Background and Hypothesis Impaired insight into the illness and its consequences is associated with poor outcomes in schizophrenia. While transcranial direct current stimulation (tDCS) may represent a potentially effective treatment strategy to relieve various symptoms of schizophrenia, its impact on insight remains unclear. To investigate whether tDCS would modulate insight in patients with schizophrenia, we undertook a meta-analysis based on results from previous RCTs that investigated the clinical efficacy of tDCS. We hypothesize that repeated sessions of tDCS will be associated with insight improvement among patients. Study Design PubMed and ScienceDirect databases were systematically searched to identify RCTs that delivered at least 10 tDCS sessions in patients with schizophrenia. The primary outcome was the change in insight score, assessed by the Positive and Negative Syndrome Scale (PANSS) item G12 following active tDCS sessions as opposed to sham stimulation. Effect sizes were calculated for all studies and pooled using a random-effects model. Meta-regression and subgroup analyses were conducted. Study Results Thirteen studies (587 patients with schizophrenia) were included. A significant pooled effect size (g) of −0.46 (95% CI [−0.78; −0.14]) in favor of active tDCS was observed. Age and G12 score at baseline were identified as significant moderators, while change in total PANSS score was not significant. Conclusions Ten sessions of active tDCS with either frontotemporoparietal or bifrontal montage may improve insight into the illness in patients with schizophrenia. The effect of this treatment could contribute to the beneficial outcomes observed in patients following stimulation.

中文翻译：

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经颅直流电刺激改善精神分裂症患者视力的功效：随机对照试验的系统回顾和荟萃分析

背景和假设 对疾病及其后果的了解受损与精神分裂症的不良预后相关。虽然经颅直流电刺激（tDCS）可能是缓解精神分裂症各种症状的一种潜在有效的治疗策略，但其对洞察力的影响仍不清楚。为了研究 tDCS 是否会调节精神分裂症患者的自知力，我们根据之前研究 tDCS 临床疗效的随机对照试验的结果进行了荟萃分析。我们假设重复进行 tDCS 治疗与患者洞察力的提高有关。研究设计 对 PubMed 和 ScienceDirect 数据库进行了系统搜索，以确定对精神分裂症患者进行至少 10 次 tDCS 治疗的随机对照试验。主要结果是洞察力分数的变化，与假刺激相比，在主动 tDCS 治疗后通过阳性和阴性症状量表 (PANSS) G12 项目进行评估。计算所有研究的效应大小，并使用随机效应模型进行汇总。进行了荟萃回归和亚组分析。研究结果 纳入 13 项研究（587 名精神分裂症患者）。观察到有利于主动 tDCS 的显着合并效应大小 (g) 为 -0.46 (95% CI [-0.78; -0.14])。基线时的年龄和 G12 分数被认为是重要的调节因素，而 PANSS 总分数的变化并不显着。结论 十次主动 tDCS 结合额颞顶或双额蒙太奇可以提高对精神分裂症患者疾病的洞察力。