Background: No population-based studies have directly compared the long-term health and mental health outcomes of conflict- versus non-conflict-affected communities from the same ethnic background.

Aims: To identify and compare levels of psychiatric morbidity between a traumatized and non-traumatized civilian community; to investigate the long-term impact of mass violence.

Methods: Double-stratified community surveys in Siem Reap and Surin provinces were conducted by highly qualified Cambodian interviewers using culturally validated survey instruments with known psychometric properties. These included Cambodian versions of the Hopkins Symptom Checklist-25, the Harvard Trauma Questionnaire and the Medical Outcome Study Short Form.

Results: Siem Reap and Surin respondents experienced 12,266 and 621 major trauma events, respectively; 745 (76.2%) Siem Reap respondents and six (0.6%) Surin respondents reported torture events; 499 (49.5%) Siem Reap respondents and 203 (19.7%) Surin respondents met the clinical threshold for depression (OR 4.01, 95% CI 3.29–4.88); 204 (20.6%) Siem Reap respondents and 23 (2.2%) Surin respondents met the clinical threshold for post-traumatic stress disorder (PTSD) (OR 11.39, 95% CI 7.3–17.7). The MOS physical disability was higher in Siem Reap versus Surin respondents (74 (7.5%) vs 13 (1.3%), 2 = 47.4 df = 1, p < .001). Health status was poorest among Siem Reap respondents when compared with Surin respondents (mean score 1.59 vs 0.59, respectively; t = 19.85 df = 2018, p < .001). Path analysis reveals that recent and past extreme violence are associated with the health and mental health status of the Siem Reap community.

Conclusion: After 25 years, the Khmer civilian population that experienced the Pol Pot genocide continues to suffer psychiatric morbidity and poor health.