Acupuncture has dose-dependent effects on the symptoms of major depressive disorder (MDD), concludes a systematic review by Chinese authors. Sixty-two studies involving 2269 MDD patients provided data for meta-analysis. The results showed that an increase in the number of acupuncture sessions received was associated with increasing symptom improvement in MDD patients. After eight acupuncture sessions, depression scores decreased from 17.68 to 8.30. After 24 acupuncture sessions, a decrease in depression scores was observed in 51% of cases. After 36 acupuncture sessions, improvement in depression scores peaked, with 66% of cases showing significant improvement.