Given the countless benefits of legalization, more and more states are preparing to move in this direction, with less severe laws aimed at improving the conditions of both the individual and the collective.
Despite this, there is no shortage of prohibitionist accusations that state that cannabis can cause psychosis. A thesis without definitive scientific evidence, which however raises concerns about the hypothetical damage to people's mental health resulting from regulation.
Below we analyze two scientific studies, conducted respectively in Canada and in the US where cannabis is legal, which openly specify that legalization it is not associated to an increase in psychosis.
Psychosis is not linked to the legalization of cannabis
"The legalization of cannabis in many jurisdictions has raised worries on the fact that such legislation could increase the burden of psychotic illnesses", so it begins Canadian study published on Canadian Journal of Psychiatry.
To evaluate associations between the legalization of cannabis in Canada, which occurred in 2018, and cases of psychosis, researchers analyzed emergency department records from Alberta and Ontario from April 1, 2015, to December 31, 2019.
Upon completion of the analysis, the researchers stated that "the implementation of the cannabis legalization framework in Canada was not associated to evidence of significant changes in presentations of cannabis-induced psychosis or schizophrenia".
USA: Cannabis legalization is not associated with an increase in psychosis
One study published on JAMA Network Open specified that there would be no connection between the legalization of cannabis for both medical and recreational use in the USA and the increase in psychotic disorders.
Researchers from Philadelphia University, Stanford University and the Veterans Affairs Palo Alto Health Care System analyzed the Optum Clinformatics Data Mart Database, a commercial and Medicare Advantage claims database made up of more than 63 million individuals only ones followed from 1 January 2003 to 31 December 2017.
The authors of the study combined the diagnosis number related to psychosis, antipsychotics prescribed and enrollees for each month of follow-up to data regarding state cannabis policies, state demographic, economic and social data.
In particular, in research period Over 7 million diagnoses linked to psychosis and more than 20 million prescriptions for antipsychotic drugs have been highlighted. At the same time, there are 29 states in which reforms on cannabis for medical or recreational use have been approved.
“In this retrospective cohort study of commercial and Medicare Advantage claims data, state policies on medical and recreational cannabis they were not associated to a statistically significant increase in rates of psychosis-related health outcomes," the researchers conclude.
Although in secondary analyzes the researchers found rates of psychosis-related diagnoses to be slightly increased Among men in states that allow adult cannabis use versus those that do not, said:
“Results from the fully adjusted models showed that, compared to no legalization policy, states with legalization policies did not experience a statistically significant increase rates of psychosis-related diagnoses,” the authors conclude.
The effectiveness of CBD to treat psychosis
While further studies are needed for cannabis with THC to definitively clarify the situation, it is now known that high CBD cannabis instead it can effectively treat psychosis.
In 2014, in fact, one study published in the magazine Neuropsychopharmacology investigated the properties of CBD as an antipsychotic. The scientists concluded that: “The compound may have antipsychotic properties,” but with advantages over traditional drugs, includingabsence of side effects obvious.
Same conclusion that some researchers from King's College London reached in 2017: that is, that cannabidiol boasts good antipsychotics without though bring the side effects of conventional drugs, which CBD does not have.
| Must read: "Does CBD have side effects? Let's clarify"
