Novel neurotherapeutics in psychiatry: use and rationale of transcranial direct current stimulation in major depressive disorder

Background : Transcranial direct current stimulation (tDCS) is a novel non-pharmacological intervention being investigated for the treatment of major depressive disorder (MDD). Objective : To perform an updated review of tDCS for MDD. Method : Systematic review in Medline/PubMed and other databases of all clinical studies evaluating the clinical efficacy of tDCS in MDD, from the first date available to December/2013. Results : Out of 55 articles, 24 were included, being 6 open-label studies; 8 randomized, double-blind, sham-controlled trials; 2 follow-up studies; 2 meta-analyses and 6 case reports. We observed an improvement of 20-40% in depressive symptoms, being slightly better in open studies. Five randomized clinical trials displayed positive results. The meta-analyses presented mixed results; although none included the study of Brunoni et al. (2013) that represents almost 50% of the evaluated sample. Open-label studies and case reports also investigated tDCS in bipolar depression, post-stroke depression and employed different parameters of stimulation. Discussion : TDCS is a novel, promising treatment for MDD. Definite evidence from large, ongoing clinical trials will be available in the next years.

研究背景：经颅直流电刺激（Transcranial direct current stimulation, tDCS）是一种新兴的非药物干预手段，目前正被研究用于治疗重度抑郁症（major depressive disorder, MDD）。
研究目的：针对经颅直流电刺激（tDCS）治疗重度抑郁症（MDD）开展更新版系统综述。
研究方法：本系统综述检索了Medline/PubMed及其他数据库中，自建库至2013年12月期间所有评估经颅直流电刺激（tDCS）治疗重度抑郁症（MDD）临床疗效的临床研究。
研究结果：初检共获取55篇文献，最终纳入24篇，其中包括6项开放标签研究、8项随机双盲假对照试验、2项随访研究、2项荟萃分析以及6篇病例报告。研究观察到抑郁症状改善幅度达20%~40%，开放标签研究的疗效略佳。其中5项随机对照临床试验呈现出积极的干预效果。相关荟萃分析结果存在分歧，且所有纳入的荟萃分析均未纳入Brunoni等人2013年的研究——该研究的受试样本量占本次综述评估总样本的近50%。此外，开放标签研究与病例报告还探讨了经颅直流电刺激（tDCS）在双相抑郁、卒中后抑郁中的应用，并采用了不同的刺激参数。
讨论：经颅直流电刺激（tDCS）是一种针对重度抑郁症（MDD）的新型且极具应用前景的治疗手段。未来几年内，大型正在开展的临床试验将提供确凿的循证证据。