The world has seen an unprecedented surge in the production of new synthetic drugs, according to a report released today by the United Nations Office on Drugs and Crime (UNODC). In its latest Global Synthetic Drugs Assessment, the agency says it identified 348 new synthetic drugs in 94 countries as of last year, with the majority emerging between 2008 and 2013. The UNODC received reports on 97 new synthetic drugs in 2013 alone, though it acknowledges that the true number of substances on the market could be much higher. The agency defines new psychoactive substances as drugs that are not controlled under international conventions, but may pose public health risks.