schoolchildren have been gerri: s gary kneweport with the centers for disease control would find the kids, children from such hyperactivity disorder is on the rise, up 63 percent of the past decade. also growing concern over the new drug used to treat the disorder. here to make sense of it, dr. mark siegel, a member of the fox news medical a-team. i have to tell you, i look at this and i think, how is it possible that all of these kids have this problem? we had not even heard of this problem 20 years ago. now one in ten kids has a ph.d. >> 6 million, more than of $4 billion industry. gerri: that is the important fact right there, 80's and industry. >> and by that iean everybody is busy diagnosing it. not necessarily only the appropriat people. pediatricians. gerri: the don't draw blood and find a phd. there is no test for it really. you're just watching behavior. at the end of the day is being over diagnosed? >> i think so, and i have some evidence. hyperactivity, impulsivity. it sounds like -- and why is it? gerri: 20% of high-school boys. >> there you go. and why are boys twice as