Relationship Between Depressive Symptoms and Activity of Daily Living Dependence in Older Japanese: The Kurabuchi Study

Few published studies have investigated the possibility of an association between depressive symptoms and dependence in activities of daily living (ADLs) in elderly adults. The objective of the study was to examine the association between depressive symptoms and future ADL dependence and to investigate how this association varies according to living circumstances and marital status.

Community-based prospective observational study.

Kurabuchi Town, Gunma Prefecture, Japan.

A total of 769 residents aged 65 and older were surveyed at baseline in 2005/06; they were followed up annually during the 7.5-year study period (follow-up rate, 99% (n = 763).

Presence of depressive symptoms was defined as a score of 2 or greater on the five-item Geriatric Depression Scale, and dependence in ADLs was defined as admission to a nursing home (institutionalization), eligibility for long-term care (LTC), or need for help in any of the six basic ADL items in the Katz Index of Independence in ADLs.

Depressive symptoms were observed in 232 of the 763 participants (30.4%). Those with depressive symptoms were more prone to future ADL dependence than those without (adjusted risk ratio = 1.29, 95% confidence interval = 1.04-1.61). There was no clear evidence of any effect modification according to living circumstances or marital status on this association, although living with other people or marriage was found to be associated with greater risk of institutionalization.

Our findings suggest that depressive symptoms are associated with future ADL dependence and that living circumstances (except for institutionalization) and marital status do not affect the association.