Novel psychoactive substances (NPS) - knowledge and expe riences of drug users from Hungary, Poland, the UK and the USA.

Background: The recent decade witnessed growing prevalence of novel psychoactive substances (NPS) among young people in Europe and elsewhere. The study, conducted in 2011 as part of the EU-funded ReDNet project, aimed at better understanding of motives behind the demand for NPS among youth as well as at their information needs in this regard. In addition to historical values, the lessons learned during the legal status of NPS may contribute to a more general understanding of use of new drugs and to current drug policies.