Reduced Freezing in Posttraumatic Stress Disorder Patients while Watching Affective Pictures.
Reduced Freezing in Posttraumatic Stress Disorder Patients while Watching Affective Pictures.
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DOI：
10.3389/fpsyt.2017.00039
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发表时间：
2017
影响因子：
4.7
通讯作者：
Hagenaars MA
中科院分区：
文献类型：
--
作者：
Fragkaki I;Roelofs K;Stins J;Jongedijk RA;Hagenaars MA
除了战斗和逃跑反应外，动物和人类对威胁的反应可能是冻结，这种反应的特征是心动过缓和身体不能动。建议在冻结过程中加强风险评估，以促进最优决策。事实上，健康的参与者对威胁线索表现出类似于冻结的反应。创伤后应激障碍（PTSD）患者的特点是高度警惕和增加的威胁反应。我们认为，威胁反应的特征在于PTSD患者的冻结度降低，消除了拒绝认知扭曲（如伤害预期）的可能性，从而有助于疾病的维持。然而，冻结反应在创伤后应激障碍中的研究很少。使用一个稳定测量平台来评估身体摇摆作为冻结行为的一个指标，我们检查了患有创伤后应激障碍的退伍军人是否会对不愉快的照片和中性和愉快的照片表现出减少的冻结反应。14名PTSD患者和14名健康对照者观看这些图片，同时持续评估身体摇摆和心率（HR）。与之前的研究结果一样，健康对照组在看到令人不快的图片时，身体摆动和心率都有所下降，这表明他们有类似于冻结的行为。相反，在PTSD患者中没有观察到这种反应模式。结果可能表明创伤后应激障碍患者的冻结反应减少。由于减少冻结可能妨碍适当的风险评估，这可能是维持创伤后应激障碍的一个重要因素。未来的研究可能会澄清，冷冻功能受损是一种ptsd特异性症状，还是一种跨诊断症状，存在于威胁相关疾病中。
Besides fight and flight responses, animals and humans may respond to threat with freezing, a response characterized by bradycardia and physical immobility. Risk assessment is proposed to be enhanced during freezing to promote optimal decision making. Indeed, healthy participants showed freezing-like responses to threat cues. Posttraumatic stress disorder (PTSD) patients are characterized by hypervigilance and increased threat responsiveness. We propose that threat responses will be characterized by decreased freezing in PTSD, eliminating possibilities for rejecting cognitive distortions, such as harm expectancy, and thereby contributing to the maintenance of the disorder. However, freezing responses have hardly been investigated in PTSD. Using a stabilometric platform to assess body sway as an indicator of freezing-like behavior, we examined whether veterans with PTSD would show diminished freezing responses to unpleasant versus neutral and pleasant pictures. Fourteen PTSD patients and 14 healthy matched controls watched the pictures, while body sway and heart rate (HR) were continuously assessed. Replicating previous findings, healthy controls showed decreased body sway and HR in response to unpleasant pictures, indicative of freezing-like behavior. In contrast, this response pattern was not observed in PTSD patients. The results may indicate a reduced freezing response in PTSD. As reduced freezing may hinder appropriate risk assessment, it may be an important factor in the maintenance of PTSD. Future research might clarify whether impaired freezing is a PTSD-specific or a transdiagnostic symptom, being present in threat-related disorders.