The prevalence of ADHD was 8.7%, with three times as many males being affected by this condition as females. The prevalence of severe ADHD was 4.2%, or approximately half of all cases in the sample. ODD was present in 12.6% of the sample (6.5% for severe cases) and 6.8% met criteria for CD (2.2% for severe cases). Although the rates of ADHD and ODD remained relatively stable by age group, rates of CD increased to a peak of 9.6% among the oldest adolescents.
