Ota Miho, Wakabayashi Chisato, Sato Noriko, Hori Hiroaki, Hattori Kotaro, Teraishi Toshiya, Ozawa Hayato, Okubo Tsutomu, Kunugi Hiroshi
1Department of Mental Disorder Research,National Institute of Neuroscience,National Center of Neurology and Psychiatry,Tokyo,Japan.
2Department of Radiology,National Center of Neurology and Psychiatry,Tokyo,Japan.
Acta Neuropsychiatr. 2015 Oct;27(5):291-6. doi: 10.1017/neu.2015.22. Epub 2015 Apr 21.
Glutamatergic dysfunction in the brain has been implicated in the pathophysiology of schizophrenia. Previous studies suggested that L-theanine affects the glutamatergic neurotransmission and ameliorates symptoms in patients with schizophrenia. The aims of the present study were twofold: to examine the possible effects of L-theanine on symptoms in chronic schizophrenia patients and to evaluate the changes in chemical mediators, including glutamate + glutamine (Glx), in the brain by using 1H magnetic resonance spectroscopy (MRS).
The subjects were 17 patients with schizophrenia and 22 age- and sex-matched healthy subjects. L-theanine (250 mg/day) was added to the patients' ongoing antipsychotic treatment for 8 weeks. The outcome measures were the Positive and Negative Syndrome Scale (PANSS), Pittsburgh Sleep Quality Index scores and MRS results.
There were significant improvements in the PANSS positive scale and sleep quality after the L-theanine treatment. As for MRS, we found no significant differences in Glx levels before and after the 8 week L-theanine treatment. However, significant correlations were observed between baseline density of Glx and change in Glx density by l-theanine.
Our results suggest that L-theanine is effective in ameliorating positive symptoms and sleep quality in schizophrenia. The MRS findings suggest that L-theanine stabilises the glutamatergic concentration in the brain, which is a possible mechanism underlying the therapeutic effect.
大脑中的谷氨酸能功能障碍与精神分裂症的病理生理学有关。先前的研究表明，L-茶氨酸会影响谷氨酸能神经传递，并改善精神分裂症患者的症状。本研究的目的有两个：一是研究L-茶氨酸对慢性精神分裂症患者症状的可能影响；二是通过使用氢磁共振波谱（MRS）评估大脑中化学介质（包括谷氨酸+谷氨酰胺（Glx））的变化。
研究对象为17例精神分裂症患者和22例年龄及性别匹配的健康受试者。在患者正在进行的抗精神病治疗基础上添加L-茶氨酸（250毫克/天），持续8周。观察指标为阳性和阴性症状量表（PANSS）、匹兹堡睡眠质量指数得分以及MRS结果。
L-茶氨酸治疗后，PANSS阳性量表得分和睡眠质量有显著改善。至于MRS，我们发现8周L-茶氨酸治疗前后Glx水平无显著差异。然而，观察到Glx的基线密度与L-茶氨酸引起的Glx密度变化之间存在显著相关性。
我们的结果表明，L-茶氨酸对改善精神分裂症的阳性症状和睡眠质量有效。MRS研究结果表明，L-茶氨酸可稳定大脑中的谷氨酸能浓度，这可能是其治疗作用的潜在机制。
