ADD is officially called Attention-Deficit/Hyperactivity Disorder, or AD/HD (American Psychiatric Association, 1994), although most lay people, and even some professionals, still call it ADD or A.D.D. (the names given in 1980) or ADHD . The disorder's name has changed as a result of scientific advances and the findings of careful field trials; researchers now have strong evidence to support the position that AD/HD [ A.D.D. or ADHD ] [as we will refer to the disorder throughout the remainder of this Briefing Paper] is not one specific disorder with different variations. In keeping with this evidence, AD/HD [ A.D.D. OR ADHD ] is now divided into three subtypes, according to the main features associated with the disorder: inattentiveness, impulsivity, and hyperactivity. The three subtypes are:

There are more than 100 different types of arthritis and the cause of most arthritis types is unknown. Scientists are currently studying and considering three major factors that contribute in one way or another to certain types of arthritis. These include the genetic factors you inherit from parents, the way that you choose to live your life, and things that happen to you during your life. The importance and relevance of these factors varies for every type of arthritis. Consider the following types of arthritis:

• AD/HD [ A.D.D. OR ADHD ] Predominantly Combined Type
• AD/HD [ A.D.D. OR ADHD ] Predominantly Inattentive Type
• AD/HD [ A.D.D. OR ADHD ] Predominantly Hyperactive-Impulsive Type

These subtypes take into account that some children with AD/HD [ A.D.D. OR ADHD ] have little or no trouble sitting still or inhibiting behavior, but may be predominantly inattentive and, as a result, have great difficulty getting or staying focused on a task or activity. Others with AD/HD [ A.D.D. OR ADHD ] may be able to pay attention to a task but lose focus because they may be predominantly hyperactive-impulsive and, thus, have trouble controlling impulse and activity. The most prevalent subtype is the Combined Type. These children will have significant symptoms of all three characteristics.

AD/HD [ A.D.D. OR ADHD ] is a neurobiologically-based developmental disability estimated to affect between 3-5% of the school age population (Professional Group for Attention and Related Disorders,1991). No one knows exactly what causes AD/HD [ A.D.D. OR ADHD ]. Scientific evidence suggests that the disorder is genetically transmitted in many cases and results from a chemical imbalance or deficiency in certain neurotransmitters, which are chemicals that help the brain regulate behavior. In addition, a landmark study conducted by the National Institute of Mental Health showed that the rate at which the brain uses glucose, its main energy source, is lower in subjects with AD/HD [ A.D.D. OR ADHD ] than in subjects without AD/HD [ A.D.D. OR ADHD ] (Zametkin et al., 1990).

Even though the exact cause of AD/HD [ A.D.D. OR ADHD ] remains unknown, we do know that AD/HD [ A.D.D. OR ADHD ] is a neurologically-based medical problem. Parents and teachers do not cause AD/HD [ A.D.D. OR ADHD ]. Still, there are many things that both can do to help a child manage his or her AD/HD [ A.D.D. OR ADHD ]-related difficulties. Before we look at what needs to be done, however, let us look at what AD/HD [ A.D.D. OR ADHD ] is and how it is diagnosed.

Professionals who diagnose AD/HD [ A.D.D. OR ADHD ] use the diagnostic criteria set forth by the American Psychiatric Association (1994) in the Diagnostic and Statistical Manual of Mental Disorders; the fourth edition of this manual, known as the DSM-IV, was released in May 1994. The criteria in the DSM-IV (discussed below) and the other essential diagnostic features listed in the box labeled "Defining Attention-Deficit/Hyperactivity Disorder" are the signs of AD/HD [ A.D.D. OR ADHD ].

As can be seen, the primary features associated with the disability are inattention, hyperactivity, and impulsivity. The discussion below describes each of these features and lists their symptoms, as given in the DSM-IV.

• Inattention - A child with AD/HD [ A.D.D. OR ADHD ] is usually described as having a short attention span and as being distractible. In actuality, distractibility and inattentiveness are not synonymous. Distractibility refers to the short attention span and the ease with which some children can be pulled off-task. Attention, on the other hand, is a process that has different parts. We focus (pick something on which to pay attention), we select (pick something that needs attention at that moment) and we sustain (pay attention for as long as is needed). We also resist (avoid things that remove our attention from where it needs to be), and we shift (move our attention to something else when needed). When we refer to someone as distractible, we are saying that a part of that person's attention process is disrupted. Children with AD/HD [ A.D.D. OR ADHD ] can have difficulty with one or all parts of the attention process. Some children may have difficulty concentrating on tasks (particularly on tasks that are routine or boring). Others may have trouble knowing where to start a task. Still others may get lost in the directions along the way. A careful observer can watch and see where the attention process breaks down for a particular child.
• Hyperactivity - Excessive activity is the most visible sign of AD/HD [ A.D.D. OR ADHD ]. The hyperactive toddler/preschooler is generally described as "always on the go" or "motor driven." With age, activity levels may diminish. By adolescence and adulthood, the overactivity may appear as restless, fidgety behavior (American Psychiatric Association, 1994).
• Impulsivity - When people think of impulsivity, they most often think about cognitive impulsivity, which is acting without thinking. The impulsivity of children with AD/HD [ A.D.D. OR ADHD ] is slightly different. These children act before thinking, because they have difficulty waiting or delaying gratification. The impulsivity leads these children to speak out of turn, interrupt others, and engage in what looks like risk-taking behavior. The child may run across the street without looking or climb to the top of very tall trees. Although such behavior is risky, the child is not really a risk-taker but, rather, a child who has great difficulty controlling impulse. Often,the child is surprised to discover that he or she has gotten into a dangerous situation and has no idea of how to get out of it.

It is important to note that, in the DSM-IV, hyperactivity and impulsivity are no longer considered as separate features. According to Barkley (1990), hyperactivity-impulsivity is a pattern stemming from an overall difficulty in inhibiting behavior.

In addition to problems with inattention or hyperactivity-impulsivity, the disorder is often seen with associated features. Depending on the child's age and developmental stage, parents and teachers may see low frustration tolerance, temper outburts, bossiness, difficulty in following rules, disorganization, social rejection, poor self-esteem, academic underachievement, and inadequate self-application (American Psychiatric Association, 1994).

Unfortunately, no simple test such as a blood test or urinanalysis exists to determine if a child has this disorder. Diagnosing AD/HD [ A.D.D. OR ADHD ] is complicated and much like putting together a puzzle. An accurate diagnosis requires an assessment conducted by a well-trained professional (usually a developmental pediatrician, child psychologist, child psychiatrist, or pediatric neurologist) who knows a lot about AD/HD [ A.D.D. OR ADHD ] and all other disorders that can have symptoms similar to those found in AD/HD [ A.D.D. OR ADHD ]. Until the practitioner has collected and evaluated all the necessary information, he or she must follow the same rule of thumb as the parent or teacher who sees the behavior and suspects that the child has the disorder: Assume the child might have AD/HD [ A.D.D. OR ADHD ].

The AD/HD [ A.D.D. OR ADHD ] diagnosis is made on the basis of observable behavioral symptoms in multiple settings. This means that the person doing the evaluation must use multiple sources to collect the information needed.

National Information Center for Children and Youth with Disabilities (NICHCY)