ADHD drugs don’t improve cognition of college students who don’t have the condition, a small pilot study suggests. Not only that, but taking them could actually impair functioning, say researchers, who anticipated a different result. “We hypothesized that Adderall would enhance cognition in the healthy students, but instead, the medication did not improve reading comprehension or fluency, and it impaired working memory,” says Lisa Weyandt, a professor of psychology and faculty member at the George and Anne Ryan Institute for Neuroscience at the University of Rhode Island.