A Double-Blind Sham-Controlled Trial of Repetitive Transcranial Magnetic Stimulation in the Treatment of Refractory Auditory Hallucinations

TLDR

Repetitive transcranial magnetic stimulation targeting the temporoparietal cortex has been suggested to benefit patients with schizophrenia who experience treatment‑resistant auditory hallucinations. This study aimed to evaluate that hypothesis in a randomized double‑blind, sham‑controlled trial. Thirty‑three patients with refractory auditory hallucinations received 15‑minute, 1‑Hz rTMS at 90 % resting motor threshold over ten consecutive weekdays, with clinical and cognitive outcomes assessed. The intervention was safe, produced no cognitive side effects, and did not outperform sham except for a significant reduction in hallucination loudness, leading the authors to conclude that the tested parameters are ineffective but warrant further investigation of alternative protocols.

Abstract

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.