Adult ADHD linked with dopamine levels

Adults with attention-deficit/hyperactivity disorder have a reduced response to the drug Ritalin, U.S. government scientists have found.

Ritalin -- methylphenidate -- increases brain dopamine levels, helping ADHD patients, the scientists noted, which suggests people with ADHD suffer from a dysfunction in the dopamine system.

Dr. Nora Volkow of the National Institute on Drug Abuse and colleagues studied 19 adults with ADHD who had never received medication, and 24 healthy controls.

Positron emission tomography brain scans were performed after blind injections of a drug that inactivates dopamine receptors. Scans were performed after injections of placebo and of Ritalin.

People with ADHD released less dopamine than controls did in response to the drug. The blunted response was associated with symptoms of inattention.

"The findings of reduced dopamine release in subjects with ADHD are consistent with the notion that the ability of stimulant medications to enhance extracellular dopamine underlies their therapeutic effects in ADHD," the researchers said.

The findings appear in the August issue of Archives of General Psychiatry.

Copyright 2007 by United Press International


Explore further

Children with certain dopamine system gene variants respond better to ADHD drug

Citation: Adult ADHD linked with dopamine levels (2007, August 9) retrieved 18 August 2019 from https://medicalxpress.com/news/2007-08-adult-adhd-linked-dopamine.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more