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.