The mediating effect of severe social withdrawal on the association between adverse childhood experiences and depression in adulthood.

BACKGROUNDS

This study examined severe social withdrawal (SSW), also known as hikikomori syndrome-a phenomenon characterized by spending most of the time at home, avoiding social situations, and experiencing psychological distress due to prolonged social isolation. Recently, SSW has been observed in multiple countries and regions, including Japan, Korea, China, parts of Europe, and North America. Some studies have identified negative early-life experiences, such as ambivalent attachment to caregivers or peer rejection, as factors influencing the development of SSW and related internalizing symptoms, including severe depression and loneliness. This study addresses the growing recognition of SSW as an urgent global mental health concern requiring prevention and intervention. In particular, South Korea has seen a rise in socially withdrawn young adults, while also maintaining one of the highest rates of depression and suicide among advanced nations. In response, the Korean government launched an investigation to better understand the persistence of SSW and their psychological status. To inform the development of an effective mental health care system, data were collected from socially withdrawn individuals in the metropolitan area of Seoul. Based on these data, we analyzed young SSW populations residing in Seoul to examine the associations between SSW and mental health outcomes. Additionally, we examined how adverse childhood experiences (ACEs) affect these internalizing symptoms, focusing on the mediating role of SSW.

METHODS

We analyzed data from 486 participants aged 19 to 39 from the National Survey on Isolated and Reclusive Youth. The South Korean government conducted the data collection using a cross-sectional survey design. The main questionnaire consisted of 114 items across 14 categories, including mental health, ACEs, and SSW status.

RESULTS

Chi-square and regression analyses in this study revealed the significant effect of ACEs on SSW, indicating that these experiences exacerbate both SSW and depression. The results elucidated that SSW is one of the important mediators in the association between ACEs and internalizing behaviors. The results indicate that individuals with a history of ACEs are more likely to experience SSW, which may contribute to internalizing symptoms and additional mental health issues, such as loneliness and depression, among those with SSW.

CONCLUSIONS

The mediation effect of SSW between ACEs and depression demonstrated that SSW should be addressed as one of the critical factors making adverse mental health outcomes. Therefore, future research should emphasize the importance of developing reliable mental health care systems aimed at socially isolated adults. Researchers should develop the prevention and interventions to enhance the positive mental health outcomes for SSW populations.