The relationship between cannabis consumption and the risk of developing psychosis has long been a topic of debate, even as cannabis continues to gain widespread acceptance and becomes increasingly legalized around the world.
While some research has pointed to connections between cannabis use and psychosis, especially among young people and adolescents, it remains uncertain whether cannabis truly plays a causal role in the onset of psychotic symptoms.
The authors of this new study claim that their findings contradict the epidemiological data, which previously indicated that cannabis use heightened the risk of developing psychotic disorders.
To explore this relationship further, researchers examined the connection between cannabis use and the incidence of psychotic disorders in individuals at clinical high risk of psychosis.
They assessed the current and past cannabis use of over 300 individuals considered to be at high risk, along with 67 healthy participants.
Comprehensive Two Year Study
For two years, all participants were followed from the beginning of the study and assessed using the Global Assessment of Functioning disability scale.
The Comprehensive Assessment of At-Risk Mental States criteria was used to evaluate transitions to psychosis and the persistence of psychotic symptoms.
According to the study, 16.2% of the clinical high-risk sample developed psychosis during the follow-up. Among those who did not become psychotic, 51.4% experienced persistent symptoms, while 48.6% went into remission.
The authors report:
“There was no significant association between any measure of cannabis use at baseline and either transition to psychosis, the persistence of symptoms, or functional outcome. These findings contrast with epidemiological data that suggest that cannabis use increases the risk of psychotic disorder.“
Past research on cannabis and psychosis has considered factors such as THC potency, frequency of use, and the age and genetics of the consumer in relation to the risk of developing psychosis.
Experts generally advise caution with cannabis use for those with a family history of psychosis or a predisposition to developing symptoms.
Despite the lack of definitive evidence, critics have often cited concerns around psychosis risks as an argument against cannabis policy reform, especially in the United Kingdom.
No sign of Psychosis in the US, either
Unsuprisingly, we are not seeing a zombie apocalype of psychotic lunatics in countries where cannabis is legal.
As more locations legalize cannabis for adult use, new studies like this one are shedding light on the subject.
For example, a paper published earlier this year by researchers from the Hospital of the University of Pennsylvania in Philadelphia examined commercial and Medicare Advantage claims data from over 63 million individuals between 2003 to 2017.
They discovered no statistically significant difference in psychosis-related diagnoses or prescribed antipsychotics in states with medical or recreational cannabis policies compared to those where cannabis remains prohibited.
Twins study adds to the facts
There is also a 2021 study that investigated the relationship between adolescent cannabis use and adult-onset psychosis through a longitudinal co-twin control analysis.
They found no dose-response relationship in models that compared twins with varying levels of cannabis use to each other in relation to psychosis-proneness in adulthood.
The researchers reported no discernible differences in the effects of cannabis exposure on the twins’ risk of developing schizophrenia later in life.
This research brings much needed clarity to the ongoing debate around cannabis use and psychosis, clearly demonstrating the fact that the mainstream media have been feeding us utter propaganda for decades.
