What really matters, Farah said, is for scientists to figure out how much enhancement these drugs can actually bring. "The effectiveness of Adderall depends crucially on the individual," she said. "The literature suggests that people who are average or below get the biggest benefit. The high performers may get no benefit or may actually be impaired by it." Farah is now measuring the performance of students on Adderall and placebos to see if that's actually the case.

Always a concern with nootropics; are the people who use them the ones who actually need them?