ESR2 and major depressive disorder: Moreover, Iqbal et al. [31] reported in a review that ERα and β were involved in negative emotional memories; ERα, ERβ, and GPER via inflammation and oxidative pathways in bipolar patients; ERα, ERβ, BDNF, and TRkB pathways in major depression; and ERα, ERβ, GPER, and the GPER- and MAPK signaling pathways in anxiety disorders (generalized anxiety and post-traumatic stress disorder) [31,39].