Department of Psychology, University of Southampton, Southampton, UK.
School of Psychology and Birmingham University Imaging Centre, University of Birmingham, Birmingham, UK.
Psychol Med. 2020 Jan;50(1):58-67. doi: 10.1017/S0033291718003951. Epub 2019 Jan 30.
Previous studies of conduct disorder (CD) have reported structural and functional alterations in the limbic system. However, the white matter tracts that connect limbic regions have not been comprehensively studied. The uncinate fasciculus (UF), a tract connecting limbic to prefrontal regions, has been implicated in CD. However, CD-related alterations in other limbic tracts, such as the cingulum and the fornix, have not been investigated. Furthermore, few studies have examined the influence of sex and none have been adequately powered to test whether the relationship between CD and structural connectivity differs by sex. We examined whether adolescent males and females with CD exhibit differences in structural connectivity compared with typically developing controls.
We acquired diffusion-weighted magnetic resonance imaging data from 101 adolescents with CD (52 females) and 99 controls (50 females). Data were processed for deterministic spherical deconvolution tractography. Virtual dissections of the UF, the three subdivisions of the cingulum [retrosplenial cingulum (RSC), parahippocampal and subgenual cingulum], and the fornix were performed and measures of fractional anisotropy (FA) and hindrance-modulated orientational anisotropy (HMOA) were analysed.
The CD group had lower FA and HMOA in the right RSC tract relative to controls. Importantly, these effects were moderated by sex - males with CD significantly lower FA compared to male controls, whereas CD and control females did not differ.
Our results highlight the importance of considering sex when studying the neurobiological basis of CD. Sex differences in RSC connectivity may contribute to sex differences in the clinical presentation of CD.
先前关于品行障碍 (CD) 的研究报告称，边缘系统存在结构和功能改变。然而，连接边缘区域的白质束尚未得到全面研究。钩束（UF）是连接边缘和前额叶区域的束，与 CD 有关。然而，其他边缘束，如扣带束和穹窿，的 CD 相关改变尚未被研究。此外，很少有研究检查性别影响，也没有足够的研究力量来测试 CD 与结构连通性之间的关系是否因性别而异。我们研究了患有 CD 的青少年男性和女性与发育正常的对照组相比，其结构连通性是否存在差异。
我们从 101 名患有 CD（52 名女性）和 99 名对照组（50 名女性）的青少年中获取了弥散加权磁共振成像数据。数据通过确定性球谐分解纤维追踪法进行处理。对 UF、扣带束的三个分支[后扣带回束（RSC）、海马旁回和扣带回支]和穹窿进行了虚拟解剖，并分析了各向异性分数 (FA) 和受阻调制取向各向异性 (HMOA) 的测量值。
CD 组右侧 RSC 束的 FA 和 HMOA 低于对照组。重要的是，这些影响受到性别调节 - CD 男性的 FA 明显低于男性对照组，而 CD 和对照组女性之间没有差异。
我们的结果强调了在研究 CD 的神经生物学基础时考虑性别的重要性。RSC 连通性的性别差异可能导致 CD 临床表现的性别差异。
