The study is a six month open-label treatment with Vyvanse, a novel preparation of the Attention Deficit Hyperactivity Disorder (ADHD) medication dextroamphetamine in which the drug is inactivated and only becomes reactivated when digested. Vyvanse is thought to be safer in youth at risk for substance use disorder because it is harder to abuse and divert. It is FDA approved to treat ADHD in children age 6 through 12. Although there are no negative studies in adolescents 13-15, efficacy has not been established in the latter age group.