Introduction

According to the U.S. National Institute of Mental Health, attention deficit hyperactivity disorder (ADHD) is a legitimate psychologic condition.

ADHD is a syndrome generally characterized by the following symptoms:

• Inattention
• Distractibility
• Impulsivity
• Hyperactivity

Some doctors categorize ADHD into three subtypes:

• Behavior marked by hyperactivity and impulsivity, but not inattentiveness
• Behavior marked by inattentiveness, but not hyperactivity and impulsivity
• A combination of the above two

There is some debate over these criteria. Some argue the condition is overdiagnosed. Others say it's underdiagnosed. (See Difficulties in Identifying Children with ADHD section in this report.) One-third of cases are accompanied by learning disabilities and other neurologic or emotional problems, making an ADHD diagnosis particularly difficult. It is likely that the term attention-deficit hyperactivity disorder will eventually give way to subgroups of problems that include some of these general symptoms.

Childhood ADHD

In the United States, about 4.7 million children ages 3 - 17 have been diagnosed at some point with ADHD. This accounts for 7.4% of all American children in this age range.

ADHD is a genuine disorder, but it is telling that the U.S. accounts for 90% of worldwide prescriptions for stimulants for ADHD. It is not known whether this reflects a real increase in ADHD, or a better ability to recognize it. Some say it may be an indication of a culture that places excessive value on normalcy and academic achievement at the expense of more frequent diagnoses.

Symptoms of ADHD usually occur around the age of 7. Studies indicate that ADHD symptoms in preschool children with ADHD do not differ significantly from older children.

The classic ADHD symptoms do not always adequately describe the child's behavior, nor do they describe what is actually happening in the child's mind. Some researchers focused on deficits in "executive functions" of the brain to understand and describe all ADHD behaviors. Such impaired executive functions in ADHD children can cause the following problems:

• Inability to hold information in short-term memory
• Impaired organization and planning skills
• Difficulty in establishing and using goals to guide behavior, such as selecting strategies and monitoring tasks
• Inability to keep emotions from becoming overpowering
• Inability to shift efficiently from one mental activity to another

Hyperactivity. The term hyperactive is often confusing since, for some, it suggests a child racing around non-stop. A boy with ADHD playing a game, for instance, may have the same level of activity as another child without the syndrome. But when a high demand is placed on the child's attention, his brain motor activity intensifies beyond the levels of the other children. In a busy environment, such as a classroom or a crowded store, children with ADHD often become distracted and react by pulling items off the shelves, hitting people, or spinning out of control into erratic, silly, or strange behavior.