Congdon Eliza, Lesch Klaus Peter, Canli Turhan
Department of Psychology, Stony Brook University, Stony Brook, New York 11794-2500, USA.
Am J Med Genet B Neuropsychiatr Genet. 2008 Jan 5;147B(1):27-32. doi: 10.1002/ajmg.b.30557.
Impulsivity, a highly prevalent symptom in multiple psychiatric disorders, is a partially heritable trait influenced by specific biological mechanisms. In particular, dopamine is proposed to play a role in impulsive behaviors and recent studies have implicated functional polymorphisms of dopamine-related genes in impulsive behaviors across different clinical and behavioral classifications. However, most have not isolated the impulsivity construct per se as a biologically based and measurable endophenotype. The present study was therefore undertaken in a sample of healthy adults to investigate the influence of two candidate dopaminergic gene polymorphisms (DRD4 and DAT) on the endophenotype of impulsivity, which we operationalized as behavioral inhibition during the Stop-signal task. We recruited an ethnically diverse sample of 119 healthy adults to complete a self-report questionnaire of impulsivity and to perform a Stop-signal task. We report significant differences in inhibitory control between individuals with at least one 7-repeat allele of the DRD4 polymorphism, as well as an interaction between DRD4 and DAT genotypes, on inhibitory control. Results of the present study support the influence of dopaminergic variation on impulsive-related measures, as well as the advantage of using measures which are likely more sensitive to the effects of such genetic variation.
冲动性是多种精神疾病中极为常见的症状，是一种受特定生物学机制影响的部分可遗传性状。具体而言，多巴胺被认为在冲动行为中起作用，最近的研究表明多巴胺相关基因的功能多态性与不同临床和行为分类中的冲动行为有关。然而，大多数研究尚未将冲动性本身作为一种基于生物学且可测量的内表型分离出来。因此，本研究以健康成年人为样本，调查两种候选多巴胺能基因多态性（DRD4和DAT）对冲动性内表型的影响，我们将冲动性定义为停止信号任务中的行为抑制。我们招募了119名种族多样的健康成年人组成样本，让他们完成一份冲动性的自我报告问卷，并执行停止信号任务。我们报告称，携带DRD4多态性至少一个7重复等位基因的个体之间在抑制控制方面存在显著差异，并且DRD4和DAT基因型之间在抑制控制方面存在相互作用。本研究结果支持多巴胺能变异对冲动相关测量的影响，以及使用可能对这种基因变异的影响更敏感的测量方法的优势。
