More THC associated with weakness in white matter linking cerebral hemispheres
People who use especially potent pot show signs of damage in a key part of their brain. The results, reported online November 27 in Psychological Medicine, are limited, though: The small brain scanning study doesn’t show that marijuana caused the brain abnormality — only that the two go hand-in-hand. But the findings suggest that potency matters, says study coauthor Tiago Reis Marques, a psychiatrist at King’s College London.
“We are no longer talking about smoking cannabis or not smoking cannabis,” Reis Marques says. Just as vodka packs more of a punch than beer, a high-potency toke delivers much more of the psychoactive substance tetrahydrocannabinol, or THC. A bigger dose of THC may have stronger effects on the brain, Reis Marques says.