A new study reveals the potency of THC in both herbal cannabis and cannabis resin has increased significantly in Europe since 2006.
Since 1993, THC potency in cannabis has increased from 3.5% to 12.3%. Researchers report those who first used cannabis in the early 90s had a 1.88% increased risk of developing cannabis use disorder, while those who started on higher potency THC marijuana are at a 4.85% increased risk.
