The aim of this study was to investigate whether impaired
response inhibition is uniquely
related to AD/HD or whether deficits in response inhibition are also
evident in other
psychopathological disorders. Furthermore, the suggestion was examined
that anxiety
disorders are associated with abnormally high levels of response inhibition.
This paper
presents the results of a meta-analysis of eight studies in which response
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 response inhibition deficit in AD/HD.
However, response
inhibition deficits did not distinguish children with AD/HD from children
with CD, nor
from children with comorbid AD/HD+CD. Contrary to predictions, anxious
children did
not demonstrate enhanced levels of response inhibition.