GRIA1 and major depressive disorder: Considering the crucial role of increased GluR1 phosphorylation in the process of membrane insertion of these subunits and in the consequent increased activity of these AMPA receptors [17], and also considering known alterations of protein kinase systems (including PKA) in mood disorders [18], I hypothesize that altered platelet GluR1 phosphorylation in MDD may contribute to comorbid MDD and CVD.