Higher all-cause mortality risk in depression with physical comorbidities: Evidence from the longitudinal study of the survey of health, ageing and retirement in Europe

BACKGROUND: Depression and diagnosed physical diseases are separately linked to higher mortality in the elderly, but mortality risks in depression in the context of physical comorbidities remain unclear. METHODS: Data from waves 4-8 of the Survey of Health, Ageing and Retirement in Europe were analyzed, covering 15 physical diseases. Depression was assessed with the EURO-D scale. Kaplan-Meier curves evaluated all-cause survival between individuals with and without depression considering the number of comorbid physical diseases. The Apriori algorithm identified physical comorbidity patterns in patients with depression. Cox regression models calculated hazard ratios (HRs) and 95 % CIs for depression versus non-depression across different physical disease numbers and patterns. RESULTS: Among 8134 European elderly (58 % women, mean age 73 years old), median follow-up was 7.83 years. Kaplan-Meier curves showed decreasing all-cause survival with increasing numbers of comorbid physical diseases in both two groups, with higher mortality in the depression group than the non-depression group. Cox models revealed that individuals with depression and 0, 1, 2, or ≥ 3 physical diseases had higher mortality risks than those without depression and physical diseases. The Apriori algorithm identified 11 comorbidity patterns associated with depression, with stroke (HR = 1.94, 95 % CI: 1.20-3.12) and fractures (HR = 1.90, 95 % CI: 1.33-2.72) posing the highest all-cause mortality risks for individuals with depression. CONCLUSIONS: There are significant differences in all-cause mortality risk between individuals with and without depression when considering numbers and patterns of physical diseases. Identifying high-risk comorbidities offers valuable insights for early prevention and clinical management of comorbid physical and mental conditions.