We compared the differences in RMT among the three groups and explored the relationships between RMT, cortical activation (reflected by prefrontal oxyhemoglobin level changes during the verbal fluency task via fNIRS), and depression severity (assessed by HAMD scores).<h4>Results</h4>The results demonstrated that the adolescents group had a significantly higher RMT than the other age groups (58.00 ± 11.14, <i>P</i> < 0.001), accompanied by the lowest prefrontal Oxy-Hb activation level (0.095 ± 0.06, <i>P</i> < 0.001). This evidence concerns the gene GSTM1 and major depressive disorder.