“Marijuana is nowhere as dangerous as alcohol. You can quite literally drink yourself to death; the same doesn’t apply to marijuana. So it’s almost certain that legalizing marijuana the same way won’t lead to all the same bad outcomes.
Still, there are some risks. A thorough review of the research, by the National Academies of Sciences, Engineering, and Medicine, found that marijuana poses a variety of possible downsides, which can include a higher risk of respiratory problems (if smoked), an increased risk of developing schizophrenia and other psychoses, an increased likelihood of car crashes, a general decrease in social achievement, and, potentially, some harm to fetuses in the womb.
There’s also the real risk of addiction and overuse. As Stanford’s Keith Humphreys put it to the Atlantic, “In large national surveys, about one in 10 people who smoke [marijuana] say they have a lot of problems. They say things like, ‘I have trouble quitting. I think a lot about quitting and I can’t do it. I smoked more than I intended to. I neglect responsibilities.’ … People will say, ‘Oh, that’s just you fuddy-duddy doctors.’ Actually, no. It’s millions of people who use the drug who say that it causes problems.”
None of that is to make the argument for prohibition, which produces its own problems”
“An obvious question is: If the standard commercial model works for alcohol, why can’t it work for a newly legal drug like cannabis, too?
But this model doesn’t work well for alcohol. The nation’s second-most popular drug (after caffeine) is linked to nearly 100,000 deaths a year in the US — about the same as all overdose deaths, and more than the combined death tolls of car crashes and murders.
A different model could help. Previous research, for example, found that states that maintained a government-operated monopoly for alcohol kept prices higher, reduced access to youth, and cut overall levels of use”