Association between living arrangements, social support, and depression among middle-aged and older adults: a mediation analysis from the CHARLS survey.

Introduction: Living alone was reported to be associated with a higher risk of depression. Social support may play a crucial role in mediating this association. However, data are limited. Methods: Data for wave 5 (2020) of the China Health and Retirement Longitudinal Study (CHARLS) were extracted. Associations between living arrangements and social support or depression were assessed by multivariable logistic regression models. Causal mediation analysis under a counterfactual framework was employed to evaluate the mediation effect of social support in the association between living arrangements and depression, which was performed by fitting two logistic regression models. The mediation effect is measured by the percentage mediated. Results: A total of 17,418 participants were included in this study, of which 208 (1.2%) lived alone. Compared to participants not living alone, those living alone were associated with a higher risk of low social support (10.6% vs. 3.9%; adjusted OR [aOR], 1.75; 95% CI, 1.10-2.80) and depression (15.4% vs. 7.2%; adjusted OR, 1.53; 95% CI, 1.02-2.28). Mediation analyses revealed that 2.7% (95% CI, -1.1% to 6.5%) of the relationship between living arrangements and depression was mediated by social support. Sensitivity analyses by varying definitions of living alone or limiting analysis in the elderly population yielded consistent results. Conclusions: Low social support did not mediate the association between living status and depression. Tailored strategies for improving living arrangements may needed to improve the mental health of living alone older adults.