Changes in depressive symptoms and functional disability among community-dwelling depressive older adults

Background: Previous studies have shown that the presence of depressive symptoms among older persons was evidently associated with subsequent physical and functional decline. However, few studies have directly examined the impact of changes in depressive symptoms or depressed mood on changes in functional ability. The present prospective study examined whether changes in the levels and remission of depressive symptoms were associated with changes in functional ability among community-living older persons who were treated for depressive symptoms in a primary care setting. Methods: Older persons aged 60 and above with depressive symptoms (N= 267) were followed up in a primary care treatment program over 12 months. Geriatric Depression Scale (GDS-15), and instrumental and basic activities of daily living (IADL and ADL) were measured at baseline and at 12-month follow-up. The associations of GDS change scores and conversion to non-depressed status with ADL and IADL change scores, controlling for baseline covariates including chronic medical comorbidity and Mini-Mental State Examination (MMSE), were examined in multiple regression analyses. Results: An improvement in GDS scores (baseline score minus 12-month score) was significantly associated with improvement (12-month score minus baseline score) in ADL (beta = 0.355, p < 0.001) and IADL scores (-beta = 0.165, p = 0.018) after adjusting for baseline functional status, MMSE, chronic medical comorbidities, and other variables. In particular, conversion in GDS status to "non-depressive" state (GDS <= 4) was associated with an improvement in ADL change scores (beta = 0.281, p = 0.019). Conclusion: In depressed older persons, an improvement in depressive symptoms was associated with improved functional ability.