Rationale

Aberrations in the stress response are associated with posttraumatic stress disorder (PTSD) symptom development, maintenance, and severity. Gamma-aminobutyric acid (GABA), the brain’s primary inhibitory neurotransmitter, may play a key role in stress recovery.

Objectives

In this preliminary study, we examined whether plasma GABA levels differed between women with PTSD and trauma-exposed healthy controls.

Methods

Thirty participants provided plasma samples during two phases of the menstrual cycle: the early follicular phase and the mid-luteal phase. During each phase, blood was drawn after 45 min of rest, and after mild and moderately stressful psychophysiological tasks. Plasma GABA levels were measured using HPLC-mass spectrometry (LC-MS/MS).

Results

In analyses using PTSD diagnosis as a categorical group variable, women with and without a diagnosis of PTSD did not differ in plasma GABA levels (ps > .18). However, in analyses examining PTSD symptom severity as a continuous variable, there was a trend-level positive association between more severe PTSD symptoms and higher plasma GABA levels across the four blood draws (p = .06). In analyses examining DSM-IV PTSD symptom clusters separately, dysphoria symptoms were positively and significantly associated with plasma GABA levels (p = .03). Similarly, there was a trend-level positive association between avoidance cluster symptoms and plasma GABA levels (p = .06). Plasma GABA levels were not modulated by experimentally induced stress or menstrual cycle phase.

Conclusions

Dysregulation in GABA may be a neurobiological marker and/or potential treatment target for women with PTSD symptom profiles characterized by prominent dysphoria and avoidance cluster symptoms.

中文翻译：

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创伤暴露女性的血浆γ-氨基丁酸 (GABA) 水平和创伤后应激障碍症状：初步报告

基本原理

应激反应的异常与创伤后应激障碍 (PTSD) 症状的发展、维持和严重程度有关。γ-氨基丁酸 (GABA) 是大脑的主要抑制性神经递质，可能在压力恢复中发挥关键作用。

目标

在这项初步研究中，我们检查了患有 PTSD 的女性和暴露于创伤的健康对照组之间的血浆 GABA 水平是否不同。

方法

三十名参与者在月经周期的两个阶段提供了血浆样本：卵泡早期和黄体中期。在每个阶段，在休息 45 分钟后以及轻度和中度紧张的心理生理任务后抽血。使用 HPLC-质谱法 (LC-MS/MS) 测量血浆 GABA 水平。

结果

在使用 PTSD 诊断作为分类组变量的分析中，诊断为 PTSD 和未诊断为 PTSD 的女性在血浆 GABA 水平上没有差异 ( p s > .18)。然而，在将 PTSD 症状严重程度视为连续变量的分析中，在四次抽血中，更严重的 PTSD 症状与更高的血浆 GABA 水平之间存在趋势水平正相关 ( p = .06)。在分别检查 DSM-IV PTSD 症状群的分析中，烦躁症状与血浆 GABA 水平呈正相关且显着相关 ( p = .03)。同样，回避集群症状与血浆 GABA 水平之间存在趋势水平正相关（p=.06）。血浆 GABA 水平不受实验诱导的压力或月经周期阶段的调节。

结论

GABA 的失调可能是神经生物学标志物和/或潜在的治疗目标，适用于具有以显着的烦躁不安和回避集群症状为特征的 PTSD 症状特征的女性。