Depression belongs to TCM “depression syndromes” category.The disease begins in the liver, and is related to brain.Based on the basic pathogenesis of depression in “qi stagnation due to depression of liver” and the key pathogenesis of brain absentia, this article proposed the pathogenesis theory of “brain depression” of depression from the theory of “liver and brain correlation”.Through the systematic study of the characteristics of TCM and TCM prescriptions for the treatment of primary depression, diabetes complicated with depression, ...