Treatment is an effective intervention for drug abusers, including those who are involved with the criminal justice system. However, the effectiveness of drug treatment depends on both the individual and the program, and on whether interventions and treatment services are available and appropriate for the individual’s needs. To alter attitudes, beliefs, and behaviors that support drug use, the drug abuser must engage in a therapeutic change process, which may include medications to help prevent relapse. Longitudinal outcome studies find that those who participate in community-based drug abuse treatment programs commit fewer crimes than those who do not participate (Prendergast et al. 2002; Butzin et al. 2006; and Kinlock et al. 2009).