Purpose

Past 30-day tobacco and marijuana use commonly occur among adolescents. It is unclear whether use of one product precedes the other, especially given the new climate surrounding marijuana legalization and the increasing popularity of e-cigarettes.

Methods

Six-panel cross-lagged regression models, with six months between each panel/Wave (2014–17), were used to model stability paths, bi-directional paths, and comorbid paths (i.e., correlations) between past 30-day use of marijuana and tobacco products. Data were derived from three cohorts of adolescents (n = 3907; weighted N = 461,069) in 6th, 8th, and 10th grades at baseline.

Results

Few bidirectional relationships between past 30-day tobacco and marijuana use were observed in early adolescence (6th grade). During the middle adolescence developmental period (8th grade), past 30-day marijuana use was prospectively associated with greater risk of past 30-day tobacco use. In late adolescence (10th grade), increased odds of past 30-day marijuana use given prior past 30-day e-cigarette use, and vice versa, were observed. For all cohorts, stability paths were common, especially for past 30-day marijuana use. Comorbid use was common in middle adolescence (8th grade) but small in magnitude.

Conclusions

This is the first study to longitudinally situate comorbid, past 30-day use of tobacco and marijuana and simultaneously examine bi-directional past 30-day use of these products for adolescents. Marijuana use more often and more strongly predicted subsequent tobacco use than the reverse, especially during middle adolescence (13–15 years old). Marijuana use should be considered when creating interventions that address adolescent e-cigarette use in the U.S.

中文翻译：

---

德克萨斯州青少年群体中烟草和大麻使用的多向途径，包括共病使用：六波交叉滞后模型

 目的

过去 30 天吸食烟草和大麻的情况常见于青少年。目前尚不清楚一种产品的使用是否先于另一种产品，特别是考虑到围绕大麻合法化的新气候和电子烟的日益普及。

 方法

六面板交叉滞后回归模型，每个面板/波浪之间有六个月（2014-17），用于对过去 30 天使用药物之间的稳定性路径、双向路径和共病路径（即相关性）进行建模大麻和烟草制品。数据来自基线时六年级、八年级和十年级的三组青少年（n = 3907；加权 N = 461,069）。

 结果

在青春期早期（六年级），几乎没有观察到过去 30 天的烟草使用和大麻使用之间的双向关系。在青春期中期（八年级），过去 30 天吸食大麻与过去 30 天吸食烟草的风险较高相关。在青春期后期（10 年级），观察到过去 30 天使用大麻的几率比过去 30 天使用电子烟的几率增加，反之亦然。对于所有群体来说，稳定性路径都很常见，尤其是对于过去 30 天吸食大麻的人来说。合并症使用在青春期中期（八年级）很常见，但程度较小。

 结论

这是第一项纵向定位青少年过去 30 天使用烟草和大麻的共病情况，并同时检查青少年过去 30 天使用这些产品的双向情况的研究。与相反情况相比，吸食大麻更频繁、更能预测随后的烟草使用，尤其是在青春期中期（13-15 岁）。在制定解决美国青少年电子烟使用问题的干预措施时应考虑大麻的使用