患有ADHD的孩童在心理上常具有不健全的強化系統(Reinforcement). 以含有獎賞與懲罰的回饋測試發現他們的心跳反應較低,且回饋測試時HRV較正常孩童低

Heart rate and reinforcement sensitivity in ADHD.

J Child Psychol Psychiatry. 2007 Sep;48(9):890-8.

Luman M, Oosterlaan J, Hyde C, van Meel CS, Sergeant JA.

Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, The Netherlands.

Abstract

BACKGROUND: Both theoretical and clinical accounts of attention-deficit/hyperactivity disorder (ADHD) implicate a dysfunctional reinforcement system. This study investigated heart rate parameters in response to feedback associated with reward and response cost in ADHD children and controls aged 8 to 12.

METHODS: Heart rate responses (HRRs) following feedback and heart rate variability (HRV) in the low frequency band (.04-.08 Hz), a measure of mental effort, were calculated during a time production paradigm. Performance was coupled to monetary gain, loss or feedback-only in a cross-over design.

RESULTS: Children with ADHD exhibited smaller HRRs to feedback compared to controls. HRV of children with ADHD decreased when performance was coupled to reward or response cost compared to feedback-only. HRV of controls was similar across conditions.

CONCLUSIONS: Children with ADHD were characterised by (a) possible abnormalities in feedback monitoring and (b) motivational deficits, when no external reinforcement is present.

PMID: 17714374 [PubMed - indexed for MEDLINE]

Vascular Effects of Attention Deficit Hyperactivity Disorder (ADHD) Medications in Youth

This study is currently recruiting participants.

Verified by University of Minnesota - Clinical and Translational Science Institute, April 2010

First Received: April 7, 2010   Last Updated: April 19, 2010   History of Changes

Sponsor:

University of Minnesota - Clinical and Translational Science Institute

Information provided by:

University of Minnesota - Clinical and Translational Science Institute

ClinicalTrials.gov Identifier:

NCT01107301

  Purpose

4.4 million children and adolescents in the United States have been diagnosed with attention deficit hyperactivity disorder (ADHD) and more than half are treated with medication. Most ADHD medications are stimulants, which activate the sympathetic nervous system (SNS). SNS activation is closely associated with vascular functional and mechanical abnormalities. Therefore, ADHD medications, via instigating SNS activation and altering the hemodynamic profile, may have untoward effects on the vasculature and increase risk of developing cardiovascular disease in children and adolescents who use them. Our overall objective in this study is to determine whether ADHD medication use is associated SNS activation, endothelial dysfunction, and arterial stiffness in children and adolescents. We will address this objective by conducting a prospective, repeated measures, observational study and obtaining non-invasive measures of SNS activation, endothelial function, and arterial stiffness at baseline (prior to initiation of ADHD stimulant drug therapy) and at 6- and 12-months after initiation of therapy in 62 children and adolescents (8-17 years old) recruited from the University of Minnesota Pediatric Neurodevelopment Clinic.