BACKGROUND:
Depression is one of the most common mental health disorders. Acupuncture is a popular complementary and alternative medicine intervention suggested in the treatment of depression, but its effectiveness is uncertain. This updated meta-analysis was conducted to more precisely assess the beneficial effect of acupuncture in depression therapy.

METHODS:
The following databases were searched: MEDLINE, EMBASE, BIOSIS, Cochrane Central Register of Controlled Trials, and Chinese Scientific Journal Database. The following terms were used: acupuncture, acupressure, depression, depressive disorder, clinical trial, and randomized controlled trial.

RESULTS:
Eight small-randomized controlled trials comparing 477 subjects were included in the meta-analysis. Our results confirmed that acupuncture could significantly reduce the severity of depression, which was indicated by decreased scores of Hamilton rating scale for depression (HAMD) or Beck Depression Inventory (BDI). The pooled standardized mean difference of the 'Improvement of depression' was -0.65 (95% CI -1.18, -0.11; P=0.02) by random effect model. However, no significant effect of active acupuncture was found on the response rate (RR 1.32, 95% CI 0.83 to 2.10; P=0.25) and remission rate (RR 1.30, 95% CI 0.57 to 2.95; P=0.53).

CONCLUSION:
Although this meta-analysis might be discounted due to the low quality of individual trials, it supported that acupuncture was an effective treatment that could significantly reduce the severity of disease in the patients with depression. More full-scale randomized clinical trials with reliable designs are recommended to further warrant the effectiveness of acupuncture.