This testimony by the Director of Education and Employment Issues of the Health, Education, and Human Services Division of the General Accounting Office (GAO) is based on a number of GAO studies of substance abuse and violence prevention programs for youth. The testimony focuses on: (1) the information available about substance-abuse and violence-prevention programs and the federal government's investment in them; (2) what is known about the effectiveness of federally funded programs reducing youth substance abuse and violence; and (3) improving the federal effort by focusing more on accountability and results. Overall, GAO reviews have raised questions about the efficiency and effectiveness of the federal effort in these areas. The system that has developed, one of multiple federal programs dispersed among several agencies, has created the potential for inefficient service and difficulty for those who are trying to access the most appropriate services and funding sources. For example, the GAO identified 70 federal programs used in 1995 to provide substance-abuse or violence-prevention services. These programs were located in 13 federal departments. In addition, state, county, and local governments provided billions of dollars for substance-abuse prevention and treatment efforts for adults and youths. Although the GAO has identified some promising approaches for preventing substance abuse and violence, the agency's research suggests that additional research is needed to test the effectiveness of these approaches and their applicability to different populations. An appendix presents a chart of federal substance-abuse and violence-prevention programs. (SLD)