This TIP, Screening and Assessing Adolescents for Substance Use Disorders, updates TIP 3, published in 1993, and presents information on identifying, screening, and assessing adolescents who use substances. Adolescents differ from adults both physiologically and emotionally as they make the transition from child to adult. Although experimentation with substances is common with this population, substance abuse can seriously impair development, leaving an adolescent unprepared for the demands of adulthood. Therefore, it is important for a wide range of professionals who come into regular contact with adolescents to recognize the signs of substance use. This TIP focuses on the most current procedures and instruments for detecting substance abuse among adolescents, conducting comprehensive assessments, and beginning treatment planning. Chapter 1 provides an overview of the document. Chapters 2 and 3 present appropriate strategies and guidelines for screening and assessment. An explanation of legal issues concerning Federal and State confidentiality laws appears in Chapter 4. Chapter 5 provides guidance for screening and assessing adolescents in juvenile justice settings. Appendix B summarizes instruments to screen and assess adolescents for substance abuse and general functioning domains, many of them updated since 1993. Appendix C excerpts a 1998 publication on drug testing juvenile detainees prepared under a grant from the Office of Juvenile Justice and Delinquency Prevention of the U.S. Department of Justice.