Socioeconomic status and mental health-related conditions among Chinese older adults: A national longitudinal cohort study and pathway analysis

Background: Clinically significant depressive symptoms and self-reported mental health-related conditions are increasing among older adults in China. Although socioeconomic status (SES) is an important upstream determinant, nationally representative evidence on its longitudinal association with mental health-related outcomes and related behavioral pathways remains limited. Objective: To examine the longitudinal association between socioeconomic status and incident mental health-related outcomes among older Chinese adults, and to assess whether social participation and sleep duration partly explain this association. Methods: Using data from the China Health and Retirement Longitudinal Study (CHARLS, 2011–2018), this study included 5,465 adults without baseline depressive symptoms or self-reported mental health-related conditions. SES was derived from latent class analysis of household income, educational attainment, and employment status, rather than from employment status alone. Incident mental health-related outcomes were identified during follow-up using Center for Epidemiologic Studies Depression Scale-10 screening results and self-reported physician diagnosis. Cox proportional hazards models, subgroup analyses, and pathway analyses were conducted. Results: Compared with the high-SES class, low SES was associated with a higher risk of incident mental health-related outcomes in the fully adjusted model (hazard ratio: 1.40, 95% confidence interval: 1.15–1.69), with a stronger association among women, while residence- and body mass index-specific patterns were interpreted cautiously. Social activity accounted for 6.1% of the SES–outcome association, whereas sleep duration showed a small suppressor effect (−2.6%). Conclusion: These findings suggest that socioeconomic disadvantage is associated with elevated mental health-related risk in later life, partly through reduced social participation. The role of sleep requires further investigation using more detailed sleep measures.