Transcranial Magnetic Stimulation in Schizophrenia

Repetitive transcranial magnetic stimulation (rTMS) has proven useful for the study and treatment of schizophrenic symptoms. This chapter describes the clinical studies with rTMS in schizophrenia identified by Medline search. There is evidence of an effect on positive symptoms of schizophrenia, using low-frequency (1 Hz) stimulation over the left temporoparietal cortex. There is also some evidence regarding beneficial effects on negative symptoms, mostly with high-frequency (8-20 Hz) stimulation over the prefrontal cortex, however including negative results. Overall, an effect of rTMS on positive symptoms of schizophrenia could be found, with promising but conflicting results regarding the effect on negative symptoms. There is also initial evidence of beneficial effects on other treatmentresistant symptoms, such as visual and somatic hallucinations. The results of current studies point to the importance of additional work focusing on frequency, number of stimuli applied and the length of treatment, as well as to the need of maintenance therapy.