There is increasing interest in the use of cannabis and its major non-intoxicating component cannabidiol (CBD) as a treatment for mental health and neurodevelopmental disorders, such as autism spectrum disorder (ASD). However, before launching large-scale clinical trials, a better understanding of the effects of CBD on brain would be desirable. Preclinical evidence suggests that one aspect of the polypharmacy of CBD is that it modulates brain excitatory glutamate and inhibitory γ-aminobutyric acid (GABA) levels, including in brain regions linked to ASD, such as the basal ganglia (BG) and the dorsomedial prefrontal cortex (DMPFC). However, differences in glutamate and GABA pathways in ASD mean that the response to CBD in people with and without ASD may be not be the same. To test whether CBD 'shifts' glutamate and GABA levels; and to examine potential differences in this response in ASD, we used magnetic resonance spectroscopy (MRS) to measure glutamate (Glx = glutamate + glutamine) and GABA+ (GABA + macromolecules) levels in 34 healthy men (17 neurotypicals, 17 ASD). Data acquisition commenced 2 h (peak plasma levels) after a single oral dose of 600 mg CBD or placebo. Test sessions were at least 13 days apart. Across groups, CBD increased subcortical, but decreased cortical, Glx. Across regions, CBD increased GABA+ in controls, but decreased GABA+ in ASD; the group difference in change in GABA + in the DMPFC was significant. Thus, CBD modulates glutamate-GABA systems, but prefrontal-GABA systems respond differently in ASD. Our results do not speak to the efficacy of CBD. Future studies should examine the effects of chronic administration on brain and behaviour, and whether acute brain changes predict longer-term response.

中文翻译：

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大麻二酚对大脑兴奋和抑制系统的影响；一项在患有和不患有自闭症谱系障碍的成年人中进行磁共振波谱研究的随机安慰剂对照单剂量试验。

人们对使用大麻及其主要无毒成分大麻二酚（CBD）来治疗精神健康和神经发育障碍（例如自闭症谱系障碍（ASD））的兴趣日益浓厚。但是，在开展大规模临床试验之前，需要对CBD对大脑的影响有更好的了解。临床前证据表明，CBD多药房的一个方面是它调节大脑兴奋性谷氨酸和抑制性γ-氨基丁酸（GABA）的水平，包括与ASD相关的大脑区域，如基底神经节（BG）和背阔肌前额叶皮层（DMPFC）。但是，ASD中谷氨酸和GABA途径的差异意味着有和没有ASD的人对CBD的反应可能是不同的。测试CBD是否会“改变”谷氨酸和GABA水平；为了检查在ASD中这种反应的潜在差异，我们使用磁共振波谱（MRS）测量了34位健康男性（17位神经典型患者，17位ASD）中的谷氨酸（Glx =谷氨酸+谷氨酰胺）和GABA +（GABA +大分子）水平。单次口服600 mg CBD或安慰剂后2小时（峰值血浆水平）开始数据采集。测试时间至少相隔13天。在各组中，CBD增加皮层下层，但减少皮层Glx。在整个地区，CBD在对照组中增加了GABA +，但在ASD中降低了GABA +。DMPFC中GABA +变化的组差异显着。因此，CBD调节谷氨酸-GABA系统，但是前额叶-GABA系统在ASD中的反应不同。我们的结果与CBD的功效无关。未来的研究应检查长期服用对大脑和行为的影响，