Efficacy and Safety of Auricular Acupuncture for Depression: A Randomized Clinical Trial

Depression is a leading cause of disability worldwide, and there is increasing interest in nonpharmacological treatments. Auricular acupuncture (AA) is a simple, low-cost, and well-tolerated option, but further studies are needed to establish its efficacy and safety.

To estimate the efficacy and safety of auricular acupuncture as a treatment for depression.

This randomized clinical trial was conducted at 4 university research centers in Brazil, from March to July 2023. Eligible patients were adults aged 18 to 50 years whose score on the Patient Health Questionnaire-9 (PHQ-9) indicated moderate depression (score 10-14) or moderately severe depression (score 15-19). Exclusion criteria included previous application of AA, risk of suicidal ideation, or severe depression (PHQ-9 score >20). An intent-to-treat analysis and modified intent-to-treat analysis were conducted.

Participants were randomized into 2 treatment groups, which included specific AA (SA) and nonspecific AA (NSA). Both groups received 12 sessions of AA with semipermanent needles with daily stimulation twice a week over 6 weeks and were followed-up for 3 months. All participants continued with their usual care for ethical reasons. The SA group's treatment protocol consisted of 6 acupuncture points on the auricular pavilion chosen according to the diagnosis of depression by traditional Chinese medicine (Shenmen, subcortex, heart, lung, liver, and kidney). The NSA group's acupuncture points were the external ear, the cheek and face area, and 4 nonspecific points in the helix region unassociated with mental health symptoms. A locator device was used to confirm which areas had neuroreactive points.

The primary outcome was a reduction of at least 50% in the PHQ-9 score (ie, depression recovery) at 3 months. Secondary outcomes included depression recovery at 4 and 6 weeks; depression remission (PHQ-9 score < 5) at 4 weeks, 6 weeks, and 3 months); and adverse events.

A total of 304 participants were screened, and 74 participants (62 women [84%]; median [IQR] age, 29 [23-27] years) were included in the intention-to-treat analysis, with 37 participants randomized to each group (SA and NSA). A total of 47 participants (64%) were followed-up through 3 months. The results showed no statistically significant difference in depressive recovery between the groups at 3 months (14 of 24 participants in the SA group [58%] vs 10 of 23 participants in the NSA group [43%]; risk ratio [RR], 1.34; 95% CI, 0.76-2.45; P = .38). The proportions of depression recovery and remission at 4 and 6 weeks based on the PHQ-9 were higher in the SA group (except for depression recovery at 6 weeks) with no statistically significant differences. However, a statistically significant difference was observed in symptom remission at 3 months (11 of 24 participants in the SA group [46%] vs 3 of 23 participants in the NSA group [13%]; RR, 1.99; 95% CI, 1.16-3.34; P = .02) in favor of SA. There were no significant differences in adverse event rates between the groups, evidencing the intervention's safety. Most participants reported mild pain at the needle application site (33 patients [94%] in the SA group vs 32 patients [91%] in the NSA group). Five participants dropped out of the study due to adverse events.

The results of this randomized clinical trial suggest that SA over 6 weeks is safe. Although there was no statistically significant difference between groups for the primary efficacy outcome, patients receiving SA did experience greater symptom remission at 3 months. A larger sample size and longer intervention are needed to further evaluate the efficacy of SA for depression.

ClinicalTrials.gov Identifier: NCT05855421.