Department of Psychiatry, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
Karakter, Child and Adolescent Psychiatry University Centre, Nijmegen, The Netherlands.
J Child Psychol Psychiatry. 2015 Jul;56(7):782-791. doi: 10.1111/jcpp.12349. Epub 2014 Oct 27.
We may improve our understanding of the role of common versus unique risk factors in attention-deficit/hyperactivity disorder (ADHD) by examining ADHD-related cognitive deficits in single- (SPX), and multi-incidence (MPX) families. Given that individuals from multiplex (MPX) families are likely to share genetic vulnerability for the disorder, whereas simplex (SPX) ADHD may be the result of sporadic (non-)genetic causes unique to the patient, we hypothesized that cognitive impairments may be different in SPX and MPX ADHD as indicated by (a) the presence of cognitive deficits in MPX, but not SPX unaffected siblings and (b) dissimilar cognitive profiles in SPX and MPX ADHD patients.
Tasks measuring total IQ, verbal attention, executive functioning, motor functioning, and time estimation were administered to 31 SPX/264 MPX ADHD probands, 47 SPX/123 MPX unaffected siblings, and 263 controls, aged 6-19 years.
SPX unaffected siblings were unimpaired compared to controls, except for verbal working memory, whereas MPX unaffected siblings showed impairments on most cognitive domains. The cognitive profiles of SPX and MPX probands were highly similar, except that verbal attention, response inhibition and motor control deficits were more pronounced in MPX probands, and -compared to their unaffected siblings- impairments in IQ, visual working memory and timing abilities were more pronounced in SPX cases.
Our results support the hypothesis that a partly different cognitive architecture may underlie SPX and MPX forms of ADHD, which becomes evident when contrasting cognitive performances within families. Cognitive factors underlying MPX forms of ADHD are familial, whereas nonfamilial in SPX ADHD. SPX-MPX stratification may be a step forward in unraveling diverse causal pathways.
通过研究单发性（SPX）和多发性（MPX）家族中与注意缺陷多动障碍（ADHD）相关的认知缺陷，我们可以更好地理解常见和独特风险因素在 ADHD 中的作用。鉴于来自多发性（MPX）家族的个体可能具有该疾病的遗传易感性，而单纯性（SPX）ADHD 可能是患者特有的散发性（非）遗传原因的结果，我们假设 SPX 和 MPX ADHD 中的认知障碍可能不同，具体表现为：（a）MPX 而非 SPX 未受影响的兄弟姐妹存在认知缺陷；（b）SPX 和 MPX ADHD 患者的认知特征不同。
我们对 31 名 SPX/264 名 MPX ADHD 先证者、47 名 SPX/123 名 MPX 未受影响的兄弟姐妹和 263 名年龄在 6-19 岁的对照者进行了总智商、言语注意力、执行功能、运动功能和时间估计任务的测试。
SPX 未受影响的兄弟姐妹与对照组相比除了言语工作记忆之外无其他缺陷，而 MPX 未受影响的兄弟姐妹在大多数认知领域都存在缺陷。SPX 和 MPX 先证者的认知特征非常相似，除了言语注意力、反应抑制和运动控制缺陷在 MPX 先证者中更为明显，与未受影响的兄弟姐妹相比，SPX 病例中智商、视觉工作记忆和定时能力的缺陷更为明显。
我们的结果支持这样一种假设，即 SPX 和 MPX 形式的 ADHD 可能具有部分不同的认知结构，当在家庭内对比认知表现时，这一点变得明显。MPX 形式的 ADHD 的认知因素是家族性的，而 SPX ADHD 则是非家族性的。SPX-MPX 分层可能是揭示不同因果途径的一个进步。
