The analysis considered outcome measures, including retention in the treatment program, abstinence from illicit drugs, lack of arrests, and employment, for random samples of 150 adult voluntary outpatients, 150 adult voluntary residential and outpatients, 150 adult involuntary residential and outpatients, and 150 juvenile clients. Results showed that 85 percent of adult clients on high- dose methadone remained in treatment for 6 months, compared to 37 percent of clients on low-dose methadone and 18 percent of abstinent clients. Eleven percent of clients on high-dose methadone were arrested during the course of the study, compared to 20 percent of clients on low-dose methadone and 39 percent of abstinent clients. There were no differences in terms of employment between groups. In the youth program, where nearly all clients were abstinent or in the process of detoxification, 34 percent remained in the program, 42 percent were arrested, and 53 percent were in full-time employment, school, or job training. 5 tables and 3 references