RESUMO
Several trials have shown preliminary evidence for the efficacy of transcranial magnetic stimulation (TMS) as a treatment for negative symptoms in schizophrenia. Here, we synthesize this literature in a systematic review and quantitative meta-analysis of double-blind randomized controlled trials of TMS in patients with schizophrenia. Specifically, MEDLINE, EMBASE, Web of Science, and PsycINFO were searched for sham-controlled, randomized trials of TMS among patients with schizophrenia. The effect of TMS vs. sham on negative symptoms in each study was quantified by the standardized mean difference (SMD, Cohen's d) with 95% confidence intervals (95%CI) and pooled across studies using an inverse variance random effects model. We identified 57 studies with a total of 2633 participants that were included in the meta-analysis. The pooled analysis showed statistically significant superiority of TMS (SMD = 0.41, 95%CI: 0.26; 0.56, p-value < 0.001), corresponding to a number needed to treat of 5. Furthermore, stratified analyses suggested that TMS targeting the left dorsolateral prefrontal cortex and using a stimulation frequency >1 Hz was most efficacious. There was, however, substantial heterogeneity and high risk of bias among the included studies. In conclusion, TMS appears to be an efficacious treatment option for patients with schizophrenia suffering from negative symptoms, but the optimal TMS parameters are yet to be established.
RESUMO
BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) has established efficacy in the treatment of unipolar depression and a growing evidence base in the treatment of bipolar depression. The objective of this study was to provide an estimate of the efficacy of rTMS in bipolar depression as an up to date synthesis of this literature is lacking. METHODS: We conducted a systematic review of the sham-controlled randomized controlled trial (RCT) literature examining rTMS in bipolar depression. Studies were included if they included participants with bipolar depression in both sham- and active arms. The primary outcome parameter was rate of clinical response, defined as a 50% reduction as compared to baseline, on an established depression rating scale. Quantitative synthesis was performed using the Maentel-Haenszel random-effects model. RESULTS: Data from a total of 274 patients from 14 studies were retained in the quantitative synthesis. The response rates were higher in rTMS compared to sham treatment (odds ratio (OR)â¯=â¯2.72. 95%CI: 1.44-5.14). When stimulation protocols were analysed separately, statistically significant clinical response was only observed for high-frequency rTMS over the left dorsolateral prefrontal cortex (ORâ¯=â¯2.57, 95%CI: 1.17-5.66). LIMITATIONS: Most data was extracted from trials including very few participants with bipolar depression (predominantly unipolar depression samples). Large confirmatory RCTs of rTMS specifically for bipolar depression are lacking. CONCLUSION: rTMS seems effective in the treatment of bipolar depression, but dedicated and adequately powered RCTs are needed in order to firmly conclude that rTMS should be offered routinely for the treatment of bipolar depression.