Background: Frailty is an important concept for risk stratification in clinical practice, but it is hardly acknowledged at all in mental healthcare settings. This paper aims to assess the impact of frailty on the course of depression and anxiety, and the impact of these affective disorders on the course of frailty.
Methods: Lifelines, a prospective population-based cohort study, evaluated 167,729 people living in the northern Netherlands. Frailty was based on the deficit accumulation model, which resulted in a 60-item frailty index (FI) at baseline and a 35-item FI at baseline and 5-year follow-up. Current depressive and anxiety disorders were assessed with the Mini International Neuropsychiatric Interview according to DSM-IV criteria. Bidirectional associations between frailty and affective disorders were investigated using separate multivariable regression analyses in younger (<60 years) and older adults (≥60 years).
Results: The FI was associated with the onset of a depressive disorder (younger adults: odds ratio [OR] = 1.12; 95% confidence interval [CI] 1.11–1.13; older adults: OR = 1.13; 95% CI 1.09–1.16) as well as any anxiety disorder (younger adults: OR = 1.10; 95% CI 1.09–1.10; older adults: OR = 1.07; 95% CI 1.04–1.09). The other way around, depressive disorder and anxiety disorders were associated with an accelerated increase of frailty over time (depressive disorder: younger adults: beta [β] = 0.03, p < 0.001; older adults: β = 0.04, p < 0.001; and any anxiety disorder: younger adults: β = 0.02, p < 0.001; older adults: β = 0.01, p < 0.142), although the effect of anxiety disorders was less equivocal among older adults.
Conclusions: Affective disorders are reciprocally related to frailty. Results with respect to the impact of anxiety disorders on frailty suggest most impact at lower levels of frailty. Our results might imply that interventions to slow biological aging should be broadened towards younger and middle-aged people as well as non-frail older patients. To develop targeted treatment, future clinical and epidemiologic studies on the underlying pathways of this bidirectional association are needed.