> But it strikes me as a bit unlikely that there was previously a large amount of undiagnosed schizophrenia.

As another commenter pointed out, US health insurance did not typically cover mental insurance until relatively recently, making diagnosis impossible for many.

I think the increase in cases is more likely to be explained by a number of factors:

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.

The high THC and lack of CBD in today's strains is concerning (to me) honestly. I'm worried that a lot of the data we've seen in the past about chronic cannabis use being relatively safe may not apply when THC/CBD ratios approach 50:1, since CBD and other cannabinoids counter act some of THCs effects.

Criminalizing is a big part of this problem. With "medical" weed you can carefully chose a fitting strain just to your liking and condition, like indica for calming and sativa for inspiring effect, in hundreds of nuances even. But no. Too much money to be made for some groups from this prohibition. Can't have that, denied.

The equivalent is alcohol being prohibited leading to everyone drinking 180 proof smuggled moonshine that makes you go blind.

also it's 2% "of diagnosis" connected to marijuana use. So the difference would be if marijuana use is more commonly known/reported, regardless of whether they have 100 or 10000 diagnosis

Might be broadened by the overlap of symptoms. Schizophrenia in particular is a broad classification of different kinds of similarly presenting thought disorders. A person exhibiting textbook symptoms but with the cause more directly attributable to use and social disruptions might have a vastly different prognosis and course of treatment than a more genetic or organic case.

> But it strikes me as a bit unlikely that there was previously a large amount of undiagnosed schizophrenia.

Why would that be unlikely?