AKT1 and psychotic disorder: Three case control studies (Van Winkel et al. 2011; Di Forti et al. 2012; Morgan et al. 2016) demonstrated that, depending on frequency of cannabis use, users with the AKT1 C/C genotype had between a two-fold (history of use) and seven-fold (daily use) increased risk in the development of psychosis compared to T/T carriers (Morgan et al. 2016; Radhakrishnan et al. 2014; Van Winkel et al. 2011; Di Forti et al. 2012).