MARIJUANA & COGNITION; CHRONIC AND ACUTE EFFECTS

长期使用大麻对学习，记忆， 和认知是严重关切的广泛使用， 这种药物，特别是随着使用已扩展到逐步 近年来，年轻人。 令人惊讶的是，虽然急性 单次服用大麻造成的记忆损伤 经常被证明的慢性实验研究 大麻对学习、记忆和认知的影响已经被 数量少，方法上薄弱， 结果。 拟议研究的第一部分将审查 通过比较“重度”慢性使用者， “轻度”慢性使用者和非使用者在智力上匹配 在开始吸食大麻之前就已经开始运作了 在非毒品项下 条件，实验室测试，强调学习和 记忆新信息，概念形成，联想 过程、语义记忆提取和心理学 成绩将与标准化考试一起进行 强调利用先前（实验前） 获取的信息。 这项研究将确定是否慢性 大麻使用者相对于匹配的非使用者受损 在这些测试，如果是这样，是否损害取决于 长期使用大麻的频率 在随后的部分中， 在这项研究中，同样的测试将在吸烟后进行。 活性或安慰剂大麻，以确定是否 个人测试对慢性大麻使用的敏感性 他们对大麻的急性反应很敏感

Adverse effects of chronic marijuana use on learning, memory, and cognition are of serious concern in view of the widespread use of this drug, especially as use has extended into progressively younger age groups in recent years. Surprisingly, although acute impairment of memory from single marijuana doses has been frequently demonstrated, experimental studies of chronic marijuana effects on learning, memory, and cognition have been few in number, methodologically weak, and ambiguous in outcome. The first portion of the proposed study will examine effects of chronic illicit marijuana use by comparing "heavy" chronic users, "light" chronic users, and non-users matched on intellectual functioning before the onset of marijuana use. Under non-drug conditions, laboratory tests that emphasize learning and remembering new information, concept formation, associative processes, semantic memory retrieval, and psychomotor performance will be administered together will standardized tests that emphasize utilization of previously (pre-experimentally) acquired information. The study will determine whether chronic marijuana users are impaired relative to matched non-users on these tests and, if so, whether the impairments depend on the frequency of chronic marijuana use. In a subsequent portion of the study, the same tests will be administered following smoking of active or placebo marijuana to determine whether the sensitivity of individual test to chronic marijuana use corresponds with their sensitivity to acute effects of marijuana.