This comprehensive overview of drug dependence approaches the subject from biological and social perspectives. It features a wide range of drugs, used both medically and non-medically and discusses the origins, effects, medical uses and history of each drug. The author emphasizes the fact that various factors contribute to drug use and dependence, problems arising from use and abuse and treatment. To reflect a contemporary study of drugs, all information is organized according to the general principles underlying drug use rather than by type of drug. Biological, psychological and social aspects of drug dependence are discussed, followed by descriptions of the medical consequences of drug use and the therapy recommended for dependence problems.