The first chapter explains how the principles of science -- determinism, parsimony, objectivity, ethical neutrality, relativism, skepticism, and empiricism -- relate to the study of drugs and how researchers adhere to these principles in studying various drug-related social phenomena. The chapter argues that students, police officers, and policymakers can benefit by putting these principles into practice in their efforts to understand and respond to the phenomenon of drugs. The second chapter provides an overview of various types of drugs, their histories, how they are used, and their effects, along with some general strategies used to classify the drugs into categories. In focusing on the way police respond to drugs, the third chapter addresses trends in drug policing, the decentralized response to drugs, police strategies for responding to drugs, and the police as educators in the response to drugs. Issues in drug policing, the subject of the fourth chapter, encompass asset forfeiture, the dangers faced by narcotics officers, police corruption in the response to drugs, the use of police drug dogs, the unintended consequences of drug crackdowns, racism and drug policing, policing prescription fraud, and drug policing from a systems perspective. The fifth chapter considers theories that have been developed specifically to explain drug use as well as more general theories of crime and delinquency that have been applied to drug use. The concluding chapter outlines arguments for and against drug legalization or decriminalization. Intended for use as a textbook for courses on drug abuse, various tools for instruction, critical thinking, and discussion are included with each chapter. 315 references and a subject index