Sibling Bullying: A Prospective Longitudinal Study of Associations with Positive and Negative Mental Health during Adolescence

Sibling bullying is associated with poor mental health outcomes, but the relevance of specific bullying roles remains unclear. Data from a population-based study (n = 17,157, 48% female) focusing on early (11 years), middle (14 years), and late (17 years) adolescence were analyzed. Associations between sibling bullying roles in early adolescence and positive and negative mental health outcomes in late adolescence were investigated. Generally, bullying, irrespective of role, was associated with poorer mental health outcomes in late adolescence. As the frequency of bullying victimization increased between early and middle adolescence so did the severity of mental health outcomes in late adolescence. The developmental trajectories of externalizing problems were influenced by bullying in early adolescence. Sibling bullying, irrespective of role, is associated with poor mental health outcomes.