Lower cortisol levels in depressed patients with comorbid post-traumatic stress disorder

Abstract

Post-traumatic stress disorder (PTSD) is often comorbid with major depressive episodes (MDEs) and both conditions carry a higher rate of suicidalbehavior. Hypothalamic-pituitary-adrenal(HPA) axis and serotonin abnormalities are associated with both conditions and suicidalbehavior, but their inter-relation is not known. We determined cortisolresponse to placebo or fenfluramine in MDE, MDE and PTSD (MDE+PTSD), and healthy volunteers (HVs) and examined the relation of cortisolresponses to suicidalbehavior. A totalof 58 medication-free patients with MDE (13 had MDE+PTSD) and 24 HVs were studied. They received placebo on the first day and fenfluramine on the second day. Cortisollevels were drawn before challenge and for 5 h thereafter. The MDE+PTSD group had the lowest plasma cortisol, the MDE group had the highest, and HVs had intermediate levels. There were no group differences in cortisol response to fenfluramine. Suicidalbehavior, sex, and childhood history of abuse were not predictors of baseline or postchallenge plasma cortisol. Cortisollevels increased with age. This study finds elevated cortisollevels in MDE and is the first report of lower cortisollevels in MDE+PTSD. The findings underscore the impact of comorbidity of PTSD with MDE and highlight the importance of considering comorbidity in psychobiology. © 2003 Nature Publishing Group.