title: Resting state vagal tone in attention deficit (hyperactivity) disorder: A meta-analysis.
abstract: To quantify evidence on resting-state vagal activity in patients with attention deficit hyperactivity disorder (ADHD) relative to controls using meta-analysis.
  
  
  
  Three electronic databases (PubMed, PsycINFO, CINAHL Plus) were reviewed to identify studies. Studies reporting on any measure of short-term, vagally mediated heart rate variability during resting state in clinically diagnosed ADHD patients as well as non-ADHD healthy controls were eligible for inclusion.
  
  
  
  Eight studies reporting on 587 participants met inclusion criteria. Random-effect meta-analysis revealed no significant main effect comparing individuals with ADHD (n = 317) and healthy controls (n = 270) (Hedges' g = 0.06, 95% CI: 0.18-0.29, Z = 0.48, P = 0.63; k = 8). Sub-group analysis showed consistent results among studies in adults (k = 2) and children (k = 6) with ADHD.
  
  
  
  Unlike a variety of internalising psychiatric disorders, ADHD is not associated with altered short-term measures of resting-state vagal tone.
authors.affiliation: a Section for Translational Psychobiology in Child and Adolescent Psychiatry, Department of Child and Adolescent Psychiatry, Centre for Psychosocial Medicine , University of Heidelberg , Heidelberg , Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Koenig
authors.affiliation: b Department of Psychology , University of Calgary , Calgary , AB , Canada.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Rash
authors.affiliation: c School of Psychology & Discipline of Psychiatry, University of Sydney , Sydney , Australia.|d Department of Psychology, Swansea University , Swansea , UK.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Kemp
authors.affiliation: e Department of Pediatrics , Caritas-Krankenhaus , Bad Mergentheim , Germany.
authors.forename: Reiner
authors.initials: R
authors.lastname: Buchhorn
authors.affiliation: f Department of Psychology , the Ohio State University , Columbus , OH , USA.
authors.forename: Julian F
authors.initials: JF
authors.lastname: Thayer
authors.affiliation: a Section for Translational Psychobiology in Child and Adolescent Psychiatry, Department of Child and Adolescent Psychiatry, Centre for Psychosocial Medicine , University of Heidelberg , Heidelberg , Germany.|g Clinic of Child and Adolescent Psychiatry, Centre for Psychosocial Medicine , University of Heidelberg , Heidelberg , Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kaess
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D014630:Vagus Nerve / Q000502:physiology*
keywords: Attention deficit hyperactivity disorder; autonomic nervous system; heart rate variability; meta-analysis; resting vagal tone