Clark L, Roiser J P, Robbins T W, Sahakian B J
Behavioural and Clinical Neuroscience Institute, Department of Experimental Psychology, School of Clinical Medicine, University of Cambridge, and Addenbrooke's Hospital, Cambridge, UK.
J Psychopharmacol. 2009 Jan;23(1):14-22. doi: 10.1177/0269881108089587. Epub 2008 May 30.
Evidence for serotonin involvement in impulsivity has generated interest in the measurement of impulsivity in regular ecstasy users, who are thought to display serotonergic dysfunction. However, current findings are inconsistent. Here, we used a recently developed Information Sampling Test to measure 'reflection' impulsivity in 46 current ecstasy users, 14 subjects who used ecstasy in the past, 15 current cannabis users and 19 drug-naïve controls. Despite elevated scores on the Impulsivity subscale of the Eysenck Impulsiveness-Venturesomeness-Empathy questionnaire, the current and previous ecstasy users did not differ significantly from the drug-naive controls on the Information Sampling Test. In contrast, the cannabis users sampled significantly less information on the task, and tolerated a lower level of certainty in their decision-making, in comparison to the drug-naive controls. The effect in cannabis users extends our earlier observations in amphetamine- and opiate-dependent individuals (Clark, et al., 2006, Biological Psychiatry 60: 515-522), and suggests that reduced reflection may be a common cognitive style across regular users of a variety of substances. However, the lack of effects in the two ecstasy groups suggests that the relationship between serotonin function, ecstasy use and impulsivity is more complex.
血清素与冲动性有关的证据引发了人们对定期使用摇头丸者冲动性测量的兴趣，这些使用者被认为存在血清素功能障碍。然而，目前的研究结果并不一致。在此，我们使用最近开发的信息采样测试，对46名当前摇头丸使用者、14名过去使用过摇头丸的受试者、15名当前大麻使用者和19名未使用过毒品的对照组进行“反思”冲动性测量。尽管艾森克冲动性-冒险性-共情问卷的冲动性分量表得分升高，但当前和过去的摇头丸使用者在信息采样测试中的表现与未使用过毒品的对照组相比并无显著差异。相比之下，与未使用过毒品的对照组相比，大麻使用者在该任务中采样的信息显著更少，并且在决策时容忍的确定性水平更低。大麻使用者的这种效应扩展了我们早期对苯丙胺和阿片类药物依赖个体的观察结果（Clark等人，2006年，《生物精神病学》60: 515 - 522），并表明减少反思可能是各类物质定期使用者共有的一种认知方式。然而，两个摇头丸组未出现效应表明血清素功能、摇头丸使用和冲动性之间的关系更为复杂。
