The chronic stress to the genetically susceptible subjects leads to the deficits of monoamine, brain-derived neurotrophic factor and hypothalamus-pituitary-adrenal pathway [1–6], which induce neuronal atrophy in brain reward circuits, such as prefrontal cortex and nucleus accumbens, in depression patients and depression-like animals [7–13]. Here, BDNF is linked to depressive disorder.