Division of Child and Adolescent Psychiatry and Center for Neurobehavioral Genetics at the UCLA Semel Institute, 760 Westwood Plaza, Room 47-448, Los Angeles, CA 90095, United States.
J Psychiatr Res. 2010 Jul;44(9):605-15. doi: 10.1016/j.jpsychires.2009.11.012. Epub 2009 Dec 16.
Abnormal brain laterality (ABL) is indicated in ADHD. ADHD and brain laterality are heritable. Genetic factors contributing to lateralization of brain function may contribute to ADHD. If so, increased ADHD family loading should be associated with greater ABL. Previous studies have shown increased rightward alpha asymmetry in ADHD. We tested whether this was more pronounced in ADHD children with increased ADHD family loading.
We compared EEG alpha asymmetry at rest and during the Conner's Continuous Performance Test (CPT) in ADHD children with and without ADHD affected parents, and replicated our findings in a second larger sample. The replication study additionally stratified the parent-affected sample by parental persistent versus non-persistent ADHD status, increased spatial resolution of EEG measures, and assessed low versus high-alpha.
Study-1: the parent-affected group showed increased rightward asymmetry across frontal and central regions and reduced rightward parietal asymmetry during an eyes closed (EC) condition, as well as increasing rightward parietal asymmetry with advancing age during the CPT. Study-2 replicated these findings and further delineated influences of low versus high-alpha, recording site, and effects of parental persistent versus non-persistent ADHD status.
Increased ADHD familial loading was associated with increased rightward frontal asymmetry. In contrast, increased rightward parietal asymmetry was associated with reduced ADHD family loading. Frontal results are consistent with an ADHD endophenotype. Parietal results suggest an ADHD adaptive trait prevalent with less ADHD family loading. Age effects indicate a unique developmental course among ADHD children whose parents have non-persistent ADHD.
ADHD 存在大脑侧化异常（ABL）。ADHD 和大脑侧化具有遗传性。导致大脑功能侧化的遗传因素可能导致 ADHD。如果是这样，那么 ADHD 家族负荷增加应该与更大的 ABL 相关。先前的研究表明 ADHD 中存在右偏 alpha 不对称。我们测试了在 ADHD 家族负荷增加的 ADHD 儿童中，这种情况是否更为明显。
我们比较了 ADHD 儿童有无 ADHD 受影响父母，在静息和 Conner 连续性能测试（CPT）期间的 EEG alpha 不对称，并在第二个更大的样本中复制了我们的发现。复制研究还按父母持续或非持续 ADHD 状态、增加 EEG 测量的空间分辨率以及评估低 alpha 与高 alpha 对受影响父母的样本进行分层，并评估了低 alpha 与高 alpha。
研究 1：受影响父母的组在闭眼（EC）条件下显示出额中和中央区域的右偏不对称增加，以及右顶叶不对称性减少，并且随着 CPT 的进行，年龄增加时右顶叶不对称性增加。研究 2 复制了这些发现，并进一步描述了低 alpha 与高 alpha、记录部位以及父母持续与非持续 ADHD 状态的影响。
ADHD 家族负荷增加与额部右偏不对称增加有关。相比之下，右顶叶不对称增加与 ADHD 家族负荷降低有关。额叶结果与 ADHD 内表型一致。顶叶结果表明，在 ADHD 家族负荷较低的情况下，存在一种 ADHD 适应性特征。年龄效应表明，在父母非持续性 ADHD 的 ADHD 儿童中存在独特的发展过程。
