title: How specific are executive functioning deficits in attention deficit hyperactivity disorder and autism?
abstract: BACKGROUND
  The objective of this study is to identify intact and deficient cognitive processes in children with attention deficit hyperactivity disorder (ADHD) and children with high functioning autism (HFA).
  
  
  METHODS
  Three rigorously diagnosed groups of children aged between 6 and 12 years (54 ADHD, 41 HFA, and 41 normal controls) were tested on a wide range of tasks related to five major domains of executive functioning (EF): inhibition, visual working memory, planning, cognitive flexibility, and verbal fluency. In addition, the role of comorbid oppositional defiant disorder (ODD) and comorbid conduct disorder (CD) in ADHD was investigated by directly comparing 20 children with ADHD and 34 children with comorbid ADHD + ODD/CD.
  
  
  RESULTS
  ADHD was associated with EF deficits in inhibiting a prepotent response and verbal fluency. Children with HFA demonstrated deficits in all EF domains, except interference control and working memory. The HFA group showed more difficulties than the ADHD group with planning and cognitive flexibility. The comorbid ADHD + ODD/CD group did not show a distinctive pattern of performance on the EF tests compared to the ADHD group.
  
  
  CONCLUSIONS
  The present study indicates that children with HFA exhibit more generalised and profound problems with EF tasks compared to children with ADHD.
authors.affiliation: Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, The Netherlands. h.m.geurst@uva.nl
authors.forename: Hilde M
authors.initials: HM
authors.lastname: Geurts
authors.forename: Sylvie
authors.initials: S
authors.lastname: Verté
authors.forename: Jaap
authors.initials: J
authors.lastname: Oosterlaan
authors.forename: Herbert
authors.initials: H
authors.lastname: Roeyers
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Sergeant
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000523:psychology*; D001321:Autistic Disorder / Q000150:complications / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D003072:Cognition Disorders / Q000209:etiology* / Q000523:psychology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D007806:Language Disorders; D008297:Male; D008568:Memory