Relationship between Frailty and Depression among Community-Dwelling Older Adults: The Mediating and Moderating Role of Social Support

Background and Objectives: Frailty is associated with depression in older adults and reduces their social support. However, the mechanism underlying such relationship remains unclear. We aim to examine whether social support acts as a mediator or moderator in the relationship between frailty and depression. Research Design and Methods: This cross-sectional study was conducted among 1,779 community-dwelling older adults aged 60 and older. Frailty, social support, and depressive symptoms were measured by the Physical Frailty Phenotype, Social Support Rating Scale, and five-item Geriatric Depression Scale, respectively. Data were also collected on age, gender, years of schooling, monthly income, cognitive function, number of chronic diseases, physical function, and pain. Results: Linear regression models showed that subjective support and support utilization, but not objective support, mediated and moderated the relationship between frailty and depressive symptoms. The Johnson-Neyman technique determined a threshold of 30 for subjective support, but not for support utilization, beyond which the detrimental effect of frailty on depressive symptoms was offset. Discussion and Implications: Social support underlies the association of frailty with depression, and its protective role varies by type. Interventions on depression should address improving perceptions and utilization of social support among frail older adults rather than simply providing them with objective support.