Marijuana and Public Health CDC

Some people think that marijuana is not truly “addictive” or that people can’t become “hooked” on the drug, but research shows that about 1 in 10 marijuana users will become addicted. For people who begin using before the age of 18, that number rises to 1 in 6.
Marijuana use directly affects the brain — specifically the parts of the brain responsible for memory, learning, attention, decision making, coordination, emotions, and reaction time.