The association between functional disability and depressive symptoms among older adults: Findings from the China Health and Retirement Longitudinal Study (CHARLS)

Background: Previous research has shown that depressive symptoms in older adults was associated with functional disability, including basic activities of daily living (BADLs) and instrumental activities of daily living (IADLs). However, little is known about the impact of different patterns of functional disability and new-onset functional disability on subsequent depressive symptoms. Objective: To determine the effect of various patterns of functional disability and new-onset functional disability on depressive symptoms among Chinese older adults aged 60 years and above. Method: The study included 3242 older adults from the China Health and Retirement Longitudinal Study (CHARLS), which was conducted from 2011 to 2018. Cox proportional hazards models were used to investigate the associations between patterns of functional disability and depressive symptoms. The associations were also examined in the population with new-onset functional disability. Result: During 15,321 person-years of follow-up, 946 depressive symptoms occurred. The hazard ratios (HRs) of depressive symptoms were 1.29 (95 % confidence intervals [CI]: 1.05-1.58) for IADLs disability, 1.22 (95 % CI: 0.75-1.55) for BADLs disability, and 1.78 (95 % CI: 1.41-2.22) for both IADLs and BADLs disabilities. In the analysis of new-onset functional disability, the HRs were 1.50 (95 % CI: 1.06-2.13) for onset IADLs disability, 1.28 (95 % CI: 0.85-1.91) for onset BADLs disability, and 1.69 (95 % CI: 1.03-2.76) for both onset BADLs and IADLs disabilities. Limitations: Depressive symptoms were assessed using the Centre for Epidemiological Studies Depression Scale, which has limitations in diagnosing clinical depression. Conclusion: Functional disability increases the risk of depressive symptoms, particularly impaired IADLs function. Psychological care for older adults with functional disability should be strengthened.