For decades, attention-deficit hyperactivity disorder has sparked debate. Is it a biological illness, the dangerous legacy of genes or environmental toxins, or a mere alibi for bratty kids, incompetent parents and a fraying social fabric? With 4.5 million U.S. children having received a diagnosis of the disorder — and more than half of them taking prescription drugs to control it — the question has divided doctors and patients, parents and teachers, and mothers and fathers.
Scientists maintain that they’ve been narrowing in on the origins and mechanics of disabling distraction, while gathering increasing evidence that ADHD is as real as such less controversial disorders as Down syndrome and schizophrenia. Their most recent progress is described in a Sept. 9 report in the Journal of the American Medical Association, based on a new study that indicates a striking difference in the brain’s motivational machinery in people with ADHD symptoms. micropile cost
“This is another big piece in the puzzle saying that there is something there, that this is not simply a matter of anxious parents,” said James Swanson, a co-author of the report and a developmental psychologist based at the University of California at Irvine.
‘An Interest Deficit’
The JAMA study said that, compared with a group of healthy subjects, brain scans of 53 adults with ADHD revealed a flaw in the way they process dopamine, which among other things, alerts people to new information and helps them anticipate pleasure and rewards. Swanson speculated that people with ADHD may even have a net deficit of dopamine.
The findings offer support for a long-held theory about why people with ADHD tend to be so easily distracted and bored — so hard to teach in school, so prone to end up in high-stimulus jobs such as in sales or the media, and so susceptible to gambling and drug abuse. According to the theory, the trouble is a lack of motivation as well as a deficit of attention: People with the disorder can’t generate the same degree of enthusiasm as other people for activities they don’t automatically find appealing.
“Parents always wonder why their children with ADHD can skateboard for hours and practice the same thing over and over but can’t stay on task in school,” said Swanson, who said he and fellow researchers have taken to calling the syndrome “an interest deficit.”
The project was led by Nora Volkow, a research psychiatrist who is director of the National Institute on Drug Abuse, together with scientists affiliated with institutions including the Brookhaven National Laboratory and the Mount Sinai Medical Center. It took eight years to complete, mostly owing to the difficulty of finding people with diagnosed ADHD who had never taken medication or recreational drugs, which might have subtly changed their brains, and had no history of other serious psychiatric illness. Children weren’t involved because of regulations against subjecting minors to unnecessary radiation.