Physical frailty and the risk of major depressive disorder: The Irish Longitudinal Study on Ageing

Although frailty is a well-established risk factor for adverse health outcomes in later life, little is known about the role of physical frailty on the development of incident major depressive disorder (MDD). The purpose of this study was to determine whether frailty is an important and independent predictor of incident major depressive disorder (MDD) in elderly people without probable depression at baseline. Of the 3671 older individuals from the population-based Irish Longitudinal Study on Ageing, we classified participants as non-frail (0), pre-frail (1-2), and frail (3-5) at baseline according to the five criteria of the physical frailty phenotype. The World Health Organization Composite International Diagnostic Interview Short-Form was used to assess whether respondents fulfilled the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria for MDD over a 4-year follow-up. After adjusting for demographic factors, living arrangements, health behaviors, common chronic diseases including hypertension, diabetes, cancer, lung disease, heart problems, and stroke, those classified as pre-frail (HR = 1.40, 95%CI = 1.14-1.73) and frail (HR = 2.20, 95%CI = 1.23-3.92) presented a higher risk to develop incident MDD over the 4-year follow-up compared to non-frail participants. Shrinking and exhaustion, as physical frailty components, were individually predictive of onset of MDD. The present study supports a significant role of physical frailty as a predictor of incident MDD in older adults. It is necessary to identify groups with a high vulnerability for MDD according to easily identifiable frailty criteria, and to delay or prevent at least in part, some of the negative health outcomes related to this disorder.