Context: Significant symptoms of depression are common in the older community-dwelling population. Although depressive symptoms and disability may commonly occur in the same person, whether depressive symptoms contribute to subsequent functional decline has not been elucidated.
Objective: To determine whether depressive symptoms in older persons increase the risk of subsequent decline in physical function as measured by objective performance-based tests.
Design: A 4-year prospective cohort study.
Setting: The communities of Iowa and Washington counties, Iowa.
Participants: A total of 1286 persons aged 71 years and older who completed a short battery of physical performance tests in 1988 and again 4 years later.
Main outcome measures: Baseline depressive symptoms were assessed by the Center for Epidemiological Studies Depression Scale. Physical performance tests included an assessment of standing balance, a timed 2.4-m (8-ft) walk, and a timed test of 5 repetitions of rising from a chair and sitting down.
Results: After adjustment for baseline performance score, health status, and sociodemographic factors, increasing levels of depressive symptoms were predictive of greater decline in physical performance over 4 years (odds ratio for decline in those with depressed mood vs those without, 1.55; 95% confidence interval [CI], 1.02-2.34). Even among those at the high end of the functional spectrum, who reported no disability, the severity of depressive symptoms predicted subsequent decline in physical performance (odds ratio for decline, 1.03; 95% CI, 1.00-1.08).
Conclusions: This study provides evidence that older persons who report depressive symptoms are at higher risk of subsequent physical decline. These results suggest that prevention or reduction of depressed mood could play a role in reducing functional decline in older persons.