Marijuana

Brief Introduction

As more and more jurisdictions move towards some form of locally legitimate availability for marijuana, science and public health are struggling to keep up. Currently nine stateshave “legalized” marijuana for recreational use and another 23 states have some formof “medical” marijuana availability. Marijuana stands apart as the only illicit drug that hasincreased in use since 2007 with almost 20 million users in the United States (about 7.5% of the total population aged 12 and over). The Monitoring the Future (MTF) survey estimates that marijuana is one of the most popular drugs used by high school seniors, eclipsing tobacco and alcohol. However, the MTF also notes that marijuana use has not increased significantly during the current legalization phase. Having said that, it is important to note that some states where marijuana is legal are not included in the MTF survey.

Research on prevention of marijuana use can be complex due to several factors including the mixed legal status of marijuana across the country and the instability of itsstatus as an illicit drug. In addition, the drug’s status as a Schedule I substanceprecluded almost all legitimate, U.S.-based research on its effects, its impact on communities, and subsequently, strategies for prevention. Much of the research on this topic includes assertions that, in many ways, marijuana is similar to alcohol and tobacco in terms of its relationship to community distribution mechanisms. This approach advocates for utilizing proven strategies for tobacco and alcohol to control a legitimized marijuana marketplace. At this stage controlled, experimental research on the efficacy of environmental strategies for marijuana use is sparse. This research indicates that specific, targeted, appropriately messaged communication campaigns can be effective at reducing use, as well as school policies that include strong enforcement and in- school punishments and counseling for use.

Methods

Data Sources and Searches

We followed a predefined protocol to identify and select peer-reviewed manuscripts to include in this literature review. We searched EBSCO for peer-reviewed articles that examined environmental strategies to address marijuana use. Our search included articles that were published between January 1, 2008 and August 31, 2018. Individual searches were conducted for each intervention (see Table M1). Searches were limited to peer-reviewed, scholarly articles from the United States.

 Table M1.

Intervention	Search Strategy	Articles Identified (#)	Articles Selected (#)
Communication Campaigns	(“Marijuana”) AND (“Media” OR “Communication Campaign” OR “Information Campaign” OR “Above The Influence”) AND (“Youth”) NOT (“Presidential”) NOT (“Obama”) NOT (“Election”)	37	3
School Policies	(“Marijuana”) AND (“School Policies”) AND (“Adolescence” OR “12 to 17”) AND (“Prevention”)	82	1

Study Selection

All titles and abstracts were independently screened and articles that were considered relevant advanced to full-text review. This included those articles directly pertaining to environmental strategies relating to marijuana in the United States. Table M1 includes the number of relevant manuscripts for each intervention.

Data Extraction and Quality Assessment

One researcher (WG) independently read selected articles. Using a standardized article assessment form, WG captured data on study design (including type of study, whether or not the study was a replication study, use of reliable and valid instruments, and measurement of intervention dose), standardization of the intervention, population studied, setting, and sample size. A brief description and overview of findings were documented. Additionally, the investigators coded the type of intervention and environmental strategy.

Three investigators (WG, MW, and KW) reviewed and discussed all the articles that underwent full-text review and data extraction in order to assess the evidence for each intervention using the operational definitions and Matrix of Level of Effectiveness, described in this report’s Introduction. The interventions were identified as: evidence- based, promising, or insufficient evidence / not evidence-based. Results are presented below.

Results

Communication Campaigns

Evidence Level	Evidence-based Rationale: While all three articles are peer-reviewed, the twoarticles testing “Above the Influence” have the mostsignificant findings, with thousands of subjects and national samples.
Transparency	3 peer-reviewed articles
Research	3 experimental
Standardization	Unknown
Replication	Yes
Fidelity Scale	Unknown
Meaningful Outcomes	These studies reflect that various types of communication campaigns are effective at either reducing marijuanainitiation and use. Specifically, “Above the Influence”decreased marijuana use and impacted youth attitudes about marijuana use. However, focusing on the “gateway drug” aspect of marijuana appears to increase marijuanause. Messages should focus on elements of the theory of reasoned action (TRA), persuasion theory, and the health belief model.

References

Scheier, L. M., Grenard, J. L., & Holtz, K. D. (2011). An empirical assessment of the Above the Influence advertising campaign. Journal of Drug Education, 41(4), 431–461. https://doi.org/10.2190/DE.41.4.f

Slater, M. D., Kelly, K. J., Lawrence, F. R., Stanley, L. R., & Comello, M. L. G. (2011). Assessing media campaigns linking marijuana non-use with autonomy andaspirations: “Be Under Your Own Influence” and ONDCP’s “Above the Influence.” Prevention Science, 12(1), 12–22. https://doi.org/10.1007/s11121- 010-0194-1

Yzer, M. C., Cappella, J. N., Fishbein, M., Hornik, R., & Ahern, R. K. (2003). The Effectiveness of Gateway Communications in Anti-Marijuana Campaigns. Journal of Health Communication, 8(2), 129–143. https://doi.org/10.1080/10810730305695

School Policies

Evidence Level	Promising Rationale: While the article discusses policies in both the U.S. and Australia, the sample size is large and has a strong experimental design.
Transparency	1 peer-reviewed articles
Research	1 experimental and no quasi-experimental studies
Standardization	UNK
Replication	Unknown
Fidelity Scale	Unknown
Meaningful Outcomes	Research describes elements of school policies that are associated with increased or decreased marijuana use. Interestingly, evidence supports the idea that out-of-school suspension was associated with increased marijuana use. Recommended policies include enforcing nonuse policies and remedial (as opposed to punitive) sanctions for violations.

References

Evans-Whipp, T. J., Plenty, S. M., Catalano, R. F., Herrenkohl, T. I., & Toumbourou, J. W. (2015). RESEARCH AND PRACTICE. Longitudinal Effects of School Drug Policies on Student Marijuana Use in Washington State and Victoria, Australia. American Journal of Public Health, 105(5), 994–1000. https://doi.org/10.2105/AJPH.2014.302421

References 

1. Evans-Whipp, T. J., Plenty, S. M., Catalano, R. F., Herrenkohl, T. I., & Toumbourou, J. W. (2015). RESEARCH AND PRACTICE. Longitudinal Effects of School Drug Policies on Student Marijuana Use in Washington State and Victoria, Australia. American Journal of Public Health, 105(5), 994–1000. https://doi.org/10.2105/AJPH.2014.302421

2. Scheier, L. M., Grenard, J. L., & Holtz, K. D. (2011). An empirical assessment of the Above the Influence advertising campaign. Journal of Drug Education, 41(4), 431–461. https://doi.org/10.2190/DE.41.4.f

3. Slater, M. D., Kelly, K. J., Lawrence, F. R., Stanley, L. R., & Comello, M. L. G. (2011). Assessing media campaigns linking marijuana non-use with autonomyand aspirations: “Be Under Your Own Influence” and ONDCP’s “Above theInfluence.” Prevention Science, 12(1), 12–22. https://doi.org/10.1007/s11121- 010-0194-1

4. Yzer,M.C.,Cappella,J.N.,Fishbein,M.,Hornik,R.,&Ahern,R.K.(2003).The Effectiveness of Gateway Communications in Anti-Marijuana Campaigns. Journal of Health Communication, 8(2), 129–143. https://doi.org/10.1080/10810730305695