Compared to the HCs, the MD group presented lower Oxy-Hb activation in the right DLPFC (channel 41; P = 0.048) and the left DLPFC (channels 18, 39, and 45; P < 0.05), and the MDD group presented lower Oxy-Hb activation in the right DLPFC (channels 27, 33, and 41; P < 0.05) and the left DLPFC (channels 39 and 45; P < 0.05). Conclusion. Here, GSTM1 is linked to major depressive disorder.