• We have developed an experimental paradigm for the behavioral evaluation of narcotic antagonists. The study specifically examined the heroin-seeking behavior of hard-core narcotic addicts on a research ward under blocked and unblocked conditions. Each patient served as his own control. A long-term follow-up program in the community, with aftercare services, was utilized to determine the relationship between behavior observed on the research ward and behavior that occurred in the community.

While preliminary one-month follow-up data offered some cause for an optimistic view of narcotic antagonist treatment, behavioral data observed on the research ward raised serious doubts about the possibility of extinguishing heroin self-administration with antagonists. The behavioral data were not consistent with laboratory descriptions of extinction. Rather, the data suggested that narcotic antagonist programs should emphasize the development of contingencies for the reinforcement of narcotic antagonist self-administration to ensure an opiate-free state, instead of focusing on an extinction approach.