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Attention Deficit/Hyperactivity Disorders: Are Children Being Overmedicated?

Press Release

NOTE TO WRITERS AND EDITORS: Dr. Richard Nakamura, Acting Director of the National Institute of Mental Health, testified this morning before the Committee on Government Reform, United States House of Representatives. The release of the text of that testimony follows:

Statement of
Richard K. Nakamura, Ph.D.
Acting Director
National Institute of Mental Health
National Institutes of Health,
U.S. Department of Health and Human Services

Before the Committee on Government Reform
United States House of Representatives

Good morning, Mr. Chairman and members of the Committee. My name is Richard Nakamura; I am Acting Director of the National Institute of Mental Health (NIMH), part of the National Institutes of Health (NIH). I have been Acting Director for approximately 10 months, and before that I served as NIMH’s Deputy Director for almost 6 years. Before that, I was a program scientist dealing with basic research grants—in total; I have been at NIMH for 26 years. First, let me tell you that I am not a clinician, nor am I a psychiatrist. I am trained in neuroscience—I am a Ph.D. scientist who studies the brain. But I am very well aware of the issue that has brought us here today. Let me begin in the way that scientists do—with a careful examination of the problem and its effects. Much of the information I will discuss is available through the NIMH web site, and I heartily recommend that you take the time to review it.

The NIMH supports research throughout the country to reduce the burden of mental illness and other behavioral disorders. We are well aware that all childhood disorders need urgent and effective attention and this position is underscored by the testimony presented in this hearing. There are many questions that need to be answered and there is no time to be lost. Parents are searching for answers because they know that childhood is all too short and the opportunity for quality development is easily lost. They know that the early years can set the path for a child’s entire future. Attention Deficit Hyperactivity Disorder (ADHD) has been the focus of much public concern and NIMH is very aware of, and sensitive to, concerns about the need for accurate treatment and diagnosis.

What Is ADHD?

ADHD is the most extensively studied mental disorder of children, with several thousands of peer-reviewed papers in the scientific literature devoted to this topic. ADHD—which affects an estimated 3-5 percent or 2 million young school-age children and an unknown number of teenagers and adults—refers to a family of related chronic neurobiological disorders that interfere with an individual’s capacity to regulate activity level, inhibit behavior, and attend to tasks in developmentally appropriate ways. The exact etiology of ADHD is unknown, although neurotransmitter deficits, genetics, and perinatal complications have been implicated. ADHD tends to run in families. Between 10 and 35 percent of children with ADHD have a first-degree relative with past or present ADHD. Approximately one-half of parents who had ADHD have a child with the disorder.

As its name implies, ADHD is characterized by two distinct sets of symptoms: inattention and hyperactivity-impulsivity. Although these problems usually occur together, one may be present without the other to qualify for a diagnosis. Inattention or attention deficit may not become apparent until a child enters the challenging environment of elementary school.

The symptoms of hyperactivity may be seen in very young preschoolers and are nearly always present before the age of 7. They include excessive restlessness, squirming around when seated, and the frequent need to walk or run around. Hyperactive children have difficulty playing quietly, and they may talk excessively, often behaving inappropriately and impulsively, not waiting their turn, and interrupting. Many of these symptoms may occur in normal children. However, in children with ADHD they occur very frequently and across several domains, at home and at school, or when playing, interfering with the child’s normal functioning. These children are often poor students and unpopular among the other children and their behavior can present significant challenges for parents.

Inattention tends to persist into adulthood, while hyperactivity and impulsivity tend to diminish with age. Hyperactive behavior is often associated with the development of other disruptive disorders. The reason for the relationship is not known. Even though a great many children with this disorder ultimately adjust, some—especially those with disruptive disorders—are more likely to drop out of school and fare more poorly in their later careers than children without ADHD. As they grow older, some teens who have had severe ADHD since middle childhood experience periods of anxiety or depression.

A large consortium of international scientists, deeply concerned about the portrayal of ADHD as a "myth, fraud or a benign condition," signed a letter in which they expressed concern over the inaccurate notion that somehow ADHD is not real. Here is how they put it. (I will be happy to insert the entire statement in the Record):

We cannot overemphasize the point that, as a matter of science, the notion that ADHD does not exist is simply wrong. All of the major medical associations and governmental agencies recognize ADHD as a genuine disorder because the scientific evidence indicating it is so is overwhelming….The central psychological deficits in those with ADHD have now been linked through numerous studies using various scientific methods to several specific brain regions (the frontal lobe, its connections to the basal ganglia, and their relationship to the central aspects of the cerebellum). Most neurological studies find that as a group those with ADHD have less brain electrical activity and show less reactivity to stimulation in one or more of these regions. And neuro-imaging studies of groups of those with ADHD also demonstrate relatively smaller areas of brain matter and less metabolic activity of this brain matter than is the case in control groups used in these studies. 1
How is ADHD Diagnosed?

A most essential step is accurate diagnosis, not to solve the problems of overcrowded or chaotic classrooms, but to find the children who need and can benefit from proper treatment. So, good treatment begins with accurate diagnosis, which can best be achieved thorough implementation of state-of-the-art diagnostic approaches in practice settings. We know through research that a clinically valid diagnosis of ADHD can be reached through a comprehensive and thorough evaluation done by specially trained professionals using well-tested diagnostic interview methods. The key elements include a thorough history covering the presenting symptoms, including ruling out other physical or mental conditions that may have the same symptoms, possible comorbid conditions, as well as medical, developmental, school, psychosocial and family history. The criteria for diagnosis with ADHD specify that symptoms of inattention must have persisted for at least 6 months to a degree that is maladaptive and inconsistent with the child’s developmental level. Proper diagnosis also avoids the possibility that these symptoms are occurring exclusively during the course of a pervasive developmental disorder, schizophrenia, or other psychotic disorder and are not better accounted for by another mental disorder (e.g., mood disorder, anxiety disorder, dissociative disorder, or a personality disorder.) The problems involved with accurate diagnosis of these illnesses are particularly acute in pediatric primary care settings, where many of these children are seen, because these evaluations take time and require multiple clinical skills, for which we have few appropriately trained professionals.

There is no doubt that the ability to diagnose childhood mental disorders is not as advanced as our capacities for diagnosing adult disorders. The NIMH is actively working to increase what we know about child mental disorders to make diagnosis more accurate. It is very difficult to distinguish the early symptoms of disorders that portend life-long difficulties from still serious, but transient dysfunction—this is a skill that takes years of highly specialized training. The paucity of normative information on the developmental progression of ADHD leads to a wide variation in clinical and research approaches for identifying and diagnosing the disorder. In response to these observations, NIMH is now supporting interdisciplinary research networks on ADHD, to translate what is already known in the basic sciences (particularly cognitive neuroscience, molecular genetics and biology) into clinical preventive, interventive and treatment strategies.

ADHD Treatment

Mental Health: A Report of the Surgeon General 2 contains an informative, thoroughly researched chapter on ADHD and includes recommendations for treatment. The practice parameters state, 'the cornerstones of treatment are support and education of parents, appropriate school placement, and pharmacology.' These practice parameters evolved out of research relating to two major types of treatment: pharmacological treatment and psychosocial treatment, particularly behavioral modification, as well as multimodal treatment, the combination of psychosocial and pharmacological treatments.

Most often, the first treatment used should be psychosocial, including behavioral therapy, social skills training, support groups and parent and educator skills training. Psychostimulant medications, including methylphenidate, are the most widely researched and commonly prescribed treatments for ADHD. Numerous studies have established the safety and efficacy of stimulants and psychosocial treatments for alleviating the symptoms of ADHD. NIMH research has indicated that the two most effective treatment modalities for elementary schoolchildren with ADHD are a closely monitored medication treatment and a treatment that combines medication with intensive behavioral interventions. In the NIMH Multimodal Treatment Study for Children with ADHD (MTA), which included nearly 600 elementary school children across multiple sites, nine out of ten children improved substantially on one of these treatments.

Failure to provide appropriate treatment for certain disorders—including ADHD—also poses a risk to brain integrity and function. The brain is a very flexible—or "plastic"—organ that needs certain stimulation in order to mature properly—to make the correct connections. In the same way that covering one eye [and eliminating visual stimulation] during a critical phase of development leads to life-long visual impairment, failure to receive and properly process cognitive and emotional stimuli during critical periods when the brain is undergoing rapid growth and maturation may result in damage with lifelong consequences. Therefore, a child who cannot pay attention, and who cannot learn, is at risk of having his or her brain and development adversely affected; and many children with ADHD develop learning delays and academic failures that lead to early school drop out. Children with ADHD who are untreated may be at increased risk for some medical and social problems such as reckless driving, drug and alcohol abuse, smoking, academic failure, difficulty in making relationships, and trouble with the law.

I would like to be sure that we focus carefully on two questions that deserve answers: 1) Are diagnoses being made effectively and are appropriately diagnosed children receiving properly selected treatments that will help them gain an upward trajectory in life? Too many children with ADHD are being ignored and remain at high risk for other lifelong problems, including depression and substance abuse. 2) While it is also well known that many children are being given medications for a variety of disorders, it is clear that not all of those children ought to be taking medications. Are some of our children, particularly active boys, being overdiagnosed with ADHD and thus are receiving psychostimulants unnecessarily? Little evidence of overdiagnosis of ADHD or overprescription of stimulant medications has been verified in research. Indeed, fewer children (2 to 3 percent of school-aged children) are being treated for ADHD than suffer from it. Treatment rates are much lower for girls, minorities, and children receiving care through public service systems. Medical and public awareness of the problem of ADHD has grown considerably so that people, who were underdiagnosed in the past, are being identified and treated. Most researchers believe that much of the increased use of stimulants reflects this better diagnosis and more effective treatment of a prevalent disorder.

These are very difficult and serious problems that we must address through better access to treatment and further research. The enormous advances occurring in the brain sciences will contribute to an increased understanding of the etiology and pathogenesis of ADHD and other brain disorders. As a neuroscientist, I am in awe of the leaps in knowledge we have taken in this arena, and I am most anxious to see these advances used to increase our understanding of the biological basis of ADHD, including finding biological markers that can lead to definitive, objective methods of diagnosis.

Accurate diagnosis and evaluation, however, is possible with our current state of knowledge. NIMH supports the largest and most long-term study to date of children with ADHD. Children received 14 months of treatment, and an extended follow-up for 6 more years is currently underway. Results have demonstrated that methylphenidate with careful medication management was safe and effective for the length of the trial, and was more effective than intensive behavioral treatments in relieving symptoms. The combination of medication management and intensive behavioral treatments was particularly advantageous when children with ADHD had symptoms of other disorders as well.

We can successfully treat ADHD, which is real and can be crippling if left alone. But I cannot emphasize too much the critical importance of careful, expert evaluation for each and every child, and for those diagnosed with ADHD, a very carefully structured treatment regimen trying behavioral interventions as a first line of defense, with the addition of carefully managed medication if necessary. Children who need, but do not receive, these services are being placed at serious risk during a critical period in their brains' development. Failing to enable them to respond to their fullest potential to both external and internal psychological stimulation will deprive their brains from the opportunity of reaching their optimal growth and maturation potential, thereby hampering mental development. For many, this will have obvious life-long, negative, preventable consequences.

I would be happy to answer your questions.

1Barkley, RA. International Consensus Statement on ADHD, January 2002, signed by over 70 leading scientists. Clinical Child Family Psychology Review, 2002, Jun 5(2): 89-111.

2U.S. Department of Health and Human Services. Mental Health: A Report of the Surgeon General. Rockville, M.D.: U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Center for Mental Health Services, National Institutes of Health, national Institute of Mental Health, 1999, Chapter 3, page 146.


About the National Institute of Mental Health (NIMH): The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit the NIMH website.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website .

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