Studies have shown that mental health risks related to military deployment depend on specific risk factors. Especially stressful experiences (SE) and lack of social support (SS) have been associated with deployment-related increases in mental disorders. Less is known about difficulties in emotion regulation (DER) in this context despite their well-known importance for the development and maintenance of mental disorders. To date, the number of prospective studies investigating the role of these potential risk factors for deployment-related psychopathology is limited.

To investigate risk factors for deployment-related increases in symptoms of common mental disorders.

To investigate associations between SE, SS and DER, and deployment-related increases in PTSD, major depression (MD) and alcohol use disorder (AUD) symptoms.

358 male soldiers were assessed before and 12 months following deployment using standardized diagnostic interviews (CIDI) and embedded questionnaires. Outcome measures were the number of PTSD, MD and AUD symptoms reported for the preceding 12 months at follow-up. Analyses were adjusted for baseline symptoms.

SE (incidence risk ratio (IRR)):1.06, p>0.001), SS (IRR:0.98, p=0.034) and DER (IRR:1.04, p=0.009) independently predicted increases in PTSD symptoms. SE (IRR:1.04, p=0.004) and SS (IRR:0.98, p=0.022) also predicted increases in MD symptoms. Increase in AUD symptoms was not predicted by SE, SS or DER, but by increase in PTSD symptoms (IRR:1.02, p=0.029).

Findings support the role of SE, SS and DER as risk factors for deployment-related disorders, particularly for PTSD symptoms. This knowledge might help to identify high-risk individuals and to develop targeted interventions.