Large variations in prevalence rates of common mental disorder (CMD) amongst refugees and forcibly displaced populations have raised questions about the accuracy and value of epidemiological surveys in these cross-cultural settings. We examined the associations of sociodemographic indices, premigration traumatic events (TEs), postmigration living difficulties (PMLDs), and psychosocial disruptions based on the Adaptive Stress Index (ASI) in relation to CMD prevalence amongst the Rohingya, Chin and Kachin refugees originating from Myanmar and relocated to Malaysia.

Parallel epidemiological studies were conducted in areas where the three groups were concentrated in and around Malaysia (response rates: 80–83%).

TE exposure, PMLDs and ASI were significantly associated with CMD prevalence in each group but the Rohingya recorded the highest exposure to all three of these former indices relative to Chin and Kachin (TE: mean = 11.1 v. 8.2 v. 11; PMLD: mean = 13.5 v. 7.4 v. 8.7; ASI: mean = 128.9 v. 32.1 v. 35.5). Multiple logistic regression analyses based on the pooled sample (n = 2058) controlling for gender and age, found that ethnic group membership, premigration TEs (16 or more TEs: OR, 2.00; 95% CI, 1.39–2.88; p < 0.001), PMLDs (10–15 PMLDs: OR, 4.19; 95% CI, 3.17–5.54; 16 or more PMLDs: OR, 7.23; 95% CI, 5.24–9.98; p < 0.001) and ASI score (ASI score 100 or greater: OR, 2.19; 95% CI, 1.46–3.30; p < 0.001) contributed to CMD.

Factors specific to each ethnic group and differences in the quantum of exposure to TEs, PMLDs and psychosocial disruptions appeared to account in large part for differences in prevalence rates of CMDs observed across these three groups.