Despite great public interest in the use and abuse of psychoactive substances this is the first comprehensive and reliable book on this fascinating and controversial topic. The encyclopedia covers the entire range of naturally occurring psychoactive species, and also a great number of man-made synthetic drugs and compounds. It explores the use of intoxicating plants by Neanderthal man through to the role of hallucinogens and narcotics in contemporary youth culture. It provides basic details on the botany and chemistry of intoxicants, and examines their influence at all levels of our culture and society. The book also tackles controversial issues such as legalisation and details the legal classification of illicit substances alongside additional relevant information on detection, prevention, punishment and other criminological subjects.