Departments of Psychiatry, State University of New York Upstate Medical University, Syracuse, New York, USA.
Depress Anxiety. 2012 Mar;29(3):202-9. doi: 10.1002/da.20901. Epub 2011 Oct 12.
Generalized anxiety disorder (GAD) is a common chronic condition that is relatively understudied compared to other psychiatric syndromes. Neuroimaging studies have begun to implicate particular neural structures and circuitry in its pathophysiology; however, no genetically informative research has examined the potential sources of reported brain differences.
We acquired spectroscopic, volumetric, and diffusion tensor magnetic resonance imaging data from a pilot study of 34 female subjects selected from monozygotic twin pairs based upon their affection status for GAD, and examined brain regions previously implicated in fear and anxiety for their relationship with affection status and genetic risk.
Lifetime GAD associated with increased creatine levels in the amygdala, smaller left hippocampal volume, and lower fractional anisotropy in the uncinate fasciculus which connects amygdala and frontal cortex. In addition, GAD genetic risk predicted increases in myo-inositol in the amygdala and, possibly, glutamate/glutamine/GABA alterations in the hippocampus. The association of lifetime GAD with smaller hippocampal volume was independent of major depression and might represent a common genetic risk marker for internalizing disorders.
These preliminary data suggest that GAD and its genetic risk factors are likely correlated with volumetric and spectroscopic changes in fear-related limbic structures and their connections with the frontal cortex.
广泛性焦虑障碍（GAD）是一种常见的慢性疾病，与其他精神综合征相比，其研究相对较少。神经影像学研究已经开始暗示其病理生理学中的特定神经结构和回路；然而，没有基于遗传信息的研究检查过报告的大脑差异的潜在来源。
我们从基于 GAD 情感状态选择的单卵双胞胎女性被试的一项先导研究中获取了光谱学、容积和弥散张量磁共振成像数据，并检查了先前与恐惧和焦虑相关的脑区，以研究它们与情感状态和遗传风险的关系。
终生 GAD 与杏仁核中肌酸水平升高、左海马体积减小和连接杏仁核和前额叶皮质的钩束各向异性分数降低有关。此外，GAD 遗传风险预测杏仁核中肌醇增加，可能预示着海马中谷氨酸/谷氨酰胺/γ-氨基丁酸的改变。终生 GAD 与海马体积减小有关，可能与内化障碍的共同遗传风险标志物有关。
这些初步数据表明，GAD 及其遗传风险因素可能与与恐惧相关的边缘结构及其与前额叶皮质的连接的体积和光谱变化有关。
