This study was supported by the European Union (New Psychoactive Substances: transnational project on different user groups, user characteristics, extent and patterns of use, market dynamics, and best practices in prevention [HOME/2014/JDRU/AG/DRUG/7077]), the Hungarian National Research, Development and Innovation Office (Grant number: KKP126835; NKFIH1157-8/2019-DT). The study was also supported for the realization of this international cofinanced science project in 2016-2017 by the Polish Ministry of Science and Higher Education. Máté Kapitány-Fövény acknowledges the support by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences and the support by the ÚNKP-19 New National Excellence Program of the Hungarian Ministry for Innovation and Technology. The funding institutions had no role in the study design or the collection, analysis and interpretation of the data, writing the manuscript, or the decision to submit the paper for publication
