Depression, pain, and seven chronic diseases in middle-aged and older adults: Findings from five prospective cohort studies.

BACKGROUND: Depression and chronic pain are major global health challenges, bidirectionally associated and significantly increasing chronic disease risk. This study aimed to systematically investigate the complex interplay, joint effects, and mediation mechanisms among depression, pain, and seven major chronic conditions.

METHODS: This population-based, multinational cohort study analyzed longitudinal data from a large number of adults aged 45 years and older across five major cohorts: the Health and Retirement Study, the English Longitudinal Study of Ageing, the Survey of Health, Ageing and Retirement in Europe, the China Health and Retirement Longitudinal Study, and the Mexican Health and Aging Study. Depression was assessed by CES-D/Euro-D, and pain and chronic conditions by self-report.

RESULTS: Participants averaged 60.62 years of age, with 28% reporting baseline depressive symptoms and approximately 36% reporting pain. Both baseline depression and pain significantly increased the incidence risk of all seven chronic diseases. Crucially, their co-occurrence amplified this risk substantially, with respiratory diseases showing an HR of 2.42 and arthritis an HR of 2.28. Causal mediation analysis revealed bidirectional roles: pain significantly mediated the association between depression and arthritis, with 56.6% mediation observed for arthritis. Meanwhile, depression mediated the association between pain and diabetes/hypertension, with 42.5% mediation observed for diabetes.

CONCLUSION: This study identifies strong associations and bidirectional mediating roles between depression, pain, and chronic disease risk, with their co-occurrence markedly increasing vulnerability. These findings highlight the importance of early detection and integrated management of depression and pain to help reduce the onset of chronic diseases.