EEG Activity in Subtypes of Attention-Deficit/ Hyperactivity Disorder

Résumé

This article is a review of electroencephalography (EEG) studies of different types and subtypes of Attention-Deficit/Hyperactivity Disorder (AD/HD). The review outlines the definitional history of AD/HD, and changes that have been made to the conceptualization of the disorder as these different definitions have impacted on the EEG literature. EEG studies are examined using various models of AD/HD based on either behaviour or underlying central nervous system (CNS) abnormalities. From these studies, it appears that AD/HD children generally have increased absolute and relative power in the theta band, either at the frontal electrode sites or over the entire scalp. Reductions in absolute and relative power in the alpha and beta bands have also been found in several studies, although relative power measures appear to be more reliable than absolute power. Increased delta activity in both absolute and relative power has also been noted in several studies. These results are discussed in terms of existing CNS-based models of AD/HD, which attribute the disorder to hypoarousal or a maturational lag in CNS development. Implications of these data for clinical use and future research and development in AD/HD are considered.