At mission's end: the long-term impact of deployment on mental health

It is well known that military deployment can lead to mental health problems in veterans, but the long-term impact is still unclear. This thesis discusses the results of the PRISMO-study, a large cohort study in a group of Dutch Afghanistan veterans with a follow-up period of ten years. It shows that at ten years post-deployment, 8% of the cohort reported severe symptoms of posttraumatic stress disorder (PTSD). Agoraphobia, anxiety, depression, and hostility symptoms are also reported more frequently at ten years post-deployment compared to pre-deployment. Furthermore, this thesis demonstrates the large heterogeneity in PTSD symptom development among veterans. Of note is the delayed onset group that experienced increasing symptom levels between five and ten years post-deployment and did not show significant symptom reduction. The results from this thesis also show that various psychological factors, such as social support, and biological factors, such as DNA methylation, are associated with the development of PTSD or other mental health symptoms after deployment. Combining these factors in a prediction model for PTSD symptoms has not led to a useful screening instrument. It does, however, offer important leads for the identification of risk factors for PTSD and the development of intervention programs. Dutch Ministry of DefenceLUMC / Geneeskund