Depressive symptoms and functional transitions over time in older persons

Objective: The authors determined the association between clinically significant depressive symptoms, often referred to as depression, and subsequent transitions between no disability, mild disability, severe disability, and death. Design: Prospective cohort study. Setting: General community in greater New Haven, Connecticut, from March 23, 1998, to December 31, 2008. Participants: Seven hundred fifty-four persons, age 70 years or older. Measurements: Monthly assessments of disability in essential activities of daily living and assessments of depressive symptoms every 18 months using a short-form of the Center for Epidemiologic Studies of Depression Scale for up to 129 months. Results: Depressed participants were more likely than those who were nondepressed to transition from a state of no disability to mild (HR = 1.52; 95% CI: 1.25-1.85) and severe disability (HR = 1.57; 95% CI: 1.22-2.01), and from a state of mild disability to severe disability (HR = 1.33; 95% CI: 1.06-1.65), and were less likely to transition from a state of mild disability to no disability (HR = 0.69; 95% CI: 0.57-0.85) and from a state of severe disability to no disability (HR = 0.50; 95% CI: 0.31-0.79). Conclusions: Depressive symptoms are associated with transitions into and out of disabled states and with increased likelihood of transitioning from mild to severe disability. More broadly, our findings underscore the complexity of the relationship between depressive symptoms and disability. Future work is needed to evaluate the likely reciprocal relationship between depression and functional transitions in older persons.