title: Transcranial Direct Current Stimulation Modulates Neuronal Networks in Attention Deficit Hyperactivity Disorder.
abstract: Anodal transcranial direct current stimulation (tDCS) of the prefrontal cortex has been repeatedly shown to improve working memory (WM). Since patients with attention deficit hyperactivity disorder (ADHD) are characterized by both underactivation of the prefrontal cortex and deficits in WM, the modulation of prefrontal activity with tDCS in ADHD patients may increase their WM performance as well as improve the activation and connectivity of the WM network. In the present study, this hypothesis was tested using a double-blind sham-controlled experimental design. After randomization, sixteen adolescents with ADHD underwent either anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC, 1 mA, 20 min) or sham stimulation with simultaneous fMRI during n-back WM task. Both in one-back and two-back conditions, tDCS led to a greater activation (compared with sham stimulation) of the left DLPFC (under the electrode), left premotor cortex, left supplementary motor cortex, and precuneus. The effects of tDCS were long-lasting and influenced resting state functional connectivity even 20 min after the stimulation, with patterns of strengthened DLPFC connectivity after tDCS outlining the WM network. In summary, anodal tDCS caused increased neuronal activation and connectivity, not only in the brain area under the stimulating electrode (i.e. left DLPFC) but also in other, more remote brain regions. Because of moderate behavioral effects of tDCS, the significance of this technique for ADHD treatment has to be investigated in further studies.
authors.affiliation: Department for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Philipps-University, Marburg, 35096, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Sotnikova
authors.affiliation: Department for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Philipps-University, Marburg, 35096, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Soff
authors.affiliation: Institute of Medical Psychology and Medical Sociology, Christian-Albrechts-University, Preußerstraße 1-9, Kiel, 24105, Germany.
authors.forename: Enzo
authors.initials: E
authors.lastname: Tagliazucchi
authors.affiliation: Department for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Philipps-University, Marburg, 35096, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Becker
authors.affiliation: Institute of Medical Psychology and Medical Sociology, Christian-Albrechts-University, Preußerstraße 1-9, Kiel, 24105, Germany. siniatchkin@med-psych.uni-kiel.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Siniatchkin
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology / Q000628:therapy*; D002648:Child; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009415:Nerve Net / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D065908:Transcranial Direct Current Stimulation
keywords: ADHD; Transcranial direct current stimulation; Working memory; fMRI