Posttraumatic stress disorder: etiology, epidemiology, and treatment outcome.

Posttraumatic stress disorder (PTSD) results from exposure to a traumatic event that poses actual or threatened death or injury and produces intense fear, helplessness, or horror. U.S. population surveys reveal lifetime PTSD prevalence rates of 7% to 8%. Potential reasons for varying prevalence rates across gender, cultures, and samples exposed to different traumas are discussed. Drawing upon a conditioning model of PTSD, we review risk factors for PTSD, including pre-existing individual-based factors, features of the traumatic event, and posttrauma social support. Characteristics of the trauma, particularly peritraumatic response and related cognitions, and posttrauma social support appear to confer the greatest risk for PTSD. Further work is needed to disentangle the interrelationships among these factors and elucidate the underlying mechanisms. Based upon existing treatment outcome studies, we recommend use of exposure therapies and anxiety management training as first-line treatment for PTSD. Among psychopharmacological treatments, selective serotonin reuptake inhibitors evidence the strongest treatment effects, yet these effects are modest compared with psychological treatments.