What have we learned from three decades of methadone maintenance treatment?

After thirty years of experience the essential questions concerning efficacy and safety of methadone have been decisively answered. Dozens of independent studies, conducted by critical evaluators in different countries, have agreed in finding that maintenance with methadone is both safe and effective over periods of years when the medicine is prescribed in adequate daily dose under competent supervision. In this editorial, I would like to supplement this general finding with several specific conclusions that, in my opinion, can be drawn from the methadone experience.