Based on the discussion of nutrient qi

defensive qi and mentality in Inner Canon of Yellow Emperor（ 黄帝内经）

the authors put forward the"nutrient qi and defensive qi mental model"hypothesis

with the core of nutrient qi and defensive qi movement

involving Zang-fu viscera

blood

vessels and nine orifices

to explain mentality.The authors think that mentality emerges under the government of heart and is from Zang-fu viscera Qi transformation.Nutrient qi and defensive qi feed five-Zang viscera and support Zang-fu viscera Qi transformation

which is the energy source of mentality. Nutrient qi and defensive qi circles all over the body

communicating Zang-fu viscera

blood

vessels and nine orifices

transmitting spiritual mechanism

coordinating Zang-fu viscera restriction and generation

which is the regulating mechanism of mentality. The authors think that "defensive qi depression and spiritual mechanism inhibition"is the basic pathogenesis of depressive disorder. Defensive qi depression might cause Qi movement changes

such as Zang-fu viscera Qi transformation dysfunction

imbalance of nutrient qi and defensive qi

blood and vessels damage

as well as blockage of nine orifices.