The Wall Street Journal recently published an article casting doubt about the ability of ADHD medications to improve school grades and achievement. Actually, casting doubt might be a little soft as the title was “ADHD Drugs Don’t Boost Grades.” In the article, the author runs through a number of studies (some not published) that find no difference between the grades of children with ADHD who do and do not take medications.
The article raises important questions that those of us who prescribe these medications need to look at objectively. Certainly, if stimulants and other ADHD medications were miracle drugs that make the vast majority of kids do much much better at school, we should be seeing that reflected in these studies, and we don’t.
However, the studies that look at this question can’t really answer it because they don’t do one critically important thing, namely RANDOMIZE. This may sound like methodological minutia, but actually it is vital because without it, the ability of a study to make conclusions about causality is grossly impaired. The other main problem is that the yes/no nature of an ADHD diagnosis doesn’t capture how incredibly different two kids with the same condition can be.
Imagine two 6-year-old children, both of whom meet criteria for ADHD. The first child has mild symptoms, is quite intelligent, and has a very involved and supportive family who do everything they can to help. The second child has more severe symptoms, may have a lower IQ, and the family struggles to provide an optimal environment. Five years later, both kids are assessed. The first one has largely grown out of his symptoms and is doing well at school. He doesn’t take medications because he doesn’t need to take medications. The second child is still having a lot of challenges and, while gaining some benefits of continued medication use, is not doing as well as the first child.
Is the difference in the achievement of these two kids all due to a useless medication? Of course not, but that is basically the design of the studies that are being used to create these headlines. The article cites the well known MTA study as evidence, which randomized subjects initially but not over the long term. Not surprisingly, stronger effects of medication were found during the period that subjects were randomized compared to when subjects were not, but the article skirts around that point.
Ironically, most of the authors of these studies realize that without randomization that their conclusions are quite limited. Their admission is often right there in their own text (usually at the end of a long article). The authors of the MTA study state that “after 14 months the MTA became an uncontrolled naturalistic follow-up study and inferences about potential advantages that might have occurred with continued long-term study-provided treatment are speculation.” Speculation indeed, but not enough to keep reporters from ignoring these limitations and plowing ahead with provocative headlines. After all, nobody reads the fine print and “wishy washy” conclusions don’t get people to buy or, perhaps, click. Another irony is the reason behind why it is so difficult to do these studies “right” and randomize. If you are the parent of a child with ADHD who is starting to do poorly at school, are you ready to sign the consent for a study that basically will give him or her a 50/50 shot at not being allowed to take a mediation for 5 years to order to find out how much they might be useful for other kids?
Those of us who actually work with youth and are responsible for their care need to be able to cut through the mountains of misinformation and guide families to do the same. We also need to be able to tolerate conclusions we might not want to believe, if they are the result of solid scientific data. For this particular and important issue, I think we probably know that ADHD medications a) can really help some kids and b) are not a silver bullet for a great number of others. Between those two statements there is a lot of ground to cover and understand that I don’t think we can trust the popular press to do for us.