The Overdiagnosis of ADHD

Three weeks ago, I watched a documentary on Netflix called “Take Your Pills”. In a super competitive world, students and adults in the United States have begun to seek a performance edge to boost their work output. The documentary chronicled the use and misuse of Adderall and other prescription stimulants as the defining drugs of this generation, highlighting not only the demand for these drugs to keep up with this hyper-competitive world but also the overdiagnosis of ADHD patients in the 1990’s. Though the documentary addresses view points of people from all scales of life, it more specifically shows us slices of lives of those children born in the 1990’s who were diagnosed with ADHD. In the unravelling of the complicated relationship with the prescribed medications, we also learn how interestingly it contrasts with the misuse of these same drugs they see among their peers.

In 2011, the CDC reported that the prevalence of attention-deficit/hyperactivity disorder in children ages 4 to 17 years was 11%, with 6.4 million children diagnosed with ADHD and 4.2 million taking psychostimulants.

These findings represent a dramatic increase from more than 30 years ago, when the rate of attention-deficit/hyperactivity disorder (ADHD) was estimated at between 3% and 5%. What is more concerning is that the prevalence of ADHD increased by about 35% just from 2003 to 2011, and there is no indication that this increase leveling out. More than 20% of high school-aged boys have been told they have ADHD!

What do these numbers indicate? Has there been a cataclysmic genetic shift recently causing ADHD to become the most prevalent childhood disease second only to obesity? A more sophisticated approach would lead us to think about how overdiagnosis may be through inadequate evaluation and/or because of societal pressure for treatment. A larger comment can also be made that there is an external force in the demands being made on the children, schools and families.

Every diagnosis of ADHD is contextual, which means that an individual with the same neurodevelopmental traits may be seen as having ADHD or not depending on their specific social and educational environment. Making the diagnosis also takes time as it is more than just filling out a standardized form and prescribing medications. The diagnosing practitioner must rule out other conditions that may present with ADHD-like symptoms, such as learning disabilities, anxiety and post-traumatic stress disorder. There needs to be proper evaluation of the family situation and the school environment of the child for a proper diagnosis to occur.

However, the prevalence rates not only differ by state, but even by county. In 2011, the prevalence of ADHD in Kentucky was 14.8%, which was 250% higher than the 5.6% prevalence reported in Colorado. Although these statewide disparities exist across the United States, there is no reasonable biological explanation for these large differences.

In 2010 in a study in the Journal of Health Economics, 10% of kindergarteners born in August (youngest in class) were diagnosed with ADHD  compared with 4.5% of those born in September (oldest in class), and those born in August were twice as likely as those born in September to be treated with psychostimulants. The authors estimated that just this factor alone could have resulted in 900,000 incorrect diagnoses of ADHD.

In Iceland, a country with a relatively high use of psychostimulants, investigators found that the entire youngest third of the class was 50% more likely to be diagnosed with ADHD and prescribed psychostimulants. What these studies tell us is that we are unable to distinguish those children who have ADHD from those who are simply immature or childish.

A possible argument for this could be that we are underdiagnosing the older children. But a more feasible argument is that there is overdiagnosis occurring because the demands being placed on the children are too high relative to their age. This is particularly so with kindergartners, who are rapidly becoming the largest age group diagnosed with ADHD, where current syllabi demand that they learn how to read even though there is no proven cognitive benefit and not every child can cope at this level.

Moreover, in the 1990’s policies like “No Child Left Behind” (signed into law in 2001) gave reason for schools to boost test scores of their students. Those states in which this law was signed into saw the largest significant increases in the diagnoses of ADHD, hinting a tragic idea of giving more children psychostimulants they don’t actually need. Hence there is much that needs to be reviewed when we think about disorders such as these, as the ramifications of their prognosis may be unexpected. 

Bibliography

1.       Centers for Disease Control and Prevention. Attention-deficit/hyperactivity disorder (ADHD): data & statistics. New data: medication and behavior treatment. Available at: http://www.cdc.gov/ncbddd/adhd/data.html. Accessed May 2, 2018.
2. 2     Miller RG, Palkes HS, Stewart MA. Hyperactive children in suburban elementary schools. Child Psychiatry Hum Dev. 1973;4(2):121-127.

3. Visser SN, Danielson ML, Bitsko RH, et al. Trends in the parent-report of health care provider-diagnosed and medicated attention-deficit/hyperactivity disorder: United States, 2003-2011. J Am Acad Child Adolesc Psychiatry. 2014;53(1):34-46.
4. Pottegård A, Hallas J, Hernandez-Diaz , Zoëga H. Children's relative age in class and use of medication for ADHD:  A Danish nationwide study. J Child Psychol Psychiatry. 2014;55(11):1244-1250