This text provides an examination of all aspects of drugs and their users, and considers drugs from all perspectives, including behavioural, pharmacological, historical, social, legal and clinical. Providing up-to-date facts, the text aims to assist readers in making well-informed decisions about behaviour and choices. This edition includes a new section on theories of addiction, including information on why certain people are predisposed to addiction problems and risk factors. The text includes DSM-IV information in a separate box, and there are also three-dimensional models of the chemical substances discussed, in order to generate greater student comprehension.