The longitudinal relationship between pain and depressive symptoms in later life: the buffering effects of social and physical activities among older Koreans.

Background and Objectives: This study examined the longitudinal relationship between pain intensity and depressive symptoms among older adults and assessed the buffering effects of social and physical activities. In addition, it explored whether these buffering effects vary by gender and educational attainment. Research Design and Methods: Using 8 waves (2006-2020) of the Korean Longitudinal Study of Aging, we analyzed a sample of 7,238 older adults aged 65 years and older. Longitudinal fixed-effects models were employed to assess how within-person changes in pain intensity were associated with within-person changes in depressive symptoms. Interaction terms were included to test the buffering effects of informal and formal social activity, as well as physical activity. Stratified analyses were conducted to explore potential heterogeneity by educational attainment and gender. Results: The fixed-effects models indicated that increases in pain intensity were significantly associated with higher levels of depressive symptoms. Interaction analyses revealed that this positive association was moderated by informal social activity, formal social activity, and physical activity. Specifically, older adults with higher levels of social or physical activity exhibited a weaker association between pain and depressive symptoms than those with lower levels of engagement. No clear differences in moderating effects were observed by education or gender. Discussion and Implications: These findings highlight that social and physical activities act as key protective factors against the adverse psychological consequences of pain among older adults. Integrative interventions that promote sustained social engagement and physical activity may help mitigate depression risk in this population.