GAD1 and schizophrenia: In the prefrontal cortex of schizophrenia, many studies have documented a reduction in GAD67 mRNA (Akbarian et al., 1995; Guidotti et al., 2000; Volk et al., 2000; Hashimoto et al., 2003, 2008b,a; Veldic et al., 2005; Ruzicka et al., 2007; Tsubomoto et al., 2019) or protein levels (Guidotti et al., 2000; Curley et al., 2011, 2013; Fish et al., 2021).