title: Reduced short interval cortical inhibition correlates with atomoxetine response in children with attention-deficit hyperactivity disorder (ADHD).
abstract: Clinical trials in children with attention-deficit hyperactivity disorder (ADHD) show variability in behavioral responses to the selective norepinephrine reuptake inhibitor atomoxetine. The objective of this study was to determine whether transcranial magnetic stimulation-evoked short interval cortical inhibition might be a biomarker predicting, or correlating with, clinical atomoxetine response. At baseline and after 4 weeks of atomoxetine treatment in 7- to 12-year-old children with ADHD, transcranial magnetic stimulation short interval cortical inhibition was measured, blinded to clinical improvement. Primary analysis was by multivariate analysis of covariance. Baseline short interval cortical inhibition did not predict clinical responses. However, paradoxically, after 4 weeks of atomoxetine, mean short interval cortical inhibition was reduced 31.9% in responders and increased 6.1% in nonresponders (analysis of covariance t 41 = 2.88; P = .0063). Percentage reductions in short interval cortical inhibition correlated with reductions in the ADHD Rating Scale (r = 0.50; P = .0005). In children ages 7 to 12 years with ADHD treated with atomoxetine, improvements in clinical symptoms are correlated with reductions in motor cortex short interval cortical inhibition.
authors.affiliation: University of Cincinnati College of Medicine, Cincinnati, OH, USA chenth@mail.uc.edu.
authors.forename: Tina H
authors.initials: TH
authors.lastname: Chen
authors.affiliation: Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Steve W
authors.initials: SW
authors.lastname: Wu
authors.affiliation: Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Welge
authors.affiliation: Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: Stephan G
authors.initials: SG
authors.lastname: Dixon
authors.affiliation: Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA Department of Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Shahana
authors.affiliation: Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Huddleston
authors.affiliation: Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: Adam R
authors.initials: AR
authors.lastname: Sarvis
authors.affiliation: Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: Floyd R
authors.initials: FR
authors.lastname: Sallee
authors.affiliation: Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Donald L
authors.initials: DL
authors.lastname: Gilbert
mesh_terms: D018759:Adrenergic Uptake Inhibitors / Q000627:therapeutic use*; D000069445:Atomoxetine Hydrochloride; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000473:pathology*; D002648:Child; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009044:Motor Cortex / Q000187:drug effects*; D009433:Neural Inhibition / Q000187:drug effects*; D011437:Propylamines / Q000627:therapeutic use*; D013997:Time Factors; D065908:Transcranial Direct Current Stimulation
chemical_list: D018759:Adrenergic Uptake Inhibitors; D011437:Propylamines; D000069445:Atomoxetine Hydrochloride
keywords: atomoxetine; attention-deficit hyperactivity disorder (ADHD); short interval cortical inhibition; transcranial magnetic stimulation