As to how BDNF correlates with depression, currently it is widely accepted that changes in BDNF expression reverses or exacerbates depression-associated dysfunction in neurogenesis, neuro-survival, and synaptic plasticity, since BDNF promotes the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses (Dean and Keshavan, 2017). The gene discussed is BDNF; the disease is depressive symptom measurement.