Transcranial magnetic stimulation in the treatment of schizophrenic symptoms: a double blind sham controlled study

Schizophrenia is a disabling disease with a significant proportion of patients experiencing persistent symptoms. Repetitive transcranial magnetic stimulation (rTMS) is a promising new therapeutic tool that could benefit to schizophrenic patients. In this study we sought to assess the efficacy of active rTMS compared to sham stimulation in the treatment of patients with schizophrenia.

Eighteen schizophrenic patients according to DSM-IV criteria were randomly allocated to receive active or sham rTMS for 10 days over the left temporoparietal cortex (80% of the motor threshold, 1Hz, five trains of 1 min). Psychopathological dimensions were measured with the positive and negative syndrome scale and clinical global impression at baseline and after 10 session of rTMS.

All patients were improved at the end of the trial but no significant group differences were found. Patients receiving sham stimulation showed the same pattern of improvement compared to active condition on all the subscales of the positive and negative syndrome scale and clinical global impression scores (p>0.05).

In our study, active rTMS failed to show superiority over sham stimulation in the treatment of schizophrenic symptoms. Although previous results have shown that rTMS reduces auditory hallucination, its efficacy on other positive schizophrenic symptoms is not yet established. Nevertheless, the results of our study, even though negative, provide further insights in the pathophysiology of schizophrenia.