Cannabis as a precursor of psychosis and its relationship with schizophrenia

Cannabis consumption is a modifiable risk factor for psychosis in vulnerable individuals, particularly those who start using before age 15 and continue frequently. However, cannabis consumers overall are not more prone to develop psychosis than non-consumers. The review concludes that cannabis acts as a componential cause for psychotic events within the schizophrenia spectrum.

Study at a glance

Abstract

Introduction: schizophrenia is a chronic mental disease affecting around 24 million people worldwide. Within this disease, it is common to find the consumption of psychoactive substances by patients, with cannabis ranking first on the list; this drug bears a particular relation to schizophrenia through the effects of the cannabinoids proper to that plant. Objective: determine the relationship between the consumption of cannabis and schizophrenia. Methodology: a narrative bibliographic review was performed to find information using databases such as Scopus and PubMed with descriptors MESH/DECS via keywords, taking into account articles from 2009 to 2023, in English and Spanish and with criteria of inclusion and exclusion of the articles to be analyzed. Results: it was assessed that cannabis consumption could trigger a psychotic episode in vulnerable individuals; the transition to psychosis was found to occur among those who started to consume cannabis before being 15 years old and continued consuming it frequently. Cannabis consumers were not more prone to develop psychosis than those who had never consumed cannabis. Conclusions: cannabis consumption is one of the most important modifiable risk factors in the development of psychosis since it works as a componential cause for the outcome of a psychotic event framed within the spectrum of schizophrenia