Self-reported vision impairment and depressive symptoms among older adults: a longitudinal mediation analysis

Though vision impairment (VI) is a strong predictor for late-life depression, the underlying mechanisms remain unclear, particularly in low-income and middle-income countries. This study aims to investigate the contribution of underlying pathways in mediating the association between self-reported VI and depression among Chinese older adults. We included three waves of data from the China Health and Retirement Longitudinal Study. Our analytical cohort consists of 7528 participants aged 45 years or older with an average follow-up of 5 years. Mediation analyses using the inverse odds ratio weighting approach were conducted to explore the mediating effects of social engagement, limitations in physical activity, and healthcare access. Participants with self-reported VI had 31% higher odds (95% CI of adjusted OR: 1.12, 1.54) of depression than those with normal vision. In the mediation analysis, the mediation effects of social engagement and physical activity were 6.3% and 21.3%, respectively, while the mediation effect via healthcare access did not differ significantly from 0. The cumulative total indirect effects stemming from these three mediating pathways were estimated at β=0.09 (95% CI: 0.04, 0.15), accounting for 26.2% of the total effect. Our findings suggest that the association of self-reported VI with depressive symptoms was partially mediated by social engagement and physical activity limitations. Therefore, promoting social engagement and rehabilitation services in activities of daily living (ADL) and instrumental ADL are potential interventions to improve mental health status among visually impaired older adults.