title: ADHD in a school sample of Brazilian adolescents: a study of prevalence, comorbid conditions, and impairments.
abstract: OBJECTIVE
  To evaluate the prevalence, comorbid conditions, and impairments of attention-deficit/hyperactivity disorder (ADHD) among young adolescents in Porto Alegre, Brazil.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Pediatric Psychopharmacology Unit, Massachusetts General Hospital, Boston, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Rohde
authors.forename: J
authors.initials: J
authors.lastname: Biederman
authors.forename: E A
authors.initials: EA
authors.lastname: Busnello
authors.forename: H
authors.initials: H
authors.lastname: Zimmermann
authors.forename: M
authors.initials: M
authors.lastname: Schmitz
authors.forename: S
authors.initials: S
authors.lastname: Martins
authors.forename: S
authors.initials: S
authors.lastname: Tramontina
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D002648:Child; D015897:Comorbidity; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D015995:Prevalence; D012494:Sampling Studies