Invasive acupuncture and transcutaneous scalp-auricular electrical acupoint stimulation (TECAS) for depressive disorder : randomized controlled trials

Abstract

Depression is a psychiatric illness that has been growing since the outbreak of COVID-19. However, its current primary treatment, antidepressants, is far from satisfactory. Many studies have been seeking a novel and safe treatment for treating major depressive disorder (MDD). Acupuncture is a traditional Chinese medical technique and has been reported to be a safe treatment for depression. However, reviews have not yet reached a consensus on its clinical efficacy. Its fundamental mechanisms are not thus far explained. Preliminary studies on transcutaneous electrical acupoints stimulation have been reported to produce an effect similar to traditional invasive acupuncture and can improve depressive symptoms.

Hence, our objective is to 1) understand the mechanisms of acupuncture and its effect on neuroregulation and 2) to improve its current applications on depression. We applied a non-invasive device to study the changes in brain connectivity in MDD patients after receiving acupuncture treatments. Later on, we proposed a novel, safe and self-administrable treatment for MDD. This treatment stimulates certain acupoints and the auricular branch of the vagus nerve, namely transcutaneous electrical cranial-auricular acupoint stimulation (TECAS).

In our first study, 70 patients were recruited (treatment (n=50), control (n=20)). The treatment group received conjunct acupuncture treatment to their regular antidepressant treatment for 3 weeks, while the control was a waiting-list group and was on their regular antidepressant treatment. 30 minutes of acupuncture was administrated twice a week for 3 consecutive weeks. In each group, 20 participants’ resting-state functional connectivity was measured. The primary outcome was the changes in HAMD-17 scores from baseline. Secondary outcomes included the changes in PHQ-9 scores, hemodynamic changes, and rsFC in the DLPFC.

PHQ-9 and HAMD-17 scores in the treatment group were significantly reduced when compared to the control group and baseline (P = 0.01) with an effect size of 0.4 and 0.61, respectively. Bilateral DLPFC rsFC in the Treatment group also showed a significant temporal correlation (p<0.05) compared to the control group. Therefore, we suggest that acupuncture combined with antidepressants may significantly improve depressive symptoms compared to using antidepressants as a monotherapy. In our second study, 70 patients were recruited (antidepressant control (n=35); TECAS treatment (n=35)). Both groups received 8 weeks of treatments. Patients in the TECAS group were required to apply the device twice a day, 30 minutes for each session; while the patients in the antidepressant group were prescribed with 10-20mg Escitalopram q.d. The primary outcome was the MADRS total score change from baseline. Secondary outcomes included the total score change of the HAMD-17, HAM-A, PSQI, SF-36, and SERS.

Both groups had significant score reductions in all assessments 8 weeks after treatment. No significant differences (p>0.05) were observed between the groups. No serious adverse events were observed during the study. This suggests that TECAS is as effective as antidepressants in reducing depression and anxiety symptoms in mild to moderate MDD patients. To conclude, adjunct acupuncture with antidepressants can improve depressive symptoms and TECAS may be a potential alternative to self-administrative antidepression treatment for mild-to-moderate patients in the future.