Dissociative symptoms, such as depersonalization and derealization, are experienced by about half of individuals with posttraumatic stress disorder (PTSD). Theoretical models propose that acute dissociation is accompanied by specific behavioral, physiological, and experiential alterations and contributes to unfavorable PTSD symptom course. Yet, empirical evidence is scarce. Here, we explored associations between dissociative and behavioral, physiological, and experiential threat responses as well as effects of dissociative responding on PTSD symptom course. Individuals with PTSD (N = 71) participated in a preregistered script-driven imagery study including exposure to standardized, detail-enriched trauma, and neutral scripts. Stabilometry, eye-tracking, facial electromyography, autonomic psychophysiology, and self-report data were collected. Moreover, PTSD symptoms were assessed before and 3 months after testing. Analyses did not link acute dissociation to bodily and facial immobility or staring in response to trauma scripts. However, dissociation displayed an inverted U-shaped relationship with heart rate and was linked to higher nonspecific skin conductance fluctuation and higher high-frequency heart rate variability in response to trauma scripts. Moreover, acute dissociation was linked to higher self-reported negative affect responses to trauma scripts and displayed a U-shaped relationship with unfavorable PTSD symptom course. While results did not confirm hypothesized behavioral markers of dissociation, they do support defense-cascade model assumptions of an inverted U-shaped relationship between dissociation and psychophysiological arousal resulting from a progression of parasympathetic versus sympathetic dominance with increasing dissociation. On an experiential level, results did not confirm posttraumatic dissociation-induced emotional numbing, questioning theoretical notions. The observed nonlinear associations may help explain the heterogeneity of prior findings and might inform an updated conceptualization of posttraumatic dissociation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

中文翻译：

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急性解离作为防御级联的一部分：与创伤后应激障碍中的行为、自主和经验威胁反应的关联。


大约一半的创伤后应激障碍 (PTSD) 患者会经历解离症状，例如人格解体和现实解体。理论模型提出，急性分离伴随着特定的行为、生理和经验改变，并导致不利的 PTSD 症状过程。然而，经验证据却很少。在这里，我们探讨了解离反应与行为、生理和体验威胁反应之间的关联，以及解离反应对 PTSD 症状过程的影响。患有创伤后应激障碍 (PTSD) 的个体 (N = 71) 参加了一项预先注册的脚本驱动的意象研究，包括接触标准化、细节丰富的创伤和中性脚本。收集稳定性测量、眼动追踪、面部肌电图、自主心理生理学和自我报告数据。此外，在测试前和测试后 3 个月对 PTSD 症状进行评估。分析并未将急性分离与身体和面部不动或对创伤脚本的反应联系起来。然而，解离与心率呈倒 U 形关系，并与响应创伤脚本时较高的非特异性皮肤电导波动和较高的高频心率变异性相关。此外，急性解离与自我报告的对创伤脚本的负面情绪反应较高有关，并与不利的 PTSD 症状过程呈 U 形关系。虽然结果没有证实假设的解离行为标记，但它们确实支持防御级联模型的假设，即解离和心理生理唤醒之间存在倒U形关系，这是由于随着解离的增加，副交感神经与交感神经的优势逐渐增强所致。 在经验层面上，结果并没有证实创伤后分离引起的情绪麻木，对理论概念提出了质疑。观察到的非线性关联可能有助于解释先前发现的异质性，并可能为创伤后解离的最新概念提供信息。 （PsycInfo 数据库记录 (c) 2023 APA，保留所有权利）。