[Usagi_yo]

There is an extensive body of medical evidence that, for a significantly large slice of the population, marijuana use triggers schizophrenia and other mental disorders. This imposes substantial risks and burdens on the general public.

Yes, filed between the studies: "black people" are inherently stupid and criminal" and "The autopsy reports from Roswell NM.

Yes, chronic use of Marijuana, just like alcohol or Captn' Crunch or McDonalds is not good for you.

[Rockingham]

Individual susceptibility to the harms of marijuana varies -- as it does with most anything else. To use your example, for people who have celiac disease, a single bowl of Captn' Crunch and a McDonald's burger are literally toxic due to the gluten they contain.

For mental illnesses triggered by marijuana, the picture is murky because there are unresolved issues as to how many of them would have developed mental illness anyway, if perhaps later in life or in a less severe form. In any event, as a matter of public policy, the proven harms of marijuana provide a credible basis for prohibition.

There is still a case for marijuana legalization based on other considerations, but intellectually honest advocates ought not to ignore the harms that legalization would advance.