A new study has found no significant association between cannabis use and the development of psychotic disorders. Published in the journal Psychiatry and Clinical Neurosciences, the research was conducted by a team of investigators from Australia, Europe, and the United Kingdom.
The study looked at the association between cannabis use and the incidence of psychotic disorders in clinically at-risk subjects. The researchers assessed 334 individuals with a high risk of psychosis and 67 healthy control subjects at baseline, and then followed up on them for a period of two years using a modified version of the Cannabis Experience Questionnaire.
The results showed that there was no significant association between any measure of cannabis use at baseline and either transition to psychosis, the persistence of symptoms, or functional outcomes.
The authors of the study concluded that their primary hypothesis was that cannabis use in clinically high-risk subjects would be associated with an increased rate of later transition to psychosis. However, they found no significant association with any measure of cannabis use.
“There was no significant association between any measure of cannabis use at baseline and either transition to psychosis, the persistence of symptoms, or functional outcomes,” researchers said.
These findings contradict previous epidemiological data linking cannabis use to an increased risk of developing psychosis. Although the use of cannabis and other controlled substances tends to be more common among those with psychotic illnesses, studies indicate that lifetime incidences of acute marijuana-induced psychosis are relatively rare among the general population.
The study’s findings suggest that a history of cannabis use is not associated with an increased risk of developing psychosis, even among those predisposed to the disorder. This could have significant implications for policymakers and healthcare professionals who have traditionally linked cannabis use to the development of psychotic disorders.
The study’s authors note that further research is needed to understand the complex relationship between cannabis use and mental health outcomes. However, their study provides an important contribution to the ongoing debate about the potential harms and benefits of cannabis use.
A 2022 study, published in the Canadian Journal of Psychiatry, analysed emergency room data relating to cannabis-induced psychosis and also found that the “implementation of Canada’s cannabis legalization framework was not associated with evidence of significant changes in cannabis-induced psychosis or schizophrenia ED presentations.”