The Dramatic Growth in the Diagnosis and Treatment for ADHD in the United States

Good Science or Dangerous Trend?

Dr. Sam Goldstein

Over the past twenty-three years, I have had the honor of serving as Managing Editor and now Editor-in-Chief of the Journal of Attention Disorders. Along with my mentor, the late Keith Conners, we started the Journal as an alternative outlet for research on Attention Deficit Hyperactivity Disorder (ADHD) and related conditions. I am very proud that under my stewardship as Editor-in-Chief over the past twelve years, the Journal has grown from four to fourteen issues per year. The Journal is ranked in the top 25% of all science journals in the world and in the top one third of all mental health and psychiatric journals. Recent issues of the Journal of Attention Disorders have focused exclusively on topics including genetics and biology of the condition, family issues, and co-morbid disorders. The April 2019 Journal issue focused exclusively on issues related to assessment. Eleven articles from authors on three continents attests to the growth of good scientific research in this field as well as the interest and recognition worldwide that ADHD is blind to ethnicity, culture or socioeconomic status.

However, along with increased interest in research and good science comes the unfortunate occurrence of pseudoscience, particularly as it relates to the diagnosis and treatment of this condition. In this article, I will begin by reviewing a recent Blue Cross Blue Shield Healthcare Bulletin published on March 28, 2019 titled The Impact of Attention Deficit Hyperactivity Disorder on the Health of America’s Children. This Bulletin describes a survey based on 2017 data from the Blue Cross Blue Shield Health Index supplemented by information from the Centers for Disease Control and Prevention. This survey highlights multiple important issues, including the continued increase in the diagnosis of ADHD in the United States. It is now the second most adversely impacting condition affecting children in the United States. Diagnoses of children ages two through eighteen years increased 31% in this sample over an eight-year period between 2010 and 2017 with an incidence report in 2017 of 6.4% in the general population. ADHD accounts for 16% of the impact all health conditions have on the current generation of youth 0-19 years of age. In 2017, approximately 2.4 million commercially insured children were diagnosed with ADHD, as noted climbing more than 30% during the previous eight years. ADHD appears to be most prevalent among middle school aged children (11-13 years old) with boys being diagnosed about twice as often as girls are). Further, diagnostic rates for 100 children in each of the fifty US states, varies from lows of 3.1% to 5.1% in some states to highs of 7.3% to 11% in other states. When youth are diagnosed with ADHD, the incidence of co-morbid or other disorders is also very high, including anxiety, Autism Spectrum Disorder, depression, disruptive behavioral disorders like Oppositional Defiance and Conduct Disorders and learning disorders. Further, nearly half of children with ADHD were treated with medication only in 2017 despite the American Academy of Pediatrics’ recommendation that medication and behavioral therapy are preferred as the treatment plan of choice.

What accounts for this continued and significant rise of the diagnosis and treatment of ADHD in American children? Is this the result of good science or a dangerous trend towards over diagnosis? Based on my understanding of the research literature, this trend, though to a lesser degree, is also mirrored throughout the majority of industrialized countries in the world. Is the increased prevalence and incidence worldwide a consequence of good care or a trend to increasingly consider nearly all problems of childhood as reflecting ADHD because of the commonality of these symptoms across many conditions in childhood? In my forty years of experience as a clinician, author, test developer, and researcher, I think there is both good and bad science operating to explain these issues. In the remainder of this article, I will briefly introduce and review my concerns.

  1. Symptom Overlap. Many of the symptoms of ADHD are demonstrated in other disorders. For some as part of the diagnosis, for others as consequential behaviors resulting from these other mental health problems. The most common problems teachers complain about in the classroom are those related to inattention, impulsivity, and hyperactivity. Yet not all of these children suffer from ADHD.
  2. DSM-5 Diagnoses are like Chinese Restaurant Menus. Because these diagnoses represent syndromes, not every child exhibits every single symptom. Therefore, diagnostic criteria for a condition such as ADHD is determined by a child demonstrating a specific number of behaviors within a group across multiple settings over an extended period of time. This type of a polythetic system leads to children with similar diagnoses exhibiting different sets of symptoms. This would be fine if each symptom was equivalent to every other in predicting current and/or future risk. However, that is not the case. We know that some symptoms have greater positive predictive power (they are more likely to reflect the disorder) while other symptoms do not. We know that some symptoms have greater negative predicative power (absence of the symptom means absence of the condition) while others do not. Finally, we know that some symptoms reflect either of the previous two while others can incorporate both positive and negative predictive power. Further, some symptoms have greater sensitivity and specificity than others. Finally, some symptoms are much more likely associated with future risk than others. This leads to a great deal of heterogeneity. That is, there is a great deal of variation among individuals who are diagnosed with ADHD.
  3. Symptom Presentation in the General Population. In my research with large populations as part of our test development, I have come to understand that some symptoms occur with fairly high frequency in the general population, while others occur with low frequency. Typical symptoms of Autism Spectrum Disorder, for example, occur with fairly low frequency in the general population. Demonstration of even a few of these symptoms sets a child apart from others. Yet, many of the symptoms of ADHD occur in the general population with fairly high frequency. It is the collection of these symptoms, their chronicity, and the level of impairment children experience that is critical in making a diagnosis of ADHD.
  4. Educational Advantage. In an effort to even the playing field in high stakes testing, the Americans for Disabilities Act has been invoked, allowing youth with defined conditions to receive accommodations which allows them to demonstrate their capabilities. Unfortunately, in other cases this accommodation may very well provide them with an advantage over others. Additionally, some of the most common accommodations for conditions like ADHD have not been proven scientifically valid. I think the most common request I receive when a child has ADHD for high stakes or school based testing, is additional time. Yet, the scientific literature has demonstrated that giving youth with ADHD additional time has not been found to lead to better performance. More time is not the issue for those students with ADHD; it is the efficient use of time. Simply assuming that providing more time will lead to greater efficiency has not been demonstrated.
  5. Stress in Childhood. We are now well aware from both behavioral and biological studies that today’s children experience a greater degree of stress than previous generations. Their resting cortisol level is typically higher. This level of stress may explain the increasing incidence and prevalence of childhood depression over the past five generations. This phenomenon may also explain in part the increase in the diagnosis of ADHD.
  6. Poor Sleep. In my last web article, I reviewed the Canadian guidelines for child health. The large-scale population based study upon which these guidelines were created demonstrated that most children were spending too much time in front of screens, not enough time engaged in aerobic exercise or hours of sleep. Sleep loss can lead not only to fatigue and inattention during the day but emotional instability as well. The issue of aerobic exercise is particularly interesting as there have been a number of good scientific studies demonstrating that following aerobic exercise children not only pay attention more effectively but also demonstrate improvements in neuropsychological abilities such as planning.
  7. Inadequate Evaluation. Some years ago, I had the occasion of speaking with an insurance company representative seeking further information before approving my request for assessment of a youth I was evaluating with suspected ADHD. It is well documented that children with ADHD have a high rate of co-morbidity. As I noted earlier in this article, they suffer from more than one condition. In many cases, it may be that their symptoms of “ADHD” are not a cause but a consequence of these other conditions. In my efforts to explain this to the insurance representative, I received the following guidance: “Diagnosis of ADHD is not complicated. You simply ask eighteen questions.” Those questions represent the eighteen symptoms of ADHD. Yet with that type of analysis, research has demonstrated that a nearly a third of all children and adults could be diagnosed with ADHD. The ADHD diagnosis includes multiple other criteria and requires a careful analysis of possible other contributors or co-morbid disorders and problems. I wonder, however, to what extent a percentage of the increasing number of children diagnosed with ADHD has been diagnosed using the “eighteen question” criteria. This problem also extends to the questionnaires we ask parents and teachers to fill out. Clinical symptom presentation of ADHD on a questionnaire is a good place to start but not a good place to finish a thorough evaluation.
  8. Big Pharma Advertising. Literally, a month does not go by when I am not contacted by a representative of one pharmaceutical company or another. The number of branded generic medications for ADHD has increased dramatically. All of these manufacturers are vying for the same closed pool of youth already being treated. One way to increase market share is to increase those in need of treatment. I am not accusing the pharmaceutical industry of unethical behavior. However, their willingness to compete in the open marketplace by advertising to consumers leads many to believe that pills will substitute for skills and that children with poor self-discipline and limited self-regulation are “normalized” when they take certain pharmaceutical agents.
  9. Medication Probe. Many years ago, medicines were used to prove conditions. That is, if a child responded to a stimulant medication it meant they must have ADHD. We are now much smarter. We know that stimulants are performance enhancers. Individuals with a broad range of mental health problems as well as those who are not symptomatic can and do report benefits from stimulant use. These medications should never be used to prove the condition.

I am confident that the next twenty-five years will bring the introduction of scientifically proven non-medicine treatments involving different forms of biofeedback and computer based activities. It will be interesting to develop an appreciation of the relationship between medications and these types of interventions. It may actually be the case that someday these new future interventions will dramatically reduce the need for and use of psychopharmacology, particularly in the treatment of ADHD. Until that time comes, as clinicians, must be thorough, ethical, and knowledgeable when asked to evaluate for the presence ADHD.