My first exposure to Ritalin was in high school. I was sitting in my friend Kelly’s bedroom watching her cut up white powder into neat lines with her library card and I remember asking her where she found cocaine. We were not savvy kids with connections to illicit drug dealers—we were studious, overachieving, and perhaps unusually naïve teenagers whose forays into the world of mind-altering substances had thus far primarily been confined to a few bottles of Zima and bungled attempts at rolling poorly structured joints. But the white powder wasn’t cocaine, it was Ritalin, and the only connection its procurement had required was Kelly’s friendship with a kid who had an ADHD diagnosis. “It’s not dangerous, people use it to study,” she reassured me before rolling up a $5 bill her mom had given her for lunch money and snorting up the crushed tablets.