What is attention-deficit hyperactivity disorder (ADHD)?

Introduction

Attention-deficit hyperactivity disorder (ADHD) is one of the most extensively studied behavior disorders that begin in childhood. Thousands of journal articles, chapters, and books have been published on the disorder. There are a number of reasons this disorder is of such interest to researchers and clinicians. The two primary reasons are that ADHD is a relatively common disorder of childhood (it is regarded as a childhood disorder although it can persist into adulthood) and that there are numerous problems associated with ADHD, including lower levels of intellectual and academic performance and higher levels of aggressive and defiant behavior.

In national and international studies of childhood emotional and behavioral disorders, ADHD has been found to be relatively common among children. Although prevalence estimates range from 1 to 20 percent, most researchers agree that between 3 and 7 percent of children could be diagnosed as having ADHD. The fifth edition of the
Diagnostic and Statistical Manual of Mental Disorders: DSM-5, published by the American Psychiatric Association in 2013, describes the diagnostic criteria for ADHD. To receive the diagnosis of ADHD according to DSM-5, a child must show abnormally high levels of inattention, hyperactivity-impulsivity, or both when compared with peers of the same age. The DSM-5 lists two sets of behavioral symptoms characteristic of ADHD. The first list contains nine symptoms of inattention such as “often has difficulty sustaining attention in tasks or play activities,” while the second list contains nine symptoms of hyperactivity-impulsivity such as “often talks excessively” and “often has difficulty awaiting turn.” To be diagnosed with ADHD, a child must exhibit at least six symptoms from at least one of the lists. Although many of these behaviors are quite common for most children at some point in their lives, the important point to consider in the diagnosis of ADHD is that these behaviors must be in excess of the levels of behaviors most frequently exhibited for children of that age and that the behaviors must cause functional impairment in at least two settings (for instance, at home and at school). Additionally, it is expected that "several inattentive or hyperactive-impulsive symptoms were present prior to age twelve."

Boys tend to outnumber girls in the diagnosis of ADHD, with the male-to-female ratio estimated at 2:1 to 9:1, depending on the source. ADHD boys tend to be more aggressive and antisocial than ADHD girls, while girls are more likely to display inattentive symptoms.

Associated Problems

There are a number of additional problems associated with ADHD, including the greater likelihood of ADHD boys exhibiting aggressive and antisocial behavior. Although some ADHD children do not show any associated problems, many ADHD children show deficits in both intellectual and behavioral functioning. For example, a number of studies have found that ADHD children score an average of seven to fifteen points below normal children on standardized intelligence tests. It may be, however, that this poorer performance reflects poor test-taking skills or inattention during the test rather than actual impairment in intellectual functioning. Additionally, ADHD children tend to have difficulty with academic performance and scholastic achievement. It is assumed that this poor academic performance is a result of inattention and impulsiveness in the classroom. When ADHD children are given medication to control their inattention and impulsiveness, their academic productivity has been shown to improve.

ADHD children have also been shown to have a high number of associated emotional and behavioral difficulties. As mentioned before, ADHD boys tend to show higher levels of aggressive and antisocial behavior than ADHD girls and normal children. Additionally, it is estimated that up to 50 percent of ADHD children have at least one other disorder, and the DSM-5 now allows ADHD to be included in a comorbid diagnosis with autism spectrum disorder. Many of these problems are related to depression
and anxiety. Many ADHD children also have severe problems with temper tantrums, stubbornness, and defiant behavior. It is also estimated that up to 50 percent of ADHD children have impaired social relations; that is, they do not get along with other children. In general, there are many problems associated with ADHD, and this may be part of the reason that researchers have been so intrigued by this disorder.

Researchers must understand a disorder before they can attempt to treat it. There are a variety of theories on the etiology of ADHD, but most researchers have come to believe that there are multiple factors that influence its development. It appears that many children may have a biological predisposition toward ADHD; in other words, they may have a greater likelihood of developing ADHD as a result of genetic factors. This predisposition is exacerbated by a variety of factors, such as complications during pregnancy, neurological disease, exposure to toxins, family adversity, and inconsistent parental discipline. Although a very popular belief is that food additives or sugar can cause ADHD, there has been almost no scientific support for these claims. Because so many factors have been found to be associated with the development of ADHD, it is not surprising that numerous treatments have been developed for the amelioration of ADHD symptoms. Although numerous treatment methods have been developed and studied, ADHD remains a difficult disorder to treat effectively.

Drug Therapies

Treatments of ADHD can be broken down into roughly two categories: medication and behavior or cognitive behavior therapy with the individual ADHD child, parents, or teachers. It should be noted that traditional psychotherapy and play therapy have not been found to be effective in the treatment of ADHD. Stimulant medications have been used in the treatment of ADHD since 1937. The most commonly prescribed stimulant medications are methylphenidate (Ritalin and Concerta), pemoline (Cylert), and dextroamphetamine (Dexedrine). As of 2014, the Federal Drug Administration (FDA) had approved three nonstimulant medications to treat ADHD. Strattera was the first nonstimulant drug approved and is prescribed to both children and adults. Intuniv and Kapvay are approved for children ages six through seventeen. Behavioral improvements caused by medications include better impulse control and improved attending behavior. Overall, approximately 75 percent of ADHD children on stimulant and nonstimulant medication show behavioral improvement, and 25 percent show either no improvement or decreased behavioral functioning. The findings related to academic performance are mixed. It appears that these medications can help the ADHD child with school productivity and accuracy but not with overall academic achievement. In addition, although ADHD children tend to show improvement while they are on a stimulant or a nonstimulant medication, there are rarely any long-term benefits to their use and can, in general, can be seen as only a short-term management tool.

Antidepressant
medications such as imipramine and fluoxetine (Prozac) have also been used with ADHD children. These medications are sometimes used when stimulant medication is not appropriate (for example, if the child has motor or vocal tics). Antidepressant medications, however, like stimulant and nonstimulant medications, appear to provide only short-term improvement in ADHD symptoms. Overall, the use or nonuse of medications in the treatment of ADHD should be carefully evaluated by a qualified physician (such as a psychiatrist). If the child is started on medication for ADHD, the safety and appropriateness of the medication must be monitored continually throughout its use.

Behavior Therapies

Behavioral and cognitive behavior therapy has been used with ADHD children, their parents, and their teachers. Most of these techniques attempt to provide the child with a consistent environment in which on-task behavior is rewarded (for example, the teacher praises the child for raising his or her hand and not shouting out an answer) and in which off-task behavior is either ignored or punished (for example, the parent has the child sit alone in a chair near an empty wall, a “time-out chair,” after the child impulsively throws a book across the room). In addition, cognitive behavior therapies try to teach ADHD children to internalize their own self-control by learning to “stop and think” before they act.

One example of a cognitive behavior therapy, which was developed by Philip Kendall and Lauren Braswell, is intended to teach the child to learn five “steps” that can be applied to academic tasks as well as social interactions. The five problem-solving steps that children are to repeat to themselves each time they encounter a new situation are the following: Ask “What am I supposed to do?” and then ask, “What are my choices?” Concentrate and focus in; make a choice and ask, “How did I do?” (If I did well, I can congratulate myself, and if I did poorly, I can try to go more slowly the next time.) In each therapy session, the child is given twenty plastic chips at the beginning of the session. The child loses a chip each time he or she does not use one of the steps, goes too fast, or gives an incorrect answer. At the end of the session, the child can use the chips to purchase a small prize; chips can also be stored in a “bank” to purchase an even larger prize in the following sessions. This treatment approach combines the use of cognitive strategies (the child learns self-instructional steps) and behavioral techniques (the child loses a desired object, a chip, for impulsive behavior).

Overall, behavioral and cognitive behavior therapies have been found to be relatively effective in the settings in which they are used and at the time they are being instituted. Like the effects of medication, however, the effects of behavioral and cognitive behavior therapies tend not to be long lasting. There is some evidence to suggest that the combination of medication and behavior therapy can increase the effectiveness of treatment. In the long run, however, no treatment of ADHD has been found to be truly effective, and in a majority of cases, the disorder persists into adulthood.

History and Changing Diagnostic Criteria

Children who might be diagnosed as having ADHD have been written about and discussed in scientific publications since the mid-1800s. A focus on ADHD began in the United States after an encephalitis epidemic in 1917. Because the damage to the central nervous system caused by the disease led to poor attention, impulsivity, and overactivity in children who survived, researchers began to look for signs of brain injury in other children who had similar behavioral profiles. By the 1950s, researchers began to refer to this disorder as “minimal brain damage,” which was then changed to “minimal brain dysfunction” (MBD). By the 1960s, however, the use of the term MBD was severely criticized because of its overinclusiveness and nonspecificity. Researchers began to use terms that more specifically characterized children’s problems, such as “hyperkinesis” and “hyperactivity.”

The Diagnostic and Statistical Manual of Mental Disorders (DSM), first published by the American Psychiatric Association in 1952, is the primary diagnostic manual used in the United States. In 1968, the second edition, called DSM-II, presented the diagnosis of “hyperkinetic reaction of childhood” to characterize children who were overactive and restless. By 1980, when the third edition (DSM-III) was published, researchers had begun to focus on the deficits of attention in these children, so two diagnostic categories were established: “attention-deficit disorder with hyperactivity (ADD with H)” and “attention-deficit disorder without hyperactivity (ADD without H).” After the publication of DSM-III, many researchers argued that there were no empirical data to support the existence of the ADD without H diagnosis. In other words, it was difficult to find any children who were inattentive and impulsive but who were not hyperactive. For this reason, in 1987, when the revised DSM-III-R was published, the only diagnostic category for these children was “attention-deficit hyperactivity disorder (ADHD).”

With the publication of the fourth version of the manual, the DSM-IV, in 1994, three distinct diagnostic categories for ADHD were identified: ADHD predominantly hyperactive-impulsive type, ADHD predominantly inattentive type, and ADHD combined type. The type of ADHD diagnosed depends on the number and types of behavioral symptoms a child exhibits. Six of nine symptoms from the hyperactivity-impulsivity list but fewer than six symptoms from the inattention list lead to a diagnosis of ADHD predominantly hyperactive-impulsive type. Six of nine symptoms the inattention list but fewer than six symptoms from the hyperactivity-impulsivity list lead to a diagnosis of ADHD predominantly inattentive type. A child who exhibits six of nine behavioral symptoms simultaneously from both lists receives a diagnosis of ADHD combined type.

The eighteen criteria used in the DSM-IV to diagnose ADHD were carried over to the DSM-5, which was published and released in 2013. The wording criterion for onset of ADHD has been changed, however, from "some" of the inattentive or hyperactive "symptoms that caused impairment were present before age seven years" in the DSM-IV to "several" inattentive or hyperactive "symptoms were present prior to age twelve" in the DSM-5. The DSM-5 also added a reduced symptom threshold for adults with a minimum of five symptoms (as opposed to the six required for children) for both the inattention and the hyperactivity/impulsivity aspects of the disorder.

Although the diagnostic definition and specific terminology of ADHD will undoubtedly continue to change throughout the years, the interest in and commitment to this disorder will most likely persist. Children and adults with ADHD, as well as the people around them, have difficult lives to lead. The research community is committed to finding better explanations of the etiology and treatment of this common disorder.

Bibliography

Alexander-Roberts, Colleen. The ADHD Parenting Handbook: Practical Advice for Parents from Parents. Dallas: Taylor Trade, 1994. Print.

Barkley, Russell A. Attention-Deficit Hyperactivity Disorder: A Handbook for Diagnosis and Treatment. 3d ed. New York: Guilford Press, 2005. Print.

Goldstein, Sam, and Joy Jansen. “The Neuropsychology of ADHD.” In The Neuropsychology Handbook, edited by Arthur MacNeill Horton, Jr., and Danny Wedding. 3d ed. New York: Springer, 2007.Print.

Hallowell, Edward M., and John J. Ratey. Driven to Distraction: Recognizing and Coping with Attention Deficit Disorder. New York: Random House, 2011. Print.

Kendall, Philip C., and Lauren Braswell. Cognitive-Behavioral Therapy for Impulsive Children. 2d ed. New York: Guilford Press, 1993.Print.

Parker, Charles E. New ADHD Medication Rules: Brain Science and Common Sense. 2nd ed. New York: Köehler Books, 2013. Print.

Ramsay, Russell J. Cognitive-Behavioral Therapy for Adult ADHD: An Integrative Psychosocial and Medical Approach. 2nd ed. New York: Routledge, 2015. Print.

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