Lawrence Natalia S, An Suk Kyoon, Mataix-Cols David, Ruths Florian, Speckens Anne, Phillips Mary L
Division of Psychological Medicine, Section of Neuroscience & Emotion, King's College London, London, United Kingdom.
Biol Psychiatry. 2007 May 1;61(9):1072-80. doi: 10.1016/j.biopsych.2006.06.033. Epub 2006 Nov 9.
Washing symptoms in Obsessive-Compulsive Disorder (OCD) are associated with increased trait sensitivity to disgust. This study explored neural systems underlying sensitivity to symptom-unrelated disgust and fear in OCD using functional neuroimaging.
Seventeen OCD subjects and 19 controls viewed facial expressions of disgust and fear (versus neutral) presented just above the level of conscious awareness in a backward masking paradigm.
The OCD group showed greater activation than controls in the left ventrolateral prefrontal cortex, but reduced activation in the thalamus, to facial expressions of disgust. There were no between-group differences in response to fear. Further analysis using a median-split to divide OCD subjects into high and low washers suggested that the enhanced ventrolateral prefrontal cortex response was being driven by predominantly female OCD subjects with high washing symptoms. These subjects also reported higher levels of trait sensitivity to disgust.
These findings are consistent with previous reports of increased response to symptom-relevant and generally disgusting stimuli in neural regions associated with disgust and autonomic response processing in OCD patients with prominent washing symptoms. Together, these findings point to increased sensitivity to disgust stimuli as a component of the pathophysiology of the washing/contamination symptom dimension of OCD.
强迫症（OCD）中的洗涤症状与对厌恶的特质敏感性增加有关。本研究使用功能性神经影像学探索了强迫症中对与症状无关的厌恶和恐惧的敏感性背后的神经系统。
17名强迫症受试者和19名对照者在反向掩蔽范式中观看了呈现于意识水平之上的厌恶和恐惧（相对于中性）面部表情。
与对照者相比，强迫症组对厌恶面部表情在左侧腹外侧前额叶皮层表现出更强的激活，但在丘脑表现出减弱的激活。对恐惧的反应在组间没有差异。使用中位数分割将强迫症受试者分为高洗涤者和低洗涤者的进一步分析表明，腹外侧前额叶皮层反应增强主要由具有高洗涤症状的女性强迫症受试者驱动。这些受试者还报告了更高水平的对厌恶的特质敏感性。
这些发现与先前的报告一致，即在具有突出洗涤症状的强迫症患者中，与厌恶和自主反应处理相关的神经区域对与症状相关且通常令人厌恶的刺激的反应增加。总之，这些发现表明对厌恶刺激的敏感性增加是强迫症洗涤/污染症状维度病理生理学的一个组成部分。
