INDEPENDENT PREDICTORS OF PTSD AND POST CONCUSSIVE SYNDROME IN OIF/OEF VETERANS

Traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) are linked to worsened physical and mental health, functional impairment, and greater healthcare utilization. TBI is a point of injury diagnosis, but Post Concussive Syndrome (PCS) is analogous to the more persistent PTSD. Current treatments are often ineffective, and many afflicted military service members (SMs) never return to duty. Upon return from deployment, many SMs experience an initial honeymoon period during which symptoms are limited in number and scope, but this is frequently followed by a sharp increase in symptoms within months. Identification of independent predictors of PTSD and PCS upon return from deployment could facilitate early intervention to prevent disability.The purpose of this study is to perform a comprehensive baseline assessment, to include demographics, neuropsychological assessment, genetic and neuroendocrine assays, brain imaging and synchronization, vestibular, olfactory, and psychophysiologic measures, of 128 National Capital Area SMs within 6 weeks post- deployment. Subsequent follow-up evaluations at 3, 6, and 12 months will primarily assess for interim development of PTSD or PCS. We will then conduct serial univariate and multivariate analyses to identify the baseline factors that are most strongly associated with the subsequent development of PTSD and PCS.This is a prospective cohort study of initially healthy combat veterans, recruited within 6 weeks after return from Iraq or Afghanistan, with serial evaluations to identify both those who develop PTSD or PCS, as well as factors obtained at the time of the initial evaluation that prove to be most strongly associated with subsequent PTSD and PCS.We anticipate the need to screen at least 260 SMs in order to establish a cohort of 128 who are eligible and agree to participate. Prior psychophysiologic measures indicate 102 SMs are needed to have 80% power to discern a relationship between heart rate response to startle and PTSD, so starting with 128 allows for 20% loss to follow up. After obtaining written informed consent from eligible SMs, the baseline assessment will include: a medical history and physical exam, blood samples for genetic and neuroendocrine measures, questionnaires, psychophysiologic measures at baseline and in response to stimuli, brain synchronization assessments, imaging studies, posturography, and olfactory, vestibular, and neuropsychological testing. Questionnaires, imaging, serum catecholamine assays, and baseline physiologic measures will be repeated at 3, 6, and 12 months. Univariate analysis will identify all baseline measures associated with the subsequent diagnosis of PTSD or PCS at p