ADHD in a school sample of Brazilian adolescents: A study of prevalence, comorbid conditions, and impairments

Luis A. Rohde, Joseph Biederman, Elus A. Busnello, Heloisa Zimmermann, Marcelo Schmitz, Silvia Martins, Silza Tramontina

Research output: Contribution to journalArticlepeer-review

203 Scopus citations


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.

Original languageEnglish
Pages (from-to)716-722
Number of pages7
JournalJournal of the American Academy of Child and Adolescent Psychiatry
Issue number6
StatePublished - 1999
Externally publishedYes


  • Attention-deficit/hyperactivity disorder
  • Hyperactivity
  • Inattention


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