Malone Stephen M, Luciana Monica, Wilson Sylia, Sparks Jordan C, Hunt Ruskin H, Thomas Kathleen M, Iacono William G
Department of Psychology, University of Minnesota - Twin Cities, Minneapolis, MN, 55455, USA,
Behav Genet. 2014 Jul;44(4):407-18. doi: 10.1007/s10519-014-9651-0. Epub 2014 Mar 28.
The present study used a monozygotic (MZ) cotwin-control (CTC) design to investigate associations between alcohol use and performance on the Iowa gambling task (IGT) in a sample of 96 adolescents (half female). The MZ CTC design is well suited to shed light on whether poor decision-making, as reflected on IGT performance, predisposes individuals to abuse substances or is a consequence of use. Participants completed structural MRI scans as well, from which we derived gray matter volumes for cortical and subcortical regions involved in IGT performance and reduced in adolescents with problematic alcohol use. Drinking was associated with poorer task performance and with reduced volume of the left lateral orbital-frontal cortex. CTC analyses indicated that the former was due to differences between members of twin pairs in alcohol use (suggesting a causal effect of alcohol), whereas the latter was due to factors shared by twins (consistent with a pre-existing vulnerability for use). Although these preliminary findings warrant replication, they suggest that normative levels of alcohol use may diminish the quality of adolescent decision-making and thus have potentially important public health implications.
本研究采用同卵双胞胎对照（MZ CTC）设计，在96名青少年（半数为女性）样本中，探究饮酒与爱荷华赌博任务（IGT）表现之间的关联。MZ CTC设计非常适合于阐明，如IGT表现所反映的决策能力差，是使人易患物质滥用的原因，还是使用物质的结果。参与者还完成了结构磁共振成像扫描，我们从中得出了参与IGT表现且在有问题饮酒的青少年中体积减小的皮质和皮质下区域的灰质体积。饮酒与较差的任务表现以及左侧眶额皮质体积减小有关。双胞胎对照分析表明，前者是由于双胞胎对中饮酒情况的差异（表明酒精有因果效应），而后者是由于双胞胎共有的因素（与预先存在的使用易感性一致）。尽管这些初步发现有待重复验证，但它们表明，正常水平的饮酒可能会降低青少年决策的质量，因此可能具有重要的公共卫生意义。
