People who smoke cigarettes are 300-500% more likely to be diagnosed with schizophrenia.
Yet those studies do not make the claim that cigarettes CAUSED it. It simply means the mentally ill are more likely to use drugs and smoke.
There has not been a single controlled twin study that shows ANY long term differences when one twin is incroduced to cannabis at ANY dose. These correlation studies do not prove any cause
Yes but if you take a bunch of monkeys and sew up their noses mouths so that only a cigarette can be inserted into the mouth and forcing them to breathe the burning cigarette for hours on hours, they will eventually get lung cancer. Which is how the first “cigarettes cause cancer” trials were done back in the 60s. From there on it was just a matter of refining the study process
But they do serve the prohibitionist agenda.