title: Sex differences in adult ADHD: a double dissociation in brain activity and autonomic arousal.
abstract: It is now estimated that up to one-half of attention deficit hyperactivity disorder (ADHD) children continue to manifest symptoms in adulthood. A striking discrepancy between juvenile and adult populations is the increasing proportion of females with an ADHD diagnosis. To shed light on the psychophysiological mechanisms underlying adult ADHD, electroencephalography (EEG) and electrodermal index of arousal (skin conductance level or SCL) measures were employed under conditions of eyes-closed resting activity. Quantitative EEG (QEEG) and SCL were measured simultaneously and continuously (2 min) in 35 ADHD adults (21 males, 14 females) and their age- and sex-matched controls. As a group ADHD adults were found to have EEG and SCL deviations consistent with previous adolescent and juvenile studies. However, adult males (but not females) with ADHD showed increased EEG theta activity. By contrast, adult females (but not males) with ADHD were autonomically hypo-aroused (decreased SCL). These results suggest that distinct mechanisms may underpin adult ADHD in males and females.
authors.affiliation: The Brain Dynamics Centre, Acacia House, Westmead Hospital, Hawkesbury Road, Westmead, NSW 2145, Australia. dher5793@mail.usyd.edu.au
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Hermens
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Williams
authors.forename: Ilario
authors.initials: I
authors.lastname: Lazzaro
authors.forename: Stephanie
authors.initials: S
authors.lastname: Whitmont
authors.forename: Dmitriy
authors.initials: D
authors.lastname: Melkonian
authors.forename: Evian
authors.initials: E
authors.lastname: Gordon
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology; D006801:Humans; D008297:Male; D012737:Sex Factors; D013826:Theta Rhythm