Neuroscience Letters 376 (2005) 177–181 A double blind study showing that two weeks of daily repetitive TMS over the left or right temporoparietal cortex reduces symptoms in patients with schizophrenia who are having treatment-refractory auditory hallucinations Seung-Hwan Lee a , Won Kim b , Young-Cho Chung a , Kyung-Hee Jung c , Won-Myong Bahk b , Tae-Yun Jun b , Kwang-Soo Kim b , Mark S. George d , Jeong-Ho Chae b,∗ a Department of Psychiatry, Ilsanpaik Hospital, Inje University of Korea, Koyang, South Korea b Department of Psychiatry, St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Yoido-dong, Youngdeungpo-gu, Seoul, 150-713, South Korea c Department of Psychiatry, Keyo Hospital, Uiwang, South Korea d Department of Psychiatry, Radiology and Neurology, Center for Advanced Imaging Research, Brain Stimulation Laboratory, Medical University of South Carolina, Charleston, USA Received 22 June 2004; received in revised form 16 November 2004; accepted 17 November 2004 Abstract The aim of this study was to evaluate the effect of repetitive transcranial magnetic stimulation (rTMS) on the left and right temporoparietal cortex compared with sham stimulation in schizophrenic patients with treatment-refractory auditory hallucinations (AH). Thirty-nine patients with schizophrenia with treatment-refractory AH were allocated randomly to one of three groups: daily left, right, and sham rTMS groups. rTMS was applied to the TP3 or 4 regions with the aid of the electroencephalography 10–20 international system at 1 Hz for 20 min per day for 10 treatment days. Symptoms were evaluated using the Auditory Hallucination Rating Scale (AHRS), the Positive and Negative Symptoms Scale (PANSS), the Clinical Global Impression—Severity (CGI-S), and Clinical Global Impression—Improvement (CGI-I) scale. For the time effect (within-subject comparison), there were significant changes in the frequency of AHs, positive symptoms of PANSS, and CGI-I. A between-group comparison revealed significant differences in the positive symptoms of PANSS, and CGI-I scores. Post hoc analysis revealed that both the right- and left-side rTMS treatment groups exhibited better CGI-I scores compared to the sham-stimulated group. This study suggests that 10 days of low-frequency rTMS applied daily for 20 min to either temporoparietal cortex significantly reduces the symptoms in patients with schizophrenia who are having refractory AH, but the left sided rTMS is not superior to right or sham rTMS. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Repetitive transcranial magnetic stimulation; Schizophrenia; Auditory hallucination Auditory hallucinations (AH) are a distressing symptom re- ported by 50–80% of patients with schizophrenia [1]. Some researchers have suggested that the hallucinated voice might actually be inner speech that is misperceived as stimulation from the outside [6]. Another hypothesis is that the halluci- nated voice occurs due to a malfunction of the speech percep- ∗ Corresponding author. Tel.: +82 2 37792019; fax: +82 2 7806577. E-mail address: alberto@catholic.ac.kr (J.-H. Chae). tion system. That is, the system itself creates speech percep- tion without any inputs from the outside. The neuroanatom- ical basis of AH is thought to involve increasing blood flow of the speech perception areas of the brain, such as the su- perior temporal cortex of the dominant hemisphere [21]. In addition, several positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) studies have suggested AH involved a distributed extensive bilateral net- work of cortical and subcortical areas [17,18]. 0304-3940/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.neulet.2004.11.048