title: Neuropsychological studies of late onset and subthreshold diagnoses of adult attention-deficit/hyperactivity disorder.
abstract: BACKGROUND
  Diagnosing attention-deficit/hyperactivity disorder (ADHD) in adults is difficult when the diagnostician cannot establish an onset prior to the DSM-IV criterion of age 7 or if the number of symptoms recalled does not achieve the DSM-IV threshold for diagnosis. Because neuropsychological deficits are associated with ADHD, we addressed the validity of the DSM-IV age at onset and symptom threshold criteria by using neuropsychological test scores as external validators.
  
  
  METHODS
  We compared four groups of adults: 1) full ADHD subjects met all DSM-IV criteria for childhood-onset ADHD; 2) late-onset ADHD subjects met all criteria except the age at onset criterion; 3) subthreshold ADHD subjects did not meet full symptom criteria; and 4) non-ADHD subjects did not meet any of the above criteria.
  
  
  RESULTS
  Late-onset and full ADHD subjects had similar patterns of neuropsychological dysfunction. By comparison, subthreshold ADHD subjects showed few neuropsychological differences with non-ADHD subjects.
  
  
  CONCLUSIONS
  Our results showing similar neuropsychological underpinning in subjects with late-onset ADHD suggest that the DSM-IV age at onset criterion may be too stringent. Our data also suggest that ADHD subjects who failed to ever meet the DSM-IV threshold for diagnosis have a milder form of the disorder.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA. faraones@upstate.edu
authors.forename: Stephen V
authors.initials: SV
authors.lastname: Faraone
authors.forename: Joseph
authors.initials: J
authors.lastname: Biederman
authors.forename: Alysa
authors.initials: A
authors.lastname: Doyle
authors.forename: Kate
authors.initials: K
authors.lastname: Murray
authors.forename: Carter
authors.initials: C
authors.lastname: Petty
authors.forename: Joel J
authors.initials: JJ
authors.lastname: Adamson
authors.forename: Larry
authors.initials: L
authors.lastname: Seidman
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001289:Attention Deficit Disorder with Hyperactivity / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D003710:Demography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests