Gene-environment interaction between an endocannabinoid system genetic polymorphism and cannabis use in first episode of psychosis.
European Neuropsychopharmacology June 1, 2019 M. Bioque, S. Mas, M. Costanzo et al.
A specific genetic variation in the endocannabinoid system interacts with cannabis use to sharply increase the risk of a first episode of psychosis. Carrying two copies of the T allele of the FAAH rs2295633 gene variant, combined with cannabis use, made the probability of a first psychotic episode ten times higher compared to cannabis users without that genotype. No such increased risk appeared in non-users. The study also found that carriers of this genotype who used cannabis were more often treated with high-potency antipsychotics. The findings are preliminary and need replication.