Child & Adolescent Psychiatry, University of Göttingen, von Siebold-Strasse 5, Göttingen, Germany.
J Child Psychol Psychiatry. 2010 Feb;51(2):210-8. doi: 10.1111/j.1469-7610.2009.02139.x. Epub 2009 Nov 19.
Attention-deficit hyperactivity disorder (ADHD) is one of the most common and highly heritable child psychiatric disorders. There is strong evidence that children with ADHD show slower and more variable responses in tasks such as Go/Nogo tapping aspects of executive functions like sustained attention and response control which may be modulated by motivational factors and/or state-regulation processes. The aim of this study was (1) to determine if these executive functions may constitute an endophenotype for ADHD; (2) to investigate for the first time whether known modulators of these executive functions may also be familial; and (3) to explore whether gender has an impact on these measures.
Two hundred and five children with ADHD combined type, 173 nonaffected biological siblings and 53 controls with no known family history of ADHD were examined using a Go/Nogo task in the framework of a multi-centre study. Performance-measures and modulating effects of event-rate and incentives were examined. Shared familial effects on these measures were assessed, and the influence of gender was tested.
Children with ADHD responded more slowly and variably than nonaffected siblings or controls. Nonaffected siblings showed intermediate scores for reaction-time variability, false alarms and omission errors under fast and slow event-rates. A slower event-rate did not lead to reduced performance specific to ADHD. In the incentive condition, mean reaction-times speeded up and became less variable only in children with ADHD and their nonaffected siblings, while accuracy was improved in all groups. Males responded faster, but also committed more false alarms. There were no interactions of group by gender.
Reaction-time variability and accuracy parameters could be useful neuropsychological endophenotypes for ADHD. Performance-modulating effects of incentives suggested a familially driven motivational dysfunction which may play an important role on etiologic pathways and treatment approaches for ADHD. The effects of gender were independent of familial effects or ADHD-status, which in turn suggests that the proposed endophenotypes are independent of gender.
注意力缺陷多动障碍（ADHD）是最常见且遗传性极高的儿童精神疾病之一。有强有力的证据表明，ADHD 儿童在执行功能任务（如 Go/Nogo 敲击）中表现出较慢且更可变的反应，这些任务涉及到持续注意力和反应控制等方面，这可能受到动机因素和/或状态调节过程的调节。本研究的目的是：（1）确定这些执行功能是否可构成 ADHD 的一个内表型；（2）首次研究这些执行功能的已知调节因素是否也具有家族性；（3）探索性别是否对这些测量结果有影响。
在一项多中心研究中，我们使用 Go/Nogo 任务对 205 名 ADHD 混合型儿童、173 名非受影响的生物学兄弟姐妹和 53 名无 ADHD 家族史的对照组进行了检查。我们检查了表现测量值以及事件率和激励的调节作用。评估了这些测量值的共享家族效应，并测试了性别的影响。
ADHD 儿童的反应速度较慢，变异性较大，而非受影响的兄弟姐妹或对照组则反应速度较快，变异性较小。在快速和慢速事件率下，非受影响的兄弟姐妹的反应时变异性、假警报和遗漏错误的中间分数。较慢的事件率并没有导致 ADHD 特异性的表现下降。在激励条件下，只有 ADHD 儿童及其非受影响的兄弟姐妹的平均反应时间加快，变得不那么可变，而所有组的准确性都有所提高。男性的反应速度较快，但假警报也较多。组与性别之间没有相互作用。
反应时变异性和准确性参数可能是 ADHD 的有用神经心理学内表型。激励的性能调节作用表明存在家族驱动的动机功能障碍，这可能在 ADHD 的发病途径和治疗方法中发挥重要作用。性别的影响独立于家族效应或 ADHD 状态，这反过来表明所提出的内表型与性别无关。
