GHSR and major depressive disorder: We selected four brain areas that have been implicated in the pathogenesis of MDD, including the medial prefrontal cortex (mPFC), the nucleus accumbens (NAc), the hippocampus, and the ventral tegmental area (VTA) (Russo et al., 2012; Malhi and Mann, 2018); as well as two other sites that display high GHSR1α expression according to the Allen Brain Atlas1, namely, the Edinger–Westphal nucleus (EW) and the nucleus tractus solitarii (NTS).