Submitted 4 days ago by cm0002@literature.cafe to science@mander.xyz
https://pmc.ncbi.nlm.nih.gov/articles/PMC4988731/
The pooled analysis reported approximately a 4-fold increase in risk for the heaviest users and a 2-fold increase for the average cannabis user in comparison to nonusers.
So it’s a rough relative analysis, not one with a quantitative threshold for “heavy use”.
As always, all things in moderation.
This has been known for awhile but it does not really depend on amount used but rather the users genetics. If that user is genetically susceptable then they will have more risk with increased use.
Cannabis users also self medicated for psychological issues. but in Canada, post legalization Schizophrenia is on the increase and higher than comparable countries. The prevalence has doubled since 2002. Cannabis was legalized in 2018, but use and simple possession was not enforced before that.
Tehdastehdas@piefed.social 3 days ago “Cannabis from the 2000s is not the same as in 2025,” … “THC content has increased by 5 times. This is likely a significant driver in the increasing link between cannabis use and schizophrenia.”
https://www.sciencedaily.com/releases/2025/08/250811104237.htm
Been smoking daily for 20+ years. No schizophrenia or psychosis. Yes, of course I know that this is anecdotal at best and doesn’t prove zilch. Plenty of depression, but that was already there before I started smoking.
Yep, because you don’t have the genes that make you susceptible.
hubertmanne@piefed.social@piefed.social 4 days ago even if you do I have multiple brothers that used cannabis and one that is schizophrenic. one that is not smoke it fairly often over a very long period. he did eventually quit but not because of psychosis.
Yeah, this is largely how I view the issue. No one in my family has ever had any schizo or psychosis disorders, so it’s not really concerning for me.
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.
BucketBong@p.hobo.social 4 days ago Yeah by my psychosis demon is waaaaaaaay nicer to me then most people are, so imma take my chances.
Well, if i get a new reality out of the deal ill consider it…
In the sidebar there is a list of "similar papers". A more recent study:
[Impact of the legalization of recreational cannabis on the risk of psychosis: A systematic review of the literature]
https://pubmed.ncbi.nlm.nih.gov/39244500/
April 2025
Abstract
Introduction: Cannabis is the most consumed illicit substance in Europe. Although its sale and use remain generally prohibited, European public policies have evolved in recent years by legalizing cannabis for medical use and considering its legalization for recreational use. However, in the literature there are arguments in favor of a particular relationship between cannabis consumption and the development of psychotic symptoms. Thus, since cannabis consumption tends to increase with legalization, the aim of this review was to investigate the impact of the legalization of cannabis for recreational use on the risk of psychosis in regions of the world already concerned.
Method: A systematic review of the literature was carried out in April 2024 in the PubMed-Medline database according to PRISMA criteria. The sequence of keywords used was as follows: ("Cannabis" [Mesh] or cannabis) AND (("Psychotic Disorders" [Mesh] or Psychotic Disorders) or ("Schizophrenia Spectrum and Other Psychotic Disorders" [Mesh]) or ("Schizophrenia" [Mesh] or Schizophrenia)) AND legal use. The inclusion criteria applied for the selection of articles in this systematic review were: (1) any article investigating the potential impact of the legalization of cannabis for recreational use on the risk of psychosis (any type of psychosis diagnosed according to ICD-9, ICD-10, DSM-4 or DSM-5) by the intermediary of epidemiological (incidence or prevalence) and/or clinical (ambulatory consultations, emergency visits or hospitalizations) criteria, (2) any type of study (cross-sectional, longitudinal, prospective, retrospective, interventional and experimental) with a methodology including a temporal and/or geographic comparison of the risk of psychosis associated with the legalization of cannabis for recreational use with the exception of literature reviews and clinical cases descriptions, (3) absence of limitation for the age of the populations studied and for the date of publication, and (4) articles written in English or French. After evaluation by the two authors of the 160 articles identified, seven studies investigating the impact of the legalization of cannabis for recreational use on the risk of psychosis were included in this systematic literature review.
Results: Four of the studies showed no increase in the use of health services for psychosis following the legalization of cannabis for recreational use whereas three other studies highlighted a negative impact of the legalization of cannabis for recreational use on the risk of psychosis. All of these studies were carried out in North America and were characterized by a low level of scientific evidence.
Conclusion: Given the complexity of assessing the impact of the legalization of cannabis for recreational use on the risk of psychosis, additional investigations through studies of better scientific quality are essential. However, based on the data already available, there is some evidence that there is a potential negative impact on mental health due to the legalization of cannabis for recreational use. In this context, in the event of legalization of cannabis for recreational use it seems essential to recommend lower risk use of cannabis (limit the frequency of use, delay the age of first consumption, control the THC content of products and promote prevention/education). Finally, in order to enable dynamic evolution of public health strategies the establishment of continued monitoring is essential as cannabis legalization evolves.
Keywords: Cannabis; Legalization; Légalisation; Psychotic disorder; Recreational use; Trouble psychotique; Usage récréatif.
The problem is weed 1960s-80s was not like weed today, THC doses are much higher. 15-20X. Schizophrenia in Canada is way up, double 20 years ago, and our ERs now see Cannabinoid Hyperemesis Syndrome (CHS), psychosis, paranoia, panic attacks and a bunch of cardiac issues.
Our fucking idiot broski PM at the time legalized cannabis, but did not regulate the dosage.
Use marijuana, get free psychosis you say?
A free trip to the public spa. Free slippers. Free bath robe. Cool wrist strap. Free drugs. Cool meals in metal trays. Showers take up whole rooms.
roknrol@beige.party 4 days ago 
Lexam@lemmy.world 4 days ago
Dr. Voices says I should ignore your study.