title: Characterization of the theta to beta ratio in ADHD: identifying potential sources of heterogeneity.
abstract: OBJECTIVE
  The goal of this study is to characterize the theta to beta ratio (THBR) obtained from electroencephalogram (EEG) measures, in a large sample of community and clinical participants with regard to (a) ADHD diagnosis and subtypes, (b) common psychiatric comorbidities, and (c) cognitive correlates.
  
  
  METHODS
  The sample includes 871 participants (595 youth and 276 adults) with and without ADHD. All participants underwent extensive assessment, including semistructured diagnostic interviews, cognitive testing, and EEG recording.
  
  
  RESULTS
  The THBR did not differ significantly by ADHD status for youth but was significantly lower in adults with ADHD compared with controls. ADHD subtype and psychiatric comorbidities such as disruptive behavior disorders and depression have opposing and significant mediating effects on the THBR.
  
  
  CONCLUSIONS
  The THBR is affected by several mediating factors associated with ADHD such as ADHD subtype and psychiatric comorbidity. More research is needed to understand the functional significance of the THBR in ADHD.
authors.affiliation: University of California Los Angeles, USA. sloo@mednet.ucla.edu
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Loo
authors.forename: Alexander
authors.initials: A
authors.lastname: Cho
authors.forename: T Sigi
authors.initials: TS
authors.lastname: Hale
authors.forename: James
authors.initials: J
authors.lastname: McGough
authors.forename: James
authors.initials: J
authors.lastname: McCracken
authors.forename: Susan L
authors.initials: SL
authors.lastname: Smalley
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D001611:Beta Rhythm; D001714:Bipolar Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D015897:Comorbidity; D019955:Conduct Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D019263:Dysthymic Disorder / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D004569:Electroencephalography; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D013826:Theta Rhythm