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

Glucocorticoid Resistance: Is It a Requisite for Increased Cytokine Production in Depression? A Systematic Review and Meta-Analysis

Background: Glucocorticoid resistance-reduced function of the glucocorticoid receptor (GR)-is seen in many depressed patients. It is argued that this resistance to glucocorticoids leads to failure of normal feedback regulation on the immune system. High levels of pro-inflammatory cytokines result. Purpose: We sought to identify evidence supporting or refuting a link between glucocorticoid resistance and immune dysregulation in depression and to summarize retrieved evidence in aggregate form. Methods: We systematically reviewed and meta-analyzed studies that examined cytokine levels in depressed patients compared with controls and that also reported a measure of glucocorticoid resistance. These measures included plasma cortisol, the dexamethasone suppression test (DST), GR expression levels, and the results of in vitro assays of GR function. We conducted four separate meta-analyses to test for moderating effects of glucocorticoid resistance on cytokine production in depression. Results: After sub-grouping 32 studies by the ratio of cortisol levels in patients compared with controls, we observed a trend for increasing glucocorticoid resistance (i.e., the most hypercortisolemic patients) to be associated with increased production of interleukin (IL)-6 [d = 0.94; 95% CI (0.29, 1.59)] and tumour necrosis factor (TNF)-α [d = 0.46; 95% CI (0.12, 0.79)]. We stratified nine studies that reported DST results by relative glucocorticoid resistance between patients and controls, identifying a trend for higher glucocorticoid resistance in patients, compared with controls, to be associated with higher cytokine production in patients (170 patients and 187 controls). This was particularly evident when studies were sub-grouped by source of cytokine-plasma (d = 1.04; 95% CI, 0.57-1.50) versus in vitro (d = 0.24; 95% CI, -0.20 to 0.67). Stratifying the four studies (147 patients and 118 controls) that used in vitro assays of GR function or GR expression to quantify glucocorticoid resistance revealed variable contributions to cytokine production in patients compared with controls (overall effect size: d = 1.35; 95% CI 0.53-2.18). Combining our analyses of studies that reported DST results with those that used in vitro assays of GR function or GR expression to quantify glucocorticoid resistance (302 patients and 277 controls), we noted that although depressed patients produced more cytokines than controls (d = 1.02; 95% CI, 0.55-1.49), there was no evident positive correlation between glucocorticoid resistance and inflammation. Conclusions: Our work provides some support for a model conceptualizing glucocorticoid resistance as a requisite for increased inflammation in depression. The limited number of studies identified highlights the need for purpose-designed investigations that directly examine the relationship between glucocorticoid resistance and cytokine production in depression.

The impact of childhood adversity on suicidality and clinical course in treatment-resistant depression

BACKGROUND

Childhood adversity is a risk factor for the development of depression and can also affect clinical course. We investigated this specifically in treatment-resistant depression (TRD).

METHODS

One hundred and thirty-seven patients with TRD previously admitted to an inpatient affective disorders unit were included. Clinical, demographic and childhood adversity (physical, sexual, emotional abuse; bullying victimization, traumatic events) data were obtained during admission. Associations between childhood adversity, depressive symptoms and clinical course were investigated.

RESULTS

Most patients had experienced childhood adversity (62%), with traumatic events (35%) and bullying victimization (29%) most commonly reported. Childhood adversity was associated with poorer clinical course, including earlier age of onset, episode persistence and recurrence. Logistic regression analyses revealed childhood adversity predicted lifetime suicide attempts (OR 2.79; 95% CI 1.14, 6.84) and childhood physical abuse predicted lifetime psychosis (OR 3.42; 95% CI 1.00, 11.70).

LIMITATIONS

The cross-sectional design and retrospective measurement of childhood adversity are limitations of the study.

CONCLUSIONS

Childhood adversity was common amongst these TRD patients and was associated with poor clinical course, psychosis and suicide attempts. Routine assessment of early adversity may help identify at risk individuals and inform clinical intervention.

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.

Assessment of the hypothalamic-pituitary-adrenal axis activity: glucocorticoid receptor and mineralocorticoid receptor function in depression with early life stress - a systematic review

OBJECTIVE

The mechanisms involved in the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, especially in the functioning of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) in depressed patients, are not well elucidated. The objective of this study was to conduct a systematic review of articles that assess the HPA axis activity from GR and MR in depressed patients and healthy controls with or without early life stress.

METHODS

We conducted a systematic review of articles in PubMed, SCOPUS and SciELO published between 2000 and 2011, using the following search terms: child abuse, depression, HPA axis, dexamethasone, prednisolone, fludrocortisone and spironolactone. Thirty-four papers were selected for this review.

RESULTS

Most studies identified in this review used the dexamethasone/corticotropin-releasing hormone test and dexamethasone suppression test. In these studies, hypercortisolaemia was associated with depression. We identified three studies with the Prednisolone suppression test, only one study with the use of fludrocortisone and one with spironolactone. This review found nine studies that evaluated the HPA axis in individuals with early life stress.

CONCLUSIONS

The majority of the studies assessed in this review show that early life stress leads to permanent changes in the HPA axis and may lead to development of depression in adults. The most consistent findings in the literature show increased activity of the HPA axis in depression associated with hypercortisolaemia and reduced inhibitory feedback. These findings suggest that this dysregulation of the HPA axis is partially attributable to an imbalance between GR and MR. Evidences have consistently showed that GR function is impaired in major depression, but few studies have assessed the activity of MR in depression and early life stress.

The relationship between childhood trauma history and the psychotic subtype of major depression

OBJECTIVE

Increasing evidence exists linking childhood trauma and primary psychotic disorders, but there is little research on patients with primary affective disorders with psychotic features.

METHOD

The sample consisted of adult out-patients diagnosed with major depressive disorder (MDD) at clinic intake using a structured clinical interview. Patients with MDD with (n = 32) vs. without psychotic features (n = 591) were compared as to their rates of different types of childhood trauma.

RESULTS

Psychotic MDD patients were significantly more likely to report histories of physical (OR = 2.81) or sexual abuse (OR = 2.75) compared with non-psychotic MDD patients. These relationships remained after controlling for baseline differences. Within the subsample with comorbid post-traumatic stress disorder, patients with psychotic MDD were significantly more likely to report childhood physical abuse (OR = 3.20).

CONCLUSION

Results support and extend previous research by demonstrating that the relationship between childhood trauma and psychosis is found across diagnostic groups.