Abstract
OBJECTIVES: The reciprocal relationship between oral health and mental health, and the underlying mechanisms remain underexplored. This study examined whether formal social engagement mediates the relationship between oral health and mental health in both directions. METHODS: Cross-lagged panel models with two-wave mediation were applied to data from 3860 older adults, aged 65 years or above, in the two waves of the Korean Longitudinal Study of Aging conducted in 2018 and 2020. Oral health was measured using the 12-item Geriatric Oral Health Assessment Index, and mental health was assessed with the 10-item Center for Epidemiologic Studies Depression Scale. RESULTS: The analysis identified a reciprocal relationship between oral health and depressive symptoms, with depressive symptoms exerting a stronger effect on oral health than vice versa. Formal social engagement partially mediated the effect of oral health on depressive symptoms, but not the other way around. CONCLUSIONS: The findings reaffirm the interplay and interdependence of oral health and mental health among older adults. Comprehensive strategies that integrate social engagement opportunities are imperative for developing interventions targeting older adults with compromised oral health.