By Regina Bussing, MD

Since the early part of this century, doctors have ascribed an array of names to this constellation of behaviors—among them hyperkinesis, hyperactivity, minimal brain damage and minimal brain dysfunction. In the late 1970s, attention deficit hyperactivity disorder ( ADHD ) became the accepted term. According to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), ADHD is characterized by a “persistent pattern of inattention and/or hyperactivity or impulsivity that is more frequent and severe than is typically observed in individuals at a comparable level of development.”

In recent years, major advances have been made in our understanding of ADHD. Consider these striking facts:

• ADHD is the most commonly diagnosed psychiatric condition in children and is a major reason for referral to a pediatrician, family physician, pediatric neurologist, child psychiatrist or psychologist. An estimated three to five percent of school-age youngsters are affected—more than two million between the ages of 5 and 18. A significant number of them display associated learning disabilities.
• Boys develop the chronic disorder three times as often as girls.
• Researchers no longer believe the symptoms of ADHD fade with the passage of time.
• Just how many adults might be affected is unclear, although some put the figure at as many as two percent of the general population. Many adults with ADHD were never diagnosed when they were young and may not even be aware they have the disorder. Some may have been wrongly diagnosed with depression or a personality disorder in childhood or as adults.
• ADHD crosses ethnic boundaries; researchers have found it exists in every nation and culture they have studied.

ADHD presents many challenges, both for the individuals who grapple with it as well as for society. At its worst, some experts say, ADHD saddles individuals with an increased risk of accidents, drug abuse, failure at school, antisocial behavior and criminal activity. And people with ADHD frequently battle associated problems. These include:

• anxiety
• various learning disabilities
• speech or hearing deficits
• obsessive-compulsive disorders
• tic disorders
• or behavioral problems such as oppositional defiant disorder (ODD) or conduct disorder (CD)

Yet others insist ADHD sparks creative genius and is the mark of an inventive mind.

Exactly what causes A...