In 1798, Alexander Crichton (1763–1856), a Scottish physician, described a mental state he had observed in people, especially children. These patients, he said, had an “unnatural degree of mental restlessness.” Today, experts say this is the earliest description of attention deficit disorder (ADD), a chronic condition of poor attention and easy distractibility. It’s often grouped together with impulsiveness and hyperactivity, or attention-deficit/hyperactivity disorder (ADHD).

Up to 5 percent of children have ADD or ADHD; symptoms of the condition can appear as early as infancy and usually manifest before the age of 7. They include not listening, forgetfulness, and being unable to pay attention to tasks or during play. These symptoms can interfere with social relationships and cause problems in school and activities. When the symptoms persist for 6 months or more, the diagnosis is usually ADD. ADD is easier to spot in boys; they are more prone to hyperactivity and disruptive behavior, while girls are more likely to daydream.

Although scientists aren’t certain of the exact cause of ADD, they believe that genes may be a factor. It’s believed that people with the disorder may have altered brain function; brain scans reveal that individuals with ADD and ADHD have less activity in the areas that control attention and concentration. Experts suggest that exposure to drugs and environmental toxins, such as polychlorinated biphenyls, during gestation or infancy may affect the development of nerve cells, raising the risk of the conditions.

Once diagnosed, ADD and ADHD are treated with counseling and prescription medications, such as methylphenidate (Ritalin) and amphetamine and dextroamphetamine (Adderall). These pills help balance out levels of brain chemicals called neurotransmitters. Many children eventually outgrow ADD and ADHD, but some 30 to 60 percent will have the condition well into adulthood.

ADDITIONAL FACTS

  1. One in four children with ADHD has at least one relative with the condition.
  2. Research shows that children who are exposed to high levels of lead are more likely to show symptoms of ADD or ADHD.