The results showed the following: (1) The oxy-Hb activation of the left DLPFC for the groups with depression-high resilience and healthy-low resilience was significantly higher under the positive emotional valence condition than under the negative emotional valence condition, while the oxy-Hb activation in the left DLPFC was not significantly different between the two emotional valence conditions for the groups with depression-low resilience and healthy-high resilience. This evidence concerns the gene GSTM1 and major depressive disorder.