Efficacy of repetitive transcranial magnetic stimulation (rTMS) on negative symptoms and cognitive functioning in schizophrenia: An umbrella review of systematic reviews and meta-analyses

Negative symptoms and cognitive dysfunction are core characteristics of schizophrenia that profoundly impact daily function and quality of life. As a noninvasive brain stimulation, repetitive transcranial magnetic stimulation (rTMS) has been proposed as a relatively new treatment for ameliorating negative symptoms and cognitive dysfunction in schizophrenia. However, there is controversy over the treatment methods and efficacy. We aimed to provide a quantitative integration of the published evidence regarding the efficacy of rTMS and analyze the feasibility of rTMS for treating negative symptoms and cognitive dysfunction in schizophrenia. A total of twenty reviews were ultimately selected and divided into thirty-three latitudes. Twenty-six analyses showed that rTMS significantly decreased the negative symptom score, and seventeen analyses were performed. Six analyses showed that rTMS treatment can increase working memory scores, and two of them had significant effects. Two analyses from the same review showed that rTMS had a long-term significant effect on treating language function. Only one analysis showed that rTMS had a significant effect on treating executive function. The analyses showed that rTMS had no significant effect on attention function and processing speed. Most reviews indicate that rTMS has an effect on negative symptoms, executive function, working memory, and language function in patients with schizophrenia. Although the quality of evidence was not high, these results are still positive and worthwhile for further study.