title: Tourette syndrome-associated psychopathology: roles of comorbid attention-deficit hyperactivity disorder and obsessive-compulsive disorder.
abstract: OBJECTIVE
  Individuals with Tourette syndrome (TS) often display comorbid symptoms of attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD), as well as externalizing and internalizing behaviors. This study was aimed to examine the impacts of tic severity, ADHD symptoms, and OCD on internalizing (e.g., anxiety) and externalizing (e.g., aggression) psychopathology.
  
  
  METHODS
  Using linear regressions, we examined how tics, ADHD, and OCD symptoms predicted the externalization and internalization behaviors measured by the Child Behavior Checklist in a clinical sample of children and adolescents with TS. In addition, Child Behavior Checklist scales were compared among children with TS without ADHD, TS and ADHD, ADHD without TS, and unaffected control group.
  
  
  RESULTS
  In the TS group, externalizing behaviors were predicted by tic severity, inattention, and hyperactivity/impulsivity but not by OCD symptoms, whereas internalizing behaviors were predicted by inattention and OCD symptoms but not by tic severity or hyperactivity/impulsivity. Comparison among different clinical groups revealed main effects of TS and ADHD on both externalizing and internalizing behaviors.
  
  
  CONCLUSIONS
  These findings suggest that tics, ADHD, and OCD symptoms differentially explain the variance in externalizing and internalizing behavioral problems in individuals with TS. In addition, the data support the notion that TS is itself a risk factor for behavioral problems, mandating that children with TS even without ADHD and OCD still need to be assessed and treated for psychopathology.
authors.affiliation: Neuropediatric Unit, Shaare Zedek Medical Center, Jerusalem, Israel. msyehu@huji.ac.il
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Pollak
authors.forename: Fortu
authors.initials: F
authors.lastname: Benarroch
authors.forename: Liana
authors.initials: L
authors.lastname: Kanengisser
authors.forename: Yuval
authors.initials: Y
authors.lastname: Shilon
authors.forename: Hilla
authors.initials: H
authors.lastname: Ben-Pazi
authors.forename: Hilla
authors.initials: H
authors.lastname: Benpazi
authors.forename: Ruth S
authors.initials: RS
authors.lastname: Shalev
authors.forename: Varda
authors.initials: V
authors.lastname: Gross-Tsur
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000523:psychology*; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009483:Neuropsychological Tests; D009771:Obsessive-Compulsive Disorder / Q000453:epidemiology / Q000523:psychology*; D012720:Severity of Illness Index; D005879:Tourette Syndrome / Q000453:epidemiology / Q000523:psychology*