Disability in late-life major depression: patterns of self-reported task abilities, task habits, and observed task performance.

This article describes patterns of concordance/discordance between self-reported abilities ("can do") and habits ("does do") and observed task performance of daily living tasks in three groups of older adults: late life depression with mild cognitive impairment (n=53), late life depression without mild cognitive impairment (n=64), and non-depressed, cognitively normal controls (n=31). Self-reported data were gathered by interview in participants' homes, followed by observation of task performance. Significant differences in the patterns of response were found between controls and respondents with both late life depression and mild cognitive impairment for the cognitive instrumental activities, and between the two depressed groups and controls for the physical instrumental activities. For both sets of activities, controls exhibited the greatest overestimation of task performance. No differences were found among the groups for the less complex functional mobility and personal care tasks. However, for the more complex instrumental activities, concordance was close to, or less than, chance. The findings led us to conclude that when performance testing is not feasible, self-reports of functional status that focus on habits may be more accurate than those that focus on abilities. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.