Cognitive and subjective dose-response effects of acute oral Δ9-tetrahydrocannabinol (THC) in infrequent cannabis users
Cognitive and subjective dose-response effects of acute oral Δ9-tetrahydrocannabinol (THC) in infrequent cannabis users
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DOI：
10.1007/s00213-002-1169-0
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发表时间：
2002-10-01
影响因子：
3.4
通讯作者：
Henry, J
中科院分区：
文献类型：
--
作者：
Curran, HV;Brignell, C;Henry, J
基本原理：虽然已知记忆功能的某些方面会受到Delta（9）-tetrahydrocannabinol（Delta（9）-THC;大麻的主要活性成分）的严重损害，但对记忆其他方面的影响尚不清楚，功能损害的时间过程也不清楚。目的：本研究旨在详细说明Delta（9）-THC对偶尔使用大麻者的急性和残留认知影响。研究方法：在15名男性志愿者中，使用平衡的双盲交叉设计来比较7.5 mg和15 mg Delta（9）-THC与匹配的安慰剂的效果。在给药前和给药后1、2、4、6、8、24和48 h对参与者进行评估。结果：Delta（9）-THC 15 mg在血浆浓度峰值时（给药后2 h）损害了两项外显记忆任务的表现。在同一时间点，内隐记忆任务的表现保持不变。较高剂量的Delta（9）-THC导致在2小时的三次试验选择性提醒任务中没有任何学习发生。工作记忆通常不受Delta（9）-THC的影响。在几项任务中，Delta（9）-THC增加了速度和错误率，反映了“更高风险”的速度-准确性权衡。主观效应在2小时时也最明显，但通常持续时间更长，参与者将自己评为“石头”8小时。参与者经历了强烈的药物作用，喜欢这种效果，直到4小时，想要更多的口服Delta（9）-THC。在摄入后24或48小时未发现Delta（9）-THC的影响，表明口服Delta（9）-THC的残留影响极小。结论：这些数据表明，口服Delta（9）-THC以剂量依赖性方式损害情景记忆和学习，同时保留感知启动和工作记忆。
Rationale: Although some aspects of memory functions are known to be acutely impaired by Delta(9)-tetrahydrocannabinol (Delta(9)-THC; the main active constituent of marijuana), effects on other aspects of memory are not known and the time course of functional impairments is unclear. Objective: The present study aimed to detail the acute and residual cognitive effects of Delta(9)-THC in infrequent cannabis users. Methods: A balanced, double-blind cross-over design was used to compare the effects of 7.5 mg and 15 mg Delta(9)-THC with matched placebo in 15 male volunteers. Participants were assessed pre and 1, 2, 4, 6, 8, 24 and 48 h post-drug. Results: Delta(9)-THC 15 mg impaired performance on two explicit memory tasks at the time of peak plasma concentration (2 h post-drug). At the same time point, performance on an implicit memory task was preserved intact. The higher dose of Delta(9)-THC resulted in no learning whatsoever occurring over a three-trial selective reminding task at 2 h. Working memory was generally unaffected by Delta(9)-THC. In several tasks, Delta(9)-THC increased both speed and error rates, reflecting "riskier" speed-accuracy trade-offs. Subjective effects were also most marked at 2 h but often persisted longer, with participants rating themselves as "stoned" for 8 h. Participants experienced a strong drug effect, liked this effect and, until 4 h, wanted more oral Delta(9)-THC. No effects of Delta(9)-THC were found 24 or 48 h following ingestion indicating that the residual effects of oral Delta(9)-THC are minimal. Conclusions: These data demonstrate that oral Delta(9)-THC impairs episodic memory and learning in a dose-dependent manner whilst sparing perceptual priming and working memory.