Depressive disorder benefits of cities: Evidence from the China

Background: Rapid urbanization is a major trend in global population migration. There is growing debate about whether this urban-rural disparity exacerbate depression at the individual level. This study aims to investigate how urban living has a beneficial impact on individual mental health. Methods: Based on the data of 15,764 participants in the 2018 China Health and Retirement Longitudinal Study (CHARLS), we perform analysis of variance to identify the gap in depression levels between urban and rural areas. Extensive comparisons and detailed statistical analyses are carried out to demonstrate the differences in social participation between urban and rural residents. Finally, we conduct a series of mediation and moderation analyses to reveal the underlying mechanisms of depressive disorder benefits of cities. Results: The results indicate that those who lived in urban areas were less likely to suffer from depression (8 = -1.461, 95 % CI = [-1.691, -1.235], p < 0.001). Social engagement is found to mediate the relationship between residence type (8 = 0.164, 95 % CI = [0.136, 0.193], p < 0.001) and individual depression (8 = - 0.462, 95 % CI = [-0.587, -0.337], p < 0.001). City size plays a moderating role in the association between urban living and social engagement. Limitations: The mechanism is conducted through cross-sectional data. Self-reported depression status is accessed in this study, which could lead to measurement error. Conclusion: This study demonstrates the beneficial effects of urban living on individual depression, and reveals the mechanism by which urbanization at different scales affects the prevalence of depression.