Different roles of social participation in socioeconomic disparities in depressive symptoms of Koreans across age groups

Aim: We investigated how socioeconomic status and positive social interactions and involvement as the key determinants of mental health outcomes are combined together to associate differentially with depressive symptoms across the life stages. Subjects and methods: We examined socioeconomic inequalities in depression and the extent to which different types of social participation can explain and reduce them from young to old-old age groups. We analyzed the data from the Korean Community Health Survey in 2017 using the negative binomial model. We additionally provided results from generalized linear models to compare indirect effects based on the product method and conditional indirect effects. We also visualized the moderating effects of socioeconomic status on the relationships between social participation and depression. Results: Socioeconomic gaps in depressive symptoms become larger in later life after 65 years of age. Activities for companionship, volunteering, and leisure and to a lesser degree daily interactions with friends partially account for higher levels of depression due to lower socioeconomic status. In contrast, social contact with family and neighbors has a suppression effect as it is rather negatively related to socioeconomic status. The overall mediation effects are strongest for the middle-aged and least for those in the old-old group. The same types of social relationships provide greater benefits for depression among socioeconomically disadvantaged groups, with the overall buffering effects strongest for the middle-aged and less for the young and young-old groups. Notably, more frequent contact with family and neighbors is associated with higher depression for the old-old in the lower strata of socioeconomic status. Conclusion: The main findings suggest appropriate interventions for depressive symptoms associated with lower socioeconomic status in different life-stage groups through reducing social disparities in formal and informal participation. Further research is needed to identify some other mechanisms and alleviating factors of increased socioeconomic inequalities in late-life depression.