In this first phase of the project, the objective was to investigate the distribution of four candidate genetic polymorphisms for functional psychosis (Ser9Gly DRD3, 5HTTLPR, the VNTR 3'-UTR SLC6A3 and Val66Met BDNF) in a case-control sample.
Val158Met (rs4680, COMT), Taq IA (rs1800497, DRD2) and Ser9Gly (rs6280; DRD3) polymorphisms were analyzed in a sample of 84 adolescent Caucasian patients with first-episode psychosis (ages 11-17) and 85 healthy Caucasian controls (ages 10-17).
Genetic polymorphisms of D2-like dopamine receptor genes, DRD2 TaqI A, DRD3 Ser-9-Gly, and DRD4 exon III variable number of tandem repeats, were compared between: (a) MAMP users as a whole and 435 normal controls, and (b) those 154 individuals with MAMP-induced psychosis and the 252 MAMP users with no psychosis.