The association between depressive trajectories and disability-free survival among middle-aged and older adults in China: a prospective cohort study.

Background: This study aims to examine the association of depressive trajectories with disability-free-survival (DFS).

Methods: This prospective cohort study used data from the China Health and Retirement Longitudinal Study, 2011-2015. Depressive symptoms were assessed using the Centre for Epidemiology Studies Depression Scale-10. Disability was assessed using activities of daily living (ADLs) and instrumental ADLs. Trajectories of depressive symptoms were identified and classified by latent mixture modelling. Logistic regression models were used to examine the association between depressive trajectories and DFS.

Results: A total of 8373 participants aged 45 years and older were included. We identified four distinct trajectories of depressive symptoms: 'no depressive symptoms', 'decreasing depressive symptoms', 'increasing depressive symptoms', and 'persistent depressive symptoms'. Compared to participants in the no depressive symptom trajectory, those in the decreasing depressive symptoms, increasing depressive symptoms and persistent depressive symptoms trajectories had an increased risk of disability or mortality, with multiple-adjusted hazard ratios (95% confidence intervals) of 1.75 (1.45-2.12), 2.05 (1.77-2.38) and 3.50 (2.77-4.42).

Conclusion: Our study shows that among middle-aged and older Chinese adults, individuals with a trajectory of depressive symptoms are at increased risk of disability or mortality. Our findings underscore the importance of early prevention, identification and intervention of depression in clinical care to promote healthy ageing.