Significant associations between single nucleotide polymorphisms of AVP and OT genes and schizophrenia were detected in the chromosomal region 20p13, specifically in the loci of rs2740204 of the shared promoter of AVP and OT, in rs4813626 of the 5′promoter of OT, and in rs3011589 of the second intron of the AVP promoter [164]. This evidence concerns the gene OXT and schizophrenia.