Disner Seth G, McGeary John E, Wells Tony T, Ellis Alissa J, Beevers Christopher G
Department of Psychology, The University of Texas at Austin, A8000, Austin, TX, 78712, USA,
Cogn Affect Behav Neurosci. 2014 Dec;14(4):1259-70. doi: 10.3758/s13415-014-0267-x.
Genetic variation within the serotonin system has been associated with biased attention for affective stimuli and, less consistently, with vulnerability for major depressive disorder. In particular, 5-HTTLPR, HTR1A (rs6295), and HTR2A (rs6311) polymorphisms have been linked with biased cognition. The present study developed a serotonergic cumulative genetic score (CGS) that quantified the number of risk alleles associated with these candidate polymorphisms to yield a single CGS. The CGS was then used to model genetic influence on the relationship between reactivity to a negative mood induction and negatively biased cognition. A passive-viewing eye-tracking task was administered to 170 healthy volunteers to assess sustained attention for positive, dysphoric, neutral, and threatening scenes. Participants were then induced into a sad mood and readministered the passive-viewing task. Change in gaze bias, as a function of reactivity to mood induction, was the primary measure of cognitive vulnerability. Results suggest that, although none of the individual genes interacted with mood reactivity to predict change in gaze bias, individuals with higher serotonin CGS were significantly more likely to look toward dysphoric images and away from positive images as mood reactivity increased. These findings suggest that a CGS approach may better capture genetic influences on cognitive vulnerability and reaffirm the need to examine multilocus approaches in genomic research.
血清素系统内的基因变异与对情感刺激的注意力偏差有关，而与重度抑郁症易感性的关联则不太一致。具体而言，5-羟色胺转运体基因启动子区域多态性（5-HTTLPR）、5-羟色胺受体1A基因（HTR1A，rs6295）和5-羟色胺受体2A基因（HTR2A，rs6311）的多态性与认知偏差有关。本研究开发了一种血清素累积遗传评分（CGS），该评分量化了与这些候选多态性相关的风险等位基因数量，以得出单一的CGS。然后，使用CGS对基因对负面情绪诱导反应性与负性认知偏差之间关系的影响进行建模。对170名健康志愿者进行了一项被动观看眼动追踪任务，以评估他们对积极、烦躁、中性和威胁性场景的持续注意力。然后诱导参与者进入悲伤情绪，并再次进行被动观看任务。作为情绪诱导反应函数的注视偏差变化是认知易感性的主要测量指标。结果表明，尽管没有一个单独的基因与情绪反应性相互作用来预测注视偏差的变化，但随着情绪反应性增加，血清素CGS较高的个体明显更有可能看向烦躁的图像并远离积极的图像。这些发现表明，CGS方法可能能更好地捕捉基因对认知易感性的影响，并再次强调在基因组研究中检查多位点方法的必要性。
