Associations Between School Bullying or Victimization and Students' Sleep Problems-A Systematic Review and Meta-Analysis.

Students experiencing victimization and those bullying others may develop subsequent sleep problems and vice versa. The existing meta-analyses have focused only on cross-sectional associations or longitudinal links from victimization to sleep problems. Therefore, this study systematically reviewed the literature and conducted a meta-analysis of cross-sectional and bidirectional longitudinal associations between victimization or bullying and sleep problems in children and adolescents. After a systematic search of studies, abstracts, and full texts of 1,205 studies were screened for eligibility. In total, 216 effects representing 52 studies were included in the meta-analysis. The results indicated moderate cumulative effect for cross-sectional relationships of sleep problems to victimization (d = 0.38; 37 studies), bullying (d = 0.27; 12 studies) and being a bully-victim (d=0.48; 5 studies). Supporting the bidirectional longitudinal model, victimization both preceded (d = 0.43; 13 studies) and followed (d = 0.36; 5 studies) sleep problems. Similarly, bullying both preceded (d = 0.34; 2 studies) and followed (d = 0.37; 3 studies) sleep problems. Methodological quality of studies varied, but it did not consistently moderate the links. Gender and age moderated some associations. The concurrent association between bullying and sleep problems was stronger in samples with higher proportions of female students. The link from victimization to subsequent sleep problems was stronger in younger than older students. Finally, a small indication of publication bias was documented. This meta-analysis provides robust evidence for bidirectional links between victimization or bullying and sleep problems and points to the need for antibullying programs to disrupt this vicious cycle.