Predictors and consequences of young adult marijuana use and concurrent and simultaneous alcohol use: Month to month variation across 24 consecutive months

摘要 酒精和大麻是年轻人（YAs）中最常用的物质， 常常是纠缠在一起。随着最近几个州大麻合法化的变化，了解大麻合法化是至关重要的。 大麻的使用可能对酒精的使用产生影响。在像华盛顿这样的州， 娱乐性大麻使用是成年人（21岁以上）的法律的，重要的是要研究这两个 物质正在被使用，并在YAs之间相互作用。大麻使用的增加可能与 如果大麻作为酒精的替代品，酒精的使用会减少，或者如果大麻作为酒精的替代品， 大麻和酒精的使用会随着时间的推移而增加。迄今为止， 研究设计没有提供数据，以允许检查，在个人层面上，是否有 随着时间的推移，预期的逐月替代或互补效应，迄今为止还没有研究 在大麻合法化的背景下研究了这些影响。此外，研究有限， 关于大麻和酒精使用重叠的不同模式的短期后果。 同时酒精和大麻（SAM;即，在同一场合，因此效果重叠）使用是 与特定急性风险相关，包括严重的法律的、学术、人际、身体和精神风险 健康问题然而，大多数使用大麻的酒精使用者同时使用大麻。本 一项申请建议对招募的青年进行前沿纵向研究， 在大麻合法化的时期，项目过渡（R 01 AA 022087） 连续24个月从YAs（研究期间年龄为18-25岁）收集每月数据。Yas （N=779）年龄在18岁至23岁之间，报告在前一年至少饮用一种酒精饮料的人， 招募并加入了过渡计划这项由NIAAA资助的研究重点是酒精使用;然而， 还提供了关于每月大麻使用、SAM使用和相关后果的丰富数据集。本 本申请提出了该独特纵向数据集的二次数据分析。从这个成本中得出的结论- 利用每月数据进行有效的二次分析研究，将使我们能够以创新和批判的方式回答问题。 重要的问题，增加我们的知识的同时发生的酒精和大麻的使用，是否 大麻可能与酒精有替代或补充作用，同时与酒精之间的联系， SAM使用的短期后果，以及这些后果如何影响未来的使用， 重要的自然发生的生活事件（即，第21章影响使用轨迹该项目将提供 回答新的研究问题，是公共卫生和政策的重要性，并有重要的 对青年预防和干预战略的影响。

ABSTRACT Alcohol and marijuana are the most commonly used substances among young adults (YAs) and their use is often intertwined. With recent changes in legalization of marijuana in several states, it is critical to understand the impact marijuana use may have on alcohol use. In states like Washington where both alcohol and recreational marijuana use are legal for adults (aged 21+), it is important to examine how these two substances are being used and interacting among YAs. Increases in marijuana use may be associated with decreases in alcohol use if marijuana acts as a substitute for alcohol, or it may lead to greater alcohol use if there are complementary effects such that both marijuana and alcohol use increase over time. To date, most study designs have not provided data to allow examination, at the individual level, of whether there are prospective month-to-month substitution or complementary effects over time and there are no studies to date that have examined these effects in the context of legalized marijuana. Also, there is limited research with respect to short-term consequences of different patterns of overlapping marijuana and alcohol use. Simultaneous alcohol and marijuana (SAM; i.e., on the same occasion so the effects overlap) use is associated with particular acute risks including serious legal, academic, interpersonal, physical and mental health problems. However, most alcohol users who use marijuana do so simultaneously. The present application proposes to conduct secondary analyses from a cutting-edge longitudinal study of YAs recruited from the community in WA State during the time of legalized marijuana. Project Transitions (R01AA022087) collected monthly data across 24 consecutive months from YAs (ages 18-25 over the course of the study). YAs (N=779) between ages 18 and 23 who reported consuming at least one alcoholic drink in the prior year were recruited and enrolled into Project Transitions. This NIAAA-funded study focused on alcohol use; however, a rich set of data on monthly marijuana use, SAM use, and related consequences is also available. The present application proposes secondary data analysis of this unique longitudinal dataset. Findings from this cost- efficient secondary analysis study utilizing monthly data will allow us to answer innovative and critically important questions that increase our knowledge of the co-occurrence of alcohol and marijuana use, whether marijuana may have substitution or complementary effects with alcohol, associations between concurrent and SAM use with short-term consequences and how these consequences may influence future use and how important naturally occurring life events (i.e., turning 21) influence trajectories of use. The project will provide answers to novel research questions that are of public health and policy importance and have important implications for young adult prevention and intervention strategies.