Genetic correlation of cannabis use and personality traits
Introduction: Cannabis is the most widely illegal recreational drug consumed in the world. Cannabinoids are active ingredients of Cannabis sativa and C. indica plants and their synthetic derivatives. They induce many central and peripheral biochemical changes. After their long-term use, tolerance and psychological dependence develops, whose neural mechanisms are not yet definitively determined. There is evidence of genetic predisposition for addiction. Genes related to receptors and CNS neurotransmitters are most often typed, the greatest attention should be paid to dopamine. In this study, two SNPs of the dopamine receptor 2 gene were selected, combined with personality traits and the ADHD testing patients. The correlation that shows the combination of psychological characteristics and genetic variants can bring us closer to the overall picture of the issue of marijuana addiction.
Material and Methods: The study group consisted of 214 cannabinoid users and 301 controls. For statistical analysis, the following tests were used to show the differences between cannabis users and the control group: Chi square for nonparametric features such as genotypes and alleles of DRD2 Tag1B rs1079597 and DRD2 Tag1D rs1800498 polymorphism; T -Student's test for parametric characteristics (sten scale) of personality traits, and multivariate ANOVA analysis to show the relationship of personality traits with the use of cannabis and the DRD2 Tag1B rs1079597 and DRD2 Tag1D rs1800498 polymorphisms.
Results: For the studied traits which are a description of personality traits in the sten scale such as STAI state, STAI trait, NEO FFI: Neuroticism, Openness, and obtained results of the ADHD in people using cannabis, the values were significantly higher than in the control group. On the other hand, lower sten values were recorded in people using cannabis compared to the control group for NEO FFI: Extraversion, Agreeability and Conscientiousness. In the STAI trait subscale, a 2% association with the polymorphism DRD2 Tag1B rs1079597 was detected in subjects using cannabis. However, for the DRD2 Tag1D rs1800498, there was no effect on the differences in personality traits between cannabis users and the control group.
This research was funded by the National Science Centre, Poland. Grant number UMO-2015/19/B/NZ7/03691