Thorell Lisa B
Department of Psychology, Uppsala University, Sweden and Stockholm Brain Institute, Karolinska Institute, Sweden.
J Child Psychol Psychiatry. 2007 Nov;48(11):1061-70. doi: 10.1111/j.1469-7610.2007.01777.x.
The present study examined the distinct properties of executive functioning in relation to ADHD symptoms, as well as functional outcomes associated with ADHD. In line with the dual-pathway model of ADHD, executive functioning and delay aversion were expected to show independent effects on ADHD symptoms. Furthermore, relations to early academic skills were examined, and it was hypothesized that the two processes of the dual-pathway model can be differentiated in terms of their effect on academic skill deficits, such that EF deficits, but not delay aversion, mediate the link between ADHD and academic functioning.
As hypothesized, both EF deficits and delay aversion were independently related to ADHD symptoms. However, when conducting separate analyses for the two ADHD symptom domains, only the effect of EF deficits was independently related to symptoms of inattention, whereas only the effect of delay aversion was independently related to symptoms of hyperactivity/impulsivity. The mediation analysis showed that EF deficits, but not delay aversion, act as a mediator in the relation between symptoms of inattention and both mathematics and language skills. In addition, there was also a significant direct effect of inattention on early academic skills.
The findings of the present study are of importance for current models of heterogeneity in ADHD as they 1) provide further support for the notion that EF deficits and delay aversion are two possible pathways to ADHD, 2) add new interesting knowledge by showing that EF deficits and delay aversion can be differentiated in terms of their relations to the two ADHD symptom domains, and 3) indicate that the two processes of the dual-pathway model can also be differentiated in terms of their effect on functional impairments associated with ADHD.
本研究考察了与注意力缺陷多动障碍（ADHD）症状相关的执行功能的独特属性，以及与ADHD相关的功能结果。根据ADHD的双路径模型，执行功能和延迟厌恶对ADHD症状预计会产生独立影响。此外，还考察了与早期学业技能的关系，并假设双路径模型的两个过程在对学业技能缺陷的影响方面可以区分，即执行功能缺陷而非延迟厌恶介导了ADHD与学业功能之间的联系。
正如所假设的，执行功能缺陷和延迟厌恶均与ADHD症状独立相关。然而，在对两个ADHD症状领域进行单独分析时，只有执行功能缺陷的影响与注意力不集中症状独立相关，而只有延迟厌恶的影响与多动/冲动症状独立相关。中介分析表明，执行功能缺陷而非延迟厌恶在注意力不集中症状与数学和语言技能之间的关系中起中介作用。此外，注意力不集中对早期学业技能也有显著的直接影响。
本研究的结果对当前ADHD异质性模型具有重要意义，因为它们1）为执行功能缺陷和延迟厌恶是ADHD的两条可能途径这一观点提供了进一步支持，2）通过表明执行功能缺陷和延迟厌恶在与两个ADHD症状领域的关系方面可以区分，增加了新的有趣知识，3）表明双路径模型的两个过程在对与ADHD相关的功能损害的影响方面也可以区分。
