Attention Deficit/Hyperactivity Disorder
Attention Deficit/Hyperactivity Disorder
Attention deficit/hyperactivity disorder (ADHD) is a developmental disorder characterized by distractibility, hyperactivity, impulsive behaviors, and the inability to remain focused on tasks or activities.
ADHD was first described in 1845. The estimated prevalence of ADHD, also known as hyperkinetic disorder (HKD) outside of the United States, is 8% to 10% of children. Although difficult to assess in infancy and toddlerhood, signs of ADHD may begin to appear as early as age two or three, but the symptom picture changes as adolescence approaches. Many symptoms, particularly hyperactivity, diminish in early adulthood; however, up to 70% of individuals with ADHD experience persistent impulsivity and problems focusing attention throughout their adult lives. Inattention is the most frequent persistent symptom in adults with ADHD.
The causes of ADHD are thought to be an interaction of environment and genes. Heredity plays a major role in the development of ADHD. A number of genes considered to confer susceptibility to ADHD have been identified, and some researchers have suggested that ADHD may arise from several different combinations of these susceptibility genes and environmental factors. These genes primarily involve the signaling proteins active in the brain’s dopamine (a nerve-signaling molecule) pathways, supporting the prevailing theory that the signaling of dopamine and other neurotransmitters is responsible for the symptoms of the disorder. Brain imaging results also support this idea. These studies have identified distinct differences in dopamine processing and uptake in the brains of people with ADHD compared to those of people without the disorder. Some researchers see a link between ADHD and obsessive-compulsive disorder (OCD) in heredity studies of families, and children with an ADHD parent or sibling are more likely to develop the disorder themselves. Studies of identical twins point to a heritability rate as high as 91%.
Some environmental factors have been strongly linked to ADHD. Studies have found that maternal smoking during pregnancy can increase a child’s overall risk of ADHD by two-and-a-half times, and if the child is a girl, the risk can be as much as 4.6 times higher. Low birth weight also has been identified as a risk factor, and lead exposure has been linked to ADHD; lead levels above a predetermined cutoff in one study were linked to a fourfold increase in the risk of having ADHD. Traumatic brain injury or neurological disorders may also trigger ADHD symptoms.
The diagnosis of ADHD requires the presence of at least six of the following symptoms of inattention, or six or more symptoms of hyperactivity and impulsivity combined:
- fails to pay close attention to detail or makes careless mistakes in schoolwork or other activities
- has difficulty sustaining attention in tasks or activities
- does not appear to listen when spoken to
- does not follow through on instructions and does not finish tasks
- has difficulty organizing tasks and activities
- avoids or dislikes tasks that require sustained mental effort (e.g., homework)
- is easily distracted
- is forgetful in daily activities
- fidgets with hands or feet or squirms in seat
- does not remain seated when expected to
- runs or climbs excessively when inappropriate (in adolescents and adults, feelings of restlessness)
- has difficulty playing quietly
- is constantly on the move
- talks excessively
- blurts out answers before the question has been completed
- has difficulty waiting turns
- interrupts and/or intrudes on others
Further criteria to establish a diagnosis also require that some symptoms develop before age seven, and that they significantly impair functioning in two or more settings (e.g., home and school) for a period of at least six months.
Many individuals with ADHD have symptoms from all three of the above categories. Some children, however, have behavior patterns in which inattention dominates, or hyperactivity and impulsivity dominate. For this reason, ADHD can be further categorized, or subdivided, into three subtypes. Children who have at least six symptoms from both of the inattention and hyperactivity-impulsivity categories may be diagnosed with ADHD, combined type. Children who meet the symptom criteria for inattention, but not for hyperactivity-impulsivity, are diagnosed with attention deficit/hyperactivity disorder, predominantly inattentive type, commonly called attention deficit disorder (ADD). Children with predominantly attentive type may go undiagnosed until negative academic consequences arise; children who daydream are much less noticeable than children who are in constant, impulsive motion. Children who experience more symptoms from the hyperactivity and impulsivity categories, but fewer than six symptoms of inattention may be diagnosed with ADHD, predominantly hyperactive-impulsive type.
The first step in determining if a child has ADHD is to consult with a pediatrician. The pediatrician can make an initial evaluation of the child’s developmental maturity compared to other children in the same age group, using guidelines for the diagnosis and evaluation of ADHD provided by the American Academy of Pediatrics. The physician should also perform a comprehensive physical examination to rule out any organic causes of ADHD symptoms, such as an over-active thyroid or vision or hearing problems.
If no organic problem can be found, a psychologist, psychiatrist, neurologist/pediatric neurologist, neuropsychologist, developmental pediatrician, or learning specialist is typically consulted to perform a comprehensive ADHD assessment. A complete medical, family, social, psychiatric, and educational history is compiled from existing medical and school records and from interviews with parents and teachers. Interviews may also be conducted with the children, depending on their age. Along with these interviews, several clinical questionnaires may also be used, such as the Conners’ Rating Scales (Teacher’s Questionnaire and Parent’s Questionnaire), Child Behavior Checklist (CBCL), and the Achenbach Child Behavior Checklist. These inventories provide valuable information on the child’s behavior in different settings and situations. In addition, the Wender Utah Rating Scale has been adapted for use in diagnosing ADHD in adults, as has the Conners’ Adult ADHD rating scale.
It is important to note that mental disorders such as depression and anxiety disorder can cause symptoms similar to ADHD: Depression can cause attention problems, and anxiety can cause symptoms similar to hyperactivity. A complete and comprehensive psychological assessment is critical to differentiate ADHD from other possible mood and behavioral disorders. Bipolar disorder, for example, may be mis-diagnosed as ADHD.
Federal law requires a public school to assess children when ADHD is suspected and there are observable effects on their schoolwork and interactions with peers. A pediatrician can also provide a referral to a psychologist or pediatric specialist for ADHD assessment. Parents should check with their insurance plans to see if these services are covered if they choose to pursue a private evaluation.
Therapy that addresses both psychological and social issues (called psychosocial therapy), usually combined with medications, is the treatment approach of choice to alleviate ADHD symptoms. This combination has proved to be the most effective treatment approach to ADHD.
For 70 years, psychostimulant medication has been used to treat symptoms of ADHD, and stimulants are still considered the first-line medication for treatment of ADHD. It may seem paradoxical to treat a disorder of hyperactivity with a stimulant medication, but people with ADHD typically experience a calming effect from stimulants. Stimulants approved by the U.S. Food and Drug Administration (FDA) for treatment of ADHD are methylphenidate (which occurs under several trade names, including Ritalin), mixed amphetamine salts (trade name Adderall), and dextroamphetamine (trade name Dexedrine). These stimulants are comparatively short acting, requiring several doses during a day to maintain appropriate levels. Some long-acting forms are available, such as Ritalin LA and Adderall XR, and a transdermal patch (trade name Daytrana) is also available for delivery of methylphenidate through the skin.
Stimulant use in children with ADHD has been associated in some studies with sudden death in a small number of cases, leading to widespread concern; however, subsequent studies have found no difference in sudden death rates among children taking stimulants for ADHD and the general population using no medication. Use of these medications is not recommended for people who have known heart disease.
Another stimulant-related side effect of concern is the effect these drugs have on growth rate. Studies do indicate that while a child is taking stimulants, growth rate can slow. Some practitioners may recommend “drug holidays,” in which the child stops taking the drug when circumstances require less focus or self-discipline, such as over a summer vacation. Studies indicate that the adverse effects on growth rate are eliminated by these drug holidays.
One of the drugs that has been used to treat ADHD, pemoline (trade name Cylert) is not recommended as a first-line approach to ADHD because of the potential for serious side effects related to the liver.
More minor side effects associated with stimulant-based treatment include decreased appetite, insomnia, increased anxiety, and irritability.
Some newer drugs for treating ADHD have also come on the market. Among these is atomoxetine (trade name, Strattera), which inhibits reuptake of noradrenaline, a nerve-signaling molecule. This drug is the only nonstimulant drug treatment for ADHD that is approved by the FDA. It is suggested as an alternative for children who cannot tolerate standard psychostimulant therapy.
Another drug, modafinil, had stirred up a great deal of interest because it was effective in treating ADHD in a couple of double-blind, placebo-controlled trials, but the FDA recently declined approval of the drug for clinical use.
Other prescription drugs used in the treatment of ADHD are not FDA-approved for that purpose and therefore their use in treating this disorder is “off-label.” These drugs include tricyclic antidepressants such as imipramine, the antidepressant buproprion, and guanfacine, a mimic of a specific form of neuro-transmitter (nerve-signaling molecule). All of these drugs have shown some effectiveness in various studies but are not specifically approved for treatment of ADHD.
Drug therapy may control the symptoms of ADHD, but most experts recommend that drug therapy accompany concerted efforts involving behavioral therapy to address the underlying causes. Behavior modification therapy uses a reward system to reinforce good behavior and task completion and can be implemented both in the classroom and at home. A tangible reward such as a sticker may be given to children every time they complete a task or behave in an acceptable manner. A chart may be used to display the stickers and visually illustrate their progress. When a certain number of stickers are collected, the child may trade them in for a bigger reward such as a trip to the zoo or a day at the beach. The reward system stays in place until the good behavior becomes ingrained. Behavioral therapy is often the first-line approach to treatment in preschool-age children diagnosed with ADHD.
A variation of this technique, cognitive-behavioral therapy, may work for some children to decrease impulsive behavior by getting the child to recognize the connection between thoughts and behavior, and to change behavior by changing negative thinking patterns.
Individual psychotherapy can help children with ADHD build self-esteem, provide a place to discuss worries and anxieties, and help them to gain insight into behavior and feelings.
Family therapy may also be beneficial to help parents and family members develop coping skills and to work through feelings of guilt or anger they may be experiencing.
Children with ADHD perform better within a familiar, consistent, and structured routine with positive reinforcements for good behavior and real consequences for bad behavior. Family, friends, and caretakers should all be educated on the special needs and behaviors of children with ADHD so that they can act consistently. Communication between parents and teachers is especially critical to ensuring that children with ADHD have appropriate learning environments.
Other important therapies for children with ADHD can include social skills training, in which the children learn appropriate social interactions from behaviors that are modeled for them.
A number of alternative treatments exist for ADHD. Although there is a lack of controlled studies to prove their efficacy, proponents report that they are successful in controlling symptoms in some ADHD patients. Some of the more popular alternative treatments include:
Antisocial personality disorder —A disorder characterized by the behavior pattern of disregard for others’ rights. People with this disorder often deceive and manipulate, or their behavior might include aggression to people, animals, property, for example. This disorder has also been called sociopathy or psychopathy.
Conduct disorder —A behavioral and emotional disorder of childhood and adolescence in which children display physical aggression and infringe on or violate the rights of others. Youths diagnosed with conduct disorder may set fires, exhibit cruelty toward animals or other children, sexually assault others, or lie and steal for personal gain.
- EEG (electroencephalograph) biofeedback. By measuring brain wave activity and teaching patients with ADHD which type of brain wave is associated with attention, EEG biofeedback attempts to train patients to generate the desired brain wave activity.
- limited sugar intake. However, data indicate that this method does not actually reduce symptoms.
- relaxation training.
If untreated, ADHD negatively affects the social and educational performance of children with ADHD and can seriously damage their sense of self-esteem. Children with ADHD have impaired relationships with their peers and may be looked upon as social outcasts. They may be perceived as slow learners or troublemakers in the classroom. Siblings and even parents may develop resentful feelings toward a child with ADHD.
Some children with ADHD also develop conduct disorder problems. For those adolescents who have both ADHD and a conduct disorder, up to 25% go on to develop antisocial personality disorder and criminal behavior, substance abuse, and a high rate of suicide attempts that can be symptomatic of that disorder. Children diagnosed with ADHD are also more likely to have a learning disorder, a mood disorder such as depression, or an anxiety disorder.
Approximately 70-80% of patients with ADHD treated with stimulant medication experience significant relief from symptoms, at least in the short term. Approximately half of children with ADHD seem to “outgrow” the disorder in adolescence or early adulthood; the other half will retain some or all symptoms of ADHD as adults. With early identification and intervention, careful compliance with a treatment program, and a supportive and nurturing home and school environment, children with ADHD can and do flourish socially and academically.
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American Academy of Child and Adolescent Psychiatry (AACAP). 3615 Wisconsin Ave. NW, Washington, DC 20016. Telephone: (202) 966-7300. <http://www.aacap.org>.
Attention Deficit Disorder Association (ADDA). 1788 Second Street, Suite 200, Highland Park, IL 60035. Telephone: (847) 432-ADDA. <http://www.add.org>.
Children and Adults with Attention Deficit Disorder (CHADD). 8181 Professional Place, Suite 201, Land-over, MD 20785. CHADD National Call Center: (800) 233-4050. Web site: <http://chadd.org>.
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Paula Anne Ford-Martin, MA
Laith Farid Gulli, MD
Nicole Mallory, MS, PA-C
Emily Jane Willingham, PhD
"Attention Deficit/Hyperactivity Disorder." The Gale Encyclopedia of Mental Health. . Encyclopedia.com. (June 25, 2019). https://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/attention-deficithyperactivity-disorder
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