Relationship between the Polymorphism of the AKT1 Gene and the Consumption of Cannabis in the Appearance of Psychosis

Introduction: Psychotic disorders are a mental illness that affect 3% of the world’s population. The external (cannabis) and internal vulnerability factors (polymorphisms of the AKT1 gene, the COMT gene and the DAT1 gene) acquire special relevance in the appearance of psychosis; this is known as the vulnerability–stress model. Objective: To analyze the scientific evidence that reflects the relationship between the polymorphism of the AKT1 gene and the consumption of cannabis in the appearance of psychosis. Material and Methods: The bibliographic search was made using databases such as Scopus, WoS, Cochrane Library, TRIP Database, PubPsych and PubMed. The criteria of the “MeSH” terminology and the inclusion and exclusion criteria were followed, obtaining a total of 22 articles that comprises this narrative review. Results: The presence of genetic variation in the locus rs2494732 of the AKT1 gene in a cannabis user raises the risk of the appearance of psychosis, especially if homozygous with the C allele. Likewise, consumption entails a slowdown in the functionality of the AKT1 gene, releasing a greater amount of dopamine in the striatum through the involvement of indirect mechanisms. Similarly, the COMT gene and the interaction of the AKT1 gene with the DAT1 gene raise the risk of developing psychotic disorder. Conclusion: The genetic polymorphism rs2494732 of AKT1 is the main factor responsible for the appearance of psychosis, although polymorphisms of the COMT and DAT1 gene are also implicated. Regarding the AKT1 gene, subjects with two copies of the C allele have a higher risk of developing psychosis compared to subjects with two copies of the T allele. It should also be noted that the muscarinic receptors rs115455482 and rx74722579 are related to a greater vulnerability to psychosis and the development of psychotic disorders.