Depression and frailty in later life: a synthetic review

BACKGROUND: Many of the symptoms, consequences, and risk factors for frailty are shared with late-life depression. However, thus far, few studies have addressed the conceptual and empirical interrelationships between these conditions. This review synthesizes existing studies that examined depression and frailty among older adults and provides suggestions for future research. METHODS: A search was conducted using PubMed for publications through 2010. Reviewers assessed the eligibility of each report and abstracted information on study design, sample characteristics, and key findings, including how depression and frailty were conceptualized and treated in the analysis. RESULTS: Of 133 abstracted articles, 39 full-text publications met inclusion criteria. Overall, both cross-sectional (n = 16) and cohort studies (n = 23) indicate that frailty, its components, and functional impairment are risk factors for depression. Although cross-sectional studies indicate a positive association between depression and frailty, findings from cohort studies are less consistent. The majority of studies included only women and non-Hispanic Whites. None used diagnostic measures of depression or considered antidepressant use in the design or analysis of the studies. CONCLUSIONS: A number of empirical studies support for a bidirectional association between depression and frailty in later life. Extant studies have not adequately examined this relationship among men or racial/ethnic minorities, nor has the potential role of antidepressant medications been explored. An interdisciplinary approach to the study of geriatric syndromes such as late-life depression and frailty may promote cross-fertilization of ideas leading to novel conceptualization of intervention strategies to promote health and functioning in later life.