BDNF and depressive disorder: Taking into consideration the observed effectiveness of Formula for Soothing Liver and Tonifying Spleen (Shugan Jianpi formula, SGJP) in the treatment of diabetes-related depression (Wang, 2008; Li, 2017), a recent study by Lei et al. indicated that SGJP improves depressive symptoms in CUMS and STZ-induced rats by upregulating the expression of BDNF mRNA and protein (Lei et al., 2017).