CHRONIC MARIJUANA USE--BRAIN AND COGNITION

描述：（申请人摘要） 这项提案的目的是研究长期使用大麻对 人类大脑结构，大脑功能和认知，使用最先进的 将神经成像技术与认知评估相结合的方法。 如果一些大麻使用者患上长期的脑功能障碍， 社会的潜在成本，增加医疗保健成本， 生产率可能很高。 大麻是使用最广泛的非法药物 在美国，经过十多年的普遍下降， 在过去的3-4年里， 人们再次担心其可能的健康后果。 药物滥用和神经影像学研究人员将联合起来， 研究复制我们早期的认知障碍的发现， 研究大麻对大脑结构的影响， 使用磁共振成像的局部脑血流量（rCBF）， 正电子发射断层扫描（PET）。 认知激活 PET成像期间进行的检查将根据我们之前的 PET工作和研究慢性大麻使用，并将强调测试 记忆和注意力。 我们假设长期吸食大麻的人 这些认知功能的障碍和大脑区域的rCBF减少 我们以前发现在这些测试中是活跃的 在正常对照组中。 这些类型的更广泛的测试将 在不涉及神经成像的单独会议中施用。 大麻 在此之前，用户和非用户将在智力功能上进行匹配 开始使用药物，使用标准化测试的分数记录， 几乎在爱荷华州的所有地方接受教育的儿童都可以使用。 类似 将对受试者进行适合成人的测试，以评估他们的 目前的能力。 只有少数以前的研究已经检查了慢性的影响， 大麻使用与神经成像技术，除了一个，所有进行 年前 神经成像技术检测神经系统细微变化的能力 近年来，大脑的结构和功能有了很大的改善。 没有 以前对长期吸食大麻的研究评估了大脑的变化， 与特定认知活动相关的功能。 大多数先前 关于大麻对认知的慢性影响的研究 方法论薄弱，除了我们自己以前的研究观察到， 大麻使用者相对于对照组的认知障碍 病态前的智力 因此，当完成时，拟议的 研究将对现有的知识作出重要的补充， 长期吸食大麻对人类大脑结构，大脑功能， 和认知。

DESCRIPTION: (Applicant's Abstract) The goal of this proposal is to examine effects of chronic marijuana use on human brain structure, brain function, and cognition using state-of-the-art methods for combining neuroimaging techniques with cognitive assessments. If some marijuana users develop long term cerebral dysfunction, the potential costs to society in increased health care costs and decreased productivity could be high. Marijuana is the most widely used illicit drug in the U.S.A. Following well over a decade of generally declining use, its popularity has increased markedly among youth in the last 3-4 yr, prompting renewed concerns about its possible health consequences. Drug abuse and neuroimaging researchers will join forces in the proposed research to replicate our earlier findings of cognitive impairments in heavy marijuana users and study marijuana's effects on brain structure and regional cerebral blood flow (rCBF) using magnetic resonance imaging and positron emission tomography (PET), respectively. Cognitive activation tests administered during PET imaging will be selected based on our previous PET work and research on chronic marijuana use, and will emphasize tests of memory and attention. We hypothesize that chronic marijuana users will show impairments in these cognitive functions and reduced rCBF in brain regions that we have previously found to be active during performance of these tests in normal controls. More extensive tests of these types will be administered in a separate session not involving neuroimaging. Marijuana users and non-users will be matched on intellectual function before the onset of drug use, using records of scores on standardized tests that are available for children educated in virtually all parts of Iowa. Similar tests suitable for adults will be administered to subjects to assess their current capabilities. Only a handful of previous studies have examined effects of chronic marijuana use with neuroimaging techniques, and all but one were conducted years ago. Abilities of neuroimaging techniques to detect subtle changes in brain structure and function have improved enormously in recent years. No previous studies of chronic marijuana use have assessed changes in brain function associated with specific cognitive activities. Most previous studies of marijuana's chronic effects on cognition have been methodologically weak, and none except our own previous study observed cognitive impairments in marijuana users relative to controls matched on premorbid intellectual abilities. Thus, when completed, the proposed research will make important additions to existing knowledge concerning effects of chronic marijuana use on human brain structure, brain function, and cognition.