Association between depression and multimorbidity in Chinese middle-aged and older adults: a prospective cohort study

BACKGROUND: The association between depression and multimorbidity and different multimorbidity patterns in Chinese middle-aged and older people remains unclear. METHODS: This prospective cohort study used the 2011-2020 China Health and Retirement Longitudinal Study (CHARLS), which included 7185 middle-aged and older adults aged 45 years and older as the study sample. Study analyses were conducted using the adjusted Cox proportional hazard model, restricted cubic spline (RCS), latent class analysis (LCA), subgroup analysis, and mediation analysis. RESULTS: Patients with depression at baseline exhibited a 47.5 % elevated risk of developing multimorbidity in comparison to the general population (HR:1.475, 95 % CI: (1.372, 1.585)). For each one-unit increase in the depression score, the risk of developing multimorbidity increases by 3.8 % (HR:1.038, 95 % CI: (1.032, 1.044)). There was an overall non-linear trend in the RCS curves (P < 0.001, P for nonlinear <0.001). Meanwhile, we found a significantly reduced risk of complex disease patterns (OR: 2.744, 95%CI: (1.990, 3.783)) and respiratory disease patterns (OR: 2.296, 95%CI: (1.508, 3.495)) in depressed participants compared to healthy participants. The mediation rate of activities of daily living (ADL) between depression and multimorbidity was 8.838 %. CONCLUSION: Chinese middle-aged and older adults with depression were more prone to multimorbidity than healthy person, and more likely to suffer from the respiratory disease pattern and the complex disease pattern. We should adopt diversified prevention and treatment measures tailored to different patterns of multimorbidity and varying degrees of chronic diseases, including weight management, physical exercise, and attention to functional health.