• CD;
  • early intervention;
  • ODD;
  • school-based program


Oppositional defiant disorder (ODD) or conduct disorder (CD) occurs when children's disruptive and antisocial behaviours start to interfere with their academic, emotional and/or social development. Recently, there has been a considerable investment to implement national school-based early intervention programs to help prevent the onset of ODD/CD.


This paper describes the delivery of the Royal Children's Hospital, Child and Adolescent Mental Health Service and Schools Early Action Program: a whole school, multi-level, multidisciplinary approach to address emerging ODD/CD and pre- versus post-delivery assessment in 40 schools over a 4-year period (2007–2010).


All children from preparatory to grade 3 (ages 4–10 years) were screened for conduct problems (n = 8546) using the Strengths and Difficulties Questionnaire. Universal, targeted and indicated interventions were delivered in school settings. In total, 304 children participated in the targeted group program where the Child Behaviour Checklist was used as a pre- and post-intervention measure. Cohen's d effect sizes and a reliability change index were calculated to determine clinical significance.


Significant reductions in both parent- and teacher-reported internalizing and externalizing symptoms were noted. Parent, teacher and child feedback were very positive.


A future randomized controlled trial of the program would address potential placebo and selection bias effects.