Attention-Deficit Hyperactivity Disorder (ADHD) in Children

What is attention-deficit/hyperactivity disorder (ADHD)?

ADHD, also called attention-deficit disorder, is a behavior disorder, usually first diagnosed in childhood, that is characterized by inattention, impulsivity, and, in some cases, hyperactivity. These symptoms usually occur together; however, one may occur without the other(s).

The symptoms of hyperactivity, when present, are almost always apparent by the age of 7 and may be apparent in very young preschoolers. Inattention or attention-deficit may not be evident until a child faces the expectations of elementary school.

What are the different types of ADHD?

Three major types of ADHD include the following:

  • ADHD, combined type. This, the most common type of ADHD, is characterized by impulsive and hyperactive behaviors as well as inattention and distractibility.

  • ADHD, impulsive/hyperactive type. This, the least common type of ADHD, is characterized by impulsive and hyperactive behaviors without inattention and distractibility.

  • ADHD, inattentive and distractible type. This type of ADHD is characterized predominately by inattention and distractibility without hyperactivity.

What causes attention-deficit/hyperactivity disorder?

ADHD is one of the most researched areas in child and adolescent mental health. However, the precise cause of the disorder is still unknown. Available evidence suggests that ADHD is genetic. It is a brain-based biological disorder. Low levels of dopamine (a brain chemical), which is a neurotransmitter (a type of brain chemical), are found in children with ADHD. Brain imaging studies using PET scanners (positron emission tomography; a form of brain imaging that makes it possible to observe the human brain at work) show that brain metabolism in children with ADHD is lower in the areas of the brain that control attention, social judgment, and movement.

Who is affected by attention-deficit/hyperactivity disorder?

Estimates suggest that about 2 million children (3 percent to 5 percent) have ADHD. Boys are two to three times more likely to have ADHD than girls.

Many parents of children with ADHD experienced symptoms of ADHD when they were younger. ADHD is commonly found in brothers and sisters within the same family. Most families seek help when their child's symptoms begin to interfere with learning and adjustment to the expectations of school and age-appropriate activities.

What are the symptoms of attention-deficit/hyperactivity disorder?

Most symptoms seen in children with ADHD also occur at times in children without this disorder. However, in children with ADHD, these symptoms occur more frequently and interfere with learning, school adjustment, and, sometimes, with the child's relationships with others.

The following are the most common symptoms of ADHD. However, each child may experience symptoms differently. The three categories of symptoms of ADHD include the following:

  • Inattention:

    • Short attention span for age (difficulty sustaining attention)

    • Difficulty listening to others

    • Difficulty attending to details

    • Easily distracted

    • Forgetfulness

    • Poor organizational skills for age

    • Poor study skills for age

  • Impulsivity:

    • Often interrupts others

    • Has difficulty waiting for his or her turn in school and/or social games

    • Tends to blurt out answers instead of waiting to be called upon

    • Takes frequent risks, and often without thinking before acting

  • Hyperactivity:

    • Seems to be in constant motion; runs or climbs, at times with no apparent goal except motion

    • Has difficulty remaining in his/her seat even when it is expected

    • Fidgets with hands or squirms when in his or her seat; fidgeting excessively

    • Talks excessively

    • Has difficulty engaging in quiet activities

    • Loses or forgets things repeatedly and often

    • Inability to stay on task; shifts from one task to another without bringing any to completion

The symptoms of ADHD may resemble other medical conditions or behavior problems. Furthermore, many of these symptoms may occur in children and teens who do not have ADHD. A key element in diagnosis is that the symptoms must significantly impair adaptive functioning in both home and school environments. Always consult your child's doctor for a diagnosis.