Relationship of temperament and character with cortisol reactivity to the combined dexamethasone/CRH test in depressed outpatients

Background: Evidence shows that depression is associated with hypothalamic-pituitary-adrenal (HPA) axis hyperactivation, although such findings are not entirely unequivocal. In contrast, various psychiatric conditions, including atypical depression, are associated with hypocortisolism. Another line of research has demonstrated that personality is associated with HPA axis alteration. It is thus hypothesized that different personality pathology in depression would be associated with distinct cortisol reactivity. Methods: Eighty-seven outpatients with DSM-IV major depressive disorder were recruited. Personality was assessed by the temperament and character inventory (TCI). HPA axis reactivity was measured by the combined dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test. According to our previous studies, two subgroups were considered based on their cortisol responses to the DEX/CRH test: incomplete-suppressors whose cortisol response was exaggerated and enhanced-suppressors whose cortisol response was blunted. Results: The analysis of covariance, controlling for age, gender and symptom severity, revealed that incomplete-suppressors scored significantly higher on cooperativeness than enhanced-suppressors (p=0.002). A multivariate stepwise logistic regression analysis predicting the cortisol suppression pattern from the seven TCI dimensions, controlling for age, gender and symptom severity, revealed that lower cooperativeness (p=0.001) and higher reward dependence (p=0.018) were significant predictors toward enhanced suppression. Limitations: The neuroendocrine challenge test was administered only once, based on a simple test protocol. Conclusions: Our findings suggest that (personality-related) subtypes of depression might be differentiated based on the different pattern of cortisol reactivity. Future studies are warranted to further characterize the HPA axis alteration in relation to various subtypes of depression.