there are no marked differences between the western balkan countries with respect to lifetime prevalence of drug abuse among school students aged years all estimates of lifetime illicit drug use falling between per cent and per cent which is times lower than the european average the drug most commonly used is cannabis between per cent and per cent of those surveyed reporting lifetime cannabis use a range considerably lower than the per cent european average the relatively high annual prevalence of cannabis abuse per cent among the general population in western and central europe has stabilized or in some cases decreased in particular in countries where cannabis consumption is longestablished