Although abuse of drugs prescribed for ADHD might be rampant among the high school and college students of America, the recreational use of these drugs might not be without consequence, as a recent article in Time suggests.

According to researchers from Drexel University College of Medicine and the University of Delaware, medications like Provigil, Concerta and Ritalin can have long-term, adverse affects on the brain, especially when taken by juveniles.

Their research shows that common ADHD drugs might help mental performance in the short-term, but in the long-term can negatively affect the brain’s plasticity, making it difficult to switch between different tasks and plan ahead. The studies, which were conducted on rats, showed that even low doses had the potential to impact the brain’s memory and complex learning abilities. The authors of the study suggest that unsupervised use of these drugs for memory can actually end up killing nerve cells.

The negative side-effects, by and large, are not the same for patients who are diagnosed with ADHD. These individuals typically have an underactive prefrontal cortex, which drugs like Concerta and Ritalin can help to stimulate. People abusing the drug, conversely, end up overstimulated. It’s worth noting, though, that many health officials worry that ADHD has been overdiagnosed in the U.S., which could increase the potential risk of people being prescribed a drug they do not need, which could cause them harm.

The study findings are especially relevant considering that the number of students taking these drugs in order to improve their academic performance has been on the rise over the past decade. Almost 20% of Ivy League university students, for example, now report having misused ADHD drugs for this reason.