International Psychogeriatrics

Research Article

Executive dysfunction correlates with impaired functional status in older adults with varying degrees of cognitive impairment

F. S. Pereiraa1, M. S. Yassudaa1a2, A. M. Oliveiraa1 and O. V. Forlenzaa1 c1

a1 Laboratory of Neuroscience (LIM-27), Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Brazil

a2 Department of Gerontology, School of Arts, Sciences and Humanities, University of São Paulo, Brazil

ABSTRACT

Background: Previous studies have reported an association between executive dysfunction and the ability to perform activities of daily living (ADL)s among older adults. This study aims to examine the association between executive functions and functional status in a cross-section of older adults with varying degrees of cognitive impairment.

Methods: 89 individuals (mean age 73.8 years) were recruited at a memory clinic in São Paulo, Brazil. Subjects underwent evaluation, and were allocated into three diagnostic groups according to cognitive status: normal controls (NC, n = 32), mild cognitive impairment (MCI, n = 31) and mild Alzheimer's disease (AD, n = 26). Executive functions were assessed with the 25-item Executive Interview (EXIT25), and functional status was measured with the Direct Assessment of Functional Status test (DAFS-R).

Results: Significantly different total DAFS-R scores were observed across the three diagnostic groups. Patients with AD performed significantly worse in EXIT25 compared with subjects without dementia, and no significant differences were detected between NC and MCI patients. We found a robust negative correlation between the DAFS-R and the EXIT25 scores (r =–0.872, p < 0.001). Linear regression analyses suggested a significant influence of the EXIT-25 and the CAMCOG on the DAFS-R scores.

Conclusion: Executive dysfunction and decline in general measures of cognitive functioning are associated with a lower ability to undertake instrumental ADLs. MCI patients showed worse functional status than NC subjects. MCI patients may show subtle changes in functional status that may only be captured by objective measures of ADLs.

(Received March 17 2008)

(Revised April 30 2008)

(Revised May 22 2008)

(Accepted May 22 2008)

(Online publication August 27 2008)

Correspondence:

c1 Correspondence should be addressed to: Dr. Orestes V. Forlenza, Laboratory of Neuroscience (LIM 27), Department and Institute of Psychiatry, Rua Dr. Ovídio Pires de Campos, 785, 3rd floor, 05403-010 – São Paulo, S.P., Brazil. Phone: +55 11 3069–7924; Fax: +55 11 3085-5412. Email: forlenza@usp.br.