Soldiers returning from deployment receive psychological screenings to try to determine whether various mental syndromes, such as depression, anxiety or post-traumatic stress disorder (PTSD) may require treatment. Even with the screenings, however, many soldiers do not disclose their problems in order to protect their advancement in their military careers. A new study provides an additional way for military personnel to be screened for PTSD as they return from a deployment. Researchers at the University of Rochester Medical Center have discovered that a slight brain injury could increase the risk that a soldier will develop PTSD. In fact, the injury could be so slight that even an imaging test that is ultra-sensitive may barely be able to detect it. The findings are significant because they may help doctors identify specific problems experienced by military personnel and decipher which individuals may be more at risk for PTSD. They may also help in treating the symptoms of mild traumatic brain injury (TBI) and PTSD that often overlap. In the past, doctors have had a challenge in deciphering the difference between PTSD and TBI. The researchers believe that their study is one of the first to show a link that can be verified using imaging. Led by Jeffrey J. Bazarian, M.D., M.P.H. an associate professor of emergency medicine at the University of Rochester, the study adds more information to the understanding of PTSD. Previously, PTSD had been believed to be caused by chronic stress experienced in ongoing, intense combat. This study's findings show that a quick, physical force may also play a role in the development of PTSD. Based on the estimate that approximately 320,000 troops experienced concussions in Afghanistan and Iraq before 2008, the information gained by the study provides important information about how PTSD can stem from a brain injury. The researchers examined 52 veterans of war who returned from combat zones where they were stationed between 2001 and 2008. About four years following the return from a tour of duty, the veterans were interviewed about their PTSD symptoms, including questions about blast exposures as well as concussions and other combat situations. The participants were given the Walter Reed Institute of Research Combat Experiences Survey to estimate their level of stress from their experiences, along with MRIs and an exam called diffusion tensor imaging (DTI) that is more sensitive. Among one of DTIs uses has been analyzing axonal injury, which is related to receiving a concussion. PTSD was shown to be associated with even minor brain injuries, suggesting that physical force may be a significant factor involved with the development of PTSD. The results are published in an online version of the Journal of Head Trauma Rehabilitation.