Every day across this great land of ours, children are swallowing pills for something called "Attention-Deficit Hyperactivity Disorder." This is still largely an American obsession, by the way-the United States spends several times as much on ADHD meds than all the rest of the world put together-although the rest of the world is catching up with us. The idea that millions of children-mostly boys-are walking around with defective brains that require...