a1 Department of Psychiatry, SUNY Upstate Medical University, Syracuse, NY, USA
a2 Department of Psychiatry, Harvard Medical School, Massachusetts General Hospital, Pediatric Psychopharmacology Unit, Yawkey Center for Outpatient Care, Boston, MA, USA
Background Diagnosing attention deficit hyperactivity disorder (ADHD) in adults is difficult when diagnosticians cannot establish onset prior to the DSM-IV criterion of age 7 or if the number of symptoms does not achieve the DSM threshold for diagnosis. Previous work has assessed the validity of such diagnoses based on psychiatric co-morbidity, family history and neuropsychological functions but none of these studies have used personality as a validation criterion.
Method We compared four groups of adults: (1) full ADHD subjects who met all DSM-IV criteria for childhood-onset ADHD; (2) late-onset subjects who met all criteria except the age at onset criterion, (3) subthreshold subjects who did not meet full symptom criteria and (4) non-ADHD subjects who did not meet any of the above criteria. Diagnoses were made by using the Structured Clinical Interview for DSM-IV (SCID) and the Temperament and Character Inventory (TCI) was used to assess personality traits.
Results We found that full ADHD and late-onset ADHD showed similar personality profiles with significant deviations on all TCI scales except reward dependence and self-transcendence. By contrast, subthreshold cases only showed deviations on novelty seeking and self-directiveness.
Conclusions These data call into question the stringent age of onset of ADHD symptom criteria for adults when making retrospective diagnoses of ADHD. Subthreshold ADHD seems to be a milder form of the disorder that is consistent with dimensional views of the disorder.
(Received February 15 2008)
(Revised May 16 2008)
(Accepted May 22 2008)
(Online publication June 30 2008)
c1 Address for correspondence: Dr S. V. Faraone, Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, 750 East Adams St, Syracuse, NY 13210, USA. (Email: firstname.lastname@example.org)