title: Validity of the age-of-onset criterion for ADHD: a report from the DSM-IV field trials.
abstract: OBJECTIVE
  To examine the validity of the DSM-IV requirement of an age of onset of impairment due to symptoms before 7 years of age for the diagnosis of attention-deficit/hyperactivity disorder (ADHD).
  
  
  METHODS
  The validity of this criterion was examined in a clinic sample of 380 youths aged 4 through 17 years by comparing youths who met symptom criteria for ADHD and either did or did not display impairment before age 7 years.
  
  
  RESULTS
  Nearly all youths who met symptom criteria for the predominantly hyperactive-impulsive subtype also met the age of onset of impairment criterion, but 18% of youths who met symptom criteria for the combined type, and 43% of youths who met symptom criteria for the predominantly inattentive type, did not manifest impairment before 7 years. For the latter two subtypes, requiring impairment before age 7 years reduced the accuracy of identification of currently impaired cases of ADHD and reduced agreement with clinicians' judgments.
  
  
  CONCLUSIONS
  These findings raise questions about the validity of the DSM-IV definition of age of onset of ADHD. Marked differences in the ages of onset of both symptoms and impairment for the three subtypes of ADHD support the validity of distinguishing among these subtypes in DSM-IV.
authors.affiliation: University of Miami, USA.
authors.forename: B
authors.initials: B
authors.lastname: Applegate
authors.forename: B B
authors.initials: BB
authors.lastname: Lahey
authors.forename: E L
authors.initials: EL
authors.lastname: Hart
authors.forename: J
authors.initials: J
authors.lastname: Biederman
authors.forename: G W
authors.initials: GW
authors.lastname: Hynd
authors.forename: R A
authors.initials: RA
authors.lastname: Barkley
authors.forename: T
authors.initials: T
authors.lastname: Ollendick
authors.forename: P J
authors.initials: PJ
authors.lastname: Frick
authors.forename: L
authors.initials: L
authors.lastname: Greenhill
authors.forename: K
authors.initials: K
authors.lastname: McBurnett
authors.forename: J H
authors.initials: JH
authors.lastname: Newcorn
authors.forename: L
authors.initials: L
authors.lastname: Kerdyk
authors.forename: B
authors.initials: B
authors.lastname: Garfinkel
authors.forename: I
authors.initials: I
authors.lastname: Waldman
authors.forename: D
authors.initials: D
authors.lastname: Shaffer
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000145:classification / Q000175:diagnosis*; D016009:Chi-Square Distribution; D002648:Child; D002665:Child Psychiatry / Q000592:standards*; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008370:Manuals as Topic / Q000592:standards*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012494:Sampling Studies