With nearly 15 million Americans using
cannabis in a given month, 3.4 million using
cannabis daily for 12 months or more and 2.1 million commencing use every year, there is a clear need to conduct robust investigations that elucidate the long-term consequences of long-term cannabis use," the study's authors wrote.
"Although modest use may not lead to significant neurotoxic effects, these results suggest that heavy daily use might indeed be toxic to human brain tissue.