DRD2 and psychotic disorder: On the contrary, among those who had never used cannabis, carrying ‘risk’ allele(s) from only one (OR=0.29; 95% confidence interval: 0.09, 0.88) or both the genes (OR=0.14; 95% confidence interval: 0.03, 0.63) was associated with lower odds of suffering a psychotic disorder compared with the DRD2 GG/AKT1 TT genotype (Figure 1a).