The independent and joint impact of social and internet isolation on depression and loneliness among older adults: evidence from cross-cultural cohort studies

OBJECTIVES: This study examined independent and joint associations of social and internet isolation with incident depression and loneliness among older adults in two culturally distinct cohorts. METHODS: = 3120). Cox proportional hazards regression models were applied to assess the independent and joint effects of social and internet isolation on depression and loneliness. Additionally, a random-effects meta-analysis was conducted to examine heterogeneity across different cultural contexts. RESULTS: In both ELSA and CHARLS cohorts, social isolation was more strongly associated with loneliness (ELSA: HR = 2.36, 95% CI: 1.81-3.09; CHARLS: HR = 1.57, 95% CI: 1.21-2.05), whereas internet isolation showed a stronger association with depression (ELSA: HR = 1.29, 95% CI: 1.05-1.58; CHARLS: HR = 1.57, 95% CI: 1.11-2.23). Both forms of isolation independently contributed to elevated risks of depression and loneliness. Participants experiencing both forms of isolation had the highest risks of depression and loneliness, particularly in the ELSA cohort. CONCLUSION: The results were consistent with social support theory and extended the understanding of the association between social and internet isolation and mental health outcomes.