of the kg of synthetic cannabinoids seized in the republic of korea in kg were imported from the united states the rapid emergence of substances not yet under control the limited forensic capability to identify such substances in some countries and the different listing classification for those substances adopted by different countries in the region are factors that create considerable challenges in mitigating the risks posed by new psychoactive substances at the regional level the abuse of ketamine remains a major problem for the region although the amount of seizures has been decreasing in some countries while not under international control ketamine has been brought under national control in a number of countries in the region china democratic people s republic of korea japan malaysia myanmar philippines republic of korea singapore and thailand medical professionals in brunei darussalam and china including macao special administrative region indicated an increase in the abuse of the substance in hong kong china the annual prevalence rate of ketamine use remained higher than that of amphetaminetype stimulants