The book begins by looking at the nature and scope of substance use in the world, providing prevalence data and describing patterns of use. In an effort to explain why substance use is omnipresent throughout history and across cultures, the book explores whether humans are innately predisposed to seeking and consuming psychoactive substances. Because modern beliefs about drug-taking behavior cloud current perspectives, considering the functional and beneficial nature of drug use as an evolutionary adaptation is particularly fascinating. Substance Use and Abuse provides a brief history of drugs, highlighting their common beginnings as medicinal agents, religious vehicles, social mediums, and agents of economic gain. Durrant and Thakker explain patterns of drug use and increasing levels of abuse and drug-related harm in terms of these changing functional contexts, with emphasis on various economic, legal, political, educational, and philosophical influences.