Some teens believe marijuana can't be that harmful if states are legalizing it. Legal or not, one real risk is addiction. In 2016, around 4 million people ages 12 and older had a marijuana use disorder. The most severe form also is known as an addiction. 1; Research also shows that marijuana can harm the developing teen brain.
This article reviews neuroimaging, neurocognitive, and preclinical findings on the effects of cannabis on the adolescent brain. Marijuana is the second most widely used intoxicant in adolescence, and teens who engage in heavy marijuana use often show disadvantages in neurocognitive performance, macrostructural and microstructural brain development, and alterations in brain functioning.