Maybe this is my pro-weed bias talking... But in the modern world where cannabis is increasingly legal and recreationally used, I'm not really sure what a meta-analysis of decades old studies is supposed to actually add to the discussion.

Is there a causative link between cannabis use and schizophrenia or psychosis? If so, are we seeing a proportionate uptick in schizophrenia and psychosis diagnoses in places where recreational cannabis use has been legalized?

There's plenty of data these days, we should be doing real, original research.