title: GABA concentration in schizophrenia patients and the effects of antipsychotic medication: a proton magnetic resonance spectroscopy study.
abstract: Gamma-amino butyric acid (GABA) is thought to play a role in the pathophysiology of schizophrenia. High magnetic field proton magnetic resonance spectroscopy ((1)H-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+/-0.45 mmol/l in schizophrenia patients and 1.52+/-0.54 mmol/l in control subjects) or the ltBG (1.13+/-0.26 mmol/l in schizophrenia patients and 1.18+/-0.20 mmol/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+/-0.24 mmol/l) than in those taking atypical antipsychotics (1.03+/-0.24 mmol/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 (1)H-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.
authors.affiliation: Department of Psychiatry, Course of Integrated Brain Sciences, Medical Informatics, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan.
authors.forename: Shin'Ya
authors.initials: S
authors.lastname: Tayoshi
authors.forename: Masahito
authors.initials: M
authors.lastname: Nakataki
authors.forename: Satsuki
authors.initials: S
authors.lastname: Sumitani
authors.forename: Kyoko
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Sumiko
authors.initials: S
authors.lastname: Shibuya-Tayoshi
authors.forename: Shusuke
authors.initials: S
authors.lastname: Numata
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Iga
authors.forename: Shu-ichi
authors.initials: S
authors.lastname: Ueno
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ohmori
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D001921:Brain / Q000473:pathology; D002908:Chronic Disease; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D011522:Protons; D012559:Schizophrenia / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D005680:gamma-Aminobutyric Acid / Q000097:blood* / Q000187:drug effects*
chemical_list: D014150:Antipsychotic Agents; D011522:Protons; D005680:gamma-Aminobutyric Acid