Factors associated with persistent posttraumatic stress disorder among US military service members and veterans

Background: Posttraumatic stress disorder (PTSD) can have long-term and far-reaching impacts on health and social and occupational functioning. This study examined factors associated with persistent PTSD among U.S. service members and veterans. Methods: Using baseline and follow-up (2001-2013) questionnaire data collected approximately every 3 years from the Millennium Cohort Study, multivariable logistic regression was conducted to determine factors associated with persistent PTSD. Participants included those who screened positive for PTSD using the PTSD Checklist-Civilian Version at baseline (N = 2409). Participants were classified as having remitted or persistent PTSD based on screening negative or positive, respectively, at follow-up. Results: Almost half of participants (N = 1132; 47%) met criteria for persistent PTSD at the first follow-up; of those, 804 (71%) also screened positive for PTSD at the second follow-up. Multiple factors were independently associated with persistent PTSD in an adjusted model at the first follow-up, including older age, deployment with high combat exposure, enlisted rank, initial PTSD severity, depression, history of physical assault, disabling injury/illness, and somatic symptoms. Among those with persistent PTSD at the first follow-up, additional factors of less sleep, separation from the military, and lack of social support were associated with persistent PTSD at the second follow-up. Conclusions: Combat experiences and PTSD severity were the most salient risk factors for persistent PTSD. Comorbid conditions, including injury/ illness, somatic symptoms, and sleep problems, also played a significant role and should be addressed during treatment. The high percentage of participants with persistent PTSD supports the need for more comprehensive and accessible treatment, especially after separation from the military.