In recent years, three main models of drug-related problems and their development have come to the fore: (1) society's model, a relatively simplistic view of drug problems and the means by which these problems may be tackled; (2) psychological models, the backbone of counseling for drug users; and (3) medical (disease) models that emphasize biological processes in addiction. A historical review of drug abuse and drug policy in the United Kingdom covers the 1900-1961 period when opiate addiction was defined as a medical problem, the 1961-1982 period that was characterized by escalating drug use and restriction to specialist treatments, and the 1982-1998 period in which the involvement of general practitioners was encouraged. The most recent policy developments involve a wide range of professionals from statutory and voluntary sectors with improved structures to deal with drug problems and to allow planning at the local level while maintaining a national focus on standards and quality. Specific laws enacted and drug policies established between 1920 and 1995 are briefly described. 21 references