Long-run abstinence after narcotics abuse: What are the odds?

We consider the long-run odds that narcotics users remain abstinent after methadone treatment. A flexible split-hazard specification that allows for individual-level differences in both the long-run probability of eventual relapse and the short-run timing of relapse is developed. The model is applied to a comprehensive data set involving individual drug abuse and treatment histories for over 800 addicts. Our findings indicate (1) that the short-run success of methadone programs does not automatically translate into long-run abstinence, which suggests the need for aftercare, (2) the value of preventing a teenager or young adult from initiating, and (3) the possibility of identifying high-risk groups, both in terms of age of first daily use and in terms of ethnicity.