Changes in depression and physical decline in older adults: a longitudinal perspective.

BACKGROUND: The impact of chronicity and changes in depression on physical decline over time in older persons has not been elucidated.
METHODS: This prospective cohort study of 2121 community-dwelling persons aged 55-85 years uses two measurement occasions of depression (CES-D scale) over 3 years to distinguish persons with chronic, remitted, or emerging depression and persons who were never depressed. Physical function is assessed by self-reported physical ability as well as by observed performance on a short battery of tests.
RESULTS: After adjustment for baseline physical function, health status and sociodemographic factors, chronic depression was associated with significantly greater decline in self-reported physical ability over 3 years when compared to never depressed persons (odds ratio (OR)=2.83, 95% confidence interval (CI)=1.86-4. 30). In the oldest old, but not in the youngest old, chronic depression was also significantly predictive of greater decline in observed physical performance over 3 years (OR=2.22, 95% CI=1.43-3. 79). Comparable effects were found for older persons with emerging depression. Persons with remitted depression did not have greater decline in reported physical ability or observed performance than persons who were never depressed.
CONCLUSIONS: Our findings among community-dwelling older persons show that chronicity of depression has a large impact on physical decline over time. Since persons with remitted depression did not have greater physical decline than never depressed persons, these findings suggest that early recognition and treatment of depression in older persons could be protective for subsequent physical decline.