No, initially I told you what they said, but since you didn’t believed me (or read them yourself) I had to quote them verbatim.

Yes I’m rude, that’s because you’re being obnoxious control freak that wants to prevent people from using one of the safest recreational drugs out there on the off possibly that a small number of people with predisposition to schizophrenia might abuse of this substance and make their condition appear earlier than it would otherwise. And I’m presumptuous because when I quote a scientific paper I read it first, and if I smell bullshit I read the thing they’re quoting, I’ve written enough papers myself and been around academia long enough to know how these meta-analysis get written.

Again, did you read the study you just quoted? Because you’re quoting the meta-analysis of it, not the study itself, here’s what that study actually concludes:

population-based estimates of cannabis-schizophrenia co-morbidity substantially overestimate their causal association. Predictions of the cases of schizophrenia that might be prevented by reduced cannabis consumption based on population associations are therefore likely to be considerably overestimated.

Also that study analyzed people with a schizophrenia diagnostic, and looked at previous arrests for drug related crimes to classify who used Marijuana, which is a very bad methodology for several reasons:

• Impulsiveness is a clinical feature of schizophrenia. Therefore it’s entirely possible that schizophrenics are simply most likely to get arrested, that would cause the same results observed.
• Risk for schizophrenia is larger between close relatives, but even between monozygotic twins it’s only 40%, so it’s entirely possible that with such a small group as in that research it’s just coincidence.

I’m not cherry-picking, I’m pointing failures in their methodologies, and misquotes from one paper to the one that’s analyzing it, to show you how “A drug related rap sheet together with family history is a predictor for schizophrenia” becomes “Marijuana causes schizophrenia”.

Edit: also forgot to quote this, it’s not just my opinion z the paper itself admits this is a possibility:

Second, we identified CA from medical and legal records, using ICD and conviction codes to capture prevalence within our study population. Although this method has the important advantage of not requiring accurate respondent recall and self-reporting, the risk for misclassification bias remains. Furthermore, we have assumed that those admitted to hospital or convicted for cannabis use represented a subsample of heavy cannabis users, which are labeled ‘cannabis abusers’ in this study (i.e. it is likely that there were many more people who used/abused cannabis than those who were registered as CA). Therefore, some risk remains that CA identification in the current sample may be contaminated by evidence of prodromal schizophrenia. Because our subjects experienced adverse medical or legal consequences of their cannabis use, our results are not directly comparable to studies that examine cannabis use or even heavy cannabis use

And finally, I don’t care if you answer or not, I’m not answering to you, I expect you read those papers and got to some conclusion. I’m answering so that other people who’re just going to read the title and your response know that that’s not exactly what the paper says, as usual people do a very shallow approximation of what the paper actually says.