What is Attention-Deficit/Hyperactivity Disorder (ADHD)?

Attention-Deficit/Hyperactivity Disorder (ADHD) is a treatable condition that affects about 11% of children between the ages of four and 17 in the United States. Symptoms of ADHD usually appear by age seven (they may appear before this age), and are seen in boys three times more often than in girls; in adulthood, symptoms are found in men and women equally.

What are the symptoms of ADHD?

The “core,” or main, symptoms of ADHD include:

  • Inattentiveness (trouble paying attention)
  • Distractibility (easily distracted)
  • Impulsivity (doing things on sudden urges)
  • Hyperactivity (restlessness)

Some children may have ADHD without hyperactivity. This condition is more difficult to discover early because these children do not "act up" in class or at home. They are often bright and manage their workload in the early grades with little effort, not drawing attention to themselves. They may seem bored and fail to complete work, or they may show signs of confusion, forgetfulness, daydreaming, and disorganization.

At times, children seem to be “overfocused” in areas they are interested in. As a result, they do not appear disobedient or defiant, but simply don’t do their assigned chores or self-care routines when their parents ask them to, since they are so absorbed in their interests.

ADHD has two main classes of symptoms: inattention and hyperactivity/impulsivity.

The child with inattention has the following signs and symptoms:

  • Fails to pay close attention to details or makes careless mistakes in schoolwork or other activities.
  • Has trouble paying attention during tasks or play.
  • Seems not to listen even when spoken to directly.
  • Has difficulty following through on instructions (for example, often fails to finish schoolwork, chores, or other tasks).
  • Often has difficulty organizing tasks or activities.
  • Avoids or dislikes tasks that require continuous mental effort, such as schoolwork or homework.
  • Frequently loses needed items, such as books, pencils, toys, or tools.
  • Can be easily distracted by surrounding activity or noise.
  • Is often forgetful.

The child with hyperactive and impulsive behavior has these signs and symptoms:

  • Fidgets or squirms frequently.
  • Leaves his/her seat in the classroom or in other situations when he/she is expected to remain seated.
  • Runs or climbs excessively when it's not appropriate.
  • May constantly feel restless (if an adolescent).
  • Has trouble playing quietly.
  • Always seems on the go or “driven by a motor.”
  • Talks too much.
  • Blurts out the answers before questions have been completely asked; older children may often finish sentences for others who are talking.
  • Frequently has trouble waiting for his or her turn.
  • Often interrupts or intrudes on others' conversations or games.

What are the causes and risk factors of ADHD?

Research has shown that ADHD is caused by neurological (nervous system) and biological (related to the body) factors, though the exact causes are not yet known.

Risk factors for ADHD include the following:

  • Hereditary: If one or both parents have been diagnosed with ADHD, their children are more likely to show signs of it, as well.
  • Biological: Studies suggest that ADHD comes from a chemical imbalance or problem with the way certain neurotransmitters (chemicals in the brain that help control behavior) work, especially dopamine.
  • Environment: Exposure to toxins (poisons) in the environment (for example, lead) is linked to ADHD in children.
  • Prenatal (during pregnancy) exposure: Smoking and/or drug and alcohol use during pregnancy are associated with ADHD in children.

Although the following factors may contribute to ADHD or make it worse, they are not causes:

  • Everyday things in the child’s life, such as the home or school setting
  • Poor parenting or poor teaching (such as too much punishment)
  • Food additives*

*Note: A small number of children with ADHD may be sensitive to food dyes, artificial flavors, preservatives, or other food additives. Children with specific sensitivities and/or allergies may have fewer ADHD symptoms on a diet without food additives. Generally, food additives are not considered a cause of ADHD.

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