As I understand the rules, there's an exception if you have a prescription for it. Shane Victorino, for example, is a guy with ADHD who uses it legitimately with a prescription. Not surprising at all IMO. Take it from someone who is just one year removed from undergrad, tons of kids use Adderall to cram during finals. More than you could ever imagine. It was a dumb mistake, but not really one that raises Randy Moss esque red flags for me personally. Yes, it can be used to improve on-field performance, but I don't think Gray's stuff this year is anywhere near even slightly dependent upon Adderall.