Although numerous studies have shown expression level changes and genetic association between other PSD genes and schizophrenia [42]–[48], our study failed to detect association between DLG1, PICK1 and MDM2, and schizophrenia in Japanese cohorts, which is in line with reports for DLG1[49] and PICK1[50]. This evidence concerns the gene DLG1 and schizophrenia.