International Psychogeriatrics

Research Article

Apathy and cognitive and functional decline in community-dwelling older adults: results from the Baltimore ECA longitudinal study

Diana E. Clarkea1a2 c1, Jean Y. Koa1, Constantine Lyketsosa3, George W. Reboka1 and William W. Eatona1

a1 Department of Mental Health, Johns Hopkins University School of Public Health, Baltimore, Maryland, U.S.A.

a2 Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada

a3 Department of Psychiatry, Johns Hopkins University School of Medicine and Johns Hopkins Bayview, Baltimore, Maryland, U.S.A.

ABSTRACT

Background: Apathy, a complex neuropsychiatric syndrome, commonly affects patients with Alzheimer's disease. Prevalence estimates for apathy range widely and are based on cross-sectional data and/or clinic samples. This study examines the relationships between apathy and cognitive and functional declines in non-depressed community-based older adults.

Methods: Data on 1,136 community-dwelling adults aged 50 years and older from the Baltimore Epidemiologic Catchment Area (ECA) study, with 1 and 13 years of follow-up, were used. Apathy was assessed with a subscale of items from the General Health Questionnaire. Logistic regression, t-tests, χ2 and Generalized Estimating Equations were used to accomplish the study's objectives.

Results: The prevalence of apathy at Wave 1 was 23.7%. Compared to those without, individuals with apathy were on average older, more likely to be female, and have lower Mini-mental State Examination (MMSE) scores and impairments in basic and instrumental functioning at baseline. Apathy was significantly associated with cognitive decline (OR = 1.65, 95% CI = 1.06, 2.60) and declines in instrumental (OR = 4.42; 95% CI = 2.65, 7.38) and basic (OR = 2.74; 95%CI = 1.35, 5.57) function at 1-year follow-up, even after adjustment for baseline age, level of education, race, and depression at follow-up. At 13 years of follow-up, apathetic individuals were not at greater risk for cognitive decline but were twice as likely to have functional decline. Incidence of apathy at 1-year follow up and 13-year follow-up was 22.6% and 29.4%, respectively.

Conclusions: These results underline the public health importance of apathy and the need for further population-based studies in this area.

(Received May 19 2009)

(Revised August 18 2009)

(Revised October 05 2009)

(Accepted October 06 2009)

(Online publication May 18 2010)

Correspondence:

c1 Correspondence should be addressed to: Dr. Diana E. Clarke, 624 N. Broadway Street, 8th floor, Baltimore, MD 21205, U.S.A. Phone: +1 (410) 955-0416; Fax: +1 (410) 955-9088. Email: dclarke@jhsph.edu.