Children spend a lot of time in school, which is an important arena for socialisation. When children display problems related to mental health, school can serve as a detector as well as an arena for treatment. 1 It is established that children that display early disruptive behaviour problems (DBP) such as aggressiveness, truancy, noncompliance, defiance, impulsiveness or oppositional behaviour, are at high risk of severe long-term problems later in life, such as oppositional defiant disorder, conduct disorder and early adulthood psychiatric and emotional problems. 2 Teachers' observations have shown to accurately identify children displaying risk behaviour. 3 In addition, relying on teachers' observations also makes it possible to target children who display DBP in school, but do not display high levels of DBP at home. 3 Children displaying DBPs are most commonly referred to child mental health services, 4 and often receive