Depressive symptomatology and incident cognitive decline in an elderly community sample

Background: It is not known whether depression is a cause or consequence of progressive cognitive decline. We assessed the relationship between depres sive symptoms and subsequent cognitive decline in the community-dwelling el derly population. Methods: Data were from a population-based cohort study that enrolled 2812 noninstitutionalized elderly residents of New Haven, Conn, and followed the m with in-home visits in 1982, 1985, 1988, and 1994. Cognitive function was assessed with the Short Portable Mental Status Questionnaire (SPMSQ). Resp onse to the SPMSQ was scored as high, medium, and low, and cognitive declin e was defined as a transition to a lower category. Depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale. Results: An elevated level of depressive symptoms was associated with an in creased risk of incident cognitive decline among medium SPMSQ performers (3 -year odds ratio [OR], 1.72; 95% confidence interval [CI], 1.04-2.82, P=.03 ; 6-year OR, 2.40; 95% CI, 1.33-4.34, P=.004; 12-year OR, 1.65; 95% CI, 0.6 2-4.38; P=.31) but not among high performers (3-year OR, 0.93; 95% CI, 0.62 -1.39; P=.71; B-year OR, 1.03; 95% CI, 0.67-1.58; P=.90; 12-year OR, 1.26; 95% CI, 0.59-2.71, P=.55), after adjustment for age, sex, race, education, income, housing type, functional disability, cardiovascular profile, and al cohol use. Conclusions: Depressive symptoms, particularly dysphoric mood, presage futu re cognitive losses among elderly persons with moderate cognitive impairmen ts. However, the data do not provide support for the hypothesis that depres sive symptoms are associated with the onset or rate of cognitive decline am ong cognitively intact elderly persons.