Cognitive ability and depressive symptoms in later life: the indirect association through social participation and the moderating role of hukou

Depression is a common and disabling condition among older adults, yet the behavioral and institutional conditions that accompany the association between cognitive ability and later-life depressive symptoms are not well understood. This study examined whether cognitive ability was associated with depressive symptoms, whether that association was accompanied by an indirect association through social participation, and whether the cognitive-participation association and the corresponding indirect association differed by household registration (hukou). Data came from five waves (2011–2020) of the China Health and Retirement Longitudinal Study (CHARLS), yielding 65,348 person-wave observations from 22,060 unique adults aged 45 and older. Models were estimated with pooled ordinary least squares, using individual-clustered robust standard errors and wave and province fixed effects; indirect and conditional indirect associations were obtained from a 5,000-replication individual cluster bootstrap. Cognitive ability was negatively associated with depressive symptoms (β = -0.282, p < 0.001). Social participation was positively associated with cognitive ability (a = 0.035, p < 0.001) and negatively associated with depressive symptoms (b = -0.166, p < 0.001), yielding a significant negative indirect association (β = -0.006, 95% bootstrap CI -0.0072 to -0.0043), while the direct association remained significant (c′ = -0.276, p < 0.001). The cognition by hukou interaction on social participation was positive and significant (β = 0.037, p < 0.001). The cognitive-participation association was significant for both groups and about 2.7 times stronger among urban than non-urban registrants, with the conditional indirect association correspondingly larger for the urban group. The index of moderated mediation was negative and significant (β = -0.006, 95% bootstrap CI -0.0082 to -0.0045). Cognitive ability is associated with fewer depressive symptoms among middle-aged and older Chinese adults, accompanied by a small indirect association through social participation that is more pronounced for urban hukou holders. Because the variables are measured concurrently, the findings reflect statistical associations rather than causal effects, and they suggest that the institutional environment may shape how cognitive resources are expressed.