Depressive symptoms worsen before combined vision and hearing impairment is first observed: a longitudinal trajectory study using CHARLS

Combined vision and hearing impairment, referred to as dual sensory impairment (DSI), has been associated with depressive symptoms, but it remains unclear whether depressive symptoms worsen mainly after DSI is first observed or whether worsening is already evident beforehand. We used data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2020. A total of 5,210 middle-aged and older adults who were free of DSI and significant depressive symptoms at baseline were included. Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10). Piecewise linear mixed-effects models were used to examine depressive symptom trajectories before and after DSI was first observed. Multiple imputation was used for missing baseline covariates. Models were adjusted for sociodemographic factors, health behaviors, chronic conditions, and body mass index. During follow-up, 3,371 participants were first observed with DSI, whereas 1,839 remained free of DSI. In fully adjusted models, participants who were first observed with DSI during follow-up had higher baseline CESD-10 scores (β = 0.777, 95% confidence interval [CI]: 0.526 to 1.028) and showed a faster increase in depressive symptoms before DSI was first observed than those who remained free of DSI (β = 0.166, 95% CI: 0.077 to 0.255). After DSI was first observed, this group continued to show a more unfavorable depressive symptom trajectory (β = 0.149, 95% CI: 0.090 to 0.209). However, the slope difference did not further increase thereafter (β = -0.017, 95% CI: -0.148 to 0.115). Participants who were first observed with DSI during follow-up showed faster worsening of depressive symptoms before DSI was first observed, rather than only afterward. These findings suggest that the association between DSI and depressive symptoms may partly reflect shared aging-related risk processes that begin earlier. Not applicable.