Therapeutic and neurophysiologic aspects of transcranial magnetic stimulation in schizophrenia

The use of repetitive transcranial magnetic stimulation (rTMS) in psychiatry provides the therapeutic field with a new tool. Since its introduction in the mid 1980s, the vast majority of studies have focussed on depression. A growing body of evidence suggests that rTMS is effective in the treatment of depression if dorsolateral prefrontal cortex is stimulated. Less is known about its efficacy in schizophrenia. Neuroimaging investigations in schizophrenia suggest abnormalities in the prefrontal and temporoparietal cortex (TPC), which are correlated with psychopathological dimensions. Based on its modulatory effect, rTMS seems to be a promising tool in exploring cortical excitability and reducing auditory hallucinations (AH) and negative symptoms. Neurophysiologic studies of patients suffering from schizophrenia using rTMS indicate high cortical excitability and a lack of transcallosal inhibition. In the therapeutic field, researches provide encouraging results, even though some studies indicate limited benefits. The most promising therapeutic effect seems to be the capability of rTMS to reduce AH if TPC is targeted using slow-frequency. The current paper aims to provide a review of the literature of the use of rTMS in schizophrenia.