The association of loneliness with health and well-being: A second-order meta-analysis.

OBJECTIVE: Lonely people are dissatisfied with the quantity or quality of their social relationships. Prior meta-analyses examined the association of loneliness with specific indices of health or well-being. Here we explored associations of loneliness with several indices of health and well-being, in addition to how such associations vary across different conditions. METHOD: We synthesized data from 49 independent meta-analyses that collectively included over 60 outcomes, 1,900 studies, and 4.8 million participants. We used second-order meta-analysis to assess relations of loneliness with health and well-being. RESULTS: We found a robust association of loneliness with broad indices of mental health, r = .37, 95% confidence interval [CI; 0.31, 0.44], psychological adjustment, r = .32, 95% CI [0.28, 0.36], and physical health, r = .15, 95% CI [0.10, 0.20], as well as specific indices of anxiety, cognitive functioning, depression, relationship functioning, social support, and problematic technology use. Loneliness associations varied significantly by loneliness measure and inclusion of unpublished studies, longitudinal studies, and covariates. However, risk of bias may have inflated effect sizes. CONCLUSIONS: Our findings clarify the association of loneliness with several indices of health and well-being as well as the conditions under which these associations are most pronounced. Additional study is needed to examine longitudinal associations, interventions, and preregistered effects. (PsycInfo Database Record (c) 2026 APA, all rights reserved).