GSTM1 and major depressive disorder: Therefore, in this study, the difference in oxy-Hb activation in the left DLPFC between the groups with depression-low resilience and depression-high resilience under the two emotional valence conditions indicated that depressed patients with low resilience may have a more severe depression subtype than those with high resilience, and the processing of positive emotional valence is affected by insufficient oxy-Hb activation in the left DLPFC due to deepening of depression for the group with depression-low resilience.