPA axis dysfunction increased from 41% with a single DST to 59% with serial DSTs. There was a poor correlation between weekly post-dexamethasone cortisol levels and Hamilton depression rating scores. In patients with evidence of LHPA axis dysfunction, a DST at discharge discriminated effectively between a good and a poor outcome group; persistent non-suppression was strongly linked with a relapse of depression in the first three months after discharge. In general, our results support previous claims that the DST is a state marker for depressive illness.

The dexamethasone suppression test and prediction of outcome in patients receiving ECT

Twenty-six in-patients satisfying DSM-III criteria for major depressive episode were assessed using the Newcastle Diagnostic and ECT Predictor Scales and the dexamethasone suppression test (DST), prior to commencing a course of electroconvulsive therapy (ECT). The Newcastle ECT Predictor Scale was successful in predicting both immediate outcome and outcome over the 6 months following ECT; the DST was unsuccessful in predicting either immediate or 6-month outcome.

Nocturnal prolactin and cortisol secretion and recovery from melancholia

Spontaneous prolactin and cortisol patterns were determined at 20 min intervals over 3 hr during the night in eight patients with melancholia, both during illness and after treatment with amitriptyline. Mean plasma prolactin levels were greater after recovery in the seven patients who responded to treatment. Mean cortisol secretion decreased upon recovery from melancholia, and such changes in two patients paralleled normalization of dexamethasone suppression test responses. The influence of assumptions of lack of interaction on the statistical significance of the analysis of variance with repeated measures for prolactin and cortisol values was evaluated.

Repeated dexamethasone suppression test in depressed patients

In 17 depressed patients with initially abnormal results on the dexamethasone suppression test (DST), serial plasma samples for the determination of cortisol concentrations were taken every 10 days, following overnight dexamethasone administration at 11 p.m. Severity ratings were repeated on the days of blood sampling. There was a gradual normalization of the DST and progressive clinical improvement during selective antidepressant therapy. The DST was closely related (r = 0.573, P less than 0.005) to the patients' clinical mood level during the depressive episode. At the point where normalization of the DST occurred, the patients were still moderately severely ill. DST conversion occurred early in the treatment, i.e. after 23.9 (+/- 15.1) days, and preceded symptomatic improvement by 24.5 (+/- 18.1) days. Normalization of the DST was a predictor (r = 0.691, P less than 0.005) of the time of clinical improvement, but not of clinical recovery. The test was a biological discriminator between severe and less severe depressions. The time of symptomatic improvement (r = 0.505, P less than 0.05), but not of biological remission, depended on age; severe depressions lasted longer in the elderly patients.

Serum melatonin in relation to clinical variables in patients with major depressive disorder and a hypothesis of a low melatonin syndrome

Maximum nocturnal serum melatonin level (MTmax) in relation to some clinical variables was studied in 32 patients with a major depressive episode and in 33 healthy subjects with reference to the outcome of the dexamethasone suppression test (DST). Significant regressions were found between MTmax levels and clinical rating scores in CPRS, interpreted as retardation symptoms. Four healthy subjects with disposition for dysthymic reactions had subnormal MTmax levels, which differed from MTmax levels in subjects without such disposition. Patients but not the healthy subjects, who reported parental loss before 17 years of age, had subnormal MTmax levels and differed from patients with no reported parental loss. Patients with no reported suicidal behaviour in clinical history had significantly lower MTmax levels than patients with reported suicide attempts. No relations were found between low MTmax levels and diagnoses, duration of illness, reported inheritance for depressive illness or sleep disturbances. A hypothetical low melatonin syndrome in depression is proposed: low nocturnal melatonin, abnormal dexamethasone suppression test, disturbed 24-h rhythm of cortisol, less pronounced daily and annual cyclic variation in depressive symptomatology.

ACTH, cortisol, and corticosterone output after ovine corticotropin-releasing factor challenge during depression and after recovery

Synthetic ovine corticotropin releasing factor (o-CRF) was administered as an intravenous bolus (100 micrograms) to eight patients suffering from a major depressive disorder, endogenous subtype. All patients showed inadequately suppressed cortisol levels after 1 mg dexamethasone. After clinical remission and normalized dexamethasone responses, these patients were reinvestigated with o-CRF stimulation. The mean adrenocorticotropic hormone (ACTH) release from the pituitary corticotroph cells was indiscriminate at both test sessions. Cortisol and corticosterone output after o-CRF tended to be higher during depression than after recovery. The o-CRF-induced increments observed with corticosterone were more marked in comparison with cortisol. Within the limitations of the current protocol, our preliminary data lend support to the view that an increased pituitary ACTH reserve or adrenocortical steroid reserve is not likely to be responsible for the defective pituitary-adrenal regulation in some dexamethasone-resistant depressives.

Effect of weekly testing on dexamethasone suppression test results in normal subjects

Four weekly repetitions of the overnight dexamethasone suppression test (DST) in each of 10 healthy volunteers yielded plasma cortisol levels that were consistently suppressed. These results suggest that unlike some dynamic tests of hypothalamic-pituitary functioning, the DST does not produce false-positive results due to weekly repetition. This finding is of interest because previous research has demonstrated that a subgroup of melancholic initial nonsuppressors continue to resist cortisol suppression despite apparent clinical improvement. The present findings do not support the hypothesis that continued nonsuppression in clinically improved patients is an artifact of serial testing.

Mean 14.00-17.00 h plasma cortisol concentration and its relationship to the 1 mg-dexamethasone suppression response in depressives and controls

Three-hour cortisol-profiles and cortisol responses to a 1 mg dose of dexamethasone were recorded in 31 depressed patients and nine controls. The data indicate that the likelihood of detecting non-suppressible cortisol concentrations after dexamethasone is significantly increased in depressed patients with a hypersecretion of cortisol. However, a considerable subsample of normosecretors shows abnormal DST results. Conversely, hypersecretion is often associated with dexamethasone suppression. In this study a 1 mg-DST did not reflect the adrenocortical activity with ultimate accuracy. Therefore any attempts which correlate psychopathological or biological data with pituitary-adrenal activity and use a DST-result as measure are criticizable . Data derived from volunteers illustrate that medical factors such as weight-loss, steroid-containing contraceptives and sleep deprivation can make a pituitary-adrenal activity test ambiguous.