Cognitive Impairment, Depressive Symptoms, and Functional Decline in Older People

OBJECTIVES: Although cognitive impairment and depressive symptoms are associated with functional decline, it is not understood how these risk factors act together to affect the risk of functional decline. The purpose of this study is to determine the relative contributions of cognitive impairment and depressive symptoms on decline in activity of daily living (ADL) function over 2 years in an older cohort. DESIGN: Prospective cohort study. SETTING: A U.S. national prospective cohort study of older people, Asset and Health Dynamics in the Oldest Old. PARTICIPANTS: Five thousand six hundred ninety-seven participants (mean age 77, 64 women, 86 white) followed from 1993 to 1995. MEASUREMENTS: Cognitive impairment and dpressive symptoms were defined as the poorest scores: 1.5 standard deviations below the mean on a cognitive scale or 1.5 standard deviations above the mean on validated depression scales. Risk of functional decline in participants with depressive symptoms, cognitive impairment, and both, compared with neither risk factor, were calculated and stratified by baseline dependence. Analyses were adjusted for demographics and comorbidity. CONCLUSIONS: In participants with no ADL dependence at baseline, cognitive impairment and depressive symptoms are risk factors for decline, but that, in participants with dependence in ADL at baseline, cognitive impairment, but not depressive symptoms, is a risk factor for additional decline.

Activities of Daily Living/Cognitive Functioning/Depressive Symptoms/Health Physical

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