379. INCIDENCE OF PSYCHOSIS AND ITS RISK FACTORS AND MORTALITY IN NORTH KOREAN DEFECTORS COMPARED TO SOUTH KOREAN CONTROLS

Abstract Background Since 1998, over 33,000 North Korean defectors (NKDs) have entered South Korea, many of whom often suffer from severe trauma experienced not only in North Korea but also during their defection. These experiences, along with sociocultural barriers such as perceived discrimination and financial instability, have been linked to poor mental health outcomes. Given that immigration and low socioeconomic status are closely associated with the development of psychosis or schizophrenia (SZ), we hypothesized that the incidence of psychosis or SZ would be higher in NKDs. Aims & Objectives This study aimed to examine the incidence, somatic comorbidities, and mortality of psychosis and schizophrenia (SZ) among NKDs using Korean national health insurance data. The results were compared to the outcomes of corresponding South Koreans (SKs) controls to identify health disparities. Method We conducted a retrospective cohort study using Korean health insurance data from 2002 to 2022, comparing NKDs with matched SK controls by age, birth year, and sex. Person-year incidence and annual incidence of psychosis or SZ and standardized mortality ratio in NKDs were obtained. Cox regression was performed to examine risk factors associated with psychosis or SZ. Results The incidence rate (IR) of psychosis was approximately four times higher among NKDs [3.22 (95% CI: 3.05–3.43) per 1,000 person-years] compared to SKs [0.81 (95% CI: 0.80–0.82) per 1,000 person-years]. However, after adjusting for sociodemographic factors such as gender, age, and health insurance quintile, and health-related factors like the Charlson Comorbidity Index, the IR ratio showed no significant difference between NKDs and SKs (0.99; 95% CI: 0.93–1.06). Regarding SZ outcomes, female NKDs exhibited a higher IR ratio (1.21; 95% CI: 1.01–1.46) than male NKDs, whereas no significant difference was observed between females and males in the SK population. Discussion & Conclusions The findings reveal that NKD exhibited a significantly higher unadjusted incidence rate of psychosis compared to SK. However, this difference diminished after adjusting for sociodemographic and health-related factors, indicating the critical role of these variables in determining psychosis development. The greater risk of SZ observed among female NKDs suggests they may respond more adversely to trauma events during their defection or psychosocial adversity. Therefore, future treatment efforts should prioritize addressing the unique vulnerabilities faced by this population.