title: Neuropsychological performance in DSM-IV ADHD subtypes: an exploratory study with untreated adolescents.
abstract: OBJECTIVE
  To explore neuropsychological performance in untreated Brazilian adolescents suffering from attention-deficit hyperactivity disorder (ADHD).
  
  
  METHODS
  We assessed 30 untreated adolescents with ADHD and 60 healthy control subjects, aged 12 to 16 years, using a neuropsychological battery including the Wisconsin Card-Sorting Test (WCST), the Stroop Test (ST), the Digit Span, and the Word Span.
  
  
  RESULTS
  We found neuropsychological differences among the DSM-IV ADHD subtypes. Adolescents with the predominantly inattentive subtype (ADHD-I) performed more poorly than did control subjects on both the Digit Span and the ST. On both the Digit Span and the WCST, adolescents with the combined subtype (ADHD-C) presented significantly more impairments than did control subjects. Adolescents with the predominantly hyperactive-impulsive type (ADHD-HI) did not differ significantly from the control subjects in any measure assessed, but had a better performance than did those with ADHD-C on both the Digit Span and the WCST. In addition, adolescents with ADHD-HI performed better on the ST than did adolescents with ADHD-I.
  
  
  CONCLUSIONS
  These findings suggest cognitive differences among ADHD subtypes, supporting the diagnostic distinction among them. Adolescents with ADHD-HI do not seem to have significant cognitive deficits.
authors.affiliation: Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Schmitz
authors.forename: Luciana
authors.initials: L
authors.lastname: Cadore
authors.forename: Marcelo
authors.initials: M
authors.lastname: Paczko
authors.forename: Letícia
authors.initials: L
authors.lastname: Kipper
authors.forename: Márcia
authors.initials: M
authors.lastname: Chaves
authors.forename: Luis A
authors.initials: LA
authors.lastname: Rohde
authors.forename: Clarissa
authors.initials: C
authors.lastname: Moura
authors.forename: Márcia
authors.initials: M
authors.lastname: Knijnik
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications* / Q000628:therapy*; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D003431:Cross-Cultural Comparison; D005260:Female; D006801:Humans; D008297:Male; D008605:Mental Health Services / Q000706:statistics & numerical data*; D009483:Neuropsychological Tests; D012720:Severity of Illness Index