natural disasters, interpersonal violence, and sexual abuse are commonplace, their individual contribution to PTSD severity and chronicity remains relatively unknown. The cumulative literature examining the prevalence and impact of trauma suggests that at least two thirds of American adults have experienced at least 1 traumatic event in the course of their lives. 1 Multiple traumas are commonplace as well. 1,2 Exposure to a traumatic event is a risk factor for a host of psychiatric disorders, including posttraumatic stress disorder (PTSD). It has been estimated that 13% to 17% of Vietnam theater veterans currently suffer from PTSD. 3 In contrast, approximately 1% of Gulf War veterans from Desert Storm have been diagnosed with PTSD. 4,5 In the only published report to date examining rates of PTSD in veterans from the Afghanistan and Iraq Wars, 6 rates of PTSD in these populations were estimated to be 11% in Afghanistan-era veterans and 15% to 17% in Iraq-era veterans. Unfortunately, more than one third of people with