At least one of every three Americans has used an illicit drug. Drugs attract considerable attention in science, legislation, and the media. Nonetheless, many people develop attitudes about drugs and drug users based on limited information. Researchers often find themselves divided into camps based on the drug they study most often, which limits their ability to benefit from important work done on other drugs. As a result, government policies form without a complete understanding of the intoxication experience. What is the nature of intoxication? At first, this question appears to be simple and straightforward, but upon closer inspection, the dichotomous distinctions between everyday awareness and its alternatives grow fuzzy. An in-depth examination of the subjective effects of drugs and the pursuit of altered states soon leads to age-old questions about free will, heredity, environment, and consciousness. Mind-Altering Drugs is the first book to bring together chapters from leading researchers that present diverse, empirically based insights into the subjective experiences of drugs a nd their links to addictive potential. By avoiding simple depictions of psychoactive chemicals and the people who use them, these recognized experts explain how modern research in many fields reveals a complex interaction between people, situations, and substances. Their work demonstrates that only a multitude of approaches can show the nuances of subjective experience, and that each substance may create a different effect with every administration in each user. Simple references to physiological underpinnings or positive reinforcement fail to explain the diverse responses to drugs. However, research has progressed to reveal broad, repeatable evidence that the subjective effects of substances play an important role in our understanding of drug abuse, and so should inform our decisions about policy. This thorough and accessible review of the subjective effects of drugs and the dominant theories behind those effects will provide a wealth of information about the experience of intoxication for lay readers, and a road map to studies in other disciples for student and professional researchers.