The Buffering Effect of Age-Friendly Communities on Depression Among Socially Isolated Older Adults with Iadl Limitations In Rural Areas In South Korea

Background: Rural communities in South Korea are facing a high proportion of older residents amidst rapid demographic shifts. The lack of family support systems and limited access to health and social services have emerged as pressing issues. These challenges often lead to social isolation, leaving many older adults without adequate care and threatening their mental health. This study investigates how health status affects depression in this population and analyzes the influence of social isolation and age-friendly environments. The goal is to identify environmental factors that can mitigate depression and support the well-being of older adults living in isolated rural settings.

Methods: This study employed a cross-sectional survey design conducted between October and December 2025 in a rural area of South Korea. Data were collected via purposive sampling to ensure a diverse representation of older adults. Researchers conducted face-to-face interviews at local senior gathering places and the residences of older adults. The outcome variable, depression, was assessed using the PHQ-9 (Patient Health Questionnaire-9), with each item measured on a 4-point Likert scale (range 1 to 4). Exposures were assessed using K-IADL limitations, a 9-item Age-Friendly Communities measure adapted from the WHO Global Age-Friendly Cities Guide (2007), and a 3-item social isolation measure from Statistics Korea. A total of 432 questionnaires were collected; after excluding incomplete responses, 395 cases were included in the final analysis. Multiple linear regression was performed to examine the associations among AFC, social isolation, and depression, incorporating a three-way interaction term with IADL while controlling for sociodemographic characteristics.

Results: A significant three-way interaction was observed among AFC, social isolation, and IADL limitations (β = 0.02, p < 0.001). Stratified analyses revealed that for older adults without IADL limitations, neither AFC nor social isolation was significantly associated with depressive symptoms (p > 0.05). However, for those with at least one IADL limitation, both AFC (β = -0.46, p < 0.001) and social isolation (β = -0.24, p < 0.001) significantly predicted lower levels of depression. Notably, within this vulnerable group, a two-way interaction between AFC and social isolation emerged (β = 0.05, p < 0.01): socially isolated individuals in highly age-friendly communities reported depression levels comparable to those who were not isolated (depression score: 1.23 vs. 1.49). Conversely, in less age-friendly environments, socially isolated individuals reported greater depression levels than those who were not isolated (depression score: 3.23 vs. 1.31).

Implications: This study demonstrates that an age-friendly environment serves as a critical protective factor for older adults facing both functional limitations and social isolation. The findings suggest that AFC can buffer the psychological distress caused by a lack of social support in rural areas. Therefore, enhancing the age-friendliness of rural infrastructures is a vital mental health intervention for those living without adequate caregiving systems.