CRH and major depressive disorder: On circulating stress hormone levels, the plasma levels of the HPA axis hormones, such as thyroid stimulating hormone (TSH), thyroxine (T4), corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and CORT significantly increased in depression group compared to those in the control group, while the LBRD standard decoction treatment significantly attenuated this increase (Fig. 3K–O, both P < 0.01).