It has been reported that BDNF, FGF-2 and VEGF, which are neurotrophic factor family members that regulate neural proliferation, neurogenesis, apoptosis, expression level of monoamine transmitters, and the function and plasticity of synapses, are closely associated with chronic stress-induced depression both in young adults and adults49, 50. This evidence concerns the gene BDNF and depressive symptom measurement.