Depression and Frailty in Late Life: Evidence for a Common Vulnerability

OBJECTIVES: The study purpose is to estimate the correlation between depression and competing models of frailty, and to determine to what degree the comorbidity of these syndromes is determined by shared symptomology. METHODS: Data come from the 2010 Health and Retirement Study. Analysis was limited to community-dwelling participants 65 and older (N = 3,453). Depressive symptoms were indexed by the 8-item Centers for Epidemiologic Studies Depression (CESD) scale. Frailty was indexed by 3 alternative conceptual models: (a) biological syndrome, (b) frailty index, and (c) functional domains. Confirmatory factor analysis (CFA) was used to estimate the correlation between depression and each model of frailty. RESULTS: Each of the 3 frailty latent factors was significantly correlated with depression: biological syndrome (ρ = .68, p < .01), functional domains (ρ = .70, p < .01), and frailty index (ρ = .61, p < .01). Substantial correlation remained when accounting for shared symptoms between depression and the biological syndrome (ρ = .45) and frailty index (ρ = .56) models. DISCUSSION: Results indicate that the correlation of frailty and depression in late life is substantial. The association between the two constructs cannot be fully explained by symptom overlap, suggesting that psychological vulnerability may be an important component of frailty.