Beneficial Effects of Acupuncture for Depression-A Possible Mediation of Peripheral Sensory Stimulation and Central Oxytocin Release

Abstract

In modern society, depression is one of the most common mental disorders. It is generally thought that depression is due to the disorders of neuronal circuits and chemical balance in the brain. Patients with depression often receive treatment with selective serotonin reuptake inhibitors (SSRIs). However, recent studies suggest that the magnitude of benefit of pharmacological treatment is quite limited for these patients. Although recent studies propose acupuncture as a non-pharmacological approach to managing depression, the mechanism of its beneficial effects is not well understood. Somatosensory pathways stimulated by acupuncture relay to the central nervous system (CNS). In animal studies, acupuncture has demonstrated the potential to ameliorate neural abnormalities associated with depression. As complex daily life stress is highly associated with depression, the procedure that suppresses stress responses would be a good candidate to treat depression. Oxytocin (OXT) is a hormone produced at the hypothalamus and mediates social bonding and stress reduction. OXT inhibits stress-induced corticotropin-releasing factor (CRF) expression at the hypothalamus, resulting in anti-stress and anti-anxiety effects. Research has demonstrated that acupuncture stimulates the release of hypothalamic OXT through somatosensory stimulation. Thus, stress-related mental disorders can be treated, at least in part, by acupuncture. It is proposed that somatosensory stimulations induced by acupuncture are a possible candidate as a non-pharmacological approach for depression.