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.
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
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.