Hyperactivity: Medical Reality or Convenient Excuse?

Few diagnoses in psychiatry have stirred up as much controversy as Attention-Deficit Hyperactivity Disorder ( ADHD). For some critics, the label "ADHD" is merely an excuse for frustrated parents and overzealous doctors to "medicate away" a child's annoying behaviors. Other critics concede that ADHD exists, but believe it is vastly overdiagnosed. While there's sometimes a grain of truth to these claims, there are now convincing clinical and research studies showing that ADHD is a real disorder with a strong biological basis -- and that, if anything, ADHD is often underdiagnosed.

The Biology of ADHD

While ADHD is not inherited like blond hair or blue eyes, the odds that both members of an identical twin pair will have ADHD are much higher than the odds for fraternal twins. This suggests that the more closely one twin's genes match the other's, the more likely they are to share the disorder. Furthermore, studies of brain activity have shown that in ADHD children, the frontal regions of the brain are actually underactive. This may seem puzzling, given that "hyperactivity" is usually linked with ADHD. But since the frontal regions of the brain exert a calming influence on more primitive regions, frontal-lobe underactivity may mean that these regions are not "keeping the lid on" disruptive behaviors.

Contrary to a popular notion, there is no convincing evidence that ADHD is caused by too much sugar in the diet. Furthermore, the last 20 years have made it clear that kids with ADHD do not always "outgrow" the disorder. Between 4 percent and 30 percent of ADHD children will show symptoms in adulthood, depending on whether we count only the full-blown disorder or even a few ADHD symptoms.

Picturing ADHD

What does ADHD look like in children? Consider Shawn, an 11-year-old who was a "problem kid" for more than five years. Beginning at the age of 5, Shawn had trouble sitting still in class. Teachers would complain that Shawn would fidget, squirm in his seat, or even leave his seat after only a half-hour of class. Sometimes he would run around the classroom, despite the teacher's firm instructions to sit down. Shawn had great difficulty paying attention to the teacher, and seemed to be "off in a cloud" during class. He almost never followed through on homework assignments, chores or duties, either in school or at home. Any task that required more than a few minutes of sustained attention was beyond Shawn's ability. He was easily distracted by the slightest noise, and had trouble remembering even simple instructions. At times Shawn would blurt out answers before the question had been completed, and he had difficulty waiting his turn in line. Sometimes Shawn would disrupt the play of other children, demanding to be let in to their activities.

While this picture is fairly typical of boys with ADHD, this disorder may declare itself in other ways. While many studies suggest that ADHD is more common in boys than in girls, this may reflect the fact that girls tend to be less disruptive than boys, and thus prompt fewer complaints from parents and teachers. Thus, severe attentional problems in girls may be due to ADHD, even though outward behavior seems normal. Of course, many other problems can cause poor attention in children, ranging from boredom to poor teaching to depression. That's why the diagnosis of childhood ADHD must be made after a careful evaluation by a mental-health professional and/or pediatrician. In adults, untreated ADHD may appear in the guise of "personality disorder," alcohol abuse, irritability or antisocial behaviors.