Methadone maintenance treatment of narcotic addiction: a unit of medical care based on over 50,000 patient treatment years.

The experience with methadone maintenance treatment by two major New York City methadone maintenance treatment programs using the Dole-Nyswander philosophy is reviewed. After more than 56,000 person-years in treatment over a 10-year period of time, a unit of medical experience exemplified by these two programs is evident. There was a high degree of patient acceptance, a small amount of recognized residual illicit drug abuse, and steeply reduced criminal activities of those patients who remained in treatment.