Pope H G, Yurgelun-Todd D
Biological Psychiatry Laboratory, McLean Hospital, Belmont, MA 02178, USA.
JAMA. 1996 Feb 21;275(7):521-7.
To assess whether frequent marijuana use is associated with residual neuropsychological effects.
Single-blind comparison of regular users vs infrequent users of marijuana.
Two samples of college undergraduates: 65 heavy users, who had smoked marijuana a median of 29 days in the last 30 days (range, 22 to 30 days) and who also displayed cannabinoids in their urine, and 64 light users, who had smoked a median of 1 day in the last 30 days (range, 0 to 9 days) and who displayed no urinary cannabinoids.
Subjects arrived at 2 PM on day 1 of their study visit, then remained at our center overnight under supervision. Neuropsychological tests were administered to all subjects starting at 9 AM on day 2. Thus, all subjects were abstinent from marijuana and other drugs for a minimum of 19 hours before testing.
Subjects received a battery of standard neuropsychological tests to assess general intellectual functioning, abstraction ability, sustained attention, verbal fluency, and ability to learn and recall new verbal and visuospatial information.
Heavy users displayed significantly greater impairment than light users on attention/executive functions, as evidenced particularly by greater perseverations on card sorting and reduced learning of word lists. These differences remained after controlling for potential confounding variables, such as estimated levels of premorbid cognitive functioning, and for use of alcohol and other substances in the two groups.
Heavy marijuana use is associated with residual neuropsychological effects even after a day of supervised abstinence from the drug. However, the question remains open as to whether this impairment is due to a residue of drug in the brain, a withdrawal effect from the drug, or a frank neurotoxic effect of the drug. from marijuana
评估频繁使用大麻是否与残留的神经心理效应相关。
大麻经常使用者与不经常使用者的单盲比较。
两组大学生样本：65名重度使用者，他们在过去30天内平均吸食大麻29天（范围为22至30天），且尿液中检测出大麻素；64名轻度使用者，他们在过去30天内平均吸食大麻1天（范围为0至9天），尿液中未检测出大麻素。
受试者在研究访问的第1天下午2点到达，然后在我们的中心接受过夜监督。从第2天上午9点开始对所有受试者进行神经心理测试。因此，所有受试者在测试前至少19小时未使用大麻及其他药物。
受试者接受一系列标准神经心理测试，以评估一般智力功能、抽象能力、持续注意力、语言流畅性以及学习和回忆新的语言和视觉空间信息的能力。
在注意力/执行功能方面，重度使用者比轻度使用者表现出明显更大的损伤，尤其是在卡片分类任务中更多的持续性错误以及单词列表学习能力下降方面表现更为明显。在控制了潜在的混杂变量，如病前认知功能估计水平，以及两组中酒精和其他物质的使用情况后，这些差异仍然存在。
即使在一天的药物监督戒断后，大量使用大麻仍与残留的神经心理效应相关。然而，这种损伤是由于大脑中的药物残留、药物戒断效应还是药物直接神经毒性作用，这个问题仍然悬而未决。 源自大麻
