Feature Archive

Hyperactivity: Medical Reality or Convenient Excuse?

ADHD

By Ronald Pies
WebMD Feature

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.