Abstract
BACKGROUND: Posttraumatic stress disorder (PTSD) is associated with abnormal functioning of the hypothalamic-pituitary-adrenal (HPA) axis; however, limited research has examined whether cortisol levels change following successful PTSD treatment. The current study examined the impact of successful PTSD treatment on the cortisol awakening response (CAR). METHOD: Twenty-nine adults participating in a treatment trial for chronic PTSD provided saliva samples (upon waking, and 30-, 45-, and 60 min postwaking) before and after receiving either prolonged exposure therapy or sertraline. PTSD responder status (i.e., loss or retention of a PTSD diagnosis) served as the predictor variable. Outcome measures included area under the curve with respect to ground and increase, reflecting total cortisol output and HPA axis reactivity, respectively. RESULTS: A series of hierarchical regressions revealed no significant main effects of PTSD responder status for either CAR outcome. However, a significant gender by treatment response interaction for cortisol reactivity revealed that female treatment nonresponders displayed higher cortisol reactivity following treatment than female responders, whereas cortisol reactivity did not change pre- to posttreatment for male responders. Findings remained after controlling for age, trauma history, baseline medication status, baseline PTSD, and baseline depressive symptoms. CONCLUSION: Loss of a PTSD diagnosis may contribute to decreased cortisol reactivity in females. Neuroendocrine changes following treatment may emerge only for specific subgroups, highlighting the importance of exploring treatment moderators.