DRD2 and psychotic disorder: Genetic factors may explain the differences in individual sensitivity to the psychosis-inducing effects of cannabis.1,2 In view of the converging data from candidate gene and genome-wide association studies that the D2-AKT1 signaling pathway is relevant for the pathophysiology and outcome of schizophrenia,3 and on the basis of previous association between cannabis-related psychosis and both DRD2 (rs1076560)1 and AKT1 (rs2494732),2 we hypothesized that these polymorphisms interact in increasing the risk of psychosis in cannabis users.