McCabe SE, et al. - Researchers investigated if sociodemographic features, nonmedical use of prescription drugs (NMUPD) features (eg, frequency), and other substance use might influence sources of NMUPD involving anxiolytics, opioids, and stimulants. Using self-administered questionnaires (2009-2016), they surveyed nationally representative samples of US high school seniors (N=18,549). Analysis revealed past-year NMUPD in approximately 11.0% of high school seniors (n=1,917). They noted the correlation of different NMUPD sources (friend/relative sources, friend/purchased sources, own leftover prescription, multiple sources, and other sources) with different substance use behaviors. Nonmedical users who were more involved in substance use attained prescription drugs from several sources, while those who used their own leftover prescriptions were less involved. Adolescent boys tended to get prescription drugs from friend/purchased sources, while adolescent girls also tended to use their own leftover prescriptions. They emphasize educating patients and their families regarding management and proper disposal of controlled medications to avoid diversion into the community. When prescribing controlled medications, prescribers should check prescription monitoring programs and screen adolescents for substance use/misuse.