Family dysfunction plays an important role in cyberbullying and cybervictimization. However, little research has investigated the longitudinal relations and the mediating mechanisms between them during adolescence. This study examined the longitudinal relations between family dysfunction and cyberbullying and cybervictimization, along with whether depressive symptoms function as mediators between them at the within-person level. A total of 3,743 Chinese adolescents (46.2% females; Mage = 9.92 years; SD = 0.51) participated a five-wave longitudinal study with a 6-month time interval. The results of random intercept cross-lagged panel model found that: (1) family dysfunction directly predicted depressive symptoms and vice versa at the within-person level; (2) depressive symptoms directly predicted cyberbullying and cybervictimization at the within-person level, but not vice versa; (3) family dysfunction indirectly predicted cyberbullying and cybervictimization via depressive symptoms at the within-person level; (4) at the between-person level, there were significant associations among family dysfunction, depressive symptoms, cyberbullying and cybervictimization. The results are discussed on the basis of the mechanisms that lead to cyberbullying and cybervictimization.

The present study used a longitudinal and discordant twin design to explore in depth the developmental associations between victimization and loneliness from mid-childhood to young adulthood. The data were drawn from the Environmental Risk (E-Risk) Longitudinal Twin Study, a birth cohort of 2,232 individuals born in England and Wales during 1994–1995. Diverse forms of victimization were considered, differing across context, perpetrator, and timing of exposure. The results indicated that exposure to different forms of victimization was associated with loneliness in a dose–response manner. In childhood, bullying victimization was uniquely associated with loneliness, over and above concurrent psychopathology, social isolation, and genetic risk. Moreover, childhood bullying victimization continued to predict loneliness in young adulthood, even in the absence of ongoing victimization. Within-twin pair analyses further indicated that this longitudinal association was explained by genetic confounds. In adolescence, varied forms of victimization were correlated with young adult loneliness, with maltreatment, neglect, and cybervictimization remaining robust to controls for genetic confounds. These findings indicate that vulnerability to loneliness in victimized young people varies according to the specific form of victimization in question, and also to the developmental period in which it was experienced.