Dual Sensory Impairment and Depressive Symptoms: Association and Pathways in Three Cohorts and a Meta-Analysis.

BACKGROUND: The overall impact of dual sensory impairment (DSI) on depressive symptoms and its underlying mechanisms remains unclear, particularly across different culture contexts. This study aimed to examine the association between DSI and depressive symptoms in three distinct populations while exploring the mediating roles of social engagement and cognitive function.

METHODS: Participants were recruited from three aging cohorts: the China Health and Retirement Longitudinal Study (CHARLS), the Health and Retirement Study (HRS), and the English Longitudinal Study of Ageing (ELSA). Harmonized survey wave data (2011/2012, 2015/2016, and 2018) were analyzed. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D), and DSI was defined based on self-reported hearing and vision impairments. To address potential confounding, logistic regression models were adjusted for demographic, lifestyle, and health factors. Mediation analyses were conducted using the PROCESS Macro (model 4) to examine the roles of social engagement and cognitive function. Furthermore, a meta-analysis was performed by integrating the results of the present study with those from previous cohort studies.

RESULTS: The study included 19,310 participants from the three cohorts. Separate analyses showed that DSI was significantly associated with higher odds of depressive symptoms across these cohorts (odds ratio [OR] = 1.24, 95% confidence interval [CI] = 1.15-1.33 in CHARLS; OR = 2.04, 95% CI = 1.78-2.31 in HRS; OR = 2.40, 95% CI = 1.79-3.00 in ELSA). A meta-analysis confirmed this association (OR = 1.73 and HR = 1.30). This relationship was partially mediated by reduced social engagement (2.31%-6.35%) and cognitive decline (5.72%-14.00%).

CONCLUSIONS: DSI is consistently associated with depressive symptoms in middle-aged and older adults across China, the United States, and England. Both reduced social engagement and cognitive decline significantly mediated this association, with comparable effect sizes. The mediation effects are largely robust, with instability observed only in one sensitivity analysis.