Cannabis Use, Public Health, and Traffic Safety: Outcomes from the Scientific Literature and Expert Opinion on the Potential Impacts of Rescheduling

Abstract

Introduction

Cannabis is currently a Schedule I controlled substance under the Federal Comprehensive Drug Abuse Prevention and Control Act (Controlled Substances Act, or CSA for short). The Drug Enforcement Administration has an ongoing process to consider moving cannabis to a Schedule III drug, thereby reducing the associated penalties. Arguments have been made in recent years inviting public support for rescheduling and legalization of cannabis in the United States.

In 2017, a committee of experts gathered by the National Academies of Sciences, Engineering, and Medicine (NASEM) concluded that there was a lack of scientific research regarding the health effects of using cannabis and cannabis-derived products. Much more modest in scope, the current report endeavors to provide a picture of the current state of scientific knowledge on the impact of cannabis use as it is associated with the factors established by the Controlled Substances Act for drug scheduling.

Methodology

This report included two main tasks. Part I offers a detailed review of the literature, including a description of the approach used to build the review; a brief portrayal of the biological mechanisms by which cannabis components affect (or could affect) human health and behavior; and a summary of findings with references. Additionally, key takeaways are presented in non-academic layman terms. Part II involved focus groups with subject matter experts, who shared their opinion on the potential impacts of cannabis rescheduling on public health and traffic safety.

For the literature review, using the 2017 NASEM report as the starting point, the research team conducted a search of the literature using a variety of scholarly and scientific databases as well as a review of resources available from professional associations and organizations. The results of the search were synthesized and summarized, and were aligned with factors considered under the CSA: Pharmacology, Potential for Abuse, and Public Health Impacts. In addition to the full results and key takeaways available in the technical report, key findings from the literature were distilled into fact sheets aligning with the aforementioned factors, with the traffic safety and other public health impacts addressed separately.

This review of the literature was complemented by two focus groups of 14 expert panelists who brought together various viewpoints about future public health and traffic safety scenarios that may occur should the rescheduling of cannabis to be approved. The invitees had expertise in multiple public health arenas that might be impacted by the rescheduling of marijuana on the federal level and included representatives from organizations and agencies that have an interest in the topics of marijuana use and related policy.

Key Findings

In general, most of the experts agreed that the main concern coming from the rescheduling relates to how the public would perceive the rescheduling. Panelists were concerned that the public would perceive the rescheduling as an indication that “it [cannabis] is safe,” increasing the likelihood that cannabis-related negative health and safety consequences would develop. On the other hand, participants agreed that the rescheduling would allow researchers to fully study the public-health consequences of cannabis, as federal restrictions on the type and strength of cannabis allowed to be used in federally funded research has limited the types of research that can be conducted. Experts also suggested that cannabis rescheduling would have an impact on traffic safety—that rescheduling could translate into an increase in the unsafe use of cannabis among drivers. The experts overwhelmingly supported continued research to understand both the use of cannabis alone, as well as its cognitive impact and impairment associated with driving. Participants also supported research to develop more tools to assess impairment and continued training efforts for law enforcement officers who are evaluating impairment during a roadside stop.