According to this study, cannabis may affect part of the brain in developing adolescent teens that control impulse control and decision making. These results were for human teens (not mice).

According to the article:

“Participants had their first scan at age 14. None reported using marijuana at this point. Five years later, the teens returned for a second scan. Now 369 of the adolescents (46 percent) reported they had tried cannabis. About three-quarters of these said they had done so at least 10 times.

“One part of the brain changed more in cannabis users than non-users. Called the prefrontal cortex, it sits right behind the forehead and above the eyes. This region is involved in decision-making and other tasks. It tends to thin during adolescence to help the brain work more efficiently. But that thinning sped up in teens who reported cannabis use. The more drug the teens used, the faster the prefrontal cortex thinned, Albaugh’s team now reports.”

This should be bone-chilling for parents of teenagers.

Cannabis may alter a teen’s developing brain

Marijuana worse for teen brains than alcohol, study finds