Background: Previous research suggests that repetitive transcranial magnetic stimulation (rTMS) applied to the temporoparietal cortex may have therapeutic benefits for patients with schizophrenia and treatment-resistant auditory hallucinations. We aimed to test this hypothesis in a randomized double-blind trial.
Methods: Thirty-three patients with treatment-resistant auditory hallucinations entered a randomized sham-controlled, double-blind trial. rTMS was applied for 10 consecutive weekdays, for 15 minutes at 1 Hz and 90% of the resting motor threshold. We assessed clinical symptoms and cognitive function.
Results: rTMS was safe with no adverse effects on memory and cognitive parameters assessed. Active treatment did not result in a greater therapeutic effect than sham on any measure except for the loudness of hallucinations where there was a significant reduction in the active versus the sham group over time.
Conclusions: The study does not support the effectiveness of rTMS using the stimulation parameters provided. However, it does suggest that rTMS methods may have a therapeutic role and indicates the need for further exploration of alternative and more effective stimulation methods.