Adolescents and young adults being treated for attention-deficit hyperactivity disorder may be at a higher risk of having a psychotic event if they are provided amphetamine medicines, such as Adderall and Vyvanse, instead of medications based on the compound methylphenidate, such as Ritalin or Concerta, according to a study published Wednesday.
The risk of psychosis was generally low, occurring in one in 660 patients, according to the study, which was published in the New England Journal of Medicine.
The risk is “low enough that you can’t say, ‘just don’t prescribe Adderall,’” said Dr. Lauren Moran, the study’s lead author. “But from a public health perspective, there’s so many millions of people being prescribed these medications that it actually leads to thousands of people at increased risk of psychosis.” Moran is an assistant professor at Harvard Medical School, and a psychiatrist who treats inpatient schizophrenic and bipolar patients at McLean Hospital.
The study is unlikely to affect which medications are used in most cases, but it could lead doctors to look more carefully at potential risk factors for other mental illnesses when they prescribe medicines for ADHD. The method by which the data were collected is also noteworthy: Researchers used “real-world evidence,” a term that refers to data collected in the course of medical practice, not in the gold-standard of randomized, controlled clinical trials.
The study was conducted with Aetion, a New York City health data startup founded by another Harvard researcher. Moran has no financial relationship with Aetion.
“I don’t think it’s a shocking finding,” said Dr. Anthony L. Rostain, a professor of psychiatry and pediatrics at the University of Pennsylvania’s Perelman School of Medicine. A small risk of psychosis is listed in the package insert for any stimulant prescription, he noted. “It will just simply be important to mention to people that the amphetamine-based compounds have a slightly higher risk… I think the take-home here should be that everyone should be informed when they are starting a medicine about risks like psychosis.” Rostain has been a consultant to Arbor Pharmaceuticals, an amphetamine maker, and to Shire, which sells Vyvanse and developed Adderall; that company is now part of the Japanese drug giant Takeda.