GSTM1 and major depressive disorder: ROI‐wise FC analysis revealed that with increasing depression scores, z‐transformed functional connectivity (zFC) value between the Hb and the nucleus accumbens (NAc), ventral pallidum (VeP), amygdala, globus pallidus internus (GPi), and substantia nigra (SN) shifted from positive to negative, indicating a transition from functional connectivity coupling to anti‐coupling.