Changes in cannabis potency and first-time admissions to drug treatment: a 16-year study in the Netherlands

Background The number of people entering specialist drug treatment for cannabis problems has increased considerably in recent years. The reasons for this are unclear, but rising cannabis potency could be a contributing factor. Methods Cannabis potency data were obtained from an ongoing monitoring programme in the Netherlands. We analysed concentrations of δ -9-tetrahydrocannabinol (THC) from the most popular variety of domestic herbal cannabis...