Adult ADHD linked with dopamine levels

Aug 09, 2007

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: Countries vow to all but eradicate malaria by 2030: WHO

Related Stories

House presses Senate to pass domestic surveillance changes

31 minutes ago

The White House and House leaders urged the Senate on Thursday to take up a bill that would end the National Security Agency's collection of American phone records while preserving other surveillance powers set to expire ...

PayPal's new chief promises new services for a mobile world

34 minutes ago

As PayPal prepares to split from its corporate parent, its new chief executive is promising to expand the popular online payment system, adding a variety of services for consumers to use when shopping on their phones or in ...

Recommended for you

Explainer: What is Chagas disease?

1 hour ago

According to an article in the Journal of the American Medical Association (JAMA), in a Los Angeles clinic treating patients with heart failure, about 20% of Latin American patients have Chagas disease. What is that?, y ...

CV autonomic neuropathy predicts urological issues

22 hours ago

(HealthDay)—For men with type 1 diabetes, cardiovascular autonomic neuropathy is associated with erectile dysfunction and/or lower urinary tract symptoms, according to a study published in the June issue ...

User comments : 0

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

Click here to reset your password.
Sign in to get notified via email when new comments are made.