The complex and constantly evolving public health threat of new psychoactive substances in Italy: addressing the main functions of a national observatory of drugs.

At the end of the 90s in Europe, the new psychoactive substances (NPS) phenomenon was limited to a small number of molecules created to mimic the actions and psychoactive effects of licensed medicines and existing drugs that are controlled by the United Nations drug conventions and therefore traded as their "legal" replacements. NPS were mostly circulating in rave parties and electronic music festivals. The globalization, the evolution of e-commerce and the growing popularity of NPS, facilitated the development of a wide illegal market in constant expansion.