Socioeconomic status and depressive symptoms among older adults in China: The mediating role of cognitive function, lifestyle and social participation

INTRODUCTION: Socioeconomic status (SES) is a key risk factor for depression in older adults, while cognitive function, lifestyle and social participation also have an impact on depression. This study aimed to investigate the mediating role of cognitive function, lifestyle and social participation in the association between SES and depressive symptoms among older adults in China. METHODS: Data were derived from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) (2017-2018). A total of 7595 community-dwelling adults aged ≥65 years were included. Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10). SES was measured as a composite index incorporating education level, occupation, and self-rated economic status. Cognitive function was evaluated via the Mini Mental State Examination (MMSE). Lifestyle and social participation scores were constructed based on relevant questionnaire items. Mediation analysis was performed to explore the indirect effects of cognitive function, lifestyle, and social participation on the association between SES and depressive symptoms. RESULTS: The prevalence rate of depressive symptoms (CES-D-10 score ≥10) was 41.1%. After adjusting for sociodemographic and health-related covariates, SES was negatively associated with depressive symptoms (β = -0.887, P < 0.001). SES had a significant mediating effect on depression in older adults respectively, through cognitive function (relative mediating effect = 8.0%, β = -0.071, 95%CI: -0.095 ~ -0.048), lifestyle (19.9%, β = -0.177, 95%CI: -0.213 ~ -0.140) and social participation (7.6%, β = -0.068, 95%CI: -0.095 ~ -0.042). Additionally, sequential mediating effects were observed for "cognitive function → lifestyle" (1.0%, β = -0.009, 95%CI: -0.012 ~ -0.006), "cognitive function → social participation" (1.0%, β = -0.009, 95%CI: -0.014 ~ -0.006), "lifestyle → social participation" (1.4%, β = -0.012, 95%CI: -0.018 ~ -0.007), and "cognitive function → lifestyle → social participation" (0.1%, β = -0.001, 95%CI: -0.001 ~ -0.001). CONCLUSION: SES influences depressive symptoms in Chinese older adults through both direct and indirect pathways. The findings highlight the need for multifaceted interventions targeting cognitive function enhancement, healthy lifestyle promotion, and social participation facilitation, particularly among socioeconomically disadvantaged older populations, to mitigate depressive symptoms and promote healthy aging.