Extinction of Fear Memories With Glucocorticoids in Veterans With PTSD

The purpose of this study is to examine the effects of glucocorticoid administration following traumatic memory reactivation on psychiatric symptoms in veterans with combat-related PTSD, in addition to examining the effects of glucocorticoid administration following traumatic memory reactivation on physiological responses to veteran's personal combat memories. The following hypotheses will be tested: 1. Subjects who receive an exogenous glucocorticoid after traumatic memory reactivation will demonstrate fewer PTSD and depression symptoms one week later, compared to those who receive a placebo after traumatic memory reactivation. 2. The glucocorticoid reduction effects will be cumulative; that is, reduction will persist, and further post-reactivation glucocorticoid administration will further reduce symptoms 3. Decreases in PTSD and depression symptoms will persist at 1, 3, and 6 months for subjects receiving an exogenous glucocorticoid compared to those subjects receiving placebo 4. Subjects who receive an exogenous glucocorticoid after traumatic memory reactivation will demonstrate decreased physiological responses one week later, compared to those who receive a placebo after traumatic memory reactivation. 5. As with the psychological measures, suppression of the physiological measures will demonstrate both persistence over time and accumulation with subsequent post-reactivation glucocorticoid administration.