The number of episodes of MDD were negatively associated with the level of BDNF (r = −0.64; p < 0.01), nodal strength of the right amygdala (r = −0.63; p < 0.01) and nodal global efficiency of the right amygdala (r = −0.56; p < 0.01) of rMDD patients. This evidence concerns the gene BDNF and major depressive disorder.