In addition, activation of neuronal nitric oxide synthases (NOS) raises the concentration of NO, which ultimately leads to the development of depression (Adell, 2020; Kang et al., 2020), while the inhibitory effects of Ber on inducible NOS has been recognized (Zhu et al., 2018; Zhu et al., 2019). This evidence concerns the gene NOS2 and major depressive disorder.