Linkages between functional independence, depressive symptoms, and social networks in aging populations: a systematic review

Activities of daily living (ADL) and instrumental ADL (IADL), main indica-tors of functional independence in older adults, are closely associated with depression and social networks and represent a critical determi-nant of well-being. Despite the growing body of research, both original and review articles to date have been limited in their ability to provide a comprehensive and coherent explanation of the interrelationships among these three domains, largely due to methodological constraints. Accordingly, this study systematically reviewed a wide range of publi-cations addressing functional ability, depression, and social networks in older adults, with the aim of providing evidence-based insights to in-form strategies for maintaining well-being and preparing for functional decline in aging populations. The synthesized findings indicate that de-clines in functional ability, as reflected by impairments in IADL/ADL, are associated with reduced instrumental ADL, increased depressive symp-toms, and decreased social participation, collectively contributing to a self-reinforcing cycle of functional and psychological deterioration. No-tably, this review demonstrates that while functional disability increases the risk of depression, robust social networks serve as protective fac-tors that mitigate both functional and psychological decline.