Attention-Deficit/Hyperactivity Disorder

What is attention-deficit/hyperactivity disorder?

Attention-deficit/hyperactivity disorder (ADHD) is an illness characterized by inattention, hyperactivity, and impulsivity. The most commonly diagnosed behavior disorder in young persons, ADHD affects an estimated three percent to five percent of school-age children.

Although ADHD is usually diagnosed in childhood, it is not a disorder limited to children -- ADHD often persists into adolescence and adulthood and is frequently not diagnosed until later years.

What are the symptoms of ADHD?

There are actually three different types of ADHD, each with different symptoms: predominantly inattentive, predominantly hyperactive/impulsive, and combined.

Those with the predominantly inattentive type often:

  • fail to pay close attention to details or make careless mistakes in schoolwork, work, or other activities
  • have difficulty sustaining attention to tasks or leisure activities
  • do not seem to listen when spoken to directly
  • do not follow through on instructions and fail to finish schoolwork, chores, or duties in the workplace
  • have difficulty organizing tasks and activities
  • avoid, dislike, or are reluctant to engage in tasks that require sustained mental effort
  • lose things necessary for tasks or activities
  • are easily distracted by extraneous stimuli
  • are forgetful in daily activities

Those with the predominantly hyperactive/impulsive type often:

  • fidget with their hands or feet or squirm in their seat
  • leave their seat in situations in which remaining seated is expected
  • move excessively or feel restless during situations in which such behavior is inappropriate
  • have difficulty engaging in leisure activities quietly
  • are "on the go" or act as if "driven by a motor" 
  • talk excessively
  • blurt out answers before questions have been completed 
  • have difficulty awaiting their turn  interrupt or intrude on others

Those with the combined type, the most common type of ADHD, have a combination of the inattentive and hyperactive/impulsive symptoms.

What is needed to make a diagnosis of ADHD?

A diagnosis of ADHD is made when an individual displays at least six symptoms from either of the above lists, with some symptoms having started before age seven. Clear impairment in at least two settings, such as home and school or work, must also exist. Additionally, there must be clear evidence of clinically significant impairment in social, academic, or occupational functioning.

How common is ADHD?

ADHD affects an estimated two million American children, an average of at least one child in every U.S. classroom. In general, boys with ADHD have been shown to outnumber girls with the disorder by a rate of about three to one. The combined type of ADHD is the most common in elementary school-aged boys; the predominantly inattentive type is found more often in adolescent girls.

While there is no specific data on the rates of ADHD in adults, the disorder is sometimes not diagnosed until adolescence or adulthood, and half of the children with ADHD retain symptoms of the disorder throughout their adult lives. (It is generally believed that older individuals diagnosed with ADHD have had elements of the disorder since childhood.)