Olin Neuropsychiatry Research Center, The Institute of Living, Hartford, Connecticut; Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois.
Olin Neuropsychiatry Research Center, The Institute of Living, Hartford, Connecticut; Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2019 Mar;4(3):233-242. doi: 10.1016/j.bpsc.2018.09.007. Epub 2018 Sep 29.
This study sought to identify attention-deficit/hyperactivity disorder (ADHD) abnormalities in relationships between brain white matter structure and individual differences in several types of impulsive behavior.
Adolescents, n = 67 with ADHD combined subtype and n = 68 without ADHD, were given neuropsychological tests and underwent diffusion tensor imaging scans. Principal component analysis reduced test scores into factors representing different types of impulsive behavior. Tract-based spatial statistics quantified white matter integrity in relationship to components of impulsive behavior. ADHD versus non-ADHD differences in the strength and nature of linear relationships between regional white matter and three impulsivity components were examined using multiple regression.
Principal component analysis found three separate impulsivity-related factors that were interpreted as motor response inhibition, impulsive choice, and delay aversion. Relationships between regional fractional anisotropy and response inhibition or impulsive choice did not differ between ADHD and non-ADHD groups. There was a significant interaction between diagnostic group and delay aversion test performance relationships with regional fractional anisotropy. For youths without ADHD, greater anisotropy in numerous tracts predicted better delay aversion test performance. In contrast, anisotropy in regions including the corpus callosum, corona radiata, internal capsule, and corticospinal tracts had either a negative or no relationship with delay aversion test performance in ADHD.
The results provide additional support that different proposed etiological pathways to ADHD have discretely different neurobiological features. Large disorganization of white matter microstructure appears to contribute to reward-based ADHD pathways rather than motor inhibition.
本研究旨在确定注意缺陷多动障碍（ADHD）与冲动行为个体差异之间脑白质结构关系的异常。
将 67 名 ADHD 混合亚型青少年和 68 名无 ADHD 的青少年进行神经心理学测试和弥散张量成像扫描。主成分分析将测试分数简化为代表不同类型冲动行为的因子。基于束的空间统计学方法将白质完整性与冲动行为成分进行量化。使用多元回归检验 ADHD 与非 ADHD 个体之间区域白质与三种冲动成分之间线性关系的强度和性质的差异。
主成分分析发现了三个独立的冲动相关因子，分别解释为运动反应抑制、冲动选择和延迟厌恶。ADHD 组和非 ADHD 组之间，区域各向异性分数与反应抑制或冲动选择之间的关系没有差异。诊断组与延迟厌恶测试表现与区域各向异性分数之间存在显著的交互作用。对于非 ADHD 青少年，大量束的各向异性分数越高，延迟厌恶测试表现越好。相比之下，ADHD 青少年中胼胝体、辐射冠、内囊和皮质脊髓束等区域的各向异性分数与延迟厌恶测试表现呈负相关或无相关性。
结果提供了额外的支持，表明 ADHD 的不同假设病因途径具有明显不同的神经生物学特征。白质微观结构的严重紊乱似乎与基于奖励的 ADHD 途径有关，而与运动抑制无关。
