RESPONSE-INHIBITION AND RESPONSE RE-ENGAGEMENT IN ATTENTION-DEFICIT HYPERACTIVITY DISORDER, DISRUPTIVE, ANXIOUS AND NORMAL-CHILDREN/

The purpose of this study was to determine whether attention-deficit/h yperactivity disorder (AD/HD) is uniquely related to impairments in tw o aspects of executive functioning: (1) response inhibition; and (2) r esponse re-engagement. AD/HD (n = 10), disruptive (n = 11): anxious (n = 11) and normal children (n = 21) were compared on the change task. Children were in the age range of 8-12 years. Il;he psychopathological groups were recruited from special educational services. Parent, teac her and child questionnaires were used to select children with pervasi ve disorders. Controls attended normal classes and scored low on all q uestionnaires. Compared with normal children, both AD/HD and disruptiv e children showed poor response inhibition, but only AD/HD children ex hibited a deficit in the underlying inhibitory process. Some evidence was found for enhanced response inhibition in anxious children. Both A D/HD and disruptive children demonstrated higher variability in the sp eed of the response re-engagement process and were less accurate. The results suggest that AD/HD involves a more pervasive impairment in cog nitive functioning, rather than a deficit restricted to the powers of response inhibition. (C) 1998 Elsevier Science B.V. All rights reserve d.