The dose-effect association between acupuncture sessions and its effects on major depressive disorder: A meta-regression of randomized controlled trials.

BACKGROUND

The benefits of acupuncture on Major depressive disorder (MDD) have been well established in previous studies. However, uncertainty exists regarding the dose-effect relationship between acupuncture and MDD. This study aims to explore the association between acupuncture and its effects on MDD based on previously published data.

METHODS

Nine databases were searched from inception until 10th September 2021. Randomized controlled trials that compared acupuncture with sham acupuncture, or anti-depressants, were included. The data extraction, and assessing the data quality and risk of bias completed by two researcher, respectively. A non-linear meta-regression approach with restricted cubic spline was used to investigate the dose-effect relationship between acupuncture sessions and their effects on the Hamilton rating scale for depression (HAMD) score.

RESULTS

Of the 20,835 citations screened, 62 studies (2269 patients of MDD) were included. The dose-effect meta-analysis suggested that acupuncture session was associated with a decline in HAMD scores. Overall, an increase in the number of acupuncture sessions received was associated with symptom improvement in MDD patients. After 8 acupuncture sessions, the HAMD score decreased from 17.68 (95% CI: -11.81, -4.80) to 8.30 (95% CI: 14.23-21.13). After 24 acupuncture sessions, a decrease in HAMD scores was observed in 51% of cases (95% CI: 48% to 54%). After 36 acupuncture sessions, the effect of improvement in HAMD scores peaked at 66% of cases (95% CI: 59% to 72%).

CONCLUSIONS

A dose-effect relationship was found between the number of acupuncture sessions and HAMD scores. 36 acupuncture sessions were associated with optimal clinical response.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021290143.