State medical marijuana laws and MTF teen marijuana use and attitudes since 1991

描述（由申请人提供）：自1996年以来，16个州通过了大麻医疗使用合法化的法律，其他州正在考虑这样的法律。由于几乎没有科学证据表明这些快速变化的法律是否会导致非法青少年大麻使用（AMU）的增加，这个问题现在主要是一个争论的问题。最近，使用来自两项全国性调查的数据，我们表明，具有医用大麻法律（MML）的州的青少年患病率显著较高（Wall等人，2011）和成人大麻使用（塞尔达等人，在新闻界）比其他国家。 这些结果强调了对MML和AMU进行进一步研究的重要性，但它们并没有解决争论-这样做需要解释我们在MML州发现的更高的AMU。我们建议调查四种替代解释：（a）通过MML直接增加AMU~（B）通过MML间接增加AMU，通过更有利的态度和/或增加的可用性介导~（c）MML和AMU相关，因为更高的使用和更有利的态度已经表征了通过MML的状态~或（d）存在互惠过程，这样，使用率较高和态度较好的州通过了MML，这进一步增加了AMU的风险。我们将使用自1991年以来每年在监测未来（MTF）调查中收集的超过1，000，000名青少年的时间序列数据进行研究。 由于方法的谨慎一致性（例如， 程序，问卷）多年来，MTF是最大的数据集，具有关于MML和AMU的相关信息，包括关键利益的潜在媒介，包括与大麻有关的态度（例如， 不赞成（感知风险）和感知大麻可用性。 在整个研究过程中，新数据将 增加了州MML的变化，以及MTF每年调查的另外47，000名学生。将使用最先进的统计方法（后分层的多水平回归建模）分析数据。我们将研究每年的州MML和AMU，测试相对于国家趋势的州内趋势，并探索不同的时间滞后。 分析将 将个人层面的青少年态度和感知的可用性作为潜在的中介，以及在州一级定义的变量（例如， 人口对大麻的态度，国家人口构成，大麻逮捕率）从人口普查和其他数据来源作为MML通过的潜在决定因素。此外，我们将探讨状态MML的变化（例如， 法律允许的）影响结果，性别，SES和种族/民族是否缓和MML和AMU之间的关系，以及关系是否具体到大麻或推广到其他物质。 调查小组包括来自哥伦比亚大学、密歇根大学的专家，以及兰德公司/国家经济研究局的MML专家，他们建立在先前存在的合作基础上。 NIDA PA 11-230鼓励对MML的研究。这项研究的信息将在科学上令人兴奋，并具有巨大的公共卫生意义。 公共卫生相关性：预防青少年大麻使用是NIDA的主要兴趣（见NIDA 2010战略计划），但很少有人知道医用大麻法律是否会导致青少年大麻使用增加，这使得关于这些法律与青少年大麻使用之间关系的辩论存在争议，而不是以证据为基础。 这项拟议中的研究将按州分析自1991年以来每年进行的全国青少年调查（目前总计超过100万青少年）的数据，以提供急需的信息。研究结果将为卫生科学家、政策制定者和公众在法律和公共卫生教育活动方面的预防工作提供信息。

DESCRIPTION (provided by applicant): Since 1996, 16 states have passed laws legalizing medical use of marijuana, and other states are considering such laws. With little scientific evidence available on whether these fast-changing laws lead to increased illicit adolescent marijuana use (AMU), the issue is now largely a matter of debate. Recently, using data from two national surveys, we showed that states with medical marijuana laws (MML) had significantly higher prevalence of adolescent (Wall et al., 2011) and adult marijuana use (Cerda et al., in press) than other states. The results underscore the importance of further research on MML and AMU, but they do not resolve the debate~ doing so requires explaining the higher AMU we found in states with MML. We propose to investigate four alternative explanations: (a) passage of MML directly increases AMU~ (b) passage of MML indirectly increases AMU, mediated by more favorable attitudes and/or increased availability~ (c) MML and AMU are associated because higher use and more favorable attitudes already characterize states that pass MML~ or (d) a reciprocal process exists, such that states with higher use and more favorable attitudes pass MML, which then further increase the risk for AMU. We will conduct the study using time series data from >1,000,000 adolescents collected annually since 1991 in the Monitoring the Future (MTF) survey. Due to the careful consistency in methods (e.g., procedures, questionnaires) across the years, MTF is the largest dataset available with relevant information on MML and AMU, including potential mediators of key interest, including attitudes related to marijuana (e.g., disapproval~ perceived risk), and perceived marijuana availability. Throughout the study, new data will be added on changes in state MML, and from the additional ~47,000 students surveyed yearly in the MTF. Data will be analyzed using state-of-the-art statistical methods (multilevel regression modeling with poststratification). We will examine yearly state MML and AMU, testing within-state trends relative to national trends, and explore varying time lags. Analyses will incorporate individual-level adolescent attitudes and perceived availability as potential mediators, and variables defined at the state level (e.g., population attitudes towards marijuana, state demographic composition, marijuana arrest rates) from Census and other data sources as potential determinants of MML passage. Further, we will explore whether variations in state MML (e.g., what the laws permit) influence the results, whether gender, SES and race/ethnicity moderate the relationship between MML and AMU, and whether relationships are specific to marijuana or generalize to other substances. The investigative team includes experts from Columbia University, University of Michigan, and a RAND/NBER expert on MML, building on pre-existing collaborations. NIDA PA 11-230 encourages research on MML. Information from the study will be scientifically exciting and have enormous public health significance. PUBLIC HEALTH RELEVANCE: Preventing adolescent marijuana use is a major interest of NIDA (see NIDA 2010 Strategic Plan), but little is known about whether medical marijuana laws lead to increased adolescent marijuana use, leaving the debate about the relationship of these laws to teen marijuana use controversial and not evidence-based. The proposed study will analyze data, by state, from yearly national surveys of adolescents conducted since 1991 (now totaling over 1,000,000 adolescents) to provide this much-needed information. The findings will inform the prevention efforts of health scientists, policy-makers, and the general public in terms of laws and public health education campaigns.