The metyrapone test in affective disorders and schizophrenia

Morning cortisol levels in schizophrenia and bipolar disorder: a meta-analysis

Increased peripheral levels of morning cortisol have been reported in people with schizophrenia (SZ) and bipolar disorder (BD), but findings are inconsistent and few studies have conducted direct comparisons of these disorders. We undertook a meta-analysis of studies examining single measures of morning cortisol (before 10 a.m.) levels in SZ or BD, compared to controls, and to each other; we also sought to examine likely moderators of any observed effects by clinical and demographic variables. Included studies were obtained via systematic searches conducted using Medline, BIOSIS Previews and Embase databases, as well as hand searching. The decision to include or exclude studies, data extraction and quality assessment was completed in duplicate by LG, SM and AS. The initial search revealed 1459 records. Subsequently, 914 were excluded on reading the abstract because they did not meet one or more of the inclusion criteria; of the remaining 545 studies screened in full, included studies were 44 comparing SZ with controls, 19 comparing BD with controls, and 7 studies directly comparing schizophrenia with bipolar disorder. Meta-analysis of SZ (N=2613, g=0.387, p=0.001) and BD (N=704, g=0.269, p=0.004) revealed moderate quality evidence of increased morning cortisol levels in each group compared to controls, but no difference between the two disorders (N=392, g=0.038, p=0.738). Subgroup analyses revealed greater effect sizes for schizophrenia samples with an established diagnosis (as opposed to 'first-episode'), those that were free of medication, and those sampled in an inpatient setting (perhaps reflecting an acute illness phase). In BD, greater morning cortisol levels were found in outpatient and non-manic participants (as opposed to those in a manic state), relative to controls. Neither age nor sex affected cortisol levels in any group. However, earlier greater increases in SZ morning cortisol were evident in samples taken before 8 a.m. (relative to those taken after 8 a.m.). Multiple meta-regression showed that medication status was significantly associated with morning cortisol levels in SZ, when the effects of assay method, sampling time and illness stage were held constant. Heightened levels of morning cortisol in SZ and BD suggest long-term pathology of the hypothalamic-pituitary-adrenal (HPA) axis that may reflect a shared process of illness development in line with current stress-vulnerability models.

Lower cortisol levels predict recurrence in remitted patients with recurrent depression: a 5.5 year prospective study

Major Depressive Disorder (MDD) is a highly recurrent disease. Stress-responsive system dysfunction seems to persist after remission. In patients with more chronic and recurrent depressive episodes, state related HPA-axis dysregulation might be a risk factor for prospective recurrence. This study examines the predictive effect of cortisol on consecutive episodes in remitted recurrently depressed patients. Cortisol was assessed in saliva in remitted recurrently depressed patients (n=55) that were followed up prospectively for 5.5 years after remission. Recurrence was assessed using a well validated structured interview. Lower mean morning cortisol levels predicted earlier time to recurrence over 5.5 year after correction for residual symptoms (p=0.015). Residual symptoms and childhood trauma slightly confounded the association between cortisol and recurrence. Lower cortisol levels were associated with having experienced traumatic childhood life events (42.3% in patients with lower cortisol versus 19.2% in patients with higher cortisol). Our study provides further support for the predictive role over 5.5 year of HPA axis dysregulation, i.e. lower morning cortisol levels, of recurrence in recurrently depressed patients. Childhood trauma is associated to having lower cortisol levels. It might have long term consequences for dealing with stress and the HPA-axis.

Synaptic regulation of the hypothalamic-pituitary-adrenal axis and its modulation by glucocorticoids and stress

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in a range of affective and stress-related disorders. The regulatory systems that control HPA activity are subject to modulation by environmental influences, and stressful life events or circumstances can promote subsequent HPA dysregulation. The brain is a major regulator of the HPA axis, and stress-induced plasticity of the neural circuitry involved in HPA regulation might constitute an etiological link between stress and the development of HPA dysregulation. This review focuses on the synaptic regulation of neuroendocrine corticotropin-releasing hormone (CRH) neurons of the hypothalamic paraventricular nucleus, which are the cells through which the brain predominantly exerts its influence on the HPA axis. CRH neuronal activity is largely orchestrated by three neurotransmitters: GABA, glutamate, and norepinephrine. We discuss our current understanding of the neural circuitry through which these neurotransmitters regulate CRH cell activity, as well as the plastic changes in this circuitry induced by acute and chronic stress and the resultant changes in HPA function.

Synaptic regulation of the hypothalamic-pituitary-adrenal axis and its modulation by glucocorticoids and stress

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been implicated in a range of affective and stress-related disorders. The regulatory systems that control HPA activity are subject to modulation by environmental influences, and stressful life events or circumstances can promote subsequent HPA dysregulation. The brain is a major regulator of the HPA axis, and stress-induced plasticity of the neural circuitry involved in HPA regulation might constitute an etiological link between stress and the development of HPA dysregulation. This review focuses on the synaptic regulation of neuroendocrine corticotropin-releasing hormone (CRH) neurons of the hypothalamic paraventricular nucleus, which are the cells through which the brain predominantly exerts its influence on the HPA axis. CRH neuronal activity is largely orchestrated by three neurotransmitters: GABA, glutamate, and norepinephrine. We discuss our current understanding of the neural circuitry through which these neurotransmitters regulate CRH cell activity, as well as the plastic changes in this circuitry induced by acute and chronic stress and the resultant changes in HPA function.

Affective disorders and endocrine disease. New insights from psychosomatic studies

This is a review of psychosomatic interactions between affective disorders (depressive and anxiety disturbances, irritable mood) and endocrine disease. Particular reference is made to stressful life events in the pathogenesis of endocrine disease, psychopathology of hormonal disturbances, and pathophysiology of hypothalamic-pituitary-adrenal axis function in depression and Cushing's disease. These psychosomatic interactions may lead to appraisal of common etiological mechanisms in endocrine and psychiatric disorders, of the value of retaining the category of organic affective syndromes in psychiatric classification, and of the need for research on quality-of-life measures in endocrine disease. The establishment of "psychoendocrine units," where both endocrinologists and psychiatrists should work, is advocated. Such psychoendocrine units may serve and benefit clinical populations who currently defy traditional medical subdivisions.

Beta-endorphin responses to metyrapone and dexamethasone in depressed patients

Controversy continues over the characteristics of beta-endorphin secretion in depression. Beta-endorphin plasma levels were measured in 30 drug-free male patients with a DSM-III-R major depressive disorder and 21 healthy controls. Depressed patients displayed significantly lower beta-endorphin plasma levels in baseline conditions, after the single dose metyrapone test, and after the dexamethasone suppression test. The activation of hypothalamic-pituitary-adrenal (HPA) axis in depression might be due, at least in part, to low levels of beta-endorphin. These results suggest that HPA axis dysregulation in depression may involve peptides other than ACTH.

Effects of metyrapone and dexamethasone upon pro-gamma-MSH plasma levels in depressed patients and healthy controls

There is current controversy over the mechanisms underlying hypothalamic-pituitary-adrenal (HPA) axis hyperactivity in depression. Pro-gamma-melanocyte-stimulating hormone (MSH), a portion of the N-terminal region of pro-opiomelanocortin, has been shown to act synergistically with adrenocorticotropic hormone (ACTH) in stimulating corticosteroid secretion both in vitro and in vivo. Pro-gamma-MSH and ACTH plasma levels were measured in 30 drug-free male patients with a DSM-IIIR major depressive disorder and 21 healthy controls. The baseline levels were similar in the two groups. After single-dose metyrapone stimulation, both hormones increased, but pro-gamma-MSH was significantly higher in control subjects than in depressives. After overnight 1-mg dexamethasone, ACTH was significantly less suppressed in depressives than controls. These results suggest that HPA axis dysregulation in depression may involve peptides other than ACTH and be more complex than previously reported.

The assessment of abnormalities in hormonal responsiveness at multiple levels of the hypothalamic-pituitary-adrenocortical axis in depressive illness

A substantial body of data suggests that excessive cortisol secretion in depression may result from dysregulation at several sites within the hypothalamic-pituitary-adrenocortical (HPA) axis. The alterations in regulatory mechanisms are thought to result from a limbic system-hypothalamic "overdrive" of corticotropin-releasing hormone (CRH). We also have demonstrated that excessive secretion of cortisol may result from an abnormal adrenocortical responsiveness to adrenocorticotropic hormone (ACTH), and we have postulated that corticotropic cells within the pituitary mediate between excessive secretion of CRH from the hypothalamus and hypercortisolemia secondary to adrenocortical hyperplasia and enhanced sensitivity to ACTH at the adrenal cortex. The present report describes a series of clinical experiments utilizing several neuroendocrine probes, as well as computer-assisted tomography, to examine the complexities of the HPA axis dysregulation in depression. These studies support the hypothesis that a limbic system-hypothalamic disturbance results in excessive CRH secretion as well as enhanced adrenocortical activity, and that these factors contribute to excessive cortisol secretion in patients with depression. These data further support the hypothesis that endogenous affective disorders are best characterized in the framework of a generalized biological disturbance of HPA axis function which involves both central and peripheral endocrine sites.

The oCRH stimulation test before and after clinical recovery from depression

A substantial body of data suggests that excessive cortisol secretion in depression may result from a dysregulation at several sites within the hypothalamic-pituitary-adrenocortical (HPA) axis. These alterations in regulatory mechanisms are thought to be the result of a hypothalamic 'overdrive' of corticotropin-releasing hormone (CRH). Previous studies have demonstrated a diminished adrenocorticotropin (ACTH) secretory response, as well as a heightened adrenocortical responsiveness after ovine-CRH administration in depressed patients. In the present investigation, we examined pituitary and adrenocortical responsiveness after an ovine-CRH stimulation test before and during clinical recovery in seven depressed patients. Cumulative ACTH responses increased significantly during clinical recovery (P = 0.014). Paradoxically, maximum and peak cortisol responses increased after recovery, suggesting that heightened adrenocortical responsiveness to ACTH during depression may take longer to 'normalize' than abnormal pituitary responsiveness to ovine-CRH stimulation.

The dexamethasone suppression and metyrapone tests in depression

The dexamethasone suppression test (DST) and the metyrapone test (MT), a useful and reliable procedure for assessing the integrity of the hypothalamic-pituitary-adrenal (HPA) axis, were performed in 28 patients suffering from major depressive illness with melancholia. The relationship between the DST and MT appeared to be complex. Patients who failed to suppress cortisol secretion after dexamethasone administration had higher postmetyrapone cortexolone levels and cortexolone/cortisol ratios than suppressors. However, there was a wide range of metyrapone responses in patients exhibiting abnormal DST results. This suggests that failure of adequate suppression after 1 mg of dexamethasone in depressed patients does not necessarily reflect homogeneity in the HPA axis disturbances of such patients.

The metyrapone test in affective disorders and schizophrenia II. Changes upon treatment

The metyrapone test was applied to groups of patients suffering from major depressive illness with melancholia, mania or schizophrenia, before and after treatment. There were interesting individual correlations between post-metyrapone cortexolone values, cortexolone/cortisol ratios and clinical improvement in depressives. Two patients who had exhibited abnormal metyrapone responses displayed a normalization of post-metyrapone cortexolone values upon clinical improvement, whereas the opposite trend was observed in a patient who did not improve and in another who became manic. These preliminary results may indicate that abnormal metyrapone responses in depression are state dependent.