Psychotrauma in civilians Towards accurate screening for PTSD risk

The findings in this thesis underscore the potential long-term impact of psychotrauma in civilians. We found that almost 5% of individuals met the diagnostic criteria for PTSD related to the traumatic event of 12-15 years ago. Long-term PTSD symptoms were associated with adverse psychological, functional and economic outcomes; adverse one-year PTSD trajectories; more exposure to additional potentially traumatic events and recent life stressors; and early post-trauma predictors (younger age, greater perceived impact of prior potentially traumatic events, higher heart rate). This high consistency between 1 year and long-term PTSD outcomes suggests that early identification of PTSD risk at 1 year post-trauma and preventive interventions towards those at high risk may also hold more long-term beneficial effects for PTSD outcome. Within this thesis we also developed machine learning models to extract a short screening instrument from a broad range of risk and protective factors. We performed external validation to ensure the generalizability of the screening instrument to a broader population of recently trauma-exposed civilians. This resulted in an accurate screening instrument for PTSD risk 1 year post-trauma based on 22 self-report questions that is applicable to a broad range of recently trauma-exposed civilians. Taken together, in this thesis we provided insights into the long-term impact of psychotrauma in civilians, and are taking a step towards accurate screening for PTSD risk.