GAD1 and schizophrenia: Schizophrenia, a neuropsychiatric disorder, also has abnormalities in the GABAergic system where the ratios of three genes related to GABA signaling are increased: GAD1 (GAD67 and GAD25), SLC12A2 (NKCC1), and SLC12A5 (KCC2) in the prefrontal cortex [19,20].