Impacts of Changing Marijuana Policies on Alcohol Use in the United States

Abstract

Background Marijuana policies are rapidly evolving. In the United States, recreational use of marijuana is now legal in four states and medical marijuana is legal in 23 states. Research evaluating such policies has focused primarily on how policies affect issues of price, access to, use, and consequences of marijuana. Due to potential spillover effects, researchers also need to examine how marijuana policies may impact use and consequences of alcohol. Methods The current paper is a critical review of articles evaluating alcohol outcomes associated with marijuana decriminalization, medical marijuana legalization, and non-medical or recreational marijuana legalization. We identified articles and reports through (1) online searches of EBSCO host database including Academic search premier, Econlit, Legal collection, Medline, Psych articles, and PsycINFO, as well as PubMed and Google Scholar databases; (2) review of additional articles cited in papers identified through electronic searches; and (3) targeted searches of state and local government records regarding marijuana law implementation. We reviewed studies with respect to their data sources and sample characteristics, methodology, and the margin of alcohol and marijuana use, timing of policy change, and the aspects of laws examined. Results The extant literature provides some evidence for both substitution (i.e., more liberal marijuana policies related to less alcohol use as marijuana becomes a substitute) and complementary (i.e., more liberal marijuana policies related to increases in both marijuana and alcohol use) relationships in the context of liberalization of marijuana policies in the United States. Conclusions Impact of more liberal marijuana policies on alcohol use is complex, and likely depends on specific aspects of policy implementation, including how long the policy has been in place. Further, evaluation of marijuana policy effects on alcohol use may be sensitive to the age group studied and the margin of alcohol use examined. Design of policy evaluation research requires careful consideration of these issues.

Marijuana Legalization and Parents' Attitudes, Use, and Parenting in Washington State

“…So, many of these parents were experiencing prime child-rearing years with children approaching ages of high risk for substance use initiation [36]. These features of the sample provided an opportunity to understand parental responses to a changing risk landscape among a diverse sample of parents that may reveal trends not evident in more homogenous samples [37, 38]. At the same time, the studies noted above suggest that these parents were not substantially dissimilar to national samples in some key marijuana attitudes and behaviors.…”

Heterogeneity of State Medical Marijuana Laws and Adolescent Recent use of Alcohol and Marijuana: Analysis of 45 States, 1991–2011

“…24,25 Unfortunately, there is limited research on how MML studies are associated with changes in alcohol use. It is particularly important to examine whether MMLs are associated with decreases in alcohol use and increases in marijuana use, i.e., “the substitution hypothesis,” or with increases in both use, i.e., “the complement hypothesis.” 26 In a recently published systematic review of studies that examined changes in alcohol use in relation to marijuana policies, Guttmannova et al found evidence for both hypotheses. 26 However, many of the studies included in that review were conducted with data from the 1990s and are now dated.…”

Focus Groups of Parents and Teens Help Develop Messages to Prevent Early Marijuana Use in the Context of Legal Retail Sales

“…Although sale to youth under age 21 remains illegal, it is possible that legalization of retail sales will lead to greater exposure to and availability of marijuana for adolescents. Community norms influenced by legalization may lead to more early initiation of marijuana use which, in turn, may lead to higher rates of heavy use and dependence (Guttmannova et al, 2016). Early onset and heavy use have been shown to disrupt individual functioning in school, peer, and family life (Hall, Degenhardt, & Teesson, 2009; Jacobus, Bava, Cohen-Zion, Mahmood, & Tapert, 2009).…”