The etiology and pathogenesis of major depressive disorder are not fully elucidated, and scholars and experts believe that the etiology and pathogenesis of depression are very complex and may be related to biological, psychological and socio-environmental factors. Among them, genetic factors play the most important role in the development of depression, and the risk of depression in first-degree relatives of depressed patients is about 2-10 times higher than that of the general population, with a heritability of 31%-42%. Intergenerational parenting, poor parental relationships, frequent violent events in the family, early parental divorce, death of a parent before adulthood, parental mental illness or serious illness, sexual assault, major changes in life circumstances, and poor interpersonal relationships in the current workplace, financial difficulties, poor health of one’s own, serious illness, loss of love or divorce are all significantly associated with the development of depression.