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.
"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.