Clinical Psychological Science, Ahead of Print.
In this meta-analysis, we aimed to evaluate the cross-sectional and longitudinal relationships between various forms of sleep problems and loneliness. A total of 84 articles (110 samples, N = 227,112) were identified for inclusion. Random effects models revealed a significant medium association between overall sleep problems and loneliness (r = .336, 95% confidence interval = [.315, .357]) as well as specific sleep complaints (i.e., insomnia, nightmares, poor sleep efficiency, and poor sleep quality) and loneliness (rs = .165–.354). The longitudinal relationships between overall sleep problems and subsequent loneliness, and vice versa, were also significant (rs = .249–.297). Although no consistent moderation patterns emerged, several significant moderators were identified for specific associations. Results support a robust association between more severe sleep problems and greater perceptions of loneliness; both also appear reciprocally associated longitudinally. Findings point to research directions that may enhance understanding of the interplay between sleep problems and loneliness—constructs with transdiagnostic relevance.