RESPONSE-INHIBITION IN AD HD, CD, COMORBID AD/HD+CD, ANXIOUS, AND CONTROL CHILDREN - A METAANALYSIS OF STUDIES WITH THE STOP TASK/

The aim of this study was to investigate whether impaired response inh ibition is uniquely related to AD/HD or whether deficits in response i nhibition are also evident in other psychopathological disorders. Furt hermore, the suggestion was examined that anxiety disorders are associ ated with abnormally high levels of response inhibition. This paper pr esents the results of a meta-analysis of eight studies in which respon se inhibition was assessed with the so-called stop task in five groups of children: children with attention deficit/hyperactivity disorder ( AD/HD), children with conduct disorder (CD), children with AD/HD + CD, children with anxiety disorders, and control children. A total of 456 children participated in the 8 studies. All children were in the age range 6-12 years. Consistent and robust evidence was found for a respo nse inhibition deficit in AD/HD. However, response inhibition deficits did not distinguish children with AD/HD from children with CD, nor fr om children with comorbid AD/HD + CD. Contrary to predictions, anxious children did not demonstrate enhanced levels of response inhibition.