Longitudinal association between ADL disability and depression in middle-aged and elderly: national cohort study

BACKGROUND: The decline in daily living abilities (ADL) among older adults is a notable predictor of depressive symptoms and the occurrence of disease. However, the effects of changes in ADL disability on the progression of depression have not been extensively studied. OBJECTIVE: This research aims to examine the relationship between current ADL disability and depression in individuals aged 45 and older, as well as to explore how ADL disability influences the progression of depression in later life within China. METHODS: This study analyzed 7-year data from the China Health and Retirement Longitudinal Study (CHARLS), involving 2,205 middle-aged and older adults. The ADL disability (BADL: such as eating, dressing; IADL: such as shopping, cooking) were obtained using ADL scale (scores 0-12, lower is better), and depression was measured by the Center for Epidemiologic Studies Depression Scale (scores 0-30, lower is better). The latent growth curve and cross-lagged models were analyzed after adjusting relevant control variables to study the effect of ADL disability on the progression of depression. RESULTS: The mean values for depression, basic activities of daily living (BADL), and instrumental activities of daily living (IADL) varied from 9.44 to 11.08, 6.45 to 6.81, and 6.86 to 7.29, respectively. The analysis indicated a potential association between depression and ADL. Specifically, the trajectory of BADL was a significant predictor of both initial depression (β = 0.138, 95%CI = 0.039-0.237) and its trajectory (β = 0.579, 95%CI = 0.403-0.754). Although IADL did not significantly predict the trajectory of depression, it was a significant predictor of initial depression (β = 0.471, 95%CI = 0.404-0.538). Additionally, cross-lag regression analysis provided further support for the relationship between depression and BADL disability. CONCLUSIONS: This research highlights how ADL disability can forecast future depression in Chinese middle-aged and older adults. The findings indicate a significant connection between ADL disability and both changes in and future instances of depression in this group. Therefore, it is crucial for the Chinese government to prioritize interventions that enhance physical functioning in the elderly, as such measures can effectively mitigate the worsening of depression and promote positive aging.