Cannabis Use and Risk of Schizophrenia: A Literature Review

Abstract

Background and Objective: Cannabis remains the most widely used illicit drug worldwide. The similarity in the chemical structure of tetrahydrocannabinol to the brain chemical anandamide allows the body to recognize it and alter normal brain functioning. The objective of this review article is to summarize the evidence for the association between cannabis and schizophrenia. Methods: A literature search was conducted using the PubMed database and other sources. The keywords used were “cannabis” and “psychosis” and “schizophrenia.” Fifty-two articles relevant to our topic have been selected for this review. Results: Evidence from observational epidemiological studies has shown a positive association between regular cannabis use and schizophrenia risk. Meta-analyses and Mendelian randomization studies support the evidence from observational study designs. Discussion and Conclusions: The association between cannabis and schizophrenia is biologically plausible. Moreover, there has been emerging evidence of genes interacting with cannabis use to confer a higher risk for schizophrenia. There are enough reason and sufficient epidemiological evidence to warn people about the risk of developing schizophrenia with cannabis use. Scientific Significance: The increasing legalization of cannabis for recreational use is of significant concern. Long-term cannabis use might predispose people to increased risk of developing schizophrenia. Health professionals have a major role to play by taking maximum advantage of social and psychological interventions to educate people about the potential danger associated with cannabis and avoid its use.