Resting state vagal tone in attention deficit (hyperactivity) disorder: A meta-analysis

Abstract

Objectives: To quantify evidence on resting-state vagal activity in patients with attention deficit hyperactivity disorder (ADHD) relative to controls using meta-analysis.

Methods: 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.

Results: 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.

Conclusions: Unlike a variety of internalising psychiatric disorders, ADHD is not associated with altered short-term measures of resting-state vagal tone.

Keywords:

• Attention deficit hyperactivity disorder
• resting vagal tone
• heart rate variability
• meta-analysis
• autonomic nervous system

Acknowledgements

We thank Dr Theodore Beauchaine for his response to requests for additional information. We thank Drs Marjolein Luman and Erica Musser, Tatiana de Carvalho and Bianca Thomas (Negrao) for providing their data. J.K. and M.K. acknowledge the financial support of a Boehringer Ingelheim Fonds Travel Grant. J.K. is supported by Physician-Scientist-Fellowship provided by the Medical School, University of Heidelberg, Germany. A.H.K. and J.F.T. would also like to acknowledge the financial support of FAPESP, a Brazilian research funding institution in the state of São Paulo and that of Ohio State University, which has helped to initiate collaborative activities between the authors of the current manuscript.

Statement of interest

None to declare.