These findings did not provide evidence of a possible role of COMT Val<sup>158</sup>Met, AKT1 rs2494732 or DRD2 rs1076560 genotypes in modifying the association between childhood adversity and onset of psychosis.
While rs2494732 was associated with the presence of psychosis (group-2, 3 and 4), rs2498804 was associated with affective symptoms (groups-1, 2 and 3).
Our findings provide strong support for the initial report that genetic variation at rs2494732 of AKT1 influences the risk of developing a psychotic disorder in cannabis users.
Follow-up analysis supported AKT1 rs2494732 × cannabis interaction in the case-only (β = 0.20; P = .007), case-sibling (interaction P = .040), and case-control (interaction P = .057) analyses, with individuals with C/C genotypes having an approximately 2-fold odds of being diagnosed with a psychotic disorder when having used cannabis.
Cannabis use preceding onset of psychotic disorder did interact significantly with AKT1 rs2494732 genotype to affect CPT reaction time (β=8.0, SE 3.9, p=0.037) and CPT accuracy (β=-1.2, SE 0.4, p=0.003).