Department of Psychiatry, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands.
Department of Psychiatry, University Medical Centre Groningen, University of Groningen, The Netherlands.
Psychol Med. 2014 Mar;44(4):881-92. doi: 10.1017/S0033291713001153. Epub 2013 May 31.
The results of twin and sibling studies suggest that executive functioning is a prime candidate endophenotype in attention deficit hyperactivity disorder (ADHD). However, studies have not assessed the co-segregation of executive function (EF) deficits from parents to offspring directly, and it is unclear whether executive functioning is an ADHD endophenotype in adolescents, given the substantial changes in prefrontal lobe functioning, EF and ADHD symptoms during adolescence.
We recruited 259 ADHD and 98 control families with an offspring average age of 17.3 years. All participants were assessed for ADHD and EF [inhibition, verbal (VWM) and visuospatial working memory (VsWM)]. Data were analysed using generalized estimating equations (GEEs).
Parental ADHD was associated with offspring ADHD and parental EF was associated with offspring EF but there were no cross-associations (parental ADHD was not associated with offspring EF or vice versa). Similar results were found when siblings were compared. EF deficits were only found in affected adolescents and not in their unaffected siblings or (un)affected parents.
The core EFs proposed to be aetiologically related to ADHD, that is working memory and inhibition, seem to be aetiologically independent of ADHD in adolescence. EF deficits documented in childhood in unaffected siblings were no longer present in adolescence, suggesting that children 'grow out' of early EF deficits. This is the first study to document ADHD and EF in a large family sample with adolescent offspring. The results suggest that, after childhood, the majority of influences on ADHD are independent from those on EF. This has potential implications for current aetiological models of causality in ADHD.
双胞胎和兄弟姐妹研究的结果表明，执行功能是注意缺陷多动障碍（ADHD）的主要候选内表型。然而，这些研究尚未直接评估从父母到后代的执行功能（EF）缺陷的共分离，并且不清楚执行功能是否是青少年 ADHD 的内表型，因为前额叶功能、EF 和 ADHD 症状在青少年时期会发生重大变化。
我们招募了 259 个 ADHD 和 98 个对照组家庭，其后代的平均年龄为 17.3 岁。所有参与者都接受了 ADHD 和 EF（抑制、言语（VWM）和视觉空间工作记忆（VsWM））的评估。使用广义估计方程（GEE）进行数据分析。
父母的 ADHD 与后代的 ADHD 相关，父母的 EF 与后代的 EF 相关，但没有交叉关联（父母的 ADHD 与后代的 EF 或反之亦然）。当比较兄弟姐妹时，也得到了类似的结果。EF 缺陷仅在受影响的青少年中发现，而在未受影响的兄弟姐妹或（未）受影响的父母中未发现。
与 ADHD 病因学相关的核心 EF，即工作记忆和抑制，在青春期似乎与 ADHD 病因学无关。在未受影响的兄弟姐妹中在儿童期记录到的 EF 缺陷在青春期不再存在，这表明儿童“摆脱”了早期的 EF 缺陷。这是第一项在具有青少年后代的大型家庭样本中记录 ADHD 和 EF 的研究。结果表明，在儿童期之后，ADHD 的大多数影响与 EF 无关。这对 ADHD 的当前病因学因果关系模型具有潜在影响。
