More likely, marijuana use accelerates the development of schizophrenia among people already at risk.
> it could also be increases in the percentage of cases that actually get diagnosed, etc.
This is generally a valid stock response to these sorts of studies. But it strikes me as a bit unlikely that there was previously a large amount of undiagnosed schizophrenia.
(Unless we have broadened the definition recently).
As another commenter pointed out, US health insurance did not typically cover mental insurance until relatively recently, making diagnosis impossible for many.
1. THC concentrations have increased which usually means there is less CBD. 2. Legalization probably increased casual use. 3. People who suffer from schizophrenia are simply more likely to be diagnosed for whatever reason.
The sum of these three things could easily account for a significant increase in diagnosis.
Sometimes increases in diagnosis correlate with better detection. Sometimes they correlate with incentives to diagnose people. I’m not even suggesting a nefarious connection. Sometimes incentives with the best intentions can have a big impact.
Why would that be unlikely?