Low levels of childhood inhibitory control (IC) are phenotypically and genetically associated with externalizing behavior problems and attention deficit hyperactivity disorder (ADHD). Unfortunately, there is little research on this topic in early childhood, when IC first emerges. This investigation extends the previous findings of contemporaneous genetic covariance between parent-rated and laboratory-assessed IC and ADHD at age 2 by examining longitudinal links between IC at age two and ADHD behavior problems at age three in a sample of 314 same-sex twin pairs (145 monozygotic or MZ, 169 dizygotic or DZ). There were significant phenotypic associations between both parent and laboratory IC assessments at age two and later ADHD behavioral problems (correlations ranged from − .15 to − .44). In our model-fitting strategy, we included measures of ADHD and IC at age 2 as predictors of ADHD at age 3. Longitudinal genetic analyses showed that phenotypic covariance between age two IC and ADHD behavior problems one year later were explained by overlapping genetic variance (genetic correlations ranged from − .28 to − .60). However, these effects were not unique to IC and reflect variance shared with ADHD at age 2. Parent-rated IC at age two showed higher phenotypic and genetic covariance with ADHD at age three than lab ratings of IC at age two. This is the first investigation examining genetic covariance between parent and lab-based IC at age two and ADHD behavior problems at age three. Findings show that after accounting for co-occurring ADHD, early temperamental IC is not a unique genetic risk factor for later ADHD.

低水平的儿童抑制控制（IC）在表型和遗传上与外部行为问题和注意力缺陷多动障碍（ADHD）相关。不幸的是，当IC首次出现时，在儿童早期对此主题的研究很少。这项研究通过检查314名同性双胞胎双胞胎样本中的2岁时IC和3岁时ADHD行为问题之间的纵向联系，扩展了之前父母评估和实验室评估的IC和ADHD在同期遗传协方差的发现。 （145个单合子或MZ，169个合子或DZ）。在两岁时的父母和实验室IC评估之间存在显着的表型关联，而ADHD以后出现行为问题（相关性介于− .15至− .44之间）。在我们的模型拟合策略中，我们纳入了2岁时ADHD和IC的测量值作为3岁时ADHD的预测指标。纵向遗传学分析显示，两年后IC和ADHD行为问题之间的表型协方差可以通过重叠的遗传方差来解释（遗传相关性介于-.28至-.60）。但是，这些效应并非仅是IC所独有，并且反映了2岁时与ADHD共享的方差。与2岁时的IC实验室评估相比，三岁时父母评估的IC与ADHD表现出更高的表型和遗传协方差。这是首次调查在两岁时父母与基于实验室的IC之间的遗传协方差和在三岁时ADHD行为问题的调查。研究结果表明，考虑到同时发生的多动症后，早期气质性IC并不是晚期多动症的独特遗传危险因素。纵向遗传学分析显示，一年后的两岁IC和ADHD行为问题之间的表型协方差可以通过重叠的遗传方差来解释（遗传相关性介于-.28至-.60之间）。但是，这些效应并非仅是IC所独有，并且反映了2岁时与ADHD共享的方差。与2岁时的IC实验室评估相比，三岁时父母评估的IC与ADHD表现出更高的表型和遗传协方差。这是首次调查父母两岁时基于父母和实验室的IC和三岁时ADHD行为问题之间的遗传协方差。研究结果表明，考虑到同时发生的多动症后，早期气质性IC并不是晚期多动症的独特遗传危险因素。纵向遗传学分析显示，一年后的两岁IC和ADHD行为问题之间的表型协方差可以通过重叠的遗传方差来解释（遗传相关性介于-.28至-.60之间）。然而，这些效应并非IC独有，并反映了2岁时与ADHD共享的方差。在2岁时，父母定级的IC与3岁时ADHD相比在ADHD中表现出更高的表型和遗传协方差。这是第一次调查父母两岁时基于父母和实验室的IC之间的遗传协方差，以及三岁时ADHD行为问题。研究结果表明，考虑到同时发生的多动症后，早期气质性IC并不是晚期多动症的独特遗传危险因素。