Neuropsychological Functioning in the Acute and Remitted States of Late-Life Depression

Article type: Research Article

Authors: Koenig, Aaron M.^{a; b} | DeLozier, Isaac J.^a | Zmuda, Michelle D.^a | Marron, Megan M.^c | Begley, Amy E.^a | Anderson, Stewart J.^c | Reynolds III, Charles F.^{a; d} | Arnold, Steven E.^b | Becker, James T.^a | Butters, Meryl A.^{a; *}

Affiliations: [a] Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA | [b] Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA | [c] Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA | [d] Department of Behavioral and Community Health Sciences, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA

Correspondence: [*] Correspondence to: Meryl A. Butters, PhD, Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Room 462, Pittsburgh, PA 15213, USA. Tel.: +1 412 246 5280; Fax: +1 412 586 9111; E-mail: [email protected].

Abstract: Late-life depression (LLD, major depression occurring in an adult 60 years or older) is a common condition that frequently presents with cognitive impairment. Up to half of individuals with LLD are estimated to have cognitive impairment greater than that of age- and education-matched comparators, with impairments of episodic memory, speed of information processing, executive functioning, and visuospatial ability being most common. To inform our understanding of the state- versus trait-effects of depression on neuropsychological functioning, and to overcome limitations of previous studies, we utilized baseline data from the longitudinal Pathways study to compare differences in single time point performance on a broad-based neuropsychological battery across three diagnostic groups of older adults, each comprised of unique participants (n = 438): currently depressed (n = 120), previously depressed but currently euthymic (n = 190), and never-depressed (n = 128). Consistent with our hypotheses, we found that participants with a history of depression (currently or previously depressed) performed significantly worse than never-depressed participants on most tests of global cognition, as well as on tests of episodic memory, attention and processing speed, verbal ability, and visuospatial ability; in general, differences were most pronounced within the domain of attention and processing speed. Contrary to our hypothesis, we did not observe differences in executive performance between the two depression groups, suggesting that certain aspects of executive functioning are “trait deficits” associated with LLD. These findings are in general agreement with the existing literature, and represent an enhancement in methodological rigor over previous studies given the cross-sectional approach that avoids practice effects on test performance.

Keywords: assessment, cognitive function, depression, elderly, geriatric, neuropsychological

DOI: 10.3233/JAD-148006

Journal: Journal of Alzheimer's Disease, vol. 45, no. 1, pp. 175-185, 2015