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Objective The increased resistance of better-educated individuals to the cognitive effects of neuropathology has been conceptualized as reflecting brain reserve. This study examined whether educational level influences the degree of neuropsychological impairment associated with late-life depression. Methods The neuropsychological performances of 115 older depressed patients and of 44 comparison subjects of similar age and education were compared as a function of educational level. Results While depressed patients performed worse than comparison subjects on all the measures, the severity of this impairment (with respect to comparison subjects) did not differ with the educational level of the patients. Conclusions Brain reserve, as indexed by the patients' level of education, does not mitigate the cognitive decrements associated with late-life depression. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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.