Understanding Attention-Deficit/Hyperactivity Disorder (ADHD)

by CDC

ADHD is one of the most common neurobehavioral disorders of childhood and can persist through adolescence and into adulthood. Currently the causes are unknown.

A person with ADHD has a chronic level of inattention, impulsive hyperactivity, or both such that daily functioning is compromised. The symptoms of the disorder must be present at levels that are higher than expected for a person's developmental stage and must interfere with the person's ability to function in different settings (e.g., in school and at home). A person with ADHD may struggle in important areas of life, such as peer and family relationships, and school or work performance.

The American Psychiatric Association's Diagnostic and Statistical Manual-IV, Text Revision (DSM-IV-TR) estimates that 3%-7% of children suffer from ADHD. Some studies have estimated higher rates in community samples. ADHD is diagnosed approximately three times more often in boys than in girls.

Three types of ADHD have been established according to which symptoms are strongest in the individual. These types are described below:

1. Predominantly Inattentive Type: It is hard for the individual to organize or finish a task, to pay attention to details, or to follow instructions or conversations. The person is easily distracted or forgets details of daily routines.

2. Predominantly Hyperactive-Impulsive Type: The person fidgets and talks a lot. It is hard to sit still for long (e.g., for a meal or while doing homework). Smaller children may run, jump or climb constantly. The individual feels restless and has trouble with impulsivity. Someone who is impulsive may interrupt others a lot, grab things from people, or speak at inappropriate times. It is hard for the person to wait their turn or listen to directions. A person with impulsiveness may have more accidents and injuries than others.

3. Combined Type: Symptoms of the above two types are equally predominant in the person.

As many as half of those with ADHD also have other mental disorders. These comorbidities of ADHD (other disorders that occur along with ADHD) can make it harder to diagnose and treat ADHD. They may also present further challenges to the individual with ADHD.

Used by mental health professionals, the DSM-IV-TR provides criteria for diagnosing ADHD. This diagnostic standard helps ensure that people are appropriately diagnosed and treated for ADHD. Using the same standard across communities will help determine the public health impact of ADHD.

Treating ADHD can be done through medical or behavioral therapies, or a combination of the two.

Symptoms of ADHD

The year 2000 Diagnostic & Statistical Manual for Mental Disorders (DSM-IV-TR) provides criteria for diagnosing ADHD. The criteria are presented here in modified form in order to make them more accessible to the general public. They are listed here for information purposes and should be used only by trained health care providers to diagnose or treat ADHD.

DSM-IV Criteria for ADHD

I. Either A or B:

A. Six or more of the following symptoms of inattention have been present for at least 6 months to a point that is disruptive and inappropriate for developmental level:

Inattention

1. Often does not give close attention to details or makes careless mistakes in schoolwork, work, or other activities.

2. Often has trouble keeping attention on tasks or play activities.

3. Often does not seem to listen when spoken to directly.

4. Often does not follow instructions and fails to finish schoolwork, chores, or duties in the workplace (not due to oppositional behavior or failure to understand instructions).

5. Often has trouble organizing activities.

6. Often avoids, dislikes, or doesn't want to do things that take a lot of mental effort for a long period of time (such as schoolwork or homework).

7. Often loses things needed for tasks and activities (e.g. toys, school assignments, pencils, books, or tools).

8. Is often easily distracted.

9. Is often forgetful in daily activities.

B. Six or more of the following symptoms of hyperactivity-impulsivity have been present for at least 6 months to an extent that is disruptive and inappropriate for developmental level:

Hyperactivity

1. Often fidgets with hands or feet or squirms in seat.
2. Often gets up from seat when remaining in seat is expected.
3. Often runs about or climbs when and where it is not appropriate (adolescents or adults may feel very restless).
4. Often has trouble playing or enjoying leisure activities quietly.
5. Is often "on the go" or often acts as if "driven by a motor". 6. Often talks excessively.

Impulsivity

1. Often blurts out answers before questions have been finished.
2. Often has trouble waiting one's turn.
3. Often interrupts or intrudes on others (e.g., butts into conversations or games).

II. Some symptoms that cause impairment were present before age 7 years.

III. Some impairment from the symptoms is present in two or more settings (e.g. at school/work and at home).

IV. There must be clear evidence of significant impairment in social, school, or work functioning.

V. The symptoms do not happen only during the course of a Pervasive Developmental Disorder, Schizophrenia, or other Psychotic Disorder. The symptoms are not better accounted for by another mental disorder (e.g. Mood Disorder, Anxiety Disorder, Dissociative Disorder, or a Personality Disorder).

Based on these criteria, three types of ADHD are identified:

1. ADHD, Combined Type: if both criteria 1A and 1B are met for the past 6 months

2. ADHD, Predominantly Inattentive Type: if criterion 1A is met but criterion 1B is not met for the past six months

3. ADHD, Predominantly Hyperactive-Impulsive Type: if Criterion 1B is met but Criterion 1A is not met for the past six months.

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC, American Psychiatric Association, 2000.

About the Author

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The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.