Gene-environment interplay between cannabis and psychosis.
Schizophrenia bulletin November 1, 2008 Cécile Henquet, Marta Di Forti, Paul Morrison et al.
Cannabis use is considered a contributory cause of schizophrenia and psychotic illness, but only a small proportion of users develop psychosis. The amount, duration, and strength of cannabis consumption, as well as age at first exposure, partly explain this. Genetic factors likely play a role in both short- and long-term effects on psychosis. This review discusses studies using genetic, epidemiological, experimental, and observational techniques to investigate gene-environment correlation and interaction within the cannabis-psychosis association. Evidence suggests that mechanisms of gene-environment interaction underlie the link, with multiple genetic variations and other environmental factors (e.g., stress) interacting with cannabis to increase psychosis risk. Further research on higher-order interactions is needed.