Aim: Functional capacity and dependency in activities of daily living (ADL) could be important mediators for an association between physical exercise and mental health. The aim of this study was to investigate whether a change in functional capacity or dependency in ADL is associated with a change in depressive symptoms and psychological well-being among older people living in residential care facilities, and whether dementia can be a moderating factor for this association.
Methods: A prospective cohort study was undertaken. Participants were 206 older people, dependent in ADL, living in residential care facilities, 115 (56%) of whom had diagnosed dementia. Multivariate linear regression, with comprehensive adjustment for potential confounders, was used to investigate associations between differences over 3 months in Berg Balance Scale (BBS) and Geriatric Depression Scale (GDS-15) scores, and in BBS and Philadelphia Geriatric Center Morale Scale (PGCMS) scores. Associations were also investigated between differences in Barthel ADL Index and GDS-15 scores, and in Barthel ADL Index and PGCMS scores.
Results: There were no significant associations between changes in scores over 3 months; the unstandardized β for associations between BBS and GDS-15 was 0.026 (P=0.31), BBS and PGCMS 0.045 (P=0.14), Barthel ADL Index and GDS-15 0.123 (P=0.06), and Barthel ADL Index and PGCMS -0.013 (P=0.86). There were no interaction effects for dementia.
Conclusion: A change in functional capacity or dependency in ADL does not appear to be associated with a change in depressive symptoms or psychological well-being among older people living in residential care facilities. These results may offer one possible explanation as to why studies of physical exercise to influence these aspects of mental health have not shown effects in this group of older people.
Keywords: activities of daily living; aged; dementia; depression; frail elderly; mental health; physical fitness; quality of life; residential facilities.