Attention-Deficit Hyperactivity Disorder or Hyperactivity (ADHD), disorder beginning in childhood, characterized by a persistent inability to sit still, focus attention on specific tasks, and control impulses. Children with ADHD show these behaviors more frequently and severely than other children of the same age. A person with ADHD may have difficulty with school, work, friendships, or family life. ADHD has also been referred to as attention-deficit disorder, hyperkinesis, minimal brain dysfunction, and minimal brain damage.
Attention-deficit hyperactivity disorder is one of the most common mental disorders of childhood, affecting 3 to 5 percent of school-age children. The disorder occurs at least four times more often in boys than in girls. Although the symptoms sometimes disappear with age, ADHD can persist into adolescence and adulthood. Some estimates show that up to 2 percent of adults have ADHD.
Diagnosing ADHD is difficult because most children are inattentive, hyperactive, and impulsive at least some of the time. In diagnosing ADHD, experts use guidelines listed in the Diagnostic and Statistical Manual of Mental Disorders. These guidelines require that a child show behaviors typical of ADHD before the age of seven. The behaviors must last for at least six months, and must occur more frequently than in other children of the same age. The behaviors also must occur in at least two settings, such as classroom and home, rather than just at a single setting.
Controversy exists over the diagnosis of ADHD. Physicians in the United States diagnose the disorder more often than doctors elsewhere in the world. Critics regard this discrepancy as evidence that physicians and psychologists too often apply psychiatric labels to children who are naturally more active or simply nuisances to teachers and parents.
Children and adults with ADHD consistently show various degrees of inattention, hyperactivity, and impulsiveness. Inattention means that people with ADHD have difficulty keeping their minds on one thing. They may get bored with homework or other tasks after a few minutes, make careless mistakes, have trouble listening, and seem to daydream. However, children with ADHD sometimes can concentrate on and complete new or unusually interesting tasks. Hyperactivity involves almost constant motion, as if driven by a motor. Children may squirm and fidget at their desks in school, get up often to roam around the room, constantly touch things, disturb other people, tap pencils, and talk constantly. ADHD also makes children unusually impulsive, so that they act before thinking. They may run into the street without looking, blurt out inappropriate comments in class, interrupt conversations, and be unusually clumsy or accident-prone.
Children with ADHD often have severe learning problems because of their difficulties in paying attention, following instructions, and completing tasks. In addition, their disruptive, demanding behavior makes them unpopular with peers. Children with ADHD often receive constant criticism and correction from teachers and parents, who believe the behavior is intentional. The combination of negative feedback, poor academic achievement, and social problems may contribute to low self-esteem and other emotional problems.
Scientists do not know what causes ADHD. However, they have discredited many theories that once were widely accepted. One theory contended that ADHD resulted from minor head injuries or undetectable brain damage due to infections or complications during birth. Experts called ADHD “minimal brain damage” and “minimal brain dysfunction” when this theory was popular in the early 1970s. Another theory linked ADHD with consumption of refined sugar and food additives. Scientists questioned this theory when studies showed that few children with ADHD benefited from diets restricting sugar and food colorings. Most experts also reject the idea that poor parenting or a dysfunctional home environment causes ADHD.
Most scientists regard ADHD as a biological disorder caused by abnormalities in the brain. Studies have shown that areas of the brain that control attention span and limit impulsive behavior are less active in people with ADHD. In addition, ADHD seems to run in families, suggesting that genetic factors may play an important role (see Genetics). One study showed that about one-third of fathers who had ADHD in childhood have children with ADHD.
Although there is no cure for ADHD, a variety of treatments may help children with this disorder. These include medication, counseling, social skills training, and other methods.
Drugs are the most common treatment for ADHD and can help reduce symptoms of the disorder. Physicians usually prescribe one of three drugs: methylphenidate (marketed under the brand names Concerta, Methylin, Metadate, and Ritalin), dextroamphetamine (Dexedrine or DextroStat), and pemoline (Cylert). These drugs are normally stimulants, yet they ease hyperactivity and other symptoms in 90 percent of children with ADHD. The drugs work by altering levels of neurotransmitters, brain chemicals that transmit nerve signals. A newer stimulant used to treat ADHD, Adderall, combines dextroamphetamine and amphetamine. At least one drug used to treat ADHD, atomoxetine (Strattera), which is manufactured by Eli Lilly and Company, is not classified as a stimulant.
Medical experts generally regard stimulants as safe. The most common side effects include stomachaches, loss of appetite, nervousness, and insomnia. Drug therapy may slow a child’s rate of growth temporarily, but growth usually returns to normal during adolescence. Low doses of stimulants do not cause a “high” sensation, sedate the child, or cause addiction. Experts often recommend that children take medication only during school, with medication breaks on weekends and holidays to reduce unwanted side effects. Doctors may prescribe other types of drugs if stimulants do not prove effective.
In 2006 the Food and Drug Administration (FDA) directed manufacturers to place warning labels on ADHD drugs to alert patients to possible serious risks associated with the drugs. Although the drugs are generally regarded as safe, an advisory panel of drug experts was convened to review their safety after reports of 25 sudden deaths among people taking ADHD stimulants. The stimulants were found to raise blood pressure and heart rate. Thus, they can increase the risk of stroke, arrhythmias (see Palpitation), and heart attack in children and adults with underlying heart problems. Another panel found that the drugs slightly increased the risk of psychiatric problems, including hearing voices, paranoia, and manic episodes. In 2007 the FDA directed drug manufacturers to develop medication guides for patients, explaining the risks and benefits of the drugs and the precautions to take.
Although the drugs are prescribed most often to treat ADHD among children, increasingly adults are taking the drugs for ADHD. From 2002 to 2005 the number of prescriptions written for adults reportedly increased by 90 percent. In the United States about 2.5 million children and about 1.5 million adults take ADHD drugs. A member of the FDA advisory panel noted that adults are more likely to have a higher risk of heart problems. Most of the 25 sudden deaths, however, were among children. The preliminary findings of the drug-safety panel showed a greater risk of heart attacks and strokes among adults taking the ADHD stimulants, and a higher than expected number of strokes among children under 18 taking these drugs.
Numerous studies have demonstrated the safety of Ritalin, which first went on the market in 1955, but no studies have been done to evaluate the long-term effects of taking these stimulants. Novartis Pharmaceuticals, the makers of Ritalin, and Shire Pharmaceuticals, which manufactures the amphetamine Adderall, defended the safety of their products.
Critics argue that physicians medicate too many children who do not have ADHD. They point out that allergies, depression, anxiety, conflicts with teachers or parents, and other problems can make normal children seem hyperactive, impulsive, and distracted.
B Other Therapies
Most children with ADHD need more than medication. Drugs only relieve symptoms of ADHD, which usually return when medication is discontinued. Although drugs may help a child to concentrate and complete schoolwork, they cannot increase a child’s knowledge, teach academic skills, or directly alter underlying learning disorders or other problems. Experts cite the need for more information on whether medication improves a child’s chances for a successful career.
Children may benefit from several different kinds of therapy. Psychological counseling, for instance, can help them recognize and deal with negative feelings that result from their symptoms. Social skills training can help them recognize how their behavior affects other people and help them develop more appropriate behavior. Children with ADHD also may benefit from special academic tutors who show them how to break school assignments down into small parts that can be completed one at a time.
Because children with ADHD often cause family turmoil, parents and other family members may benefit from therapy or support groups in which other parents share their experiences. Parental skills training can teach parents to manage a child’s behavior with praise and other rewards, and with penalties such as “time-outs” in which a child must sit alone to calm down.
VI ADHD IN ADULTS
Many children with ADHD continue to have problems as adolescents and adults. Adults with ADHD may be unusually impatient and restless and may become bored before finishing a task. They may constantly arrive late for appointments, lose things, change jobs often, fail to organize their time or set priorities, and have difficulty maintaining friendships and other relationships. Studies suggest they are more likely than others to develop other mental illnesses such as anxiety and depression, as well as substance-abuse problems such as alcoholism and drug dependence.
See also Special Education; Education of Students with Learning Disorders.