Some experts say that attention deficit hyperactivity disorder (ADHD) is an epidemic. Others, that it doesn't even exist. Some point to studies that show alarmingly high percentages of schoolchildren  -- especially boys  -- taking anti-ADHD drugs like Ritalin. The disorder is undertreated, the U.S. surgeon general has said. Too many toddlers are being treated for it with drugs, the White House declared last spring, announcing a conference on the topic.

The controversy has made it practically impossible for parents who are concerned about their child to figure out what to do. So many opinions cloud the debate that it's difficult to extract the few facts that are known. This is especially unfortunate, because if one thing is clear, it's that whether a child is properly diagnosed with ADHD and treated effectively  -- or treated at all  -- depends largely on his parents' active involvement.

Gurney Williams III is a science lecturer and award-winning journalist who writes frequently about health issues.

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