Behaviour problems in a population of seven-year-old children: prevalence, stability and types of disorder--a research report.

A sample of 951 children in Dunedin, New Zealand was assessed at age 7 years to examine the prevalence, nature and stability of behaviour problems. The identification of children with behaviour problems was based upon reports of parents and teachers. About 30% of the sample were identified by the parent and/or teacher as having a high level of problem behaviour. The most prevalent problem reported was antisocial behaviour, which was more common among boys than girls. Over 9% of the sample were identified as having a stable behaviour problem. Such stable problems were associated with specific reading retardation, independent ratings of behaviour during psychological testing and use of professional services for help. These children, together with those identified by both parent and teacher at age 7 years, should be regarded as having a significant behaviour disorder.