Taking the cat-and-mouse game to the next level: different perspectives on the introduction of the German New Psychoactive Substances Act.

Background: To counteract the spread of new psychoactive substances (NPS) and to prevent the emergence of novel substances, specifically designed as a response to the legal control of individual substances, a new law was introduced in Germany in 2016: the New Psychoactive Substances Act (NpSG). The NpSG combines a generic approach with the waiver of criminal liability for the acquisition and possession of NPS for personal use, which is a novelty in German narcotics law. The present study aimed at exploring the impact of the introduction of the NpSG from three different perspectives-NPS users, staff of addiction care facilities, and members of law enforcement authorities-to better understand the dynamics surrounding such a change in legislation and to contribute to the body of international experience in dealing with NPS.