Prior Assault and Posttraumatic Stress Disorder after Combat Deployment

Background: Factors that make people vulnerable to or resilient against posttraumatic stress disorder (PTSD) following overwhelming stress are not well understood. The objective of this study was to prospectively examine the relation between prior assault and newonset PTSD symptoms in a large US military cohort deployed in the wars in Iraq and Afghanistan. Methods: Data on exposures and health outcomes were collected in the Millennium Cohort study at enrollment (July 2001 to June 2003) and follow-up (June 2004 to February 2006) from over 55,000 participants. Of these, 5324 were deployed in Iraq and Afghanistan, reported combat exposures, and were free of PTSD at baseline (881 women and 4443 men). We used multivariate logistic regression analysis to model the odds of new-onset PTSD in relation to prior assault. Results: New-onset PTSD symptoms or diagnosis among deployers reporting combat exposures occurred in 22% of women who reported prior assault and 10% not reporting prior assault. Among men reporting prior assault, rates were 12% and 6%, respectively. Adjusting for baseline factors, the odds of new-onset PTSD symptoms was more than 2-fold higher in both women and men who reported assault prior to deployment. Conclusions: Prior assault appears to confer increased vulnerability for, rather than resilience against, PSTD symptoms among military professionals deployed to recent combat operations.