Posttraumatic stress disorder and risk of selected autoimmune diseases among US military personnel

Background: Increasing evidence suggests a link between posttraumatic stress disorder (PTSD) and physical health. Stress disorders may lead to impairment of the immune system and subsequent autoimmune disease. This study investigated the association between PTSD and risk of selected autoimmune diseases (i.e. rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel diseases, and multiple sclerosis) among US active duty service members. Methods: Using data from the Millennium Cohort Study, incident autoimmune cases between study initiation and September 2015 were identified from medical encounter records in the Military Health System Data Repository (MDR). Participants were classified as having a history of PTSD if they self-reported receiving a health care provider's diagnosis of PTSD or if they screened positive using the PTSD Checklist-Civilian Version. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression models adjusted for demographics and history of another mental health condition. Results: Among 120,572 participants followed for a mean of 5.2 years, risk of any of the selected autoimmune diseases was 58% higher for those with a history of PTSD (HR = 1.58, 95% CI: 1.25, 2.01) compared with no history of PTSD. Further adjustment for BMI, smoking status, and alcohol use had little impact on the effect estimates, and results were not appreciably different according to combat experience and history of physical or sexual trauma. Conclusions: Active duty military personnel with PTSD may have an elevated risk of a range of autoimmune diseases, regardless of combat experience or prior trauma. Future research is needed to understand potential mechanisms which may inform future mitigative strategies in reducing extra-neuropsychiatric health problems among those with PTSD.