Background: The use of repetitive transcranial magnetic stimulation (rTMS) remains a promising therapeutic tool in the treatment of schizophrenia. Symptoms such as auditory hallucinations (AH) find contradictory results in many studies. Here we present an up-to-date systematic review and meta-analysis of rTMS in the treatment of AH in schizophrenia.
Methods: We searched Pubmed-MEDLINE from 1999 to 2013 for double-blinded randomized sham-controlled trials that applied slow rTMS on the left temporoparietal cortex and assessed the outcome results using Hallucination Change Scale or Auditory Hallucination Rating Scale or Scale for Auditory Hallucinations (SAH). We identified 10 studies suitable for the meta-analysis.
Results: We found a positive sized effect in favor of rTMS [random-effects model Hedges' g = 0.011, I-squared = 58.1%]. There was some variability between study effect sizes, but the sensitivity analysis concluded that none of them had sufficient weight to singularly alter the results of our meta-analysis.
Discussion: rTMS appears to be an effective treatment for AH. The left temporoparietal cortex seems to be the area in which rTMS is effective. Although meta-analysis is a powerful analytical tool, more studies must be conducted in order to obtain a more expressive sample size to perform a more accurate analytical approach.
Keywords: Transcranial magnetic stimulation; auditory hallucination; rTMS; schizophrenia.