Psychophysiologic identification of subthreshold PTSD in combat veterans

Posttraumatic stress disorder (PTSD) is linked with adverse health outcomes, and many military service members (SMs) are afflicted with it after they return from combat. Since many SMs have an initial honeymoon period characterized by limited symptoms before the onset of full-blown PTSD, the identification of independent predictors of PTSD upon return from deployment could facilitate early intervention. We measured psychophysiologic responses to stimuli including explosions in a Virtual Iraq/Afghanistan environment, as well as a fear potentiated startle paradigm, in a prospective cohort of SMs who did not meet criteria for PTSD and were within 2 months after return from deployment. We report marked psychophysiologic differences between those with (n=29) and without (n=30) subthreshold PTSD symptoms (PTSD Checklist score ≥28 vs. <28). We believe this is evidence that psychophysiologic measures can help to identify individuals at high risk for PTSD.