Sex differences in hormonal responses to a social stressor in chronic major depression

Background: Acute depression has been associated with increased hypothalamic-pituitary-adrenal (HPA) reactivity. White chronicity of depressive illness influences symptoms, course and outcome, its effect on the HPA axis has not been extensively evaluated. The current study evaluated cortisol stress responses to a social challenge in chronic major depressive disorder (CMDD). Methods: Cortisol stress responses to the Trier Social Stress Test (TSST) were compared in 26 participants with CMDD and 28 healthy controls using repeated measures analysis of variance (RANOVA). In addition, group differences in area under the curve (AUC) and peak percentage change in cortisol were examined. Results: The RANOVA indicated a significant sex by condition interaction in cortisol. responses to the social challenge. Post-hoc testing of pair-wise group differences revealed that in females, CMDD subjects had greater cortisol levels in response to the TSST than did controls. Similarly, AUC was greater in females with CMDD than in female controls. Neither of these differences was significant in mates. However, mate CMDD subjects exhibited a significantly decreased peak percentage change in cortisol in response to the TSST than did mate controls. Conclusions: Mates and females with CMDD exhibited unique differences in cortisot responses to the social challenge relative to controls. In females, CMDD subjects had greater overall secretion of cortisot whereas in mates, CMDD subjects had a blunted peak response to the social stressor. Sex differences are an important consideration in future work in this population. (C) 2009 Elsevier Ltd. All rights reserved.