ADHD

Definition

Attention-deficit/hyperactivity disorder (ADHD) is a brain disorder marked by an ongoing pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development.

• Inattention means a person wanders off task, lacks persistence, has difficulty sustaining focus, and is disorganized; and these problems are not due to defiance or lack of comprehension.
• Hyperactivity means a person seems to move about constantly, including in situations in which it is not appropriate; or excessively fidgets, taps, or talks. In adults, it may be extreme restlessness or wearing others out with constant activity.
• Impulsivity means a person makes hasty actions that occur in the moment without first thinking about them and that may have high potential for harm; or a desire for immediate rewards or inability to delay gratification. An impulsive person may be socially intrusive and excessively interrupt others or make important decisions without considering the long-term consequences.

Signs and Symptoms

Inattention and hyperactivity/impulsivity are the key behaviors of ADHD. Some people with ADHD only have problems with one of the behaviors, while others have both inattention and hyperactivity-impulsivity.Most children have the combined type of ADHD.

In preschool, the most common ADHD symptom is hyperactivity.

It is normal to have some inattention, unfocused motor activity and impulsivity, but for people with ADHD, these behaviors:

• are more severe
• occur more often
• interfere with or reduce the quality of how they functions socially, at school, or in a job

Inattention

People with symptoms of inattention may often:

• Overlook or miss details, make careless mistakes in schoolwork, at work, or during other activities
• Have problems sustaining attention in tasks or play, including conversations, lectures, or lengthy reading
• Not seem to listen when spoken to directly

Hyperactivity-Impulsivity

People with symptoms of hyperactivity-impulsivity may often:

• Fidget and squirm in their seats
• Leave their seats in situations when staying seated is expected, such as in the classroom or in the office
• Run or dash around or climb in situations where it is inappropriate or, in teens and adults, often feel restless

Diagnosis of ADHD requires a comprehensive evaluation by a licensed clinician, such as a pediatrician, psychologist, or psychiatrist with expertise in ADHD. For a person to receive a diagnosis of ADHD, the symptoms of inattention and/or hyperactivity-impulsivity must be chronic or long-lasting, impair the person’s functioning, and cause the person to fall behind normal development for his or her age. The doctor will also ensure that any ADHD symptoms are not due to another medical or psychiatric condition. Most children with ADHD receive a diagnosis during the elementary school years. For an adolescent or adult to receive a diagnosis of ADHD, the symptoms need to have been present prior to age 12.

Risk Factors

Scientists are not sure what causes ADHD. Like many other illnesses, a number of factors can contribute to ADHD, such as:

• Genes
• Cigarette smoking, alcohol use, or drug use during pregnancy
• Exposure to environmental toxins during pregnancy
• Exposure to environmental toxins, such as high levels of lead, at a young age
• Low birth weight
• Brain injuries

ADHD is more common in males than females, and females with ADHD are more likely to have problems primarily with inattention. Other conditions, such as learning disabilities, anxiety disorder, conduct disorder, depression, and substance abuse, are common in people with ADHD.