The British child and adolescent mental health survey 1999: the prevalence of DSM-IV disorders.

Objective: To describe the prevalence of DSM-IV disorders and comorbidity in a large population-based sample of British children and adolescents. Method: Using a one-phase design, 10,438 children were assessed using the Development and Well-Being Assessment (DAWBA), a structured interview with verbatim reports reviewed by clinicians so that information from parents, teachers, and children was combined in a manner that emulated the clinical process. The authors' analysis examined comorbidity and the influence of teacher reports. Results: The overall prevalence of DSM-IV disorders was 9.5% (95% confidence interval 8.8-10.1%), but 2.1% of children were assigned "not otherwise specified" rather than operationalized diagnoses. After adjusting for the presence of a third disorder, there was no longer significant comorbidity between anxiety and conduct disorder or attention-deficit/hyperactivity disorder (ADHD), or between depression and oppositional defiant disorder. A comparison of the disorders in children with and without teacher reports suggested that the prevalence of conduct disorders and ADHD would be underestimated in the absence of teacher information. Conclusions: Roughly 1 in 10 children have at least one DSM-IV disorder, involving a level of distress or social impairment likely to warrant treatment. Comorbidity reported between some childhood diagnoses may be due to the association of both disorders with a third. Diagnoses of conduct disorder and ADHD may be missed if information is not sought from teachers about children's functioning in school