Preschool Attention-Deficit/Hyperactivity and Oppositional Defiant Problems as Antecedents of School Bullying.

OBJECTIVE To examine whether early manifestations of attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) increase children's later risk of bullying or victimization. METHOD Using a population-based, prospective cohort, our multi-informant approach comprised reports of parents, teachers, and peers. ADHD and ODD behavioral problems at ages 1.5, 3, and 5 years were determined from parental reports on the Child Behavior Checklist. Later bullying behavior at school was reported by teachers using a questionnaire (n = 3,192, mean age 6.6 years), and by peer/self-reports using peer nominations (n = 1,098, mean age 7.6 years). We examined the following: whether problem behavior scores at age 1.5, 3, or 5 years predicted a risk of bullying involvement; and whether high or increasing behavioral problems throughout ages 1.5 to 5 years were associated with bullying involvement at school. Analyses were adjusted for a range of child and maternal covariates. RESULTS Behavioral problems at a young age each predicted later bullying involvement at school. For example, higher ADHD problem scores at age 3 years were associated with the risks of becoming a bully or a bully-victim (ORBULLY = 1.20, 95% CI = 1.07-1.35 [teacher report], ORBULLY-VICTIM = 1.28, 95% CI = 1.14-1.43 [teacher report], and ORBULLY-VICTIM = 1.35, 95% CI = 1.03-1.78 [peer/self-report]). Children whose behavioral problem scores were high or increased over time consistently had elevated risks of becoming a bully or a bully-victim. CONCLUSION Behavioral problems at a young age may predispose children to bullying involvement in early elementary school.