Here we show that miR-223, a miRNA known to be secreted via exosomes [48, 49], is significantly increased in the orbitofrontal cortex (OFC) of subjects with SCZ and in BD patients with psychosis at the time of death, is positively correlated to SERPINA3 expression, and negatively associated with its targets [50] glutamate ionotropic receptor α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type subunit 2 (GRIA2, also known as GLUR2) and glutamate ionotropic receptor NMDA-type subunit 2B (GRIN2B, also known as NR2B). Here, GRIN2B is linked to psychotic disorder.