Loneliness and sleep disturbance as serial mediators in the association between social isolation and depressive symptoms among older Korean–American residents of subsidized senior housing

Objectives: The study examined the dynamics among social isolation, loneliness, sleep disturbance, and depressive symptoms in older Korean–American residents of subsidized senior housing. Building upon the well-established link between social isolation and depressive symptoms, we hypothesized three indirect effect models with (1) loneliness as a sole mediator, (2) sleep disturbance as a sole mediator, and (3) loneliness and sleep disturbance as serial mediators. Methods: Survey data from 318 participants (M age = 79.5 years, SD = 6.66) were used to examine the direct and mediation effect models. Results: We confirmed that social isolation independently predicted depressive symptoms and found partial support for the mediation models. Among the three mediation pathways proposed, significance was found in the sole mediation by loneliness (B [SE] = 0.86 [0.29], bias-corrected 95% CI = [0.31, 1.47]) and the sequential mediation by loneliness and sleep disturbance (B [SE] = 0.12 [0.06], bias-corrected 95% CI = [0.03, 0.25]). The alternative path, where sleep disturbance precedes loneliness, was not significant, confirming the robustness of the proposed serial path. Conclusion: Findings underscore the importance of addressing both loneliness and sleep disturbances as interconnected factors in interventions aimed at alleviating the mental health impacts of social isolation.