Is acupuncture beneficial in depression: A meta-analysis of 8 randomized controlled trials?

Abstract

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.

Introduction

Depressive disorders are one of the more common psychiatric disorders in adults (Prince et al., 2007). Symptoms associated with depression generally include fatigue, depressed mood and a decrease of interest in people or activities. Other symptoms may include sleep difficulties, anxiety, irritability, poor concentration and poor appetite. The most common conventional treatments for depression, such as antidepressant medication and psychotherapy, are well researched and known to be efficacious. However, their effectiveness is always reduced by lack of effect in some individuals, intolerable adverse effects, and high rates of dropout. This reality drives patients and also researchers to search for other modalities of treatment in an attempt to further improve outcomes (Pilkington et al., 2006).

In recent years, acupuncture, which was long used for emotional, psychological and spiritual disorders including anxiety, stress, insomnia and depression in China, Japan and Korea, has become a subject of major interest and one of the most popular complementary therapies in the West. On human body, there are more than 2000 acupuncture points connecting with 12 main and 8 secondary pathways called meridians, which conduct energy - qi - between the surface of the body and the internal organs. Qi regulates spiritual, emotional, and physical balance. The opposing forces of yin and yang influence qi. According to traditional Chinese medicine, when yin and yang are balanced, they work together with the natural flow of qi to help the body achieve and maintain health. Acupuncture is believed to balance yin and yang, keep the normal flow of energy unblocked, and restore health to the body and mind. Present interpretation of the treatment effect of acupuncture on depression is that acupuncture stimulates afferent Group III nerve fibers that transmit impulses to various parts of the central nervous system and induce the release of serotonin, norepinephrine, substance P, dopamine, b-endorphin, enkephalin, and dynorphins, primarily in the hypothalamus. This suggests a direct influence on the pathogenic mechanisms of depression (Ulett et al., 1998, Colbert, 2000, Zhang et al., 2006, Shi et al., 2006, Siedentopf et al., 2005). Otherwise, building evidence implicates a role for the plasticity of specific neuro-circuitry in both the pathophysiology and treatment of depression. Electro-acupuncture could reverse the decreased level of cyclic AMP responsive element binding protein (CREB), a molecule playing an important role in neuronal plasticity, in cortex, hippocampus and hypothalamus regions in rat depression model, which may contribute to the treatment effect of acupuncture (Husseini et al., 2001, Nair and Vaidya, 2006, Lu et al., 2006).

Compared to conventional treatment, several potential advantages are associated with acupuncture, such as its low cost, relatively few complications, and possibility of a personalized treatment. Complications of acupuncture can arise from inadequate sterilization of needles and improper delivery of treatments, which cause infections and punctured organs, and can be avoided and rectified easily by using it properly. Thus, researchers started to design and conduct randomized controlled trials to assess the efficacy of acupuncture in depression from 1990s. Although several randomized clinical trials have reported a benefit from acupuncture in the treatment of depression, generally results appear contradictory, suggesting both beneficial and detrimental effects. For example, the first randomized controlled trial, which recruited a small sample of woman with major depression, has reported that after 8-week treatment there was a significant difference in symptom reduction between acupuncture (Mean = − 11.7, SD = 7.3) and placebo groups (Mean = − 2.9, SD = 7.9) on HAMDs, indicating a beneficial effect of acupuncture on symptom relief in depression (Allen et al., 1998). However, in a larger scale clinical trial published in 2006, the same authors failed to support the efficacy of acupuncture as a monotherapy for major depression. Compared with the waitlist group, greater decreases in severity were exhibited by both acupuncture (z = 3.5, P < 0.001) and sham acupuncture (z = 4.3, P < 0.001) groups, but the two groups did not differ in the rate of change from one another (z = 1.1, P > 0.2) (Allen et al., 2006).

Thus, with the aim of detecting moderate treatment effects, which are unlikely to be reliably detected in small studies, and objectively assessing the sources of the conflicting results achieved in different trials, we conducted this updated meta-analysis with the results from all relevant randomized clinical trials that had compared acupuncture with sham acupuncture in depression patients.