Welcome to Module 4 which looks at questioning prohibition-based policies. In this Module, you will discover that most drug policies in the world are based on prohibition law enforcement and criminalization of drug use ; and see that such policies have a number of negative consequences on people’s health as well as on their human rights. This Module will also look at law enforcement more closely and reveal how it can cooperate to improve health. You will learn about the human rights framework and the drug control framework and see what human rights violations, stemming from the implementation of prohibitionist drug policies, look like around the world. Finally, you will also see that drug policies are connected to development and the environment, most often not in a good way, with prohibition fueling violence, crime and corruption and impeding development. By the end of this Module you will be able to: • Evaluate the extent to which prohibition-based policies have succeeded or failed in reducing drug production, trafficking and consumption; • Describe the negative impacts of prohibition-based policies on health, human rights and development; • Recall how prohibition-based policies fuel organized crime and trafficking. We hope this week will provide you with valuable insight into the reality of prohibitionist drug policies, for people in communities all over the world ; and help you see what have been the consequences of these policies, in terms of their impact on human rights, health and development. We also hope you enjoy the essential reading and optional additional resources we have prepared for you. Best wishes,The Drugs, Drug Use, Drug Policy and Health team