Peruse an online marketplace like Craigslist, and you’ll find coded classified ads for “Study Help” and “Study Hall”, or calls looking for a “Study Buddy”. Despite the scholarly language, these aren’t people looking for pre-final cram session. They’re plugs for Adderall: the trade name for a combination of amphetamine salts long prescribed as a first-choice treatment for attention deficit hyperactivity disorder (ADHD).