Sensory impairment and risk of incident depression in older adults: a harmonized longitudinal analysis of 72,177 individuals across six international cohorts

Background: Evidence linking sensory impairment to depression is predominantly Western. We quantified longitudinal associations of single and dual sensory impairment (DSI) with incident depression using harmonized data from six countries. Methods: We analyzed 72,177 older adults (aged ≥50) from HRS (USA), ELSA (UK), SHARE (Europe), CHARLS (China), KLOSA (South Korea), and MHAS (Mexico). Participants free of depression at baseline (2010-2015) were followed for 2-10 years. Sensory status was categorized as no impairment, vision impairment only (VI), hearing impairment only (HI), and DSI. We used multivariable Cox models and individual participant data (IPD) meta-analysis to estimate pooled hazard ratios (HRs). Findings: Sensory impairment was consistently associated with an increased depression risk. DSI conferred the highest risk (pooled HR 1.39, 95% CI 1.32-1.46), followed by HI (HR 1.21, 1.16-1.27) and VI (HR 1.15, 1.11-1.20). Associations were stronger in Western cohorts (DSI HRs ≥1.84 in UK/USA) than in Asian and Latin American populations. Subgroup analyses showed higher DSI-associated risk among individuals with college education (HR 1.68) compared to those with lower education (HR 1.35). Interpretation: Sensory impairment, particularly DSI, is robustly associated with incident depression globally, though effects vary by geopolitical and socioeconomic context. Integrated sensory and mental health screening is critical for preventing late-life depression.