Block R I, Ghoneim M M
Department of Anesthesia, University of Iowa, Iowa City 52242.
Psychopharmacology (Berl). 1993;110(1-2):219-28. doi: 10.1007/BF02246977.
Impairments of human cognition and learning following chronic marijuana use are of serious concern, but have not been clearly demonstrated. To determine whether such impairments occurred, this study compared performance of adult marijuana users and non-users (N = 144 and N = 72, respectively) matched on intellectual functioning before the onset of drug use, i.e., on scores from standardized tests administered during the fourth grade of grammar school (Iowa Tests of Basic Skills). Subjects were given the twelfth grade versions of these tests (Iowa Tests of Educational Development) and other, computerized cognitive tests in successive test sessions. "Heavy" marijuana use (defined by use seven or more times weekly) was associated with deficits in mathematical skills and verbal expression in the Iowa Tests of Educational Development and selective impairments in memory retrieval processes in Buschke's Test. The retrieval impairments were restricted to words that were easy to visualize. Impairments depended on the frequency of chronic marijuana use, i.e., "light" and "intermediate" marijuana use (defined by use one to four and five to six times weekly, respectively) were not associated with deficits. Intermediate use was associated with superior performance in one condition ("fuzzy" concepts) of a Concept Formation test.
长期使用大麻后人类认知和学习能力受损令人严重担忧，但尚未得到明确证实。为了确定是否发生了此类损害，本研究比较了成年大麻使用者和非使用者（分别为N = 144和N = 72）在开始使用毒品之前在智力功能方面的表现，即在小学四年级时进行的标准化测试（爱荷华基本技能测试）中的分数。在连续的测试环节中，让受试者接受这些测试的十二年级版本（爱荷华教育发展测试）以及其他计算机化认知测试。 “重度”大麻使用（定义为每周使用七次或更多次）与爱荷华教育发展测试中的数学技能和语言表达缺陷以及布施克测试中记忆检索过程的选择性损害有关。检索损害仅限于易于视觉化的单词。损害程度取决于长期使用大麻的频率，即“轻度”和“中度”大麻使用（分别定义为每周使用一至四次和五至六次）与缺陷无关。中度使用在概念形成测试的一种情况（“模糊”概念）下与更好的表现相关。
