Depressive symptoms as an independent risk factor for mortality in elderly persons: Results of a national longitudinal study

Abstract

Objective: Depressive symptoms have been associated with increased mortality risk in previous cohort studies, but there is a paucity of research on Asian elderly in recent years. The authors investigated the depression–mortality link using data from a representative national cohort.

Methods: Data came from the Survey of Health and Living Status of the Elderly in Taiwan. A cohort of 2416 men and women in Taiwan aged 65 or older were followed up for eight years from 1999 to 2007. Depressive symptoms were assessed by the 10-item Center for Epidemiologic Studies Depression Scale. The mortality risk of depression was computed after adjustment for a variety of covariates. Data on the presence or absence of chronic diseases were further analyzed.

Results: Overall, depressive symptoms were associated with all-cause mortality (hazard ratio (HR), 1.21; 95% confidence interval (CI), 1.03–1.42) after eight years follow-up, but this mortality risk was detected in men only (HR, 1.27; 95% CI, 1.03–1.56), not in women (HR, 1.1; 95% CI, 0.86–1.4). Further analyses showed that in the group without chronic diseases (without diabetes mellitus, stroke, lung disease, cancer, or cognitive impairment), depressive symptoms were associated with mortality (HR, 1.40; 95% CI, 1.12–1.76) after eight years follow-up; however, there was no association between depressive symptoms and mortality in participants with chronic diseases (HR, 1.02; 95% CI, 0.82–1.26).

Conclusion: Depressive symptoms are an independent risk factor for mortality in the elderly. Elderly depressive men and elderly without chronic diseases seemed to have a greater mortality risk.

Keywords:

• depressive symptoms
• elderly
• mortality
• cohort study

Acknowledgments

The data were provided by the Bureau of Health Promotion, Department of Health. The authors thank these institutions for allowing us access to the data sets.