BDNF and depressive disorder: Consistent with previous studies, where BDNF gene expression levels are markedly downregulated in the hippocampus and medial prefrontal cortex of individuals with depression [35], and VEGF is similarly reduced in the hippocampus of animals exposed to depressive‐like conditions [26], our results demonstrated that CUMS significantly decreased BDNF and VEGF expression in the hippocampus.