The prevalence of attention-deficit/hyperactivity disorder (ADHD) has increased with each new edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM), raising concern among some experts that the condition is overdiagnosed, doing more harm than good.
According to investigators led by Rae Thomas, PhD, from Bond University in Robina, Australia, reducing the threshold for diagnosing ADHD devalues the diagnosis in individuals who actually have serious problems and exposes those at the lower end of the diagnostic threshold to unnecessary and potentially harmful side effects from stimulant medications used to treat the disorder and may cause psychological harm from the stigma of such a diagnosis.
"There is such a large variation between and within countries regarding the prevalence of ADHD that it raises questions about diagnostic practices rather than children's symptoms," Dr. Thomas told Medscape Medical News.
"We think ADHD is overdiagnosed and that many children and their families may be harmed due to costs of medication, particularly if it is not needed, medication side effects, and psychological labels," she said.
The article was published online November 5 in BMJ.
Creating Self-fulfilling Prophecies
According to Dr. Thomas, the cost of medication for an inappropriate ADHD diagnosis could be as much as $500 million in the United States alone.
"Medical costs can be very large for families, and if subsidized, can be costly for healthcare systems in general," she said.
For most children diagnosed with ADHD, the condition is described as "mild or moderate," and this is concerning because it is likely that these children will be prescribed medications. Yet, there is limited evidence of long-term medication benefits, but some short-term harms are known, she said.
"The drugs used to treat ADHD have side effects such as weight loss, weight gain, and growth problems, and we don't know whether they work in the long term."
There are also psychological harms associated with an ADHD diagnosis.
"When compared with children diagnosed with asthma, children diagnosed with ADHD have been described as lazier, less clever, less caring, and are more likely to be socially excluded," Dr. Thomas said. "Also, teachers and parents may have preconceptions about the academic achievements of a child diagnosed with ADHD, and these can create self-fulfilling prophecies."
Prescribing of methylphenidates and amphetamines in the United States increased steadily between 1996 and 2008, with the greatest increase in adolescents aged 13 to 18 years. In the Netherlands, prevalence and prescribing rates for children who had been diagnosed with ADHD doubled between 2003 and 2007.
"The pharmaceutical industry is one of the drivers of overdiagnosis, but there are others," Dr. Thomas said.
"Direct-to-consumer advertising can drive consumer demand and alter physician practices. Also, although this is meant to reduce stigma, celebrities' efforts to raise awareness about ADHD can help drive overdiagnosis, and financial ties of pharmaceutical companies to patient advocacy groups have the potential to bias information," she said.
Shifting definitions and unmet criteria also contribute to overdiagnosis of ADHD. Changes to the DSM-IV criteria for ADHD were estimated to raise prevalence rates by 15%, but this was exceeded, Dr. Thomas said.
Of particular concern to the researchers is the subjectivity of the impairment criterion for making the diagnosis of ADHD.
"DSM-IV stated that an individual had to experience 'clinically significant' impairment in a range of settings, suggesting a large degree of impairment. However, DSM-5 reworded the criterion to "interfere with or reduce the quality of social, academic, or occupational functioning," which suggests some impairment," Dr. Thomas said.
DSM-IV criteria required symptoms to be present by the age of 7 years, but now DSM-5 has increased that to 12 years, which expands the age of onset.
"Raising of the age of onset will raise the prevalence further as the threshold for diagnosis has widened, so you are lowering impairment criterion at one end and raising the age a person has to have experienced symptoms at the other," Dr. Thomas said.
Commenting on the article for Medscape Medical News, Harold S. Koplewicz, MD, president of the Child Mind Institute in New York City, said that he was troubled by some of the authors' conclusions.
"Sometimes the increase in diagnosis means that kids who weren't getting the attention they needed are now getting it because of increased access to care, better information, or a decrease in the stigma that has so long been attached to seeking mental health care," he said.
Dr. Koplewicz conceded that there is always a danger of inappropriate diagnosis or overtreatment. But, he said, there is a bigger risk of not diagnosing ADHD.
"The kids who don't get diagnosed or don’t get treatment are at heightened risk for substance abuse, at higher risk for school dropout, for having more car accidents, and having a higher risk of having an interaction with the juvenile justice system," he said.
Functional magnetic resonance imaging (fMRI) can now be used to differentiate between children who have typical brains vs children who have ADHD, he said.
"We're not in the Dark Ages. These are real disorders that clearly do come in mild, moderate, or severe forms. Not every kid who has a mild form of this needs treatment, but children who are experiencing distress or disruption, who are very unhappy because they're constantly struggling and can't make friends, can't sit still long enough to follow instructions, who are always being yelled at by their parents, those kids need a diagnosis, and they need treatment that works," Dr. Koplewicz said.
The fact that the prescribing of drugs to treat ADHD has increased in the United States and the Netherlands is not necessarily a bad thing, he added.
"There are hundreds of studies that show that the psychostimulants are effective for children who have ADHD. And these children need effective treatment."
Meds Are Effective
Dr. Koplewicz also took issue with the authors' claims of little evidence for long-term benefit for the drugs that are used to treat ADHD.
"The authors state that there is little data on long-term benefits with treatment, but that is not true. It's like taking insulin; if you stop taking it, your diabetes will flare up and you will die from your diabetes, but you can't say that insulin gives you long-term benefit.
"In the same way, if you take your medication for ADHD, you are more likely to stay in school, you are more likely to be able to use the IQ points you have. The medicine won't give you more IQ points, but it will help you get to the ones you do have."
Dr. Koplewicz also spoke of the authors' focus on adverse drug reactions with ADHD drugs.
"Any pill has side effects. Aspirin can kill you. Tylenol has side effects. Any time you take a drug, there is a cost-benefit ratio. You have to be an informed consumer. Parents should be aware that, yes, for some kids, there is some temporary weight loss, but I have never seen a kid get suicidal on psychostimulants in all my years of practice."
He also countered that the research currently being done on ADHD is relevant and will ultimately lead to better ways to diagnose the disorder.
"Let's not count out the research, because much of the research funding is focused on biomarkers for ADHD. We at Child Mind, and others, are trying very hard and investing a tremendous amount of time and resources trying to identify an objective marker, including the differences seen on fMRI between kids who have the disorder with kids who do not."
No Biomarker Yet
Finding objective tests for psychiatric disorders is important because once such tests are found, some of the stigma associated with these disorders will disappear.
"If you have an objective test, you are going to get treatment. Unfortunately with ADHD, we do not have a biological marker. I don't believe that the public recognizes how real, how common, and how treatable these disorders are," he said.
Broadening the definition of ADHD to include onset of symptoms before the age of 12 vs the age of 7 is also a positive step, Dr. Koplewicz said.
"These are important years because there are a lot of kids who do not have hyperactivity but do have ADHD inattentive type. But when they are in elementary school, they have a very controlling, superengaged teacher and very involved mother and father. Especially if it is a bright kid, you won't see the symptoms of ADHD because the child is being controlled.
"But then you put that kid in the 5th grade, in middle school, and now the child is moving from one class to another, with 7 different teachers, and no matter how smart that kid is, if he or she is more impulsive than the average kid and less attentive, then all of a sudden the child becomes a C student where before they were an A or a B student. And that is because they've lost their executive assistant or parent to guide them.
"Their world has become much less organized, and we know that ADHD becomes more prevalent as the world gets more disorganized. So changing the onset of symptoms from 7 to 12 will pick up a lot more children with ADHD," he said.
On the other hand, the article does touch on important issues, but it does not go deep enough, Dr. Koplewicz concluded.
"The fact is, it's a more complex situation. We might be overdiagnosing, misdiagnosing, and even overtreating certain kids, but the overwhelming majority of kids who have these disorders are going undiagnosed and untreated."
Dr. Thomas and Dr. Koplewicz report no relevant financial relationships.
BMJ. Published online November 5, 2013. Full article
Medscape Medical News © 2013 WebMD, LLC
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Cite this: Broader Definition of ADHD Will 'Do More Harm Than Good' - Medscape - Nov 12, 2013.