Abstract The Netherlands is well known for its early adoption of harm reduction (HR) programs at the height of its heroin crisis in the 1970s/1980s. including the implementation of the first needle and syringe program worldwide. In this manuscript. we describe how the Amsterdam Cohort Studies (ACS) among people who use drugs (PWUD) was conceived within the context of the Dutch HR appr... https://www.soiebiologique.com/