Marijuana policy opinions in Washington state since legalization: Would voters vote the same way?

Health, safety, and socioeconomic impacts of cannabis liberalization laws: An evidence and gap map

Background

Globally, cannabis laws and regulations are rapidly changing. Countries are increasingly permitting access to cannabis under various decriminalization, medicalization, and legalization laws. With strong economic, public health, and social justice incentives driving these domestic cannabis policy reforms, liberalization trends are bound to continue. However, despite a large and growing body of interdisciplinary research addressing the policy-relevant health, safety, and socioeconomic consequences of cannabis liberalization, there is a lack of robust primary and systematic research that comprehensively investigates the consequences of these reforms.

Objectives

This evidence and gap map (EGM) summarizes the empirical evidence on cannabis liberalization policies. Primary objectives were to develop a conceptual framework linking cannabis liberalization policies to relevant outcomes, descriptively summarize the empirical evidence, and identify areas of evidence concentration and gaps.

Search Methods

We comprehensively searched for eligible English-language empirical studies published across 23 academic databases and 11 gray literature sources through August 2020. Additions to the pool of potentially eligible studies from supplemental sources were made through November 2020.

Selection Criteria

The conceptual framework for this EGM draws upon a legal epidemiological perspective highlighting the causal effects of law and policy on population-level outcomes. Eligible interventions include policies that create or expand access to a legal or decriminalized supply of cannabis: comprehensive medical cannabis laws (MCLs), limited medical cannabidiol laws (CBDLs), recreational cannabis laws (RCLs), industrial hemp laws (IHLs), and decriminalization of cultivations laws (DCLs). Eligible outcomes include intermediate responses (i.e., attitudes/behaviors and markets/environments) and longer-term consequences (health, safety, and socioeconomic outcomes) of these laws.

Data Collection and Analysis

Both dual screening and dual data extraction were performed with third person deconfliction. Primary studies were appraised using the Maryland Scientific Methods Scale and systematic reviews were assessed using AMSTAR 2.

Main Results

The EGM includes 447 studies, comprising 438 primary studies and nine systematic reviews. Most research derives from the United States, with little research from other countries. By far, most cannabis liberalization research focuses on the effects of MCLs and RCLs. Studies targeting other laws-including CBDLs, IHLs, and DCLs-are relatively rare. Of the 113 distinct outcomes we documented, cannabis use was the single most frequently investigated. More than half these outcomes were addressed by three or fewer studies, highlighting substantial evidence gaps in the literature. The systematic evidence base is relatively small, comprising just seven completed reviews on cannabis use (3), opioid-related harms (3), and alcohol-related outcomes (1). Moreover, we have limited confidence in the reviews, as five were appraised as minimal quality and two as low quality.

Authors’ Conclusions

More primary and systematic research is needed to better understand the effects of cannabis liberalization laws on longer-term-and arguably more salient-health, safety, and socioeconomic outcomes. Since most research concerns MCLs and RCLs, there is a critical need for research on the societal impacts of industrial hemp production, medical CBD products, and decriminalized cannabis cultivation. Future research should also prioritize understanding the heterogeneous effects of these laws given differences in specific provisions and implementation across jurisdictions.

Characteristics of the Washington cannabis market from 2014 to 2016

BACKGROUND

The state of Washington legalized cannabis for adult use in 2012 and retail stores began to open in 2014. While details of the legal market have been tracked by the state, the total market for cannabis and characteristics of purchasers can only be identified through surveys.

METHODS

Six cross-sectional samples of the Privatization of Spirits in Washington (PSW) surveys were collected between January 2014 and October 2016 with two in each year. Random digit dial procedures were used to recruit a sample aged 18 and older, with 40% of cases from mobile phones. A total of 5492 respondents participated. Analyses of the population-weighted sample utilized purchasing amounts and frequencies, use frequency and related measures to estimate total and mean amounts and expenditures. Sensitivity analyses were conducted for key assumptions.

RESULTS

The market for cannabis flower is estimated to have increased from 158 metric tons and $1.23 billion in 2014 to 222 metric tons and $1.7 billion in 2016, with little change from 2014 to 2015. Purchases from legal sources, retail and dispensaries, were estimated at 69% of the total market. Daily or near daily (DND) users accounted for about 83% of sales in 2014, rising to 91% in 2016. The prevalence of past year use rose substantially from 25% in 2014 to 32% in 2016, with DND use rising from 10.2 to 11.3%. Average purchase amounts for DND users rose from 291 g in 2014 to 374 g in 2016, while mean amounts among non-DND users declined from 78 to 28.6 g.

CONCLUSIONS

The expansion of retail cannabis stores in Washington appears to have led to increased market size in 2016 with all of the increase attributed to DND users. Frequent users may be important to consider in legalization evaluations.

Estimating Usual Grams per Day of Marijuana Use from Purchases

BACKGROUND

Quantifying average amounts of marijuana used per day or per occasion of use helps inform understanding population-level patterns of use and use-related harm, but better estimates and estimation methods are needed. Users have difficulty in reporting use amounts, but purchase amounts may be more clearly recalled.

METHODS

Measures of individual's use and purchasing frequency and details of purchases such as the amounts and products bought and the cost of these were collected in six cross-sectional representative surveys of the population 18 and older in the state of Washington from 2014 to 2016. Analyses utilize purchase information on both flower and other marijuana products to estimate mean amounts per use day and predict use amounts for non-purchasers.

RESULTS

Mean marijuana use per use day among purchasers was 1.35 grams and non-purchasers estimated mean use amount per day was 0.71 grams. Lower mean use per day was a found for women and the most frequent users. Based on these estimates, total past year marijuana use for purchasers had a mean of 184.8 grams and the mean for non-purchasers was 28 grams.

CONCLUSIONS

Methods based on purchasing details can be used to estimate individual's marijuana quantity per occasion and total use amount per year, providing additional outcome measures for analyses of predictors of individual marijuana consumption and facilitating more detailed analyses of risks for marijuana harms.

Drug Legalization, Elite Support, and Government Effectiveness in Latin America

In Latin America, the legalization of drugs—where it occurred—has been driven mainly by elites, although much attention has been placed on public opinion. Considering that efforts toward legalization have been top-down, analysis should concentrate on opinions of the governing elites. To undertake such an analysis, we draw on data from surveys conducted in 18 Latin American parliaments (2012–2018), and we examine elite perspectives on the legalization of all drugs. Results from a Bayesian hierarchical logistic analysis show that in countries where the government is less effective, and where public health problems persist, legislators are less likely to support legalization. We argue that this is due to a lack of trust by MPs in legalization as a solution to trafficking. Wherever those concerned with drug trafficking see the current government as problematic, they will be less likely to support so challenging and complex a policy as drug legalization.

GEOGRAPHICAL ACCESS TO RECREATIONAL MARIJUANA

We investigate whether adult marijuana use in Washington responds to increased local access as measured by drive time to the nearest legal marijuana retailer as well as measures of retail density. Using survey data from the Behavioral Risk Factor Surveillance System, we find that as retailers open closer to where they live, more individuals use marijuana and more frequently. These effects are concentrated among young adults (ages 18-26), women, and rural residents. Controlling for distance to the nearest retailer, we find that whether retail density affects marijuana use depends on how it is measured.

Drug Legalization and Decriminalization Beliefs Among Substance-using and Nonusing Individuals

OBJECTIVES

There has been advocacy for legalization of abusable substances, but systematic data on societal beliefs regarding such legalization are limited. People who use substances may have unique beliefs about legalization, and this study assessed whether they would be in favor of drug legalization/decriminalization. It was hypothesized that those who use particular drugs (especially marijuana) would support its legalization/decriminalization, but that this would not be the case across all classes (especially opioids and stimulants).

METHODS

A nationwide sample of 506 adults were surveyed online to assess demographic characteristics, substance misuse, and beliefs regarding drug legalization/decriminalization. Legalization/decriminalization beliefs for specific drugs were assessed on an 11-point scale (0, strongly disagree; 10, strongly agree).

RESULTS

For persons with opioid misuse (15.4%), when asked about their agreement with: "heroin should be legalized," the mean score was 4.6 (SEE = 0.4; neutral). For persons with stimulant misuse (12.1%), when asked about their agreement with: "cocaine should be legalized," the score was 4.2 (0.5). However, for persons with marijuana misuse (34.0%), when asked about their agreement with: "medical marijuana should be legalized" the score was 8.2 (0.3; indicating agreement), and for "recreational marijuana" the score was also 8.2 (0.3).

CONCLUSIONS

These results suggest that persons who used marijuana strongly support the legalization of both recreational and medical marijuana, whereas persons who primarily have opioid or stimulant misuse have less strongly held beliefs about legalization of substances within those respective categories. By including those who misuse drugs, these data assist in framing discussions of drug legalization and have the potential to inform drug policy considerations.

Is substance use disorder more prevalent in patients with hidradenitis suppurativa?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that disproportionately affects women and is associated with significant physical and psychosocial impact. Recent studies have reported an increased prevalence of substance abuse among patients with HS, including increased alcohol, opioid, and cannabis use. Whether substance use disorder is more prevalent among patients with HS is controversial because these data come from small studies and a major confounder is that patients with HS are often prescribed opioids for HS-associated pain. This review summarizes the current literature on substance use in HS to investigate whether substance use disorder is more likely in this patient population. We also highlight possible cofounders and areas of unmet need in HS that are potential causes of abuse, such as adequate pain control and impaired quality of life, and suggest opportunities for provider intervention. Evidence suggests that there is an increased prevalence of substance use disorder in patients with HS, but the full extent is still difficult to determine. However, with early screening and appropriate referrals to specialists, dermatologic providers may properly intervene and prevent substance use disorder in patients with HS.

From prohibition to regulation: A comparative analysis of the emergence and related outcomes of new legal cannabis policy models (Colorado, Washington State and Uruguay)

An effective approach to drug regulation is a growing concern. Since 2012, 10 US States and Uruguay have taken the step to revoke prohibition and legalize the recreational cannabis market. Based on the findings from a study ('Cannalex') carried out in 2015-2017 in Colorado, Washington and Uruguay by the French Monitoring Centre for Drugs and Drug Addiction (OFDT) and the Institute of Security and Justice (INHESJ), relying on a hundred of in-depth interviews analyzed in line with the existing official statistics and studies, this paper shows heterogeneous policy-making models and contexts for reform. It also examines the early outcomes of the cannabis policy change. A mixed picture is emerging from the regulatory regimes currently implemented. This paper discusses the reform processes and their early outcomes, with a specific focus on the less documented area: the political processes that led to legalizing cannabis, analyzed with qualitative data. It argues that the different outcomes reported across Colorado, Washington and Uruguay are framed by the regulatory options that were taken, depending on specific dynamics of reform. The discussion focuses on some hot topics raised by the effective regulations, stressing that the array of cannabis regulatory options is a public debate that has just begun.

A Systematic Review of the Efficacy of Cannabinoid Agonist Replacement Therapy for Cannabis Withdrawal Symptoms

BACKGROUND

About 30% of regular cannabis users report withdrawal symptoms on cessation of prolonged use, such as irritability, insomnia, decreased appetite, depressed mood, anxiety, and restlessness. However, among highly dependent and/or in-treatment users, the incidence of withdrawal can be even higher, reaching up to 50-95% of individuals. This syndrome was only recognized by the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) as a diagnosis with specific criteria in 2013. The treatment options are poor, with high rates of relapse and non-responders. In this scenario, agonist replacement therapy with cannabinoids has demonstrated potential as a promising therapeutic intervention, with a series of studies having been carried out in recent years.

OBJECTIVE

This review sought to summarize trials with cannabinoid agonist replacement therapy for cannabis withdrawal symptoms with the aim of evaluating the efficacy of this pharmacological intervention.

DATA SOURCES

We entered the following search terms on the PubMed, Web of Science and PsycINFO databases: (marijuana OR marihuana OR cannabis OR THC OR tetrahydrocannabinol OR hashish OR pot) AND (treatment OR medication) AND (withdrawal OR abstinence) AND (dronabinol OR nabilone OR nabiximols OR sativex OR cesamet OR synthetic cannabinoid). The date of the most recent search was September 2017.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

Original trials, published in English, performed on humans and dealing with cannabis users who were treated for cannabis withdrawal symptoms using synthetic cannabinoids were all included in the present systematic review. Quality and risk of bias across studies were assessed using a Cochrane tool.

STUDY APPRAISAL AND SYNTHESIS METHODS

The first, second, and last authors read the abstracts of all studies found in the search (n = 243). The inclusion and exclusion criteria were applied, and 233 articles were excluded. The first and second authors independently developed a data extraction sheet based on the included articles.

RESULTS

The present review included ten original articles. Despite the limited number of studies and methodological differences, our findings demonstrate that the use of dronabinol, nabilone, or nabiximols, either alone or in combination with other drugs, shows promise in reducing cannabis withdrawal symptoms, probably with a dose-dependent effect. This has also been considered a safe group of medications with good tolerability and few adverse effects.

LIMITATIONS

No method of handling data and combining results of studies was carried out, representing a limitation of the review.

CONCLUSIONS AND IMPLICATION OF THE KEY FINDINGS

Cannabinoids appear to be a promising group of drugs for the treatment of cannabis withdrawal symptoms. These medications may help decrease the rate of relapse in the treatment of cannabis dependence due to withdrawal symptoms occurring within the first few weeks of treatment.

SYSTEMATIC REVIEW REGISTRATION

The protocol for this review has been registered in the PROSPERO International prospective register of systematic reviews (PROSPERO 2014:CRD42014014118).

Changes in Marijuana Use Across the 2012 Washington State Recreational Legalization: Is Retrospective Assessment of Use Before Legalization More Accurate?

OBJECTIVE

The purpose of this study was to evaluate changes in marijuana use prevalence and user characteristics across the 2012 recreational legalization in Washington State. Differences in change estimates between retrospective and contemporaneous pre-legalization measures are compared and considered in relation to potential social acceptability and illegality effects on reporting.

METHOD

Four representative surveys of the Washington State population 18 years and older were conducted by telephone, two in 2014 and two in 2015, which are combined by year for analyses (N = 3,451). Respondents reported their current past-year use frequency and retrospective frequency of use in 2012 before the election in which legalization was passed. They also provided demographic information and details of alcohol use, including simultaneous use with marijuana.

RESULTS

A small and not statistically significant increase of 1.2 percentage points in past-year use prevalence, from 24.3% (22.3-26.5) to 25.6% (23.6-27.6), was found when combining the surveys. No statistically significant change was found in the prevalence of simultaneous use with alcohol, which decreased from 12.9% (11.3-14.7) to 12.6% (11.0-14.4). In contrast, estimates from the National Survey on Drug Use and Health (NSDUH) indicate substantially increased prevalence, from 15.5% (13.8-17.3) in 2010-2012 to 19.1% (16.9-21.4) in 2013-2014, although this change is not statistically significant. Other findings of interest from the Washington State surveys include new users after legalization tending to be older, White, and moderate drinkers who do not use marijuana simultaneously with alcohol.

CONCLUSIONS

A retrospective pre-legalization measure showed only a small increase in marijuana use prevalence in contrast to larger changes found in prospectively assessed use in the NSDUH. Changes in the social acceptability and legal status of marijuana after legalization may have increased reporting of pre-legalization use compared with concurrent assessments.

Big data on a big new market: Insights from Washington State's legal cannabis market

INTRODUCTION

Voters in eight U.S. states have passed initiatives to legalize large-scale commercial production of cannabis for non-medical use. All plan or require some form of "seed-to-sale" tracking systems, which provide a view of cannabis market activity at a heretofore unimagined level of detail. Legal markets also create a range of new matters for policy makers to address.

DATA

Publicly available data were obtained on approximately 45 million individually priced items purchased in the 35 million retail transactions that took place during the first two and a half years of Washington State's legal cannabis market. Records include product type (flower, extract, lotion, liquid edible, etc.), product name, price, and potency with respect to multiple cannabinoids, notably THC and CBD. Items sold can be traced back up the supply chain through the store to the processor and producer, to the level of identifying the specific production batch and mother plant, the firm that tested the product, and test results.

METHOD

Data visualization methods are employed to describe spatial-temporal patterns of multiple correlated attributes (e.g., price and potency) broken down by product. Text-analytic methods are used to subdivide the broad category of "extracts for inhalation" into more homogeneous sub-categories. To understand the competitiveness of the legal cannabis market in Washington we calculate the Herfindahl-Hirschman index (HHI) for processors and retailers.

RESULTS

Cannabis prices fell steadily and proportionally at the processor and retailer levels. Retail and wholesale price maintained a roughly 3:1 ratio for multiple product types after some initial fluctuations. Although a wide range of edibles are sold, they account for a modest share of consumer spending; extracts for inhalation are a larger and heterogeneous market segment. The HHI indicates the cannabis market is highly competitive at the processor level, but less so for retail markets at the county level.

CONCLUSIONS

Washington's state-legal cannabis market is diverse and rapidly evolving in terms of pricing, products, and organization. Post-legalization, researchers and policy makers may need to think in terms of a family of cannabis products, akin to how we think of new psychoactive substances and amphetamine-type stimulants, not a single drug "cannabis."

Trends and age, period and cohort effects for marijuana use prevalence in the 1984-2015 US National Alcohol Surveys

BACKGROUND AND AIMS

Epidemiological trends show marijuana use in the United States to have increased in recent years. Previous research has identified cohort effects as contributing to the rising prevalence, in particular birth cohorts born after 1945. However, given recent policy efforts to regulate marijuana use at the state level, period effects could also play a contributory role. This study aimed to examine whether cohort or period effects play a larger role in explaining trends in marijuana use.

DESIGN

Using data from seven National Alcohol Surveys, we estimated age-period-cohort decomposition models for marijuana use, controlling for socio-demographic measures.

SETTING

United States.

PARTICIPANTS

US general population aged 18 and older from 1984 to 2015.

MEASUREMENTS

Any past-year marijuana use.

FINDINGS

Results indicated that period effects were the main driver of rising marijuana use prevalence. Models including indicators of medical and recreational marijuana policies did not find any significant positive impacts.

CONCLUSIONS

The steep rise in marijuana use in the United States since 2005 occurred across the population and is attributable to general period effects not linked specifically to the liberalization of marijuana policies in some states.

Support for marijuana legalization in the US state of Washington has continued to increase through 2016

BACKGROUND

Support for the legalization of recreational marijuana continues to increase across the United States and globally. In 2016, recreational marijuana was legalized in the most populous US state of California, as well as three other states. The primary aim of this study was to examine trends in support for recreational marijuana legalization in Washington, a state which has had legal recreational marijuana for almost four years, using data collected over the four years post-legalization. A secondary aim was to examine trends in support for the cultivation of marijuana for personal use.

METHODS

Data come from geographically representative general population samples of adult (aged 18 and over) Washington residents collected over five timepoints (every six months) between January 2014 and April 2016 (N=4101). Random Digit Dial was used for recruitment. Statistical analyses involved bivariate comparisons of proportions across timepoints and subgroups (defined by age, gender, and marijuana user status), and multivariable logistic regression controlling for timepoint (time) to formally test for trend while controlling for demographic and substance use covariates. All analyses adjusted for probability of selection.

RESULTS

Support for legalization in Washington has significantly increased: support was 64.0% (95% CI: 61.2%-67.8%) at timepoint 1 and 77.9% (95% CI: 73.2%-81.9%) at timepoint 5. With each six months' passing, support increased 19% on average. We found no statistically significant change in support for home-growing.

CONCLUSIONS

Support for marijuana legalization has continued to significantly increase in a state that has experienced the policy change for almost four years.