Objective: To evaluate the prevalence, comorbid conditions, and impairments of attention-deficit/hyperactivity disorder (ADHD) among young adolescents in Porto Alegre, Brazil.
Method: 1,013 students aged 12 to 14 years were evaluated at 64 state schools, using a screening instrument based on the 18 DSM-IV ADHD symptoms. All positive screened students (n = 99) and a random subset of negative screened subjects (n = 92) had a psychiatric evaluation carried out within a hospital setting or at home.
Results: The prevalence of ADHD was estimated to be 5.8% (95% confidence interval = 3.2-10.6), and the comorbidity with other disruptive behavior disorders was high (47.8%). Youths with ADHD (n = 23) had significantly higher rates of school repetitions, suspensions, and expulsions (p < .01) than controls (n = 168). No association was identified between ADHD and alcohol, marijuana, and inhalant use.
Conclusion: The results extend to adolescents well-documented findings in children, indicating that ADHD is quite prevalent in early adolescence and affected youths are at high risk for impairment and dysfunction in multiple domains.