This Is Your Brain on Marijuana
Teens who think marijuana is safe to use are mistaken, Volkow says. “I think that the data are quite clear that smoking marijuana during adolescence is harmful to your brain.”
A National Institutes of Health-funded study, published in August in theProceedings of the National Academy of Sciences, found a significant drop in IQ — an average of eight points — between the ages of 13 and 38 in people who had been heavy marijuana users since their teens. Even those who quit using the drug showed impaired mental abilities if they had started smoking marijuana in their teens.
“Findings are suggestive of a neurotoxic effect of cannabis on the adolescent brain and highlight the importance of prevention and policy efforts targeting adolescents,” the researchers concluded.