GRM5 and major depressive disorder: These sex-specific GRM5 findings are consistent with Gray et al. [84] report of extensive sex-dependent differences in glutamate receptor gene expression in post-mortem samples from MDD and control subjects, and higher expression levels of GRIN1, GRIN2A-D, GRIA2-4, GRIK1-2, GRM1, GRM4, GRM5 and GRM7 in female MDD patients; amongst males only GRM5 expression differed and in the opposite direction from females.