Potency of cannabis resin has 'increased substantially' - report

The doubling in the potency of cannabis over the last ten years could be behind the growth in people seeking treatment for the drug, the European drugs agency has said.

While it said conclusions regarding the connection should be treated with “caution”, the European Monitoring Centre for Drugs and Drug Addiction said that adverse effects become “more severe” with higher doses of THC, which is the main active constituent of cannabis.