BDNF and schizophrenia: They found significant evidence for a gene x environment interaction in V-akt murine thymoma viral oncogene homolog 1 (AKT1), brain-derived neurotrophic factor (BDNF), dystrobrevin binding protein 1 (DTNBP1), and glutamate receptor metabotrophic (GRM) genes in developing schizophrenia.