ABSTRACT
Depression is a mental or affective disorder， whose occurrence is closely related to the physical， psychological， and social environmental factors. Clinically， patients with depression often present with significant and long-lasting blue mood， impaired thinking and cognitive functions， reduced mobility， and even self-harm and suicide attempts. The pathogenesis of depression is complex and diverse， and there mainly exist the neurotransmitter hypothesis， immunodeficiency hypothesis， hypothalamus-pituitary-adrenal （HPA） axis activation hypothesis， brain-derived neurotrophic factor （BDNF） hypothesis， and intestinal flora hypothesis. In western medicine， it is mostly treated with antidepressant drugs， but the resulting side effects and repeated attack cannot be ignored. Traditional Chinese medicine（TCM） has obvious advantages in dealing with depression. The advocates of treating "Qi"， "phlegm"， "stasis"， and "five zang organs" have all been proved effective. Depression is characterized by a long course of disease and repeated attack， which coincides with the concept of "deficiency" in TCM. Tonifying deficiency is a method for treating depression based on TCM syndrome differentiation. Under the guidance of this principle， the formulated prescriptions will produce the desired effects. This article reviewed the related clinical and experimental studies on depression treatment via deficiency tonification in recent years， and summarized the corresponding prescriptions for benefiting Qi， replenishing blood， nourishing Yin， and tonifying yang， respectively， so as to enrich the TCM theory of depression and provide new ideas for its clinical treatment.