Definition

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