@houstonpublicmedia

>"Profit over people is never an excuse to ignore the people," Perry said. "I'll tell you, the taxes we collect does not cover the behavioral health issues that’s created an addiction that the state budgets of the day have to cover."

BAHAHAHAHAHAHAHAHAHA. That's rich.

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>Multiple studies suggest THC use can increase the risk of schizophrenia and acute psychosis. [link: https://pmc.ncbi.nlm.nih.gov/articles/PMC10874830/]

HPM, you're pulling a reefer madness here. That paper is concerning developing better biological metrics for cannabis exposure. It certainly does not support the claim that "THC use can increase the risk of schizophrenia and acute psychosis." The closest the paper comes to suggesting such a thing is in the introduction:

"In Canada, the number of patients presenting to emergency departments with a “cannabis-induced psychoses” doubled between 2015 and 2019.[12] This is a major issue, as many of these individuals subsequently develop a psychotic disorder.[13]"

The [12] citation is, frankly, malicious in the context of the Chesney et al usage, as [12] makes plain in its results:

>ED presentations for cannabis-induced psychosis doubled between April 2015 and December 2019. However, across all four SARIMA models, there was no evidence of significant step-function effects associated with cannabis legalization on post-legalization weekly ED counts of: (1) cannabis-induced psychosis [0.34 (95% CI −4.1; 4.8; P = 0.88)]; (2) schizophrenia [24.34 (95% CI −18.3; 67.0; P = 0.26)]; (3) alcohol-induced psychosis [0.61 (95% CI −0.6; 1.8; P = 0.31); or (4) amphetamine-induced psychosis [1.93 (95% CI −2.8; 6.7; P = 0.43)].

And conclusion:

>Implementation of Canada's cannabis legalization framework was not associated with evidence of significant changes in cannabis-induced psychosis or schizophrenia ED presentations. Given the potentially idiosyncratic rollout of Canada's cannabis legalization, further research will be required to establish whether study results generalize to other settings.

Both of which make clear that the doubling was statistical noise that does not support the assertion that legalization brought about greater incidence of schizophrenia or psychosis.

The [13] (Murrie et al) citation does not claim that THC-induced psychosis episodes themselves *induce* schizophrenia where risk for it was not previously established. Murrie et al studied how often substance-induced psychosis patients eventually received a schizophrenia diagnosis, as compared to non-substance-induced psychosis patients eventually receiving a schizophrenia diagnosis. Their study hypothesized that there would be no difference:

"We hypothesized that substance-induced psychosis would be associated with the same risk for transition to a later diagnosis of schizophrenia as is observed in other brief and atypical psychoses, based on the findings of the clinical follow-up and register studies described above."

And actually found that the transition risk was *lower* for substance-induced psychosis (Table 2):

>Substance-induced psychosis had a lower rate of transition to schizophrenia than for other brief, atypical, and unspecified psychoses. However, the pooled rate of transition for substance-induced psychoses was similar to that for brief and atypical psychoses (excluding psychosis not otherwise specified). The available data, therefore, suggest that people with substance-induced psychoses, particularly those associated with cannabis, have almost the same rate of transition to schizophrenia as those with other brief and atypical psychoses.

though their confidence intervals do overlap:

>Substance-induced transition rate: 25% (18%–35%)
>Brief, atypical and NOS transition rate: 36% (30%–43%)

Nevertheless, Murrie et al choose to instead highlight in their abstract (in my opinion, an instance of #AbstractAbuse) that THC, as the abused substance, was most likely to predict a transition to schizophrenia later.

Their discussion ultimately qualifies their claim of THC causing increased risk of schizophrenia diagnosis to already **vulnerable individuals**.

>This study adds to evidence that cannabis interacts with other risk factors to double the risk for schizophrenia **in vulnerable individuals**.

In short, [13] adds additional weight to the suggestion that those with risk factors for schizophrenia or other serious disorders may want to abstain from, or at least reduce intake of, THC (and *all* forms of psychoactive substances). It does *not* suggest that THC is, itself, *causing* schizophrenia.