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: American Ebola doc: 'I am thrilled to be alive'

add to favorites email to friend print save as pdf

Related Stories

New type of solar concentrator desn't block the view

6 hours ago

(Phys.org) —A team of researchers at Michigan State University has developed a new type of solar concentrator that when placed over a window creates solar energy while allowing people to actually see through ...

Cities, states face off on municipal broadband

6 hours ago

Wilson, N.C., determined nearly a decade ago that high-speed Internet access would be essential to the community's social and economic health in the 21st century, just as electricity, water and sewers were in the previous ...

Recommended for you

American Ebola doc: 'I am thrilled to be alive'

5 hours ago

Calling it a "miraculous day," an American doctor infected with Ebola left his isolation unit and warmly hugged his doctors and nurses on Thursday, showing the world that he poses no public health threat ...

User comments : 0