There is no single test used to diagnose ADHD. ADHD is diagnosed after a person has shown some or all of symptoms of ADHD on a regular basis for more than 6 months.

Diagnosing ADHD in Children

Health care providers, such as pediatricians or child psychologists can diagnose ADHD with the help of standard guidelines from the American Academy of Pediatrics. The diagnosis involves gathering information from several sources, including school, caregivers and parents. The health care provider will consider how a child's behavior compares with that of other children the same age.

Some symptoms suggestive of ADHD in children include inattention, hyperactivity, and/or impulsivity in a variety of ways. Many children with ADHD:

Are in constant motion.
Squirm and fidget.
Do not seem to listen.
Are easily distracted.
Do not finish tasks.

Learn more about the symptoms of ADHD in children.

To diagnose ADHD, your child should receive a full physical examination. That includes a discussion of medical history to screen for other conditions that may affect a child's behavior. Among the possible causes of ADHD-like behavior are:

A sudden life change (such as divorce, a death in the family, or moving).
Undetected seizures.
Thyroid problems.
Lead toxicity.
Sleep problems.
Anxiety.
Depression.

Diagnosing ADHD in Adults

It is not easy for a health care provider to diagnose ADHD in an adult. Sometimes, an adult will recognize the symptoms of ADHD in himself or herself when a son or daughter is diagnosed. Other times, they will seek professional help for themselves and find that their depression anxiety or other symptoms are related to ADHD.

Symptoms of ADHD in adults can include:

Chronic lateness and forgetfulness.
Anxiety.
Lack of organizational skills.
Low self-esteem.
Employment problems.
Difficulty controlling anger.
Impulsiveness.

If these difficulties are not managed appropriately, they can cause emotional, social, occupational and academic problems in adults.

In order to be diagnosed with ADHD, an adult must have childhood-onset and persistent, current symptoms. ADHD symptoms continue as problems into adulthood for more approximately 60% of children with ADHD. For an accurate diagnosis, the following are recommended:

A history of the adults behavior as a child.
An interview with the adults life partner, parent, close friend, or other close associate.
A physical examination.
Psychological tests.

Reviewed by the doctors at The Cleveland Clinic Children's Hospital.

WebMD Medical Reference provided in collaboration with the Cleveland Clinic