In particular, under regulatory control by miRNA-146a-5p, tropomyosin receptor kinase B (NTRK2), as the preferred receptor of brain-derived neurotrophic factor (BDNF), plays a key role in the neurotrophic hypothesis of depression (Chao, 2003; Lopez et al., 2013). The gene discussed is BDNF; the disease is depressive symptom measurement.