The Effects of Deployment Intensity on Post-Traumatic Stress Disorder: 2002-2006

Objectives: This study examines whether deployment location and the duration of deployment affects the likelihood of being screened positive for PTSD. Methods: Retrospective study of all sailors returning from an overseas deployment between 2002 and 2006 who have completed the Post-Deployment Health Assessment survey. The primary outcome is whether the sailor is screened positive for PTSD. Multivariate analysis is conducted using probit models. Results: Deployment to Iraq and Afghanistan increases the probability of screening positive for PTSD by 6.3 and 1.6 percentage points compared to those who were deployed on ships. This probability is increased by 2.2 percentage points for those deployed longer than 180 days. The negative effect of longer deployments is exacerbated if the deployment is to Iraq or Afghanistan. Conclusions: Our results highlight the importance of providing adequate mental health care resources for those returning from hostile deployments and raise concerns about combat effectiveness of long deployments.