At present, ADHD is a diagnosis applied to children
and adults who consistently display certain characteristic behaviors over a period of time. The most common behaviors fall
into three categories: inattention, hyperactivity, and impulsivity.
People who are inattentive have a hard time keeping their mind on any one thing and may get bored with a task after only a
few minutes. They may give effortless, automatic attention to activities and things they enjoy. But focusing deliberate, conscious
attention to organizing and completing a task or learning something new is difficult.
For example, Lisa found it agonizing to do homework.
Often, she forgot to plan ahead by writing down the assignment or bringing home the right books. And when trying to work,
every few minutes she found her mind drifting to something else. As a result, she rarely finished and her work was full of
People who are hyperactive always seem to be in motion. They can't sit still. Like Mark, they may dash around or talk incessantly.
Sitting still through a lesson can be an impossible task. Hyperactive children squirm in their seat or roam around the room.
Or they might wiggle their feet, touch everything, or noisily tap their pencil. Hyperactive teens and adults may feel intensely
restless. They may be fidgety or, like Henry, they may try to do several things at once, bouncing around from one activity
to the next.
People who are overly impulsive seem unable to curb their immediate reactions or think before they act. As a result, like
Lisa, they may blurt out inappropriate comments. Or like Mark, they may run into the street without looking. Their impulsivity
may make it hard for them to wait for things they want or to take their turn in games. They may grab a toy from another child
or hit when they're upset.
Not everyone who is overly hyperactive, inattentive,
or impulsive has an attention disorder. Since most people sometimes blurt out things they didn't mean to say, bounce from
one task to another, or become disorganized and forgetful, how can specialists tell if the problem is ADHD?
To assess whether a person has ADHD, specialists consider
several critical questions: Are these behaviors excessive, long-term, and pervasive? That is, do they occur more often than
in other people the same age? Are they a continuous problem, not just a response to a temporary situation? Do the behaviors
occur in several settings or only in one specific place like the playground or the office? The person's pattern of behavior
is compared against a set of criteria and characteristics of the disorder. These criteria appear in a diagnostic reference
book called the DSM (short for the Diagnostic and Statistical Manual of Mental Disorders).
According to the diagnostic manual, there are three
patterns of behavior that indicate ADHD. People with ADHD may show several signs of being consistently inattentive. They may
have a pattern of being hyperactive and impulsive. Or they may show all three types of behavior.
Because everyone shows some of these behaviors at times,
the DSM contains very specific guidelines for determining when they indicate ADHD. The behaviors must appear early in life,
before age 7, and continue for at least 6 months. In children, they must be more frequent or severe than in others the same
age. Above all, the behaviors must create a real handicap in at least two areas of a person's life, such as school, home,
work, or social settings. So someone whose work or friendships are not impaired by these behaviors would not be diagnosed
with ADHD. Nor would a child who seems overly active at school but functions well elsewhere.
The fact is, many things can produce these behaviors.
Anything from chronic fear to mild seizures can make a child seem overactive, quarrelsome, impulsive, or inattentive. For
example, a formerly cooperative child who becomes overactive and easily distracted after a parent's death is dealing with
an emotional problem, not ADHD. A chronic middle ear infection can also make a child seem distracted and uncooperative. So
can living with family members who are physically abusive or addicted to drugs or alcohol. Can you imagine a child trying
to focus on a math lesson when his or her safety and well-being are in danger each day? Such children are showing the effects
of other problems, not ADHD.
In other children, ADHD-like behaviors may be their
response to a defeating classroom situation. Perhaps the child has a learning disability and is not developmentally ready
to learn to read and write at the time these are taught. Or maybe the work is too hard or too easy, leaving the child frustrated
Tyrone and Mimi are two examples of how classroom conditions
can elicit behaviors that look like ADHD. For months, Tyrone shouted answers out in class, then became disruptive when the
teacher ignored him. He certainly seemed hyperactive and impulsive. Finally, after observing Tyrone in other situations, his
teacher realized he just wanted approval for knowing the right answer. She began to seek opportunities to call on him and
praise him. Gradually, Tyrone became calmer and more cooperative.
Mimi, a fourth grader, made loud noises during reading
group that constantly disrupted the class. One day the teacher realized that the book was too hard for Mimi. Mimi's disruptions
stopped when she was placed in a reading group where the books were easier and she could successfully participate in the lesson.
Like Tyrone and Mimi, some children's attention and
class participation improve when the class structure and lessons are adjusted a bit to meet their emotional needs, instructional
level, or learning style. Although such children need a little help to get on track at school, they probably don't have ADHD.
It's also important to realize that during certain
stages of development, the majority of children that age tend to be inattentive, hyperactive, or impulsive--but do not have
ADHD. Preschoolers have lots of energy and run everywhere they go, but this doesn't mean they are hyperactive. And many teenagers
go through a phase when they are messy, disorganized, and reject authority. It doesn't mean they will have a lifelong problem
controlling their impulses.
ADHD is a serious diagnosis that may require long-term
treatment with counseling and medication. So it's important that a doctor first look for and treat any other causes for these
What Can Look Like ADHD?
- Underachievement at school due to a learning disability
- Attention lapses caused by petit mal seizures
- A middle ear infection that causes an intermittent
- Disruptive or unresponsive behavior due to anxiety
Understandably, one of the first questions parents
ask when they learn their child has an attention disorder is "Why? What went wrong?"
Health professionals stress that since no one knows
what causes ADHD, it doesn't help parents to look backward to search for possible reasons. There are too many possibilities
to pin down the cause with certainty. It is far more important for the family to move forward in finding ways to get the right
Scientists, however, do need to study causes in an
effort to identify better ways to treat, and perhaps some day, prevent ADHD. They are finding more and more evidence that
ADHD does not stem from home environment, but from biological causes. When you think about it, there is no clear relationship
between home life and ADHD. Not all children from unstable or dysfunctional homes have ADHD. And not all children with ADHD
come from dysfunctional families. Knowing this can remove a huge burden of guilt from parents who might blame themselves for
their child's behavior.
Over the last decades, scientists have come up with
possible theories about what causes ADHD. Some of these theories have led to dead ends, some to exciting new avenues of investigation.
One disappointing theory was that all attention disorders
and learning disabilities were caused by minor head injuries or undetectable damage to the brain, perhaps from early infection
or complications at birth. Based on this theory, for many years both disorders were called "minimal brain damage" or
"minimal brain dysfunction." Although certain types of head injury can explain some cases of attention disorder, the
theory was rejected because it could explain only a very small number of cases. Not everyone with ADHD or LD has a history
of head trauma or birth complications.
Another theory was that refined sugar and food additives
make children hyperactive and inattentive. As a result, parents were encouraged to stop serving children foods containing
artificial flavorings, preservatives, and sugars. However, this theory, too, came under question. In 1982, the National Institutes
of Health (NIH), the Federal agency responsible for biomedical research, held a major scientific conference to discuss the
issue. After studying the data, the scientists concluded that the restricted diet only seemed to help about 5 percent of children
with ADHD, mostly either young children or children with food allergies.
ADHD Is Not Usually Caused by:
- too much TV
- food allergies
- excess sugar
- poor home life
- poor schools
In recent years, as new tools and techniques for studying
the brain have been developed, scientists have been able to test more theories about what causes ADHD.
Using one such technique, NIMH scientists demonstrated
a link between a person's ability to pay continued attention and the level of activity in the brain. Adult subjects were asked
to learn a list of words. As they did, scientists used a PET (positron emission tomography) scanner to observe the brain at work. The researchers measured the level of glucose used by
the areas of the brain that inhibit impulses and control attention. Glucose is the brain's main source of energy, so measuring
how much is used is a good indicator of the brain's activity level. The investigators found important differences between
people who have ADHD and those who don't. In people with ADHD, the brain areas that control attention used less glucose, indicating
that they were less active. It appears from this research that a lower level of activity in some parts of the brain may cause
The next step will be to research WHY there is less
activity in these areas of the brain. Scientists at NIMH hope to compare the use of glucose and the activity level in mild
and severe cases of ADHD. They will also try to discover why some medications used to treat ADHD work better than others,
and if the more effective medications increase activity in certain parts of the brain.
Researchers are also searching for other differences
between those who have and do not have ADHD. Research on how the brain normally develops in the fetus offers some clues about
what may disrupt the process. Throughout pregnancy and continuing into the first year of life, the brain is constantly developing.
It begins its growth from a few all-purpose cells and evolves into a complex organ made of billions of specialized, interconnected
nerve cells. By studying brain development in animals and humans, scientists are gaining a better understanding of how the
brain works when the nerve cells are connected correctly and incorrectly. Scientists at NIMH and other research institutions
are tracking clues to determine what might prevent nerve cells from forming the proper connections. Some of the factors they
are studying include drug use during pregnancy, toxins, and genetics.
Research shows that a mother's use of cigarettes, alcohol,
or other drugs during pregnancy may have damaging effects on the unborn child. These substances may be dangerous to the fetus's
developing brain. It appears that alcohol and the nicotine in cigarettes may distort developing nerve cells. For example,
heavy alcohol use during pregnancy has been linked to fetal alcohol syndrome (FAS), a condition that can lead to low birth
weight, intellectual impairment, and certain physical defects. Many children born with FAS show much the same hyperactivity,
inattention, and impulsivity as children with ADHD.
Drugs such as cocaine--including the smokable form
known as crack--seem to affect the normal development of brain receptors. These brain cell parts help to transmit incoming
signals from our skin, eyes, and ears, and help control our responses to the environment. Current research suggests that drug
abuse may harm these receptors. Some scientists believe that such damage may lead to ADHD.
Toxins in the environment may also disrupt brain development
or brain processes, which may lead to ADHD. Lead is one such possible toxin. It is found in dust, soil, and flaking paint
in areas where leaded gasoline and paint were once used. It is also present in some water pipes. Some animal studies suggest
that children exposed to lead may develop symptoms associated with ADHD, but only a few cases have actually been found.
Other research shows that attention disorders tend
to run in families, so there are likely to be genetic influences. Children who have ADHD usually have at least one close relative
who also has ADHD. And at least one-third of all fathers who had ADHD in their youth bear children who have ADHD. Even more
convincing: the majority of identical twins share the trait. At the National Institutes of Health, researchers are also on
the trail of a gene that may be involved in transmitting ADHD in a small number of families with a genetic thyroid disorder.
One of the difficulties in diagnosing ADHD is that
it is often accompanied by other problems. For example, many children with ADHD also have a specific learning disability (LD),
which means they have trouble mastering language or certain academic skills, typically reading and math. ADHD is not in itself
a specific learning disability. But because it can interfere with concentration and attention, ADHD can make it doubly hard
for a child with LD to do well in school.
A very small proportion of people with ADHD have a
rare disorder called Tourette's syndrome. People with Tourette's have tics and other movements like eye blinks or facial twitches
that they cannot control. Others may grimace, shrug, sniff, or bark out words. Fortunately, these behaviors can be controlled
with medication. Researchers at NIMH and elsewhere are involved in evaluating the safety and effectiveness of treatment for
people who have both Tourette's syndrome and ADHD.
More serious, nearly half of all children with ADHD--mostly
boys--tend to have another condition, called oppositional defiant disorder. Like Mark, who punched playmates for jostling
him, these children may overreact or lash out when they feel bad about themselves. They may be stubborn, have outbursts of
temper, or act belligerent or defiant. Sometimes this progresses to more serious conduct disorders. Children with this combination
of problems are at risk of getting in trouble at school, and even with the police. They may take unsafe risks and break laws--they
may steal, set fires, destroy property, and drive recklessly. It's important that children with these conditions receive help
before the behaviors lead to more serious problems.
At some point, many children with ADHD--mostly younger
children and boys--experience other emotional disorders. About one-fourth feel anxious. They feel tremendous worry, tension,
or uneasiness, even when there's nothing to fear. Because the feelings are scarier, stronger, and more frequent than normal
fears, they can affect the child's thinking and behavior. Others experience depression. Depression goes beyond ordinary sadness--people
may feel so "down" that they feel hopeless and unable to deal with everyday tasks. Depression can disrupt sleep, appetite,
and the ability to think.
Because emotional disorders and attention disorders
so often go hand in hand, every child who has ADHD should be checked for accompanying anxiety and depression. Anxiety and
depression can be treated, and helping children handle such strong, painful feelings will help them cope with and overcome
the effects of ADHD.
(Graphic Omitted: Diagram showing the overlapping of
other disorders with ADHD.)
Of course, not all children with ADHD have an
additional disorder. Nor do all people with learning disabilities, Tourette's syndrome, oppositional defiant disorder, conduct
disorder, anxiety, or depression have ADHD. But when they do occur together, the combination of problems can seriously complicate
a person's life. For this reason, it's important to watch for other disorders in children who have ADHD.
third grade, Mark's teacher threw up her hands and said, "Enough!" In one morning, Mark had jumped out of his seat
to sharpen his pencil six times, each time accidentally charging into other children's desks and toppling books and papers.
He was finally sent to the principal's office when he began kicking a desk he had overturned. In sheer frustration, his teacher
called a meeting with his parents and the school psychologist.
But even after they developed a plan for managing
Mark's behavior in class, Mark showed little improvement. Finally, after an extensive assessment, they found that Mark had
an attention deficit that included hyperactivity. He was put on a medication called Ritalin to control the hyperactivity during
school hours. Although Ritalin failed to help, another drug called Dexedrine did. With a psychologist's help, his parents
learned to reward desirable behaviors, and to have Mark take "time out" when he became too disruptive. Soon Mark was able
to sit still and focus on learning.
Lisa wasn't disruptive in class, it took a long time for teachers to notice her problem. Lisa was first referred to the school
evaluation team when her teacher realized that she was a bright girl with failing grades. The team ruled out a learning disability
but determined that she had an attention deficit, ADHD without hyperactivity. The school psychologist recognized that Lisa
was also dealing with depression.
Lisa's teachers and the school psychologist developed
a treatment plan that included participation in a program to increase her attention span and develop her social skills. They
also recommended that Lisa receive counseling to help her recognize her strengths and overcome her depression.
Henry's son entered kindergarten, it was clear that he was going to have problems sitting quietly and concentrating. After
several disruptive incidents, the school called and suggested that his son be evaluated for ADHD. As the boy was assessed,
Henry realized that he had grown up with the same symptoms that specialists were now finding in his son. Fortunately, the
psychologist knew that ADHD can persist in adults. She suggested that Henry be evaluated by a professional who worked with
adults. For the first time, Henry was correctly diagnosed and given Ritalin to aid his concentration. What a relief! All the
years that he had been unable to concentrate were due to a disorder that could be identified, and above all, treated.