Association between hikikomori (social withdrawal) and depression in Korean young adults

Background: Major depressive disorder (MDD) is a prevalent mental illness, particularly affecting women. The World Health Organization projects that by 2030, MDD will be the leading cause of disease burden. The phenomenon of hikikomori-initially observed in Japan-is increasingly associated with depression, a key risk factor for which is social isolation. This study analyzed the impact of social withdrawal on depression among South Korean young adults, focusing on (1) the relation between withdrawal duration and causes, and (2) its effect on depression severity. Methods: Data from the 2022 Korean Youth Survey, including 14,966 participants aged 19-34, were used. Depression levels were assessed using the Patient Health Questionnaire-9 (PHQ-9), and multiple logistic regression was conducted to examine the association between hikikomori behavior and depression. Results: The reference group for all analyses was youth who were not socially withdrawn. The association between hikikomori and depression was statistically significant for the two sexes (males: OR: 2.25, 95 % CI: 1.60-3.19; females: OR: 2.34, 95 % CI: 1.63-3.36). Household size influenced depression risk among hikikomori, and sex differences were observed in social withdrawal's effect on suicide risk. Conclusion: This study highlights the link between hikikomori and depression in South Korean youth, with sexspecific differences in depression and suicide risk, suggesting the need for tailored mental health programs. Future research should explore the long-term effects of prolonged social withdrawal through longitudinal studies and conduct cross-cultural comparisons of hikikomori.