Developmental Psychiatry Section, University of Cambridge, United Kingdom. g
Am J Psychiatry. 2011 Jun;168(6):624-33. doi: 10.1176/appi.ajp.2010.10081184. Epub 2011 Mar 31.
The developmental taxonomic theory proposes that neurodevelopmental factors play a critical role in the etiology of early-onset conduct disorder, whereas adolescent-onset conduct disorder arises as a result of social mimicry of deviant peers. Recent studies have challenged this theory by demonstrating that adolescents with both early- and adolescent-onset forms of conduct disorder show impaired emotional learning and abnormal neural activation during facial expression processing. The present study extends this work by investigating brain structure in both subtypes of conduct disorder.
Voxel-based morphometry was used to compare gray matter volumes in four regions of interest (amygdala, insula, anterior cingulate, and orbitofrontal cortex) in male adolescents with early-onset (N=36) or adolescent-onset (N=27) conduct disorder and in healthy comparison subjects (N=27). Whole-brain structural analyses were also performed.
The combined conduct disorder group displayed gray matter volume reductions in the bilateral amygdala, extending into the insula, relative to healthy comparison subjects. Separate comparisons between healthy subjects and each conduct disorder subgroup revealed lower amygdala volume in both subgroups and reduced right insula volume in the adolescent-onset subgroup. Regression analyses within the conduct disorder subjects alone demonstrated a negative correlation between conduct disorder symptoms and right insula volume.
The results demonstrate that gray matter volume reductions in brain regions involved in processing socioemotional stimuli are associated with conduct disorder, regardless of age of onset. Brain structural abnormalities may contribute to the emergence of adolescent-onset as well as early-onset conduct disorder.
发展分类理论提出，神经发育因素在儿童期品行障碍的病因学中起着关键作用，而青少年期品行障碍则是由于对异常同伴的社会模仿而产生的。最近的研究通过证明在面部表情处理过程中，具有早期和青少年期品行障碍的青少年表现出情绪学习受损和神经激活异常，对这一理论提出了挑战。本研究通过研究品行障碍的两种亚型中的大脑结构，扩展了这一工作。
使用基于体素的形态计量学比较了 36 名有早期起病（早期起病组）和 27 名青少年起病（青少年起病组）的品行障碍男性青少年以及 27 名健康对照者在杏仁核、岛叶、前扣带回和眶额皮质四个感兴趣区的灰质体积。还进行了全脑结构分析。
与健康对照组相比，合并的品行障碍组双侧杏仁核和岛叶灰质体积减少，向内侧延伸。健康对照组与每个品行障碍亚组的单独比较显示，两个亚组的杏仁核体积均较小，青少年起病组的右侧岛叶体积减少。在品行障碍受试者中进行的回归分析表明，品行障碍症状与右侧岛叶体积呈负相关。
研究结果表明，与处理社会情感刺激有关的大脑区域的灰质体积减少与品行障碍有关，而与发病年龄无关。大脑结构异常可能导致青少年期和早期起病的品行障碍的发生。
