Attention deficit hyperactivity disorder (ADHD) is not a clinically
definable illness or disease. Rather, as of December 2003, ADHD is a
diagnosis that is made for children and adults who display certain
behaviors over an extended period of time. The most common of these
behavioral criteria are inattention, hyperactivity, and marked
impulsiveness.

In the American description, there are three types of ADHD, depending
on which diagnostic criteria have been met. These are: ADHD that is
characterized by inattention, ADHD characterized by impulsive behavior,
and ADHD that has both behaviors.

The European description of ADHD places the disorder in a subgroup of
what are termed hyperkinetic disorders (hallmarks are inattention and
over-activity).

Description

ADHD is also known as attention deficit disorder (ADD), attention
deficit disorder with and without hyperactivity, hyperkinesis,
hyperkinetic impulse disorder, hyperactive syndrome, hyperkinetic
reaction of childhood, minimal brain damage, minimal brain dysfunction,
and undifferentiated deficit disorder.

The term attention deficit is inexact, as the disorder is not thought
to involve a lack of attention. Rather, there appears to be difficulty
in regulating attention, so that attention is simultaneously given to
many stimuli. The result is an unfocused reaction to the world. As
well, people with ADHD can have difficulty in disregarding stimuli that
are not relevant to the present task. They can also pay so much
attention to one stimulus that they cannot absorb another stimulus that
is more relevant at that particular time.

For many people with ADHD, life is a never-ending shift from one
activity to another. Focus cannot be kept on any one topic long enough
for a detailed assessment. The constant processing of information can
also be distracting, making it difficult for an ADHD individual to
direct his or her attention to someone who is talking to him or her.
Personally, this struggle for focus can cause great chaos that can be
disruptive and diminish self-esteem.

The neurological manifestations of ADHD are disturbances of what are
known as executive functions. Specifically, the six executive functions
that are affected include:

the ability to organize thinking
the ability to shift thought patterns
short-term memory
the ability to distinguish between emotional and logical responses
the ability to make a reasoned decision
the ability to set a goal and plan how to approach that goal
About half or more of those people with ADHD meet criteria set out by
the American Psychiatric Association (Diagnostic and Statistical Manual
of Mental Disorders [DSM-IV]) for at least one of the following other
illnesses:

learning disorder
restless leg syndrome
depression
anxiety disorder
antisocial behavior
substance abuse
obsessive-compulsive behavior
Demographics

ADHD is a common childhood disorder. It is estimated to affect 3-7%
of all children in the United States, representing up to two million
children. The percent in fact be even higher, with up to 15% of boys in
grades one through five being.....

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