Six-month treatment with atypical antipsychotic drugs decreased frontal-lobe levels of glutamate plus glutamine in early-stage first-episode schizophrenia

Abstract

Naoki Goto1, Reiji Yoshimura1, Shingo Kakeda2, Joji Nishimura2, Junji Moriya2, Kenji Hayashi1, Asuka Katsuki1, Hikaru Hori1, Wakako Umene-Nakano1, Atsuko Ikenouchi-Sugita1, Yukunori Korogi2, Jun Nakamura11Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan; 2Department of Radiology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, JapanObjective: To study the effects of treatment with atypical antipsychotic drugs on brain levels of glutamate plus glutamine in early-stage first-episode schizophrenia.Participants: Sixteen patients (eight males, eight females; aged 30 ± 11 years) completed the study.Methods: We used administered 6 months of atypical antipsychotic drugs and used proton magnetic resonance spectroscopy to evaluate the results.Results: We found that the administration of atypical antipsychotic drugs for 6 months decreased the glutamate plus glutamine/creatine ratio in the frontal lobe. These results suggest that the administration of atypical antipsychotic drugs for at least 6 months decreased glutamatergic neurotransmissions in the frontal lobe in early-stage first-episode schizophrenia, but there was no difference in frontal-lobe levels between patients and control subjects before administration.Conclusion: Taking these findings into account, the glutamatergic and GABAergic neurons are implicated in early-stage first-episode schizophrenia, but in complex ways.Keywords: Proton magnetic resonance spectroscopy, creatine, frontal lobe, parieto-occipital node, left basal ganglia