Longitudinal Relationship Between Activities of Daily Living and Depression in Older Adults Based on Parallel Process Latent Growth Curve Model with Mediation.

Objective: The parallel process latent growth curve model (PP-LGCM) was used to examine the longitudinal relationship between activities of daily living (ADL) and depression and further tested whether chronic diseases (CDs) were associated with depression via mediating variable ADL. Methods: A sample of 2014 Chinese older adults aged 60 and over from the China Health and Retirement Longitudinal Survey (CHARLS) was used. The activities of daily living scale, self-rating depression scale, and chronic diseases scale were used to investigate the ADL, depression, and CD levels of older adults. Following certain statistical analysis steps, we used SPSS 26 and Mplus 8.0 to perform statistical analysis on the data. Results: Firstly, ADL significantly declined in older adults from 2011 to 2018, while depression had a significant rise. Secondly, the intercept of ADL was correlated with the intercept of depression (r = 0.487, p < 0.001), and the slope of ADL was positively correlated with the slope of depression (r = 0.844, p < 0.001). Finally, the intercept of ADL mediated 39% of the association of chronic diseases and the intercept of depression. Conclusions: Our findings showed the trajectories of ADL and depression in older adults and demonstrated that ADL have various associations with depression in longitudinal development. In addition, the effect of chronic diseases on depression is partially mediated by ADL. The ADL play a partial mediating role between chronic diseases and depression in older adults, with an indirect effect of 39%, indicating that ADL are very important. Grasping the mediating mechanism of ADL will help alleviate depression levels in older adults with chronic diseases.