Alterations in cortisol negative feedback inhibition as examined using the ACTH response to cortisol administration in PTSD

SummaryObjectiveStudies using the dexamethasone suppression test (DST) have demonstrated an enhanced negative feedback inhibition at the pituitary in PTSD, but have not provided information about central feedback effects, since dexamethasone (DEX) does not penetrate the brain well. The authors therefore examined the change in ACTH and cortisol before and after cortisol administration, which acts at central feedback sites in addition to peripheral targets.MethodBlood was obtained from 31 male veterans (18 with PTSD) before, and 8, 40 and 95 min following injection of 17.5 mg cortisol and placebo.ResultsA greater decline in ACTH was observed after cortisol injection in PTSD.ConclusionsCentral as well as peripheral negative feedback inhibition may be altered in PTSD.