Pre-deployment sleep duration predicts longitudinal posttraumatic stress disorder symptom trajectories in US Army...

War zone deployment increases risk for posttraumatic stress disorder (PTSD) symptoms, but symptom development and course varies across individuals. Thus, identifying modifiable pre-exposure risk and protective factors is critical to improving prevention. Pre-exposure sleep is a modifiable factor known to influence risk for PTSD development, but its relationship to the long-term course of PTSD symptoms remains unclear. In the present study, we examined pre-deployment sleep duration as a predictor of longitudinal PTSD symptom trajectories in 1059 US Army soldiers who deployed to Iraq and were followed prospectively from pre-deployment to > 5 years post-deployment. Participants self-reported sleep duration prior to deployment. PTSD symptom trajectories (asymptomatic, mild, post-deployment worsening, high chronic) were previously established using latent growth mixture modeling based on PTSD Checklist-Civilian Version summary scores obtained at pre-deployment and multiple post-deployment assessments. Multinomial logistic regression was used in the current study to examine associations of pre-deployment sleep duration with odds of membership in the four PTSD trajectory classes after adjusting for relevant covariates. Results indicated that participants with one additional hour of pre-deployment sleep were 1.27 times more likely to belong in the asymptomatic trajectory class than the post-deployment worsening trajectory class (OR=0.79, 95% CI: 0.63-0.98). Effects on high chronic (OR=0.87, 95% CI: 0.75-1.02) and mild (OR=0.91, 95% CI: 0.78-1.06) trajectory class membership were non-significant. Findings suggest an association between pre-deployment sleep duration and post-deployment development and worsening over time of PTSD symptoms, highlighting pre-deployment sleep as a potentially important factor to consider when assessing risk for post-deployment PTSD onset and worsening.