ABSTRACT: OBJECTIVE:Adolescent controlled prescription drug misuse (PDM) co-occurs with significant consequences, including lower educational achievement, substance use disorder (SUD) symptoms, and psychopathology. Nonetheless, adolescent PDM sources and the prevalence of other substance use, SUD, and mental health outcomes associated with sources remain poorly understood. METHOD:Data were from the 2009 to 2014 National Survey on Drug Use and Health, including 103,920 adolescents (12-17 years of age). Six mutually exclusive sources were used: physician source only, theft/fake prescription only, friend/relative for free only, purchases only, other source only, or multiple sources. Analyses occurred separately for prescription opioids, stimulants, and tranquilizer/sedatives. PDM source prevalence across adolescents and by sex and school enrollment/engagement were estimated. Adjusted odds of past-year DSM-IV substance-specific SUD, marijuana use, any SUD, major depressive disorder (MDD), anxiety diagnosis, mental health treatment, and past-month binge drinking were estimated by source. RESULTS:Friends/relatives, for free, was the most common source (29.0%-33.2%), followed by physician sources for opioids (23.9%), purchases for stimulants (23.5%), and tranquilizer/sedatives (22.7%). Few school enrollment/engagement differences existed, but female adolescents were more likely to use multiple sources. Over 70% of adolescents using multiple sources had a past-year SUD. Multiple sources, purchases, and theft/fake prescription were more strongly associated with other substance use than physician source use, and multiple source use was linked with MDD. CONCLUSION:Adolescents using multiple sources, purchases and theft/fake prescriptions have elevated rates of other substance use, SUD and MDD and particularly warrant intervention. Also, adolescents with other SUD and MDD should be screened for PDM and misuse sources.