Adverse childhood experiences and social isolation in older adults: Japan Gerontological Evaluation Study 2016–2019

Adverse childhood experiences (ACEs) can have lasting life-course consequences, including a potential impact on social isolation in later life. Longitudinal evidence capturing incident isolation is particularly needed, as cross-sectional studies cannot establish the temporal sequence between ACEs and later-life social isolation. However, this longitudinal association remains insufficiently examined, particularly among older adults in Japan. We investigated the longitudinal association between ACEs and social isolation in older adults and explored subgroup differences and ACE-specific patterns. We conducted a longitudinal cohort study using data from the Japan Gerontological Evaluation Study from 2016 to 2019, including 7,688 functionally independent older adults. The primary outcome was incident social isolation in 2019, and ACEs were reported in 2016. Subgroup- and item-specific ACEs analyses were performed. Among the participants, 1.8% reported four or more ACEs, and 11.3% developed social isolation. Using multivariable modified Poisson regression adjusting for demographic, socioeconomic, and health-related factors, participants with four or more ACEs had a higher risk of developing social isolation than those with fewer ACEs (relative risk [RR], 2.11; 95% confidence interval [CI], 1.61–2.77). This association was stronger among those aged 65–74 years, those with higher educational attainment, and those with lower income. Across individual ACE items, physical abuse (RR, 2.06; 95% CI, 1.49–2.84) and parental mental illness (RR, 1.95; 95% CI, 1.44–2.65) showed particularly strong associations. These findings suggest that early-life adversity may contribute to social isolation in later life and underscore the potential value of early-life and life-course intervention strategies for promoting healthy aging.