In addition to increasing evidence to show that BDNF is one of the representative molecules for depression, we previously demonstrated that 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF; Figure 1), a citrus polymethoxyflavone, has the potential to accelerate the synthesis of BDNF in the hippocampus following ischemia [8,9]. This evidence concerns the gene BDNF and depressive disorder.