In 1997, the National Institute on Drug Abuse (NIDA) published the first edition of "Preventing Drug Use among Children and Adolescents: A Research-Based Guide" to share the latest NIDA-funded prevention research findings with parents, educators, and community leaders. The guide introduced the concept of "research-based prevention" with questions and answers on risk and protective factors, community planning and implementation, and 14 prevention principles derived from effective drug abuse prevention research. Examples of research-tested prevention programs were also featured. The purpose was to help prevention practitioners use the results of prevention research to address drug abuse among children and adolescents in communities across the country. Since then, NIDA's prevention research program has more than doubled in size and scope to address all stages of child development, a mix of audiences and settings, and the delivery of effective services at the community level. The Institute now focuses on risks for drug abuse and other problem behaviors that occur throughout a child's development. This second edition, reflecting NIDA's expanded research program and knowledge base, is more than double the size of the first edition. The prevention principles have been expanded to provide more understanding about the latest research, and principles relevant to each chapter accompany the discussion. Additional questions and answers, a new chapter on community planning, and more information on the core elements in research-based prevention programs have been added. Each chapter ends with a "Community Action Box" for primary readers--parents, educators, and community leaders. As in the first edition, the descriptions of prevention programs are presented as examples of research-based programs currently available. The expanded "Selected Resources" section offers Web sites, sponsored by Federal and private-sector agencies. Some feature registries of effective prevention programs with agency-specific selection criteria and other resources for community planning. The "Selected References" section includes up-to-date books and journal articles that provide more information on prevention research. NIDA hopes that this revised guide is helpful to drug abuse prevention efforts among children and adolescents in homes, schools, and communities nationwide. [For "Preventing Drug Use among Children and Adolescents: A Research-Based Guide for Parents, Educators, and Community Leaders. Second Edition. In Brief," see ED521517. For the first edition (1997), see ED424525.]