This news release from Indiana University reports on an observational study that suggests the use of attention deficit hyperactivity disorder (ADHD) medication is tied to a lower risk of substance use disorders.
While the news release puts a positive spin on the use of stimulants for ADHD, it doesn’t mention that some co-authors have financial conflicts of interest with makers of ADHD medications. In addition, the release overstates the benefits of ADHD medication by reporting the relative risk reduction rather than absolute numbers. It also omits any mention of medication side effects.
ADHD is both a common diagnosis and a hot-button issue, especially for parents concerned about putting their children and teens on stimulant drugs. It would be tempting for parents to think that by putting their children on ADHD medications they could also help them avoid future substance use. But this observational study overstates the protective effect of stimulant medications on future substance abuse.
There was no discussion of costs. It would have been helpful to include the average cost of ADHD drugs with and without insurance. A 30-day supply of generic Adderall averages $25, according to GoodRx.
The release notes that, “The risk of substance use problems during periods of medication use was 35 percent lower in men and 31 percent lower in women in the study.” The release doesn’t give us any indication of what “problems” the authors were referring to. Further, this is purely an observational finding and does not prove cause and effect.
We were also concerned that the release conflated the odds ratio and risk.
We’ve written before about how it is tricky to refer to odds ratios when writing about clinical trials since the results always seem more impressive when using odds ratios instead of relative or absolute risks. The two numbers — odds ratio and relative risk — can be quite close when the outcome of interest happens rarely (say less than 10 percent). Otherwise, they can be drastically different and we should be told the relative risk. There’s a rather simple formula for converting odds ratio to relative risk. A google search reveals several such calculators.
The release did not make any mention of potential side effects of stimulants used to treat ADHD. Common side effects include headache, upset stomach, increased blood pressure, dizziness, decreased appetite, insomnia and dry mouth.
The release briefly described how the study was conducted, but didn’t offer any analysis on what the methods meant for the quality of the evidence. The release didn’t mention any limitations of the study. One thing that could have used more clarification was the term “substance use,” and how it was defined. The study looked at trips to the emergency room because of drugs or alcohol, but there are many substance users that don’t go to the emergency room. Emergency room visits were used as a surrogate marker of general substance abuse, but the release made no mention of that.
Furthermore, the researchers collected data from a database of employee health insurance coverage, meaning everyone in their sample was employed and had commercial insurance. This automatically leaves out anyone who is unemployed, has personal insurance, or paid for their emergency room trip via cash or other methods.
Other limitations that should have been mentioned: the fact that this was an observational study so it is unable to prove causality, and the fact that the researchers did not have enough data to calculate long-term benefits among the women of the study.
No disease mongering in this release.
The release noted the funders but did not mention any of the authors’ conflicts of interest. One of the authors has served as a speaker for Eli Lilly and Shire, and was awarded a research grant from Shire. Shire produces ADHD medications, including Vyvanse and Adderall. Eli Lilly also produces an ADHD medication, Strattera. This is a big conflict of interest that should have been noted in the release, particularly since both Adderall and Strattera were mentioned by brand name in the release.
The release did not mention any alternatives for treating ADHD such as non-stimulant medications or cognitive behavioral therapy.
The release did not discuss the availability of ADHD medications. However, these are commonly prescribed medications that are widely available in the US and Europe.
The release did not claim that this study was novel. In fact, it mentioned that it built upon previous work from the same authors which found benefits to ADHD medication in other studies based in the US and Sweden.
There was no sensational language.