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

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 Nakamura<sup>1

1</sup>Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan; ²Department of Radiology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan

Objective: 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

A Letter to the Editor has been received and published for this article.