Exactly. It just basically says, from the people who requested mental health care, more of them used cannabis than from the control group. Great. They also present higher rates of smoking, alcohol use, self harm, obesity, and various disabilities. Some may be cause, some consequence, some none of them. The title is correct, there is a link, but that link has not established causality of any kind. This is basically repeating uncountable studies saying the same thing.
CBD, present in cannabis, is known to be antipsychotic, so the self-medication hypothesis is pretty strong. It's the same case as nicotine, schizophrenics have way higher rates of smoking, only because nicotine has a mild antipsychotic effect, not because smoking turns people crazy.
I'm saddened to read a plea for more causality (a topic that should definitely be more popular in all social and scientific claims), followed by personal and very unproven opinions, presented as tangible hypotheses.
I have not read the study so I can’t confirm that this one does not establish causality, but how are studies that don’t establish causality still published? At least shouldn’t they be appropriately labeled? We get some much pop sci drama from misinterpreting papers like that, it seems like it should be standard practice to show whether strong causality was or was not found/proven.
Paranoia from weed is a well-known phenomenon among smokers, and was so even long before clinical discussions about the effect became common. I'm surprised how defensive some (usually liberal-leaning) people become when the connection is suggested. I guess they have limited experience with cannabis, or they feel the need to protect a certain narrative.
Or they like good science that doesn't attribute causality without evidence? "Cannabis use increases the chance of psychosis" is just one of the three potential relationships. The other two are "The chance of psychosis increases cannabis use" and "A third factor increases both the use of cannabis and the chance of psychosis".
In reality, the effect is probably not just one, but some mixture of all three. It is extremely likely that people are self-medicating against psychosis with cannabis, that cannabis can increase the risk of psychosis in some people, and that the risk of psychosis is usually co-morbid with other mental health issues for which people also self medicating.
A study like this does nothing to help us understand the link, but yet the Authors seem willing to make strong claims about that link:
> The researchers suggested that if high potency cannabis was no longer available, the incidence of psychosis in Amsterdam would be expected to halve from 37.9 to 18.8 per 100,000 people per year, while in London, it would fall from 45.7 to 31.9 per 100,000 people per year.
That is irresponsible and bad science. It should be called out as such.
CBD, present in cannabis, is known to be antipsychotic, so the self-medication hypothesis is pretty strong. It's the same case as nicotine, schizophrenics have way higher rates of smoking, only because nicotine has a mild antipsychotic effect, not because smoking turns people crazy.