GABA concentration in schizophrenia patients and the effects of antipsychotic medication: A proton magnetic resonance spectroscopy study

Tayoshi, Shin'Ya; Nakataki, Masahito; Sumitani, Satsuki; Taniguchi, Kyoko; Shibuya-Tayoshi, Sumiko; Numata, Shusuke; Iga, Jun-ichi; Ueno, Shu-ichi; Harada, Masafumi; Ohmori, Tetsuro

doi:10.1016/j.schres.2009.11.011

« Previous Next »Schizophrenia Research
Volume 117, Issue 1 , Pages 83-91, March 2010

GABA concentration in schizophrenia patients and the effects of antipsychotic medication: A proton magnetic resonance spectroscopy study

Shin'Ya Tayoshi
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
Masahito Nakataki
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
- Corresponding author. Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-8-15 Kuramoto-cho Tokushima 770-8503, Japan. Tel.: +81 88 633 7130; fax: +81 88 633 7131.
Satsuki Sumitani
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
Kyoko Taniguchi
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
Sumiko Shibuya-Tayoshi
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
Shusuke Numata
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
Jun-ichi Iga
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
Shu-ichi Ueno
- Department of Neuropsychiatry, Neuroscience, Ehime University Graduate School of Medicine, Japan
Masafumi Harada
- Department of Radiology, Major in Radiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
Tetsuro Ohmori
- Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan

Received 17 November 2008; received in revised form 18 November 2009; accepted 21 November 2009. published online 21 December 2009.

Abstract

Gamma-amino butyric acid (GABA) is thought to play a role in the pathophysiology of schizophrenia. High magnetic field proton magnetic resonance spectroscopy (¹H-MRS) provides a reliable measurement of GABA in specific regions of the brain. This study measured GABA concentration in the anterior cingulate cortex (ACC) and in the left basal ganglia (ltBG) in 38 patients with chronic schizophrenia and 29 healthy control subjects.

There was no significant difference in GABA concentration between the schizophrenia patients and the healthy controls in either the ACC (1.36±0.45mmol/l in schizophrenia patients and 1.52±0.54mmol/l in control subjects) or the ltBG (1.13±0.26mmol/l in schizophrenia patients and 1.18±0.20mmol/l in control subjects). Among the right handed schizophrenia patients, the GABA concentration in the ltBG was significantly higher in patients taking typical antipsychotics (1.25±0.24mmol/l) than in those taking atypical antipsychotics (1.03±0.24mmol/l, p=0.026). In the ACC, the GABA concentration was negatively correlated with the dose of the antipsychotics (rs=−0.347, p=0.035). In the ltBG, the GABA concentration was positively correlated with the dose of the anticholinergics (rs=0.403, p=0.015).

To the best of our knowledge, this is the first study to have directly measured GABA concentrations in schizophrenia patients using ¹H-MRS. Our results suggest that there are no differences in GABA concentrations in the ACC or the ltBG of schizophrenia patients compared to healthy controls. Antipsychotic medication may cause changes in GABA concentration, and atypical and typical antipsychotics may have differing effects. It is possible that medication effects conceal inherent differences in GABA concentrations between schizophrenia patients and healthy controls.

Keywords: Schizophrenia, GABA, Magnetic resonance spectroscopy (MRS), Atypical antipsychotics, Typical antipsychotics