The interaction effects of social support and four types of bullying on sleep quality in Chinese adolescents.

OBJECTIVES: The aims of this study were to examine the association of verbal, social, physical, and cyber bullying victimizations with sleep quality while taking social support as a moderator and to further examine gender and grade differences in the moderating effects of social support on bullying-associated sleep quality among Chinese adolescents. METHODS: An online cross-sectional survey was conducted in a province of northwestern China. A total of 20,320 students were included in our analyses. Multivariable linear regression analyses were conducted to examine the association between bullying victimization and sleep quality as well as the moderating effects of social support on these relationships. RESULTS: After adjusting for confounding variables, four types of bullying victimization were significantly associated with sleep quality. Social support only moderated the relationship of verbal, physical, and social bullying with sleep quality. Moreover, these positive moderating effects were found only for girls and, in terms of grade difference, only for primary students. Some reversed moderating effects of social support were also observed in the relationship of cyber, physical bullying with sleep quality. LIMITATIONS: This was a cross-sectional study, limiting the causal inference. CONCLUSIONS: This study revealed that bullying is a risk factor for poor sleep quality among adolescents in northwestern China. Furthermore, social support moderated the relationship between bullying and sleep quality in different ways depending on grade, gender, and type of bullying. More efforts are needed to prevent bullying and improve both school climate and students' sleep quality.