An innovative prospective risk study--called the Texas Combat-Related PTSD Project--is now under way to determine the factors that may predispose service members to post-traumatic stress disorder (PTSD). While previous studies on combat PTSD-vulnerability have been mostly retrospective, researchers hope this study will help them understand how genetic, neurobiological and psychological/cognitive factors interact with a soldier's level of stress to predict the development of PTSD.

Led by principal investigator Michael Telch, PhD, a professor at the University of Texas at Austin, a team of psychologists and neuroscientists began recruiting soldiers from Army units at Fort Hood, Texas, last summer. Before deployment, participants with no history of prior combat experiences undergo MRI and fMRI scans, with particular attention paid to activity in the amygdala, medial prefrontal cortex and hippocampus, the brain areas tied to stress reactivity and emotional regulation.

Soldiers also complete a battery of tests and interviews to determine any pre-existing mental health conditions, their levels of cognitive functioning and their reactivity to stress, both mental and physical. Finally, the participants provide saliva samples for analyses of potential genetic markers of PTSD vulnerability.

While serving in Iraq, soldiers fill out a Web-based combat experiences log every 30 days, reporting on any stressful or traumatic experiences, such as moving in convoys, witnessing the injury or death of a U.S. or ally soldier or surviving a mortar attack. Once they're home, participants come back for a second round of MRI and fMRI scans and psychological assessments.

The researchers have already completed pre-deployment assessments on 96 soldiers who deployed last year and hope eventually to enroll 480 soldiers in the study.

Long-term, Telch hopes he and his team can help researchers find ways to "inoculate" vulnerable service members against developing PTSD.

"We hope the information from the study will provide important new insights as to the cause of combat-stress disorders, and potentially lead to the development of more effective early prevention," he says.

-C. Munsey