title: Do executive deficits and delay aversion make independent contributions to preschool attention-deficit/hyperactivity disorder symptoms?
abstract: OBJECTIVE
  To test whether deficits in executive function and delay aversion make independent contributions to levels of attention-deficit/hyperactivity disorder (ADHD) symptoms exhibited by preschool children.
  
  
  METHODS
  One hundred fifty-six children between 3 and 5.5 years old (78 girls and 78 boys) selected from the community completed an age-appropriate battery of tests measuring working memory, set shifting, planning, delay of gratification, and preference for delayed rewards. Parents completed a clinical interview about their children's ADHD symptoms.
  
  
  RESULTS
  Analysis of test performance revealed two factors: executive dysfunction and delay aversion. Multivariate analysis demonstrated that when other factors (i.e., age, IQ, and conduct problems) were controlled, executive dysfunction and delay aversion each made significant independent contributions to predictions of ADHD symptoms.
  
  
  CONCLUSIONS
  Preschool ADHD symptoms are psychologically heterogeneous. Executive dysfunction and delay aversion may represent two distinct and early appearing neurodevelopmental bases for ADHD symptoms.
authors.affiliation: School of Psychology, University of Southampton, Southampton SO17 1BJ, UK. ejb3@soton.ac.uk
authors.forename: Edmund J S
authors.initials: EJ
authors.lastname: Sonuga-Barke
authors.forename: Lindy
authors.initials: L
authors.lastname: Dalen
authors.forename: Bob
authors.initials: B
authors.lastname: Remington
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology*; D002675:Child, Preschool; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D012720:Severity of Illness Index