School of Biomedical and Health Sciences, Universidad Europea de Madrid, Madrid, Spain.
Eur Psychiatry. 2012 Apr;27(3):147-55. doi: 10.1016/j.eurpsy.2011.07.006. Epub 2011 Dec 1.
To determine the efficacy of vagus nerve stimulation (VNS) for treatment of depression.
We conducted a systematic review and meta-analysis of analytical studies. Efficacy was evaluated according to severity of illness and percentage of responders.
We identified 687 references. Of these, 14 met the selection criteria and were included in the review. The meta-analysis of efficacy for uncontrolled studies showed a significant reduction in scores at the Hamilton Depression Rating Scale endpoint, and the percentage of responders was 31.8% ([23.2% to 41.8%], P<0.001). However, the randomised control trial which covered a sample of 235 patients with depression, reported no statistically significant differences between the active intervention and placebo groups (OR=1.61 [95%CI 0.72 to 3.62]; P=0.25). To study the cause of this heterogeneity, a meta-regression was performed. The adjusted coefficient of determination (R2(Adj)) was 0.84, which implies that an 84% variation in effect size across the studies was explained by baseline severity of depression (P<0.0001).
Currently, insufficient data are available to describe VNS as effective in the treatment of depression. In addition, it cannot be ruled out that the positive results observed in the uncontrolled studies might have been mainly due to a placebo effect.
确定迷走神经刺激（VNS）治疗抑郁症的疗效。
我们对分析性研究进行了系统评价和荟萃分析。根据疾病严重程度和应答者百分比评估疗效。
我们共检索到 687 篇参考文献，其中 14 篇符合入选标准并纳入综述。对未进行对照研究的荟萃分析显示，在汉密尔顿抑郁评定量表终点评分方面有显著降低，应答者百分比为 31.8%（[23.2%至 41.8%]，P<0.001）。然而，一项纳入 235 例抑郁症患者的随机对照试验报告称，活性干预与安慰剂组之间无统计学差异（OR=1.61 [95%CI 0.72 至 3.62]；P=0.25）。为研究这种异质性的原因，进行了荟萃回归分析。调整后的决定系数（R2(Adj)）为 0.84，这意味着研究间效应大小的 84%变化可由基线抑郁严重程度解释（P<0.0001）。
目前，尚无足够数据描述 VNS 治疗抑郁症的有效性。此外，不能排除未进行对照研究中观察到的阳性结果主要归因于安慰剂效应。
