Attention deficit hyperactivity disorder (ADHD) is the most commonly diagnosed bio-behavioral disorder of childhood. It occurs in 6% to 9% of children--about the same prevalence as childhood asthma. It is also one of the most controversial diagnoses in children; parents are often perplexed about whether ADHD is underdiagnosed or overdiagnosed, or undertreated or overtreated. A good deal of this confusion stems from the fact that there are no laboratory tests, imaging studies, or psychological testing profiles that can be used to make the diagnosis.
