For each study, the major depressive disorder associated with early adversity, the differential levels of the tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), and the structural and physiological plasticity neurons in the prefrontal cortices, amygdala, and hippocampus will be collected. The gene discussed is IL6; the disease is major depressive disorder.