Relationship Between Socioeconomic Status and Depression in Older Adults: The Roles of Cognitive Function and Sleep Quality

BACKGROUND: Socioeconomic status (SES) is an important social factor associated with a wide range of health outcomes, but this relationship could be influenced by individual's intrinsic factors. The aim of this study was to examine the relationship between SES and depressive symptoms, the mediating role of cognitive function, and the moderating role of sleep quality in community-dwelling older adults. METHODS: A total of 1000 community-dwelling older adults were recruited for the cross-sectional study. Socioeconomic factors, cognitive function, sleep quality, and related covariates were investigated or assessed. Mediating and moderating effects were analyzed using R 4.2.2 and SPSS 25.0 software. RESULTS: The results showed that SES was negatively associated with depressive symptoms (β=-0.234, p<0.001) and positively associated with cognitive function (β=0.566, p<0.001) after controlling for covariates; cognitive function played a partial mediating role between SES and depressive symptoms, and the indirect effect was β=-0.09 (95% CI: -0.129~ -0.06, p<0.001), accounting for 38.5% of the total effect; and sleep quality positively moderated the mediating effect of cognitive function on relationship between SES and depressive symptoms (βsleep ×cognition =-0.015, p<0.05). CONCLUSION: Depressive symptoms in community-dwelling older adults are affected by their SES and cognitive function. Improving individual cognitive ability and sleep quality can effectively reduce depression in community-dwelling older adults with low SES.