Indlekofer F, Piechatzek M, Daamen M, Glasmacher C, Lieb R, Pfister H, Tucha O, Lange K W, Wittchen H U, Schütz C G
Department of Psychiatry and Psychotherapy, Ludwig Maximilian University, Munich, Germany.
J Psychopharmacol. 2009 Jul;23(5):495-509. doi: 10.1177/0269881108091076. Epub 2008 Jul 17.
Regular use of illegal drugs is suspected to cause cognitive impairments. Two substances have received heightened attention: 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy') and delta-9-tetrahydrocannabinol (THC or 'cannabis'). Preclinical evidence, as well as human studies examining regular ecstasy consumers, indicated that ecstasy use may have negative effects on learning, verbal memory and complex attentional functions. Cannabis has also been linked to symptoms of inattention and deficits in learning and memory. Most of the published studies in this field of research recruited participants by means of newspaper advertisements or by using word-of-mouth strategies. Because participants were usually aware that their drug use was critical to the research design, this awareness may have caused selection bias or created expectation effects. Focussing on attention and memory, this study aimed to assess cognitive functioning in a community-based representative sample that was derived from a large-scale epidemiological study. Available data concerning drug use history allowed sampling of subjects with varying degrees of lifetime drug experiences. Cognitive functioning was examined in 284 young participants, between 22 and 34 years. In general, their lifetime drug experience was moderate. Participants completed a neuropsychological test battery, including measures for verbal learning, memory and various attentional functions. Linear regression analysis was performed to investigate the relationship between cognitive functioning and lifetime experience of drug use. Ecstasy and cannabis use were significantly related to poorer episodic memory function in a dose-related manner. For attentional measures, decrements of small effect sizes were found. Error measures in tonic and phasic alertness tasks, selective attention task and vigilance showed small but significant effects, suggesting a stronger tendency to experience lapses of attention. No indication for differences in reaction time was found. The results are consistent with decrements of memory and attentional performance described in previous studies. These effects are relatively small; however, it must be kept in mind that this study focussed on assessing young adults with moderate drug use from a population-based study.
长期使用非法药物被怀疑会导致认知障碍。有两种物质受到了更多关注：3,4-亚甲基二氧甲基苯丙胺（MDMA，即“摇头丸”）和Δ⁹-四氢大麻酚（THC，即“大麻”）。临床前证据以及针对经常使用摇头丸者的人体研究表明，使用摇头丸可能会对学习、言语记忆和复杂注意力功能产生负面影响。大麻也与注意力不集中以及学习和记忆缺陷的症状有关。该研究领域中大多数已发表的研究是通过报纸广告或口碑策略招募参与者的。由于参与者通常意识到他们的药物使用情况对研究设计至关重要，这种认知可能导致了选择偏差或产生了期望效应。本研究聚焦于注意力和记忆，旨在评估来自一项大规模流行病学研究的社区代表性样本中的认知功能。有关药物使用史的现有数据使得能够对具有不同程度终生药物使用经历的受试者进行抽样。对284名年龄在22至34岁之间的年轻参与者的认知功能进行了检查。总体而言，他们的终生药物使用经历处于中等水平。参与者完成了一套神经心理学测试，包括言语学习、记忆和各种注意力功能的测量。进行线性回归分析以研究认知功能与终生药物使用经历之间的关系。使用摇头丸和大麻与较差的情景记忆功能呈剂量相关的显著关系。对于注意力测量，发现了效应量较小的下降。在持续性和相位性警觉任务、选择性注意力任务和警觉性方面的错误测量显示出虽小但显著的影响，表明出现注意力失误的倾向更强。未发现反应时间存在差异的迹象。这些结果与先前研究中描述的记忆和注意力表现下降一致。这些影响相对较小；然而，必须记住的是，本研究聚焦于评估来自基于人群研究的、有中等药物使用量的年轻成年人。
