Marijuana could be worse for teen brains than alcohol, a new study found.
The study published in the American Journal of Psychiatry tested the memory and reasoning of 3,800 teens ages 13-17.
They found that marijuana affected teens' long-term cognitive abilities more than alcohol. The study also found that even when students stopped smoking pot, their memory did not get better.
Scientists say they need to do more research to find out how and why the brain is affected by early marijuana use.