DR. PATRICIA QUINN: I think the primary cause is genetic, in that we do see family histories of other members having the same or similar problems—usually several children from one family. There have actually been some recent studies diagnosing certain subtypes of ADHD, finding a gene and a chromosome and being able to identify it by that means.
There's other ways, though, and other conditions. We know chronic low levels of lead can lead to problems. Fetal alcohol syndrome. Prematurity. Obstetrical complications during the pregnancy. Or even infectious disease: meningitis or encephalitis can lead to hyperactive symptoms or inattentiveness in the children who've had these disorders.
LISA CLARK: And just as important as discussing some of the causes is to discuss some of the things that do not cause ADHD. Dr. Jensen, I'll throw that one your way. For one thing, too much sugar is not causing ADHD in children.
DR. PETER JENSEN: No, too much sugar does not cause ADHD. The things that we think have been misunderstood, but at one time were thought to be supposed causes, are bad parenting and bad teachers, not enough discipline, sugar, and food additives. And so there's a lot of myth and misunderstanding. And many times parents or others will chase those supposed causes down, sometimes causing them a lot of grief, and sometimes delaying an effective intervention that really could be helpful to the children.
LISA CLARK: How many children actually have ADHD?