It is very important that hyperactivity of hypothalamic-pituitary-adrenocortical (HPA) axis is one of the pathophysiological mechanism of depression.Previous studies have festimated that plasma level of corticotropin-releasinghormone(CRH)

adrenocorticotropichormone(ACTH)

glucocorticoid (GC) have increased significantly

meanwhile the sustained increasing level of GC has reduced the number of the hippocampus in the glucocorticoid receptor (GR)

and mineralocorticoid receptor (MR)/GR ratio became imbalance

therefore destroying the hippocampal neurons.The hippocampus itself could mediate the activities of HPA axis

the destruction of hippocampal neurons has become so weaker to mediate the HPA axis;while the increasing level of GC

so that the number and function of GR have reduced

GC negative feedback inhibition to HPA axis has decreased to make it function more hyperactivity.