According to the UNODC early warning advisory, Costa Rica continued to report substances in the groups of phenethylamines, piperazines and other substances in 2015. Use of those substances may have serious health consequences, as the effects of such substances on the human body are not fully understood or known. In addition, the trafficking of those substances creates additional challenges for the regulatory and enforcement authorities. Cannabis abuse patterns and trends in the region have remained fairly stable. The prevalence of cocaine abuse in Central America and the Caribbean remains higher than the global average,30 with an estimated average annual prevalence of 0.6 per cent for both subregions. As regards the use of opioids in Central America, UNODC has estimated annual prevalence at 0.2 per cent, which is below the global average.