This Ain't Your Dad's Weed: Pot Potency Jumps
THC concentration has been climbing for decades
By Matt Cantor,  Newser User
Posted May 14, 2009 11:20 AM CDT
In 1983, marijuana's potency was said to be under 4%, CNN reports.   (Shutterstock)

(Newser) – Marijuana’s average potency, as measured by the concentration of psychoactive component THC, has broken 10% for the first time after decades of steady increase, a government report says—and is expected to keep increasing, CNN notes. Potency will likely plateau at some 15% in the next 5-10 years, though some pot already has potency above 30%, scientists found.

High concentrations of THC have the opposite effect of low, and new users may not be careful about how much they take, potentially leading to dysphoria, paranoia, and irritability. Officials are particularly concerned about high-potency marijuana’s effect on adolescent brains. But warnings may have little effect on youths, said a psychiatrist: “I don’t think they reflect on what it might have been like 30 years ago.”