Association between posttraumatic stress disorder severity and amygdala habituation to fearful stimuli
Association between posttraumatic stress disorder severity and amygdala habituation to fearful stimuli
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DOI：
10.1002/da.22928
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发表时间：
2019-07-01
影响因子：
7.4
通讯作者：
Stevens, Jennifer S.
中科院分区：
文献类型：
--
作者：
Kim, Ye Ji;van Rooij, Sanne J. H.;Stevens, Jennifer S.
杏仁核对威胁的过度反应被认为是创伤后应激障碍（PTSD）的一个原因。然而，在健康样本中出现的文献表明，与对威胁的反应性相比，杏仁核习惯化（对重复刺激的反应随时间的变化）的重测可靠性更高。尽管杏仁核习惯化在PTSD的病因学中起着关键作用，但它与PTSD的关系却很少受到关注。因此，我们在大量创伤暴露的非裔美国妇女中调查了对重复恐惧面孔刺激的习惯和创伤后应激障碍。方法从一家非营利性医院招募非裔美国妇女（N = 100），该医院主要服务于创伤暴露高风险的低收入人群。参与者接受了功能性磁共振成像，被动地观看恐惧和中性的面部刺激，并报告了他们的创伤暴露史和当前的创伤后应激障碍症状。我们检查了PTSD症状严重程度与杏仁核反应性（恐惧b>中性）和对恐惧面孔的习惯化（早期b>晚期）之间的关系。二级分析测试了杏仁核对恐惧面孔的习惯化是否介导了童年创伤和创伤后应激障碍之间的联系。结果PTSD症状严重程度和PTSD状态（基于自我报告测量）均与杏仁核对重复恐惧面孔刺激的习惯化呈正相关。全脑分析表明，这种关联扩展到双侧海马和左侧梭状回。在控制创伤史和抑郁症状时，这种联系仍然成立。杏仁核对恐惧面孔的习惯部分介导了童年创伤严重程度与PTSD症状严重程度之间的关联。结论PTSD症状严重程度越高的个体，其杏仁核对社会威胁线索（恐惧面孔）的适应程度越高，这可能部分解释了童年创伤暴露与当前PTSD症状之间的关系。进一步研究杏仁核对威胁线索的反应动力学可能会在理解和治疗压力相关疾病方面产生新的见解。
Background Amygdala hyperreactivity to threat has been proposed to be a causal contributor to posttraumatic stress disorder (PTSD). However, emerging literature in healthy samples shows higher test-retest reliability for amygdala habituation (the change over time in response to repeated stimuli) than for its reactivity to threat. Amygdala habituation has received relatively little attention in relationship to PTSD, despite the key role of this region in the etiology of the disorder. Thus, we investigated habituation to repeated fearful face stimuli and PTSD, in a large sample of trauma exposed African American women. Methods African American women (N = 100) were recruited from a nonprofit hospital serving a largely low-income population with a high risk of trauma exposure. Participants underwent functional magnetic resonance imaging, passively viewing fearful and neutral face stimuli, and reported their history of trauma exposure and current PTSD symptoms. We examined associations between PTSD symptom severity and amygdala reactivity (fearful > neutral) and habituation (early > late) to fearful faces. Secondary analyses tested whether amygdala habituation to fearful faces mediated the association between childhood trauma and PTSD. Results PTSD symptom severity and PTSD status (based on self-report measure) were both positively associated with amygdala habituation to repeated fearful face stimuli. Whole-brain analysis showed that this association extended to the bilateral hippocampus and left fusiform gyrus. The association held when controlling for trauma history and depressive symptoms. Amygdala habituation to fearful faces partially mediated the association between childhood trauma severity and PTSD symptom severity. Conclusion Individuals with greater PTSD symptom severity showed greater amygdala habituation to social threat cues (fearful faces), and greater habituation may partly explain the association between childhood trauma exposure and current PTSD symptoms. Further examination of the dynamics of the amygdala response to threat cues may lead to new insights in the understanding and treatment of stress-related disorders.