Abstract
OBJECTIVES: To determine whether there was greater disability in subjects with depression than in those without, the correlation between disability and depression severity and quality of life, and whether improvement in disability after antidepressant pharmacotherapy was greater in those who responded to antidepressant treatment. DESIGN: Disability in subjects with and without depression from two different studies was compared for 22 weeks. Correlations were performed for the subjects with depression between disability and depression, anxiety, health-related quality of life (HRQOL), and medical comorbidity. T-tests were used to compare disability between subjects who did and did not respond to antidepressant treatment and change in disability after pharmacotherapy. SETTING: Late-life depression research clinic. PARTICIPANTS: The 313 subjects were recruited from primary care and the community and were aged 60 and older; 244 subjects were participants in a depression treatment protocol, and 69 subjects without depression participated in a separate longitudinal observational study of the mental and cognitive health of depression-free older adults. MEASUREMENTS: The Late-Life Function and Disability Instrument (LL-FDI), a measure of instrumental activity of daily living, personal role, and social role functioning. RESULTS: Subjects with depression scored lower than controls for domains measuring limitation (can do) and frequency (does do) of activities. Both disability domains correlated with depression severity, anxiety, HRQOL, and cognition. Disability improved with antidepressant treatment; for partial responders who continued to receive higher-dose antidepressant treatment out to 22 weeks, there was continued improvement, although not to the level of comparison subjects without depression. CONCLUSION: The LL-FDI appears to discriminate subjects with depression from those without, correlates with depression severity, and demonstrates sensitivity to antidepressant treatment response. We recommend further investigation of the LL-FDI and similar disability instruments for assessing depression-related disability.