ABSTRACT
Major depressive disorder (MDD) is a main type of mood disorder, characterized by significant and lasting depressed mood. Until now, the pathogenesis of MDD is not clear, but it is certain that biological, psychological, and social factors are involved. Childhood trauma is considered to be an important factor in the development of this disease. Previous studies have found that nearly half of the patients with MDD have experienced childhood trauma, and different types of childhood trauma, gender, and age show different effects on this disease. In addition, the clinical characteristics of MDD patients with childhood trauma are also different, which often have more severe depressive symptoms, higher risk of suicide, and more severe cognitive impairment. The response to antidepressants is also worse. In terms of biological mechanisms and marker characteristics, the serotonin transporter gene and the FKBP prolyl isomerase 5 have been shown to play an important role in MDD and childhood trauma. Moreover, some brain imaging and biomarkers showed specific features, such as changes in gray matter in the dorsal lateral prefrontal cortex, and abnormal changes in hypothalamic-pituitary-adrenal axis function.