“ADHD wasn’t even considered a diagnosis for the adult population until after 2006, when the American Journal of Psychiatry published a study claiming that 4.4 percent of the U.S. adult population had ADHD. That opened the floodgates for adult use of ADHD drugs. More ADHD diagnoses translated to more ADHD prescriptions, causing a 53 percent increase in those prescriptions from 2008 to 2012, according to the New York Times.”