COGNITIVE CONSEQUENCES OF LONG-TERM MARIJUANA USE

描述：(申请人摘要) 在长期使用大麻的健康和医疗后果中， 残留神经心理影响的可能性--例如 注意力、记忆和其他认知功能--仍然是 担忧。但这些影响仍然知之甚少，因为 现有研究的方法论局限性。具体地说，许多研究 对吸食大麻的人进行了调查，他们一生中只接触过少量的大麻 因此，这种药物存在第二类错误的风险--未能检测到 如果确实存在的话会产生影响。在余下的研究中， 有大量接触的用户，大多数测试用户仅在24-48小时后 戒除大麻，在许多情况下，戒烟期不是 有人监督。因此，观察到的任何赤字可能只是反映了残留物 大脑中最近吸食的大麻素，或者，急性 突然停止吸食大麻产生的戒断效应。因此， 显然需要进一步的研究来解决这一问题 长期使用大麻会产生具有临床意义的残留 神经毒性。 在本申请中提出的研究试图解决方法论问题 在几个方面存在早期调查的问题。首先， 调查人员将研究吸食大麻至少5000人 (相当于在13.7年内每天吸烟一次)，以便 如上所述，将发生第二类错误的风险降至最低。第二，用户将 在28天的时间里接受一系列神经心理测试 通过每日观察监测大麻和其他药物的戒断情况 收集尿液。这项技术将使调查人员能够 区分由药物残留或药物残留引起的暂时性损害 戒断效应，以及由于坦率的神经毒性而导致的长期损害。 调查人员进行的一项可行性研究表明， 有可能招募大量长期吸食大量大麻的人 吸烟者(平均一生吸烟次数=19,000次)，年龄30至54岁， 无论男女以及一系列种族和社会经济群体，谁会是 愿意参与对这一拟议设计的研究。一组 神经心理测试，其中许多已经被 研究人员在之前一项关于大麻对大学生影响的研究中表示， 被选择来评估广泛的皮质功能，包括 尤其是以前发现的注意力/执行功能受损 该中心和其他中心对大麻使用者的研究。其他内容 调查人员自己设计的神经心理测试和其他 成瘾研究中心连续尿液和血液样本分析 在马里兰州巴尔的摩，将提供关于 大麻使用、大麻素水平和各种可能的 神经心理效应。 鉴于大麻在当代美国人中的广泛使用，这些 结果应为立法和监管提供重要信息 与这种药物有关的身体。

DESCRIPTION: (Applicant's Abstract) Among the health and medical consequences of long-term marijuana use, the possibility of residual neuropsychological effects - such as impairments of attention, memory and other cognitive functions - remains an area of concern. But these effects are still poorly understood because of the methodological limitations of existing studies. Specifically, many studies have examined marijuana users with only modest total lifetime exposure to the drug, and, thus, are at risk for a type II error - failing to detect an effect if one in fact exists. Of the remaining studies which have examined users with substantial exposure, most tested users after only 24-48 hours of abstinence from marijuana and in many cases the abstinence period was not supervised. Thus, any deficits observed may have simply reflected a residue of recently smoked cannabinoids in the brain, or alternatively, acute withdrawal effects from abrupt discontinuation of marijuana. Therefore, further study is clearly required to resolve the question of whether long-term marijuana use produces clinically meaningful residual neurotoxicity. The study proposed in this application seeks to address the methodological problems of earlier investigations in several ways. First, the investigators will study individuals who have smoked marijuana at least 5000 times (the equivalent of smoking once per day for 13.7 years) in order to minimize the risk of a type II error as described above. Second, users will receive serial neuropsychological tests over the course of a 28-day period of abstinence from marijuana and other drugs, monitored by daily observed urine collections. This technique will allow the investigators to distinguish between temporary impairment due either to a residue of drug or to withdrawal effects, and prolonged impairment due to frank neurotoxicity. A feasibility study, performed by the investigators, has demonstrated that it is possible to recruit substantial numbers of long-term heavy marijuana users (mean lifetime number of episodes of smoking = 19,000), age 30 to 54, of both genders and a range of ethnic and socioeconomic groups, who would be willing to participate in a study of this proposed design. A battery of neuropsychological tests, many of which have already been used by the investigators in a previous study of marijuana effects in college students, has been chosen to assess a wide range of cortical functions, including particularly the attentional/executive functions found impaired in previous studies of marijuana users at this center and others. Additional neuropsychological tests of the investigators' own design and additional analyses of serial urine and blood samples at the Addiction Research Center in Baltimore, MD, will provide further data on the relationship between marijuana use, cannabinoid levels and various types of possible neuropsychological effects. Given the widespread use of marijuana among contemporary Americans, these results should provide important information for legislative and regulatory bodies concerned with this drug.