Tasios K, Michopoulos I
2nd Department of Psychiatry, School of Medicine, National and Kapodistrian University of Athens, "Attikon" Hospital, Athens, Greece.
Psychiatriki. 2017 Jul-Sep;28(3):242-250. doi: 10.22365/jpsych.2017.283.242.
Body dysmorphic disorder (BDD) is characterized by a preoccupation with a perceived defect or flaw in physical appearance that is not observable or appears slight to others. It leads to severe distress and functional impairment. Cognitive-behavioural and neurobiological similarities to obsessive compulsive disorder (OCD) have led to its newly conceived classification as an obsessive compulsive related disorder (OCRD). In the process of investigating the neurobiology of BDD, neuroimaging and neuropsychological studies have been conducted. This review presents the most recent research findings and their connection with BDD clinical features. Imaging studies have shown increased total white matter volume and caudate volume asymmetry in BDD patients. These findings are consistent with the striatal topography model of OCRDs. Other studies have showed perfusion deficits in bilateral anterior-medial temporal and occipital regions and asymmetric perfusion in parietal lobes. In addition, correlation between symptom severity and left inferior frontal gyrus volume reflects the degree of detailed, analytic encoding that occurs on day-to-day basis when viewing others and themselves, and that likely underlies their symptoms. Finally, positive correlation between right amygdala volume and symptom severity signifies pathological fear circuitry engagement, hypervigilance and heightened sensitivity to social situations. Neuropsychological studies of BDD reveal deficits in strategic organization, learning and free recall after short and long delays. Executive function deficits are related to spatial working memory and subsequent thinking speed as well as impaired higher level planning ability. BDD patients' organizational strategies tend to focus on detail rather than on larger, global clustering features. They are characterized by abnormal visual processing of both details and global elements, inaccurate processing of global elements and reduced flexibility in switching visual attention between global and local features. Moreover, BDD patients seem to have deficits in identifying facial emotional expressions and they tend to misinterpret expressions of disgust (and others) as anger. Poor insight and ideas of reference, common in BDD, might be related to emotion recognition biases for angry expressions. These findings have been supplemented by combined neuroimaging and neuropsychological studies. Left hemisphere hyperactivity for low and normal spatial frequency face tasks and abnormal activation of the amygdala for high and low spatial frequency face tasks suggests detail encoding and analysis in BDD. Patients may primarily perceive details but they are impaired in their ability to contextualize them holistically.
躯体变形障碍（BDD）的特征是过度关注自身外貌中存在的、他人无法观察到或认为微不足道的缺陷或瑕疵。这会导致严重的痛苦和功能损害。由于与强迫症（OCD）在认知行为和神经生物学方面存在相似性，它最近被重新归类为一种强迫相关障碍（OCRD）。在对BDD神经生物学的研究过程中，已经开展了神经影像学和神经心理学研究。本综述介绍了最新的研究发现及其与BDD临床特征的联系。影像学研究显示，BDD患者的白质总体积增加，尾状核体积不对称。这些发现与OCRD的纹状体拓扑模型一致。其他研究表明，双侧前内侧颞叶和枕叶区域存在灌注不足，顶叶存在不对称灌注。此外，症状严重程度与左下额叶回体积之间的相关性反映了在日常观察他人和自己时发生的详细分析编码程度，这可能是其症状的基础。最后，右侧杏仁核体积与症状严重程度之间的正相关表明存在病理性恐惧回路参与、过度警觉以及对社交情境的高度敏感。BDD的神经心理学研究揭示了在短期和长期延迟后的策略组织、学习和自由回忆方面存在缺陷。执行功能缺陷与空间工作记忆、随后的思维速度以及受损的高级规划能力有关。BDD患者的组织策略往往侧重于细节，而不是更大的全局聚类特征。他们的特点是对细节和全局元素的视觉处理异常、对全局元素的处理不准确以及在全局和局部特征之间切换视觉注意力时灵活性降低。此外，BDD患者在识别面部情绪表达方面似乎存在缺陷，他们倾向于将厌恶（及其他）表情误解为愤怒。BDD中常见的洞察力差和牵连观念可能与对愤怒表情的情绪识别偏差有关。这些发现得到了神经影像学和神经心理学联合研究的补充。在低空间频率和正常空间频率面部任务中左半球活动亢进，在高空间频率和低空间频率面部任务中杏仁核激活异常，表明BDD中存在细节编码和分析。患者可能主要感知细节，但他们在整体情境化方面存在能力缺陷。
