title: A review of electrophysiology in attention-deficit/hyperactivity disorder: I. Qualitative and quantitative electroencephalography.
abstract: OBJECTIVE
  This article reviews the electroencephalography (EEG) literature in relation to attention-deficit/hyperactivity disorder (AD/HD).
  
  
  METHODS
  The review briefly outlines the history of the disorder, focusing on the changing diagnostic systems which both reflect and constrain research into AD/HD. Both qualitative and quantitative EEG studies are examined, and their results are discussed in relation to various models of AD/HD. Implications of these data for future research and development in AD/HD are considered.
  
  
  RESULTS
  In terms of resting EEG, elevated relative theta power, and reduced relative alpha and beta, together with elevated theta/alpha and theta/beta ratios, are most reliably associated with AD/HD. Theta/alpha and theta/beta ratios also discriminate diagnostic subgroups of AD/HD. Recent studies of EEG heterogeneity in this disorder indicate the existence of different profiles of cortical anomalies which may cut across diagnostic types.
  
  
  CONCLUSIONS
  The research to date has identified a substantial number of EEG correlates of AD/HD which hold promise for improving our understanding of the brain dysfunction(s) underlying the disorder. Further work in this field may benefit from a broader conceptual approach, integrating EEG and other measures of brain function.
authors.affiliation: Department of Psychology and Brain & Behaviour Research Institute, University of Wollongong, Northfields Avenue, 2522, Wollongong, NSW, Australia. robert_barry@uow.edu.au
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Barry
authors.forename: Adam R
authors.initials: AR
authors.lastname: Clarke
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Johnstone
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography / Q000379:methods*; D006801:Humans