title: Re-examining comorbidity of Obsessive Compulsive and Attention-Deficit Hyperactivity Disorder using an empirically derived taxonomy.
abstract: BACKGROUND
  Using an empirically derived instrument to reduce the assessor bias inherent in structured diagnostic interviews, we sought to re-examine and validate the putative comorbidity between Obsessive Compulsive Disorder (OCD) and Attention-Deficit/Hyperactivity Disorder (ADHD) in children and adolescents.
  
  
  METHODS
  We examined the correlation between Child Behavior Checklist (CBCL) syndrome, competence, and composite scores in children with: 1) OCD plus ADHD (OCD + ADHD), N = 47; 2) OCD without comorbid ADHD (OCD), N = 33; 3) ADHD without comorbid OCD (ADHD) N = 43; and 4) comparison controls recruited from general pediatric clinics,N = 32.
  
  
  RESULTS
  CBCL findings in our ADHD children were similar to previous findings reported in ADHD youth, irrespective of the presence or absence of comorbid OCD. Comorbid youth generally had additive scores on the CBCL scales, reflecting the independent contribution of symptomatic and functional impairment from each disorder.
  
  
  CONCLUSIONS
  These findings suggest that when ADHD-like symptoms are seen in OCD youth, they reflect a true comorbid state of OCD plus ADHD. The CBCL may provide a rapid assessment tool to identify comorbid ADHD in OCD youth.
authors.affiliation: Pediatric OCD Clinic, Massachusetts General Hospital, WACC 725, 15 Parkman Street, Boston, MA 02114, USA. dageller@partners.org
authors.forename: D A
authors.initials: DA
authors.lastname: Geller
authors.forename: J
authors.initials: J
authors.lastname: Biederman
authors.forename: S
authors.initials: S
authors.lastname: Faraone
authors.forename: T
authors.initials: T
authors.lastname: Spencer
authors.forename: R
authors.initials: R
authors.lastname: Doyle
authors.forename: B
authors.initials: B
authors.lastname: Mullin
authors.forename: M
authors.initials: M
authors.lastname: Magovcevic
authors.forename: N
authors.initials: N
authors.lastname: Zaman
authors.forename: C
authors.initials: C
authors.lastname: Farrell
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D002652:Child Behavior / Q000523:psychology; D002653:Child Behavior Disorders / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000453:epidemiology*; D010552:Personality Assessment / Q000592:standards; D000297:Psychology, Adolescent; D002666:Psychology, Child; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires