Endocrine changes and clinical profiles in depression: I. The dexamethasone suppression test

Glucocorticoids. Mood, memory, and mechanisms

Elevated circulating levels of glucocorticoids are associated with psychiatric symptoms across several different conditions. It remains unknown if this hormonal abnormality is a cause or an effect of the psychiatric conditions. For example, the hypercortisolemia observed in a subset of patients with depression may have a direct impact on the symptoms of depression, but it is also possible that the hypercortisolemia merely reflects the stress associated with depression. Further, rather than causing depression, hypercortisolemia could represent a homeostatic attempt to overcome glucocorticoid resistance. Each of these possibilities will be considered, and correlational and causal evidence will be reviewed. This article will focus on the relationships between glucocorticoids and psychiatric symptoms in Cushing's syndrome, major depression, and steroid psychosis/steroid dementia, as well as the effects of exogenously administered glucocorticoids in normal volunteers. Similarities and differences in the relationship of glucocorticoid hormones to psychiatric symptoms in these conditions will be reviewed. Possible mediators of glucocorticoid effects on the brain and behavior, as well as possible "pro-aging" effects of glucocorticoids in certain cells of the body, will be reviewed. The article concludes with a conceptual model of glucocorticoid actions in the brain that may lead to novel therapeutic opportunities.

Does the dexamethasone suppression test reliably discriminate between psychotic and nonpsychotic major depression?: an exploratory analysis of potential confounds

Previous research has shown that psychotic major depression (PMD) is often associated with higher rates of nonsuppression on the dexamethasone suppression test (DST) compared with nonpsychotic major depression (NMD), suggesting the potential importance of cortisol hypersecretion in the psychotic subtype of the disorder. However, these patient groups also are known to differ from one another on a variety of other clinical variables, and there are numerous factors independent of diagnostic status known to affect the DST. Thus, we investigated possible confounds that could help account for the apparent DST abnormalities in PMD sometimes reported in past research. Hospitalized patients with PMD (n = 11) and NMD (n = 58) were compared on the DST and other clinical variables. As expected, PMD patients showed significantly higher rates of DST nonsuppression (55% vs. 24%; p = 0.04). However, PMD patients also had significantly higher levels of anxiety severity (p = 0.01). The higher rates of nonsuppression in the PMD group were attenuated when these patients were compared with a subsample of NMD patients matched on anxiety severity (55% vs. 55%). Implications for future research on biological markers of PMD are discussed.

Selective serotonin reuptake inhibitor efficacy in severe and melancholic depression

Depression with melancholic features appears to be a discrete affective syndrome characterised by profound psychomotor, cognitive and mood disturbances that are qualitatively different from other forms of depression. Some investigators have hypothesised that melancholia may have a neurological basis with psychomotor disturbances associated with selective alterations in dopamine neurotransmission and disturbances in basal ganglia function. A number of studies have examined the role of selective serotonin reuptake inhibitors (SSRIs) in the treatment of melancholia. Although relatively few prospective trials have focused on melancholic depression, several retrospective meta-analyses and trials in populations that are likely to include a high proportion of melancholic patients have provided a wealth of data. While some early studies suggested that SSRIs might be less effective in the treatment of melancholia, the results of these may have been biased and confounded by several side-effects of tricyclic antidepressants (TCAs), which might contribute to their apparent efficacy. It appears, however, that the SSRIs may vary among themselves in their apparent efficacy in melancholia. In this regard, sertraline may be more efficacious than other SSRIs and similar to TCAs in the treatment of patients with melancholia. Several studies have suggested that the presence of melancholic features may predict a good response to sertraline, and it has been hypothesised that this may be the result of the relatively potent dopaminergic activity of sertraline, compared with other SSRIs.

Dexamethasone response, thyrotropin-releasing hormone stimulation, rapid eye movement latency, and subtypes of depression

Most prior studies of mood disorders have used a single laboratory test to assist in differential diagnosis, prediction of treatment response, and prediction of relapse. This study compared three laboratory measures in a combined in- and outpatient sample of depressed patients. Dexamethasone suppression test (DST) nonsuppression occurred in 46% of patients with endogenous major depression, in 15% with nonendogenous major depression, and in 56% with bipolar, depressed phase disorder. A blunted thyrotropin-releasing hormone stimulation test (TRH-ST) occurred in 25% of patients with endogenous, 10% with nonendogenous, and 44% with bipolar, depressed phase disorder. Reduced REM latency was found in 65% of endogenous major depressions, in 34% of nonendogenous major depressions, and in 53% of bipolar, depressed phase disorders. Fifty-one percent of those with reduced REM latency also evidenced DST nonsuppression. When the endogenous major depression and bipolar, depressed phase groups were combined, 28% had no laboratory abnormality, whereas 8% evidenced all three. These findings suggest that 1) endogenous/nonendogenous unipolar groups are distinguished by all three laboratory tests; 2) most patients with a blunted TRH-ST also evidence DST nonsuppression; and 3) one half of patients with reduced REM latency evidence DST nonsuppression. Sensitivity is greatest and specificity is lowest for REM latency, followed by the DST and then the TRH-ST.

Depressive psychomotor disturbance, cortisol, and dexamethasone

We examine the dexamethasone suppression test as a biological correlate of melancholia as defined by the CORE system, a scale for rating objective signs of psychomotor disturbance. Postdexamethasone cortisol concentrations and rates of nonsuppression were higher in CORE, Newcastle, and DSM-III-R defined melancholic groups. These differences, however, were no longer significant after partialling out the combined effects of age, dexamethasone, and basal cortisol concentrations. There was a significant correlation between the CORE (but not the Newcastle) scale and 8:00 AM postdexamethasone cortisol levels, which persisted after partialling out those same three covariates. Dexamethasone concentrations themselves were lower in CORE- and Newcastle-defined melancholics, though these were no longer significant after covarying for cortisol concentrations. Dexamethasone levels were also significantly inversely correlated with CORE and Newcastle scales. A significant correlation between CORE (but not Newcastle) scores and dexamethasone levels at 4:00 PM persisted after partialling out the effects of age and cortisol. These findings indicate an intriguing relationship between the CORE system as a dimensional construct for rating psychomotor disturbance, and both postdexamethasone cortisol and dexamethasone concentrations.

Corticotropin-releasing hormone challenge in prepubertal major depression

This study investigates cortisol and ACTH (corticotropin) responses to an infusion of human CRH (corticotropin-releasing hormone) in prepubertal children with major depressive disorder (MDD). Following a period of 24 hours of adaptation to the laboratory environment with an intravenous catheter in place, 34 children with MDD and 22 healthy controls received 1 microgram/kg of human CRH at 5:00 PM. Blood samples for cortisol and ACTH were measured at baseline and post-CRH. Overall, there were no significant differences between the MDD and the normal controls in baseline or post CRH stimulation values of either cortisol or ACTH. Melancholic (n = 4) patients had significantly higher baseline cortisol levels than nonmelancholic (n = 24) patients. Compared with the outpatients and the nonmelancholics, the inpatients (n = 10) and the melancholics showed significantly lower total ACTH secretion (effect size: 0.9 and 1.4, respectively) after CRH infusion. These results are consistent with a broad literature suggesting that the HPA axis abnormalities occur less frequently in early-onset depression than reported in adult studies. The pattern of results in the subgroups of inpatients and in melancholic children, however, raise questions about possible continuities with adult studies.

The similarities and dissimilarities between community and clinic cases of depression

It has been hypothesised that community cases of depression compared with clinic cases: (a) have fewer symptoms; (b) have milder symptoms; (c) have different symptoms; (d) are of shorter duration; (e) are less incapacitating; (f) are more environmentally and less biologically caused; and (g) respond better to psychological than pharmacological intervention. A review of the literature indicates that some of these hypotheses have not been tested, others have not been adequately tested, and none has been unequivocally confirmed. Further investigations of these important issues are required.

Serial dexamethasone suppression test in psychiatric inpatients

A sample of 100 consecutively admitted cases were recruited to test the hypothesis that an abnormal dexamethasone suppression test (AbDST) is associated with decreasing clinical severity during the course of hospitalization in various diagnostic categories. Serial DSTs and psychopathological ratings were done at the end of the first and the third week postadmission, and 1 week before discharge. DST was also done at 1-year follow-up after discharge. The results of this study strongly suggest that a dual mechanism is responsible for the prevalence of AbDST. One is related to the global psychopathology of a nonspecific quantitative mechanism in various diagnostic categories. The other is a specific qualitative mechanism relating to the depressive state, as reflected in the higher prevalence of AbDST and more consistent AbDST results across different study time points in melancholia, and also in higher AbDST rates in disorders with higher depressive scores.

The dexamethasone suppression test in relation to symptomatology: preliminary findings controlling for serum dexamethasone concentrations

A diagnostically heterogeneous sample of psychiatric inpatients (n = 52) was administered the 1 mg dexamethasone suppression test (DST) shortly after hospital admission. Each was also assessed using the Hamilton Rating Scale for Depression (HRSD) and selected items of the Present State Examination (PSE) representing psychomotor retardation and anxiety. A potent determinant of postdexamethasone serum cortisol concentrations was found to be the level of serum dexamethasone concentration achieved following the oral dose. No relationship was found between postdexamethasone cortisol concentration and the scores on either the HRSD or an anxiety scale derived from selected PSE items. However, symptoms of psychomotor retardation were significantly related to postdexamethasone serum cortisol concentration, particularly when the serum dexamethasone concentrations were taken into account. It may be that DST nonsuppression in psychiatric patients is in part a reflection of the presence of psychomotor retardation, a phenomenon that cuts across diagnostic categories.

The Camberwell Collaborative Depression Study. I. Depressed probands: adversity and the form of depression

The Camberwell Collaborative Depression Study is an investigation of a series of 130 patients (76 female; 54 male) attending the Maudsley Hospital Services with unipolar depression of recent onset (the probands), and of their first-degree relatives. This paper describes the first element of the study, the investigation of the index cases or probands, which was carried out by members of the MRC Social Psychiatry Unit over the period 1982-1985. A description of the methods of the study is followed by an analysis of life events in relation to the symptomatic pattern of the depressive state. An 'endogenous' group was defined as cases of depression falling within Catego classes D and R, and compared with a 'neurotic' group conforming to classes N and A. The hypothesis that the 'endogenous' group of disorders would be relatively independent of prior life stress was not confirmed. Depressed women were more likely to have experienced life events or difficulties than their male counterparts, and there was some evidence that sex, but not age or social class, influenced the relationship between adversity and the type of depression. Examination of the timing of life events was strongly suggestive of a causal effect, with a pronounced rise in the month before onset. This was not limited to the most severe events. Differences between the 'endogenous' and 'neurotic' groups in the temporal patterning of events before onset are discussed. The findings are interpreted in terms of the literature on the topic.

Anxiety and the dexamethasone suppression test monitored with saliva

To assess the effect of anxiety on response to the Dexamethasone Suppression Test (DST), cortisol concentrations were determined in patients who had various diagnoses, with anxiety as a secondary characteristic. Saliva was collected before and after venepuncture at 4:05 PM following completion of the Leeds Questionnaire at 3:00 PM. Matrix effects, which caused an initial artefactual decrease in cortisol levels in some saliva samples in patients with high anxiety, could be eliminated by repeated freezing/thawing. There was no significant difference between salivary cortisol concentrations before and after venepuncture, indicating that variability in response to the DST is not a correlate of anxiety and stressful venepuncture. There was no association between anxiety scores and plasma or salivary cortisol values: thus, anxiety is unlikely to be a major contributory cause of nonsuppression of hypercortisolemia in the DST.

The effects of dieting and weight loss upon the stimulation of thyrotropin (TSH) by thyrotropin-releasing hormone (TRH) and suppression of cortisol secretion by dexamethasone in men and women

The effects upon basal hormone levels and neuroendocrine responses of a weight reducing diet allowing 1200 kcal daily were determined in male and female volunteers. Thyrotropin (TSH) responses to thyrotropin-releasing hormone (TRH) were unchanged in men but attenuated in women; this effect was associated with a fall in basal TSH in women, not in men. Rates of non-suppression of cortisol in response to oral dexamethasone (1 mg) were unchanged during dieting although basal morning cortisol levels rose in males and females. The implications for the use of the TRH test and the dexamethasone suppression test (DST) in depressive illness are discussed.

Neuroendocrine aspects of primary endogenous depression. III. Cortisol secretion in relation to diagnosis and symptom patterns

In order to ascertain the extent of hypothalamo-pituitary-adrenal cortical (HPA) hyperactivity in endogenous depression, we determined circadian serum cortisol patterns, cortisol responses to dexamethasone (DEX) administration, and urine free cortisol excretion before and after DEX administration in 40 definite endogenous depressives diagnosed with the Research Diagnostic Criteria. The cortisol measures ranged from normal to clearly elevated. To elucidate the clinical correlates of these hormone measures in the patients, we examined the relationships of the pre- and post-DEX cortisol measures to the diagnosis of endogenous/melancholic depression by different systems and to the overall severity and specific dimensions of depressive symptomatology. In this group of endogenous depressives, none of the diagnostic schemes for endogenous/melancholic depression which we studied was significantly related to the pre- or post-DEX cortisol measures. Of the other subject and symptom variables, only age and the agitation/anxiety factor of the Hamilton depression scale shown consistent relationships with the cortisol measures. Both were positively correlated, to a moderate degree, with the hormone measures, and they were not correlated with each other. Together they explained approximately 20% of the variance in the cortisol measures. Thus, within a group of moderately to severely ill endogenous depressives, the older and the more agitated anxious patients have a significantly greater likelihood of showing increased HPA activity. These findings indicate that age should be controlled in studies of the HPA axis and that the subjective experience of anxiety may contribute to HPA hyperactivity in endogenous depression.

Misery and beyond: the pursuit of disease theories of depression

Psychiatric phenomena can usefully be studied by the establishment of syndromes which can then be used as the basis of investigations of aetiology, treatment and so on. The delineation of syndromes of affective illness has a long history. It implies a distinction from normal lowering of mood. This distinction has been related to the concepts of diathesis and disregulation. However, studies of psychosocial adversity have not been able to add greatly to the concept of affective illness. It is concluded that for it to be maintained that the distinction between simple distress and affective illness is useful, major aetiological differences must be demonstrated. It is likely that this can only be done through multidisciplinary studies.

The relationship between age and post-dexamethasone cortisol: a test of three hypotheses

Previous studies report that DST nonsuppressors are older than normal suppressors. Data are presented on 188 primary unipolar major depressive inpatients and 35 healthy controls. In males, age appeared to correlate positively with post-dexamethasone cortisols in depressed patients and normal controls, although mean levels were higher in depressives. Female controls showed no consistent relationship between age and post-dexamethasone cortisol. A positive relationship did exist for depressed women. However, the association disappeared when age-of-onset was entered into the model, suggesting that in females early onset may identify a subtype of depression with normal DST suppression.

Clinical utility of the dexamethasone suppression test assessed by plasma and salivary cortisol determinations

Concentrations of cortisol in saliva and plasma were compared in matched samples during a standard 1 mg dexamethasone suppression test. The study involved 185 routine psychiatric admissions, all of whom were classified according to DSM-III criteria. In a group of 122 matched samples of saliva and plasma, there was a Pearson correlation coefficient of 0.867 and a Spearman rank correlation coefficient of 0.869. Medication with anticholinergic side effects had little effect on the correlation and was not associated with major difficulties in salivary sampling due to "dry mouth." In a group of 178 diagnoses where both saliva and plasma were obtained, results were almost identical. Although nonsuppression was found in all psychiatric conditions, there was a very significant association with major depressive episode with melancholia.

Depression: distress or disease? Some epidemiological considerations

Surveys using clinical-type interviews have documented a high rate of depression among working-class women, and this is discussed in the light of a recent survey in an inner-city area. While women with caseness of depression contacting a psychiatrist did not differ in number of core depressive symptoms from those who did, they did in certain characteristics that would make them worrying for a general practitioner to deal with. It is concluded that there is a considerable overlap in the severity of depressive conditions between those seen by psychiatrists and those defined as cases in population surveys; any differences that do exist may relate more to the way symptoms are expressed than to the severity of the depressive disorder as such.

Life events, depression and hypothalamic-pituitary-adrenal axis function

The relationship between antecedent life events, clinical profile, and hypothalamic-pituitary-adrenal function was examined in 72 depressed patients. Antecedent life events were associated with first episodes of depression and with greater severity of illness, but their presence did not distinguish between patients diagnosed as endogenous or neurotic, and status on the dexamethasone suppression test was not associated with a greater or lesser likelihood of antecedent events. However, urinary free cortisol levels were higher in those patients with life events and difficulties.

Endocrine changes and clinical profiles in depression: II. The thyrotropin-releasing hormone test

Thirty-one (43%) of 68 patients with primary depression were found to have a blunted thyroid-stimulating hormone (TSH) response to thyrotropin-releasing hormone (TRH). Increased thyroid activity, as measured by the free thyroxine index (FTI), was present in 16 (24%) of the patients. Patients with blunted responses had a higher mean FTI level than those with normal responses. Patients with blunted responses were significantly more likely to exhibit the symptoms of depersonalization, derealization and agitation. There was no clear association between blunting and any particular diagnostic category of depression. Patients with blunted responses and high FTI values were more likely to report significant long-term environmental difficulties than patients with blunted responses and normal FTI values. It is suggested that there may be more than one mechanism responsible for blunting of the TSH response in depressed patients. In some patients blunting may be due to negative feedback from increased output of thyroid hormones, possibly released as part of a stress response. In other patients blunting may be due to a different mechanism, possibly involving pituitary gland dysfunction. These mechanisms would not necessarily be mutually exclusive in any one patient.