The spectacle of illicit drug use or doping among high-profile athletes has become a staple feature of news outlets worldwide. Beyond carrying implications for competition results, titles, and sport-specific records, such cases are read as compelling morality tales, and consumed as popular entertainment. In fact, there is little evidence that athletes' consumption of controlled substances has increased over time, or represents a new problem; yet perception has shaped substance use policies in both sport and society at large - making and breaking careers, fueling fears, and generating unanticipated consequences. This book presents a broad epidemiological portrait of psychoactive drug use among athletes, bolstered by a theoretical framework that highlights salient sociological features of sport and the social psychology of athletic teams and competition. Sport at all levels is explored as a "risk environment" for drug use, which serves to modulate not only the likelihood of psychoactive substance use, but the associated harms. Interventions, policy options, and sporting contexts that may reduce or minimize drug-related harms, or encourage controlled substance use, are considered throughout the text. In addition to sketching a global history of psychoactive drug use in sport, two drug-specific case studies are presented in detail: alcohol use and overuse among university and non-elite "club" athletes, and the non-medical consumption of opioids within contact sports. An interdisciplinary text, this book provides a comprehensive review of current research in psychoactive drug use in sport, as well as a guide to evidence-based interventions.