Arthritis and longitudinal trajectories of depressive symptoms and cognition in middle-aged and older adults: a prospective tri-cohort study.

BACKGROUND: The long-term effects of arthritis on psychological well-being and cognitive trajectories across diverse cultural contexts remain inadequately characterized. This study systematically examines the associations between baseline arthritis and the subsequent risk of developing depressive symptoms and cognitive impairment, as well as the longitudinal evolution of these outcomes over time. METHODS: We utilized harmonized longitudinal data from three large prospective cohort studies: the China Health and Retirement Longitudinal Study (CHARLS), the English Longitudinal Study of Ageing (ELSA), and the Health and Retirement Study (HRS). Cox proportional hazards models were applied to estimate hazard ratios (HRs) for incident depressive symptoms and cognitive impairment. Longitudinal changes in depressive symptoms (measured by CES-D scores) and global cognitive function were assessed using linear mixed-effects models. RESULTS: Across all three cohorts, arthritis was consistently associated with a significantly elevated risk of incident depressive symptoms, with fully adjusted HRs ranging from approximately 1.2 to 1.6. Trajectory analyses further indicated that individuals with arthritis not only had higher levels of depressive symptoms at baseline but also experienced a more rapid worsening of symptoms over time compared with those without arthritis. In contrast, associations between arthritis and cognitive outcomes were weak and inconsistent. Hazard ratios for cognitive impairment were close to null or only modestly elevated, and differences in cognitive trajectories were small with substantial overlap of prediction intervals. No stable domain-specific cognitive deficits were observed. CONCLUSION: Arthritis is strongly associated with an accelerated onset and progression of depressive symptoms among older adults, while its direct influence on cognitive decline appears limited. These findings underscore the importance of incorporating routine mental health screening and management into rheumatologic and geriatric care to reduce the cumulative burden of coexisting physical and psychological conditions.