title: Frontal EEG asymmetry during emotional challenge differentiates individuals with and without lifetime major depressive disorder.
abstract: BACKGROUND
  Although it has been argued that frontal electroencephalographic (EEG) asymmetry at rest may be a risk marker for major depressive disorder (MDD), it is unclear whether a pattern of relatively less left than right activity characterizes depressed individuals during emotional challenges. Examination of frontal asymmetry during emotion task manipulations could provide an assessment of the function of systems relevant for MDD, and test the limits of frontal EEG asymmetry as a marker of risk for depression.
  
  
  METHODS
  EEG data were assessed during a facial emotion task, wherein 306 individuals age 18-34 (31% male) with (n=143) and without (n=163) DSM-IV defined lifetime MDD made directed facial actions of approach (angry and happy) and withdrawal (afraid and sad) expressions.
  
  
  RESULTS
  Lifetime depressed individuals displayed less relative left frontal activity than never-depressed individuals during all facial expressions across four EEG reference montages, findings that were not due to emotional experience, facial expression quality, electromyographic (EMG) activity, or current depression status.
  
  
  CONCLUSIONS
  Although this was a sizable sample, only one emotion task was utilized.
  
  
  CONCLUSIONS
  Results provide further support for frontal EEG asymmetry as a risk marker for MDD.
authors.affiliation: Department of Psychology, University of Arizona, Tucson, AZ 85721-0068, United States. j6stewart@ucsd.edu
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Stewart
authors.forename: James A
authors.initials: JA
authors.lastname: Coan
authors.forename: David N
authors.initials: DN
authors.lastname: Towers
authors.forename: John J B
authors.initials: JJ
authors.lastname: Allen
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000503:physiopathology*; D004569:Electroencephalography; D004576:Electromyography; D004644:Emotions / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D012307:Risk Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers