Association between depression and stroke in a socially isolated population: Mediating role of unhealthy lifestyle behaviors

BACKGROUND: Although depression was considered as a preventable determinant for stroke, its pathway within the specific vulnerable population remains to be clarified. This study aims to examine the relationship between depression and stroke among socially isolated individuals and to clarify the mediation effect of unhealthy lifestyle behaviors in this association. METHODS: This cross-sectional study utilized data from two nationally representative aging cohorts: the English Longitudinal Study of Ageing (ELSA; n = 4,454) and the China Health and Retirement Longitudinal Study (CHARLS; n = 8,615) (age ≥ 50). Social isolation was identified based on limited participation in social activities. Depression was evaluated following the Center for Epidemiologic Studies Depression Scale. Logistic regression analyses were employed to assess the association between depression and stroke. Mediation analysis was performed to quantify the indirect pathways through unhealthy behaviors (smoking/alcohol consumption). RESULTS: After adjusting for covariates, depression was significantly linked to an increased risk of stroke among socially isolated individuals, with OR (95% CI) of 1.98(1.39-2.82) (ELSA) and 1.94(1.64-2.28) (CHARLS). Mediation analysis indicated that alcohol consumption mediated 14.10% of the association in the ELSA, while smoking served as a significant partial mediator in the CHARLS. CONCLUSION: Depression is independently associated with an increased risk of stroke among socially isolated individuals, and this association is partially explained by behavioral pathways. Our findings indicate the necessity of integrating psychosocial interventions with unhealthy behavioral management to inform the primary prevention strategies of stroke.