This report presents the results and outlines the key achievements and challenges faced by mechanism set up by the Council Decision in 2007. In 2007, 15 new psychoactive substances were officially notified for the first time in the European Union through the Early-Warning System (EWS). The number of new substances notified in 2007 was higher than those notified in 2006; it was, however, comparable with the number of new substances reported in 2005. The group of notified substances was rather diverse and, beside new synthetic drugs per se, included medicinal products, a metabolite/derivative of a medicinal product and naturally occurring substances. They included phenethylamines, tryptamines and piperazines, as well as substances with a less common chemical make-up. The group was equally divided between substances that had pronounced hallucinogenic effects and those that exhibited predominantly stimulant properties. Furthermore, this report describes in detail the active monitoring report of mCPP and the risk assessment of BZP. The lessons learnt from the process and outcome of the risk assessment exercise provide insight into the mechanism's advantages and limitations in producing sound scientific evidence for decision-making within rigorous deadlines and at reasonable costs.