Depression, antidepressants, and falls among community-dwelling elderly people: the MOBILIZE Boston study.

Background: The mechanisms linking falls and depression are still unknown. The aim of the study is to examine the association between depression and antidepressants, with indoor and outdoor falls, and to investigate how antidepressants mediate this relationship.

Methods: The study included 763 men and women aged 70 and older with baseline measures for depression and antidepressant use are captured with prospective data on falls from the "Maintenance of Balance, Independent Living, Intellect and Zest in the Elderly" (MOBILIZE) Boston study, which is a population-based longitudinal study (from 2005 to 2009).

Results: Overall, the rate of falls was 26 falls/100 person-years. Seventeen percent of participants had clinically significant depressive symptoms (CSDS), and 12% used antidepressants. CSDS increased the risk of indoor and outdoor falls (incidence rate ratio [IRR] = 1.6, 95% confidence interval [CI] = 1.2-2.3, p < .01; IRR = 1.6, 95% CI = 1.2-2.2, p < .01). Antidepressant use increased the risk of outdoor falls by 70% and partially mediated the association between CSDS and outdoor falls (IRR = 1.7, 95% CI = 1.2-2.5, p < .05). There was no relationship between antidepressant use and indoor falls. Similar results were observed when depression was considered as a continuous variable.

Conclusions: Depression increased the risk of indoor and outdoor falls. Antidepressant use among older adults with CSDS increased the risk of outdoor, but not indoor falls. Clinicians should carefully consider the role of antidepressants among older adults with CSDS and their potential increase for the risk of outdoor falls.