Historically the focus with adolescents has tended to be on steering young people clear of drugs before problems arise. But the reality is that different interventions are needed for adolescents at different places along the substance use spectrum, and some require treatment, not just prevention. Fortunately, scientific research has now established the efficacy of a number of treatment approaches that can address substance use during the teen years. This US guide describes those approaches, as well as presents a set of guiding principles and frequently asked questions about substance abuse and treatment in this age group. I hope this guide will be of great use to parents, health care providers, and treatment specialists as they strive to help adolescents with substance use problems get the help they need.