Attention Deficit Hyperactivity Disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) is a behavioural disorder in which a child has a consistently high level of activity and/or difficulty in attending to tasks. Attention deficit hyperactivity, or hyperkinetic, disorder affects up to five per cent of children in the UK. The disorder, which is more common in boys, should not be confused with the normal boisterous conduct of a healthy child. Children with ADHD show abnormal patterns of behaviour over a period of time. An affected child is likely to be constantly restless, unable to sit still for more than a few moments, inattentive, and impulsive.

Attention deficit hyperactivity disorder in more detail - non-technical


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, also called hyperkinetic disorder (HKD) outside of the United States, is the most commonly diagnosed neurological disorder in children. It is estimated to affect 3–7% of school-age children in the United States and is 3–5 times more common in boys than in girls, although in adults, the ratio of males to females is closer to 2 to 1. Worldwide, diagnosed rates of ADHD range from less than 1% in Great Britain (which has stringent standards for diagnosis) to 12%. ADHD is a disorder of childhood; symptoms must begin before age 7, although they may continue into adulthood. Although childhood ADHD has been studied extensively, less information is available on adult ADHD. Studies on adults have produced a wide range of sometimes conflicting results. These studies report that anywhere from 30–80% of children with ADHD continue to have symptoms into adulthood. One reason for the wide range of findings is that the hyperactive component of the disorder often becomes less noticeable as individuals mature and develop more self-control.

Three types of ADHD are recognized by the American Psychiatric Association and outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revised (DSM-IV-TR):

  • predominately hyperactive. This is characterized by excessive physical activity (e.g., constant fidgeting, inability to stay seated, inability to engage in quiet play) and impulsive behaviors (e.g., interrupting, difficulty waiting in line).
  • predominately inattentive. This is characterized by inability to pay close attention to detail, stay on task, and organize tasks. This form of ADHD sometimes is referred to as attention deficit disorder (ADD).
  • combined hyperactive and inattentive. This combines an inappropriately high activity level with a high level of distractibility.

Causes and symptoms

Although the exact causes of ADHD are not known, it is clear that specific parts of the brain are involved including the frontal cortex, parietal lobe, and possibly the cerebellum. Functional magnetic resonance imaging (fMRI) studies comparing the brains of children with ADHD and those without the disorder show that children with ADHD have weaker brain activation of the frontal area when responding to tasks that require inhibition. Researchers believe that this is related to an imbalance in certain neurotransmitters (the chemicals in the brain that carry messages between nerve cells). Deficits in the neurotransmitters dopamine and norepinephrine are strongly suggested. One characteristic of drugs used to treat ADHD is that they make dopamine and/or norepinephrine more available in the brain. ADHD also appears to have a hereditary component. Children with a parent or sibling with ADHD are 2–8 times more likely to develop the disorder. Scientists have suggested at least 20 genes that may make a person more vulnerable to ADHD or contribute to the disorder in some way.

A widely publicized study conducted by Dr. Ben Feingold in the early 1970s suggested that allergies to certain foods and food additives caused the characteristic hyperactivity of ADHD children. Although some children may have adverse reactions to certain foods that can affect their behavior (for example, a rash might temporarily cause a child to be distracted from other tasks), carefully controlled follow-up studies have uncovered no link between food allergies and ADHD. Another popularly held misconception about food and ADHD is that the consumption of sugar causes hyperactive behavior. Again, studies have shown no link between sugar intake and ADHD. It is important to note, however, that a nutritionally balanced diet is important for normal development in all children.

Children with ADHD have short attention spans, becoming easily distracted or frustrated with tasks. Although they may be quite intelligent, their lack of focus frequently results in poor grades and difficulties in school. ADHD children act impulsively, taking action first and thinking later. They are constantly moving, running, climbing, squirming, and fidgeting, but often have trouble with motor skills and, as a result, may be physically clumsy and awkward. Their clumsiness may extend to the social arena, where they are sometimes shunned due to their impulsive and intrusive behavior. 


There is no single test for ADHD. Psychiatrists and other mental health professionals use the criteria listed in the DSM-IV-TR as a guideline for determining the presence of the disorder. A 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. These symptoms must occur before age 7, be present in at least two different environments (e.g., home and school) for at least 6 months, and not be attributable to any other developmental or mental health disorder.


  • Often fails to pay close attention to detail or makes careless mistakes in schoolwork or other activities
  • Often has difficulty sustaining attention in tasks or activities
  • Often does not appear to listen when spoken to
  • Often does not follow through on instructions and does not finish tasks
  • Often has difficulty organizing tasks and activities
  • Often avoids or dislikes tasks that require sustained mental effort (e.g., homework)
  • Often loses things necessary for tasks (e.g., books, tools).
  • Often is easily distracted
  • Often 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


  • Blurts out answers before the question has been completed
  • Has difficulty waiting (e.g., to take turns, to stand in line)
  • Interrupts and/or intrudes on others

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 his or her age group. The physician also can perform a comprehensive physical examination to rule out any organic causes of ADHD symptoms, such as an overactive thyroid, vision problems, or hearing problems.

If no organic problem is found, a psychologist, psychiatrist, neurologist, neuropsychologist, or learning specialist typically is 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 child, depending on his or her age. Along with these interviews, several clinical inventories may also be used, such as the Conners Rating Scales (Teacher’s Questionnaire and Parent’s Questionnaire), Child Behavior Checklist (CBCL), and the Barkley Home Situation Questionnaire. 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. Continuous Performance Tests, which involve tasks performed on a computer, may support a diagnosis of attention deficit type ADHD but by themselves are not diagnostic.

As many as 50–60% of people diagnosed with ADHD also meet the diagnostic criteria for another major psychiatric disorder such as anxiety disorders, depression, antisocial personality disorder, substance abuse disorder, or conduct disorder. These individuals also have a high likelihood of having a learning disorder. A complete and comprehensive psychiatric assessment is critical to differentiate ADHD from other mood and behavioral disorders.

In the United States, public schools are required by federal law to offer free ADHD testing upon request. A pediatrician also can provide a referral to a psychologist or pediatric psychiatrist for ADHD assessment. Parents should check with their insurance plans to see if these services are covered.


The use of stimulant drugs has proved to be the most effective treatment for ADHD. These drugs generally increase the availability of neurotransmitters in the brain. Drug therapy must be highly individualized with the benefits balanced against the risk of undesirable side effects. Dextroamphetamine (Dexedrine), dextroamphetamine/amphetamine mixture (Adderall), methylphenidate (Ritalin, Metadate), and dexmethylphenidate (Focalin) are common stimulant drug treatments. These drugs are available in both immediate release and extended release forms. Atomoxetine (Strattera) is a nonstimulant norepinephrine reuptake inhibitor. Its effect is to make the norepinephrine the brain produces remain in the brain longer, thus increasing the amount of norepinephrine available.

The use of pemoline (Cylert) to treat ADHD was stopped in 2005 because the United States Food and Drug Administration (FDA) ruled that the risk of liver damage outweigh the benefits of this drug.

Stimulant drugs may have adverse side effects in some children and that may make them inappropriate choices. These side effects include loss of appetite, insomnia, mood disturbance, headache, and gastro- intestinal distress. Tics may also appear and should be monitored carefully. Psychotic reactions are among the more severe side effects. There is some evidence that long-term use of stimulant medication may interfere with physical growth and weight gain. Some experts feel that these effects are ameliorated by ‘‘medication breaks’’ over school vacations or weekends. Increasingly, there is concern about use of long-term stimulant medications in very young children.

In the past children who did not respond well to stimulant therapy often were given tricyclic antidepressants such as desipramine (Norpramin, Pertofane) and imipramine (Tofranil). By 2009, these drugs were rarely used because they have a much higher risk of causing serious side effects including and cardiac arrhythmia (irregular heartbeat that can be life threatening). Other medications prescribed for ADHD therapy include buproprion (Wellbutrin) and venlafaxine (Effexor), both atypical, non-tricyclic antidepressants. Clonidine (Catapres) and guanfacine (Tenex), both systemic antihypertensive (blood pressure lowering) medications, also have been used to control aggression and hyperactivity in some ADHD children, although these drugs can have serious side effects if taken with methylphenidate (Ritalin). A child’s response to medication will change with age and maturation, so ADHD symptoms should be monitored and prescriptions adjusted accordingly.

It is important that drug treatment be carefully monitored and not be used exclusively in the management of ADHD. Behavior modification is often used in conjunction with drug therapy. Behavior modification 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 the child every time he or she completes a task or behaves in an acceptable manner. A chart system may be used to display the stickers and visually illustrate the child’s 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.

A variation of this technique, cognitive-behavioral therapy, works to decrease impulsive behavior by getting the child to recognize the connection between thoughts and behavior. Behavior is changed by changing negative thinking patterns.

Individual psychotherapy may help ADHD children build self-esteem, give them a place to discuss their worries and anxieties, and help them gain insight into their behavior and feelings. Family therapy also may be beneficial in helping family members develop coping skills and in working through feelings of guilt or anger parents may be experiencing.

Alternative treatment

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. Nevertheless, none of these treatments meet the standards of safety and effectiveness required by conventional medicine. Some of the more popular alternative treatments include:

  • EEG (electroencephalograph) biofeedback. By measuring brainwave activity and teaching the ADHD patient which type of brainwave is associated with attention, EEG biofeedback attempts to train patients to generate the desired brainwave activity.
  • Dietary therapy. Based in part on the Feingold food allergy diet, dietary therapy focuses on a nutritional plan that is high in protein and complex carbohydrates and free of white sugar and salicylate-containing foods such as strawberries, tomatoes, and grapes.
  • Herbal therapy. Herbal therapy uses a variety of natural remedies to address the symptoms of ADHD, such as ginkgo (Gingko biloba) for memory and mental sharpness and chamomile (Matricaria recutita) extract for calming. The safety of herbal remedies has not been demonstrated in controlled studies. For example, it is known that gingko may affect blood coagulation, but controlled studies have not yet evaluated the risk of the effect.
  • Homeopathic medicine. The theory of homeopathic medicine is to treat the whole person at a core level. Constitutional homeopathic care requires consulting with a well-trained homeopath who has experience working with ADD and ADHD individuals.


Approximately 70–80% of ADHD patients treated with stimulant medication experience significant relief from symptoms at least in the short term. About half of all ADHD children seem to ‘‘outgrow’’ symptoms of the disorder in adolescence or early adulthood; the other half retain some or all symptoms of ADHD as adults. Some children diagnosed with ADHD also develop a conduct disorder. For those adolescents who have both ADHD and a conduct disorder, as many as 25% go on to develop antisocial personality disorder and the criminal behavior, substance abuse, and high rate of suicide attempts that frequently accompany this psychiatric disorder. 

Untreated, ADHD negatively affects a child’s social and educational performance and can seriously damage his or her sense of self-esteem. ADHD children 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 towards the ADHD child.

Each child should have an individual educational plan that outlines modifications to the regular mode of instruction that will facilitate the child’s academic performance. Teachers need to consider the needs of the ADHD child when giving instructions, making sure that they are well paced with cues to remind the child of each one. They must also understand the origins of impulsive behavior—that the child is not deliberately trying to ruin a lesson or activity by acting unruly. Teachers should be structured, comfortable with the remedial services the child may need, and able to maintain good lines of communication with the parent.

Specialists should devise a series of compensatory strategies that will enable the child to cope with his or her attentional or activity challenges. These strategies might include simple things like checklists of things to do before handing in assignments (name on top, check spelling, etc.), putting a clock on the child’s desk to help structure time for activities, or covering the pictures on a page until the child has read the words so that he is not distracted.

Special assistance may not be limited to educational settings. Families frequently need help in coping with the demands and challenges of the ADHD child. Inattention, shifting activities every five minutes, difficulty completing homework and household tasks, losing things, interrupting, not listening, breaking rules, constant talking, boredom, and irritability can take a toll on any family.

Parents may not understand how attention regulation or impulsivity affect daily functioning, and they might not be trained in the kind of techniques that help ADHD children manage their behavior. Siblings may be resentful of what the ADHD child seems to ‘‘get away with’’ or the inordinate amount of attention he or she receives. The ADHD child may be resentful of the younger sibling who is more accomplished at school or never seems to get in any trouble. Family interaction patterns may set up vicious cycles that become destructive and difficult to break.

Support groups for families with any ADHD member are increasingly available through school districts and health care providers. Community colleges frequently offer courses in discipline and behavior management. Counseling services are available to complement any type of pharmacological treatment that the family obtains for its member. There are also a number of popular books that are informative and helpful. Some of these are listed below.



Alexander-Roberts, Colleen. The AD/HD Parenting Handbook: Practical Advice for Parents From Parents, 2nd ed. Lanham: Taylor Trade Pub., 2006.

Brynie, Faith Hickman. ADHD: Attention-Deficit Hyperactivity Disorder. Minneapolis: Twenty-First Century Books, 2008.

Conners, Keith, C. Attention Deficit Hyperactivity Disorder in Children and Adolescents: The Latest Assessment and Treatment Strategies, 4th ed. Kansas City, MO: Compact Clinicals, 2008.

McBurnett, Keith, and Linda Pfiffner, eds. Attention Deficit Hyperactivity Disorder: Concepts, Controversies, New Directions. New York: Informa Healthcare, 2008.


Dennis, Tanya, et al. ‘‘Attention Deficit Hyperactivity Disorder: Parents’ and Professionals’ Perceptions.’’ Community Practitioner 81.3 (March 2008):24-29.

Chen, Mandy, Carla M. Seipp, and Charlotte Johnston. ‘‘Mothers’ and Fathers’ Attributions and Beliefs in Families of Girls and Boys with Attention-Deficit/ Hyperactivity Disorder.’’ Child Psychiatry and Human Development 39.1 (March 2008):85-100.


‘‘Attention Deficit Hyperactivity Disorder.’’ MedlinePlus. January 12, 2009 [cited November 20, 2009].

Soreff, Stephen and Kiki D. Chang. ‘‘Attention Deficit Hyperactivity Disorder.’’ August 12, 2008 [cited November 20, 2009].


Attention Deficit Disorder Association (ADDA), P.O. Box 7557, Wilmington, DE, 19803-9997, (800) 939-1019,,

Children and Adults with Attention Deficit Disorder (CHADD), 8181 Professional Place, Suite 150, Landover, MD, 20785, (301) 306-7070, (800) 233-4050,,

Key terms

Conduct disorder—A behavioral and emotional disorder of childhood and adolescence. Children with a conduct disorder act inappropriately, infringe on the rights of others, and violate societal norms.

Dopamine—A neurotransmitter and the precursor of norepinephrine.

Nervous tic—A repetitive, involuntary action, such as the twitching of a muscle or repeated blinking.

Neurotransmitter—One of a group of chemicals secreted by a nerve cell (neuron) to carry a chemical message to another nerve cell, often as a way of transmitting a nerve impulse. Examples of neurotransmitters include acetylcholine, dopamine, serotonin, and norepinephrine.

Norepinephrine—A hormone released by nerve cells and the adrenal medulla that causes constriction of blood vessels. Norepinephrine also functions as a neurotransmitter.

Oppositional defiant disorder—A disorder characterized by hostile, deliberately argumentative, and defiant behavior toward authority figures.