Excess beta activity in children with attention-deficit/hyperactivity disorder: an atypical electrophysiological group

Studies of children with attention deficit/hyperactivity disorder (ADHD) ha ve typically found elevated levels of slow wave activity in their EEGs, but in two of our previous studies, a small subset of ADHD children with exces s beta activity in the EEG was identified. The aim of this study was to det ermine whether children with excess beta activity represent a distinct elec trophysiological subtype of ADHD, to quantify the differences in their EEGs , and to determine if this group of children with ADHD have behavioural pro files different from other children with ADHD. Results indicated that child ren with excess beta represent a small independent subset of children diagn osed with ADHD, which primarily consists of children with a diagnosis of AD HD combined type. Behaviourally, this group was similar to other children w ith ADHD, although the excess-beta group were more prone to temper tantrums and to be moody. The excess in beta activity was found primarily in the fr ontal regions and may be associated with frontal lobe self-regulation and i nhibition control. (C) 2001 Elsevier Science Ireland Ltd. All rights reserv ed.