Assessing Mental Illness Risk Among North Korean Refugees and Immigrants Resettled in South Korea

IMPORTANCE The global increase in the numbers of refugees and immigrants has made mental health a major public concern. Although they are divided, North and South Korea share a common ethnic heritage. OBJECTIVE To investigate mental illness risk among North Korean immigrants living in South Korea and compare it with that of the general South Korean population. DESIGN, SETTING, AND PARTICIPANTS This retrospective, population-based cohort study was based on National Health Insurance claims data from 2007 to 2019, and North Korean immigrants and refugees (NKIRs) and age-matched and sex-matched members of the general population (GP) were included with a 1:3 ratio. Data were analyzed from March 2022 to August 2022. EXPOSURE Emigration from North Korea to South Korea. MAIN OUTCOMES AND MEASURES Mental illness incidence and risk through a Cox proportional risk model adjusted for sex, age, disability, region, Charlson Comorbidity Index score, and insurance premium percentile. RESULTS A total of 37 209 NKIRs and 111 627 members of the GP were enrolled. The final analysis examined 112 851 individuals (73 238 [64.9%] female, median [IQR] age 34 [19-47] years), with 90 235 (80.0%) in the GP and 22 616 (20.0%) in the NKIR group. The propensity score-matching population numbered 24 532 in total, with 12 266 each in the NKIR and GP groups. NKIR patients had a higher mental illness risk than the GP (hazard ratio [HR], 2.12; 95% CI, 2.04-2.21). The multivariable adjusted HRs (95% CI) for developing mental disorderswere 4.91 (3.59-6.71) for posttraumatic stress disorder, 3.10 (2.90-3.30) for major depressive disorder, 2.27 (2.11-2.44) for anxiety and panic disorder, 2.03 (1.58-2.60) for bipolar affective disorder, 1.85 (1.53-2.24) for alcohol use disorder, and 1.89 (1.46-2.45) for schizophrenia. CONCLUSIONS AND RELEVANCE In this study, NKIR individuals showed a significantly higher risk of developing most mental disorders. Interventional strategies can prevent psychiatric morbidity and ensure adequate care for this population.