The availability of medical marijuana dispensary and adolescent marijuana use

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.

Associations of recreational cannabis dispensaries' availability, storefront signage and health benefit signs with cannabis use: findings from a representative adult sample in California, United States

BACKGROUND AND AIMS

There are concerns that availability of recreational cannabis dispensaries (RCDs) and point-of-sale marketing may lead to increased cannabis use in jurisdictions where cannabis retail sale is legal. This paper examined whether the availability RCDs and the presence of storefront signage indicative of cannabis and signs promoting health benefits in RCDs were associated with cannabis use and risk perceptions.

DESIGN

Cross-sectional, secondary data analysis.

SETTING

California, USA.

PARTICIPANTS

A representative sample of 3385 adults in California who participated in the 2020 probability-based Marijuana Use and Environment Survey.

MEASUREMENTS

Binary outcomes included past-month overall cannabis use, perceiving cannabis smoking as harmful and past-month cannabis use by purpose (medical only, recreational only and dual). The objectively assessed predictors included proximity and density of RCDs and presence of storefront signage indicative of cannabis and signs promoting health benefits in RCDs.

FINDINGS

In terms of proximity, thepresence of storefront signage in the nearest RCD was associated with smaller odds of perceiving cannabis smoking as harmful [odds ratio (OR) = 0.63, 95% confidence interval (CI) = 0.39, 0.99] if the RCD was located within 2 miles of home. Presence of health benefit signs in the nearest RCD was associated with greater odds of overall cannabis use (OR = 2.45, 95% CI = 1.17, 5.16) and recreational use (OR = 3.50, 95% CI = 1.027, 11.91) if the RCD was located within 2-4 miles of home. In terms of density, count of RCDs, count of RCDs with storefront signage and count of RCDs with health benefit signs within 2 miles of home were each separately associated with greater odds of overall cannabis use and cannabis use for dual purposes.

CONCLUSIONS

The availability of recreational cannabis dispensaries within 2 miles of one's home and the presence of storefront signage indicating the availability of cannabis and signs promoting health benefits of cannabis appear to be associated with increased cannabis use and reduced risk perceptions among adults in California, USA.

Cannabis positivity rates in 17 emergency departments across the United States with varying degrees of marijuana legalization

BACKGROUND

Many states in the United States have progressed towards legalization of marijuana including decriminalization, medicinal and/or recreational use. We studied the impact of legalization on cannabis-related emergency department visits in states with varying degrees of legalization.

METHODS

Seventeen healthcare institutions in fifteen states (California, Colorado, Connecticut, Florida, Iowa, Kentucky, Maryland, Massachusetts, Missouri, New Hampshire, Oregon, South Carolina, Tennessee, Texas, Washington) participated. Cannabinoid immunoassay results and cannabis-related International Classification of Diseases (ninth and tenth versions) codes were obtained for emergency department visits over a 3- to 8-year period during various stages of legalization: no state laws, decriminalized, medical approval before dispensaries, medical dispensaries available, recreational approval before dispensaries and recreational dispensaries available. Trends and monthly rates of cannabinoid immunoassay and cannabis-related International Classification of Diseases code positivity were determined during these legalization periods.

RESULTS

For most states, there was a significant increase in both cannabinoid immunoassay and International Classification of Diseases code positivity as legalization progressed; however, positivity rates differed. The availability of dispensaries may impact positivity in states with medical and/or recreational approval. In most states with no laws, there was a significant but smaller increase in cannabinoid immunoassay positivity rates.

CONCLUSIONS

States may experience an increase in cannabis-related emergency department visits with progression toward marijuana legalization. The differences between states, including those in which no impact was seen, are likely multifactorial and include cultural norms, attitudes of local law enforcement, differing patient populations, legalization in surrounding states, availability of dispensaries, various ordering protocols in the emergency department, and the prevalence of non-regulated cannabis products.

Associations between Local Jurisdiction Ordinances and Current Use of Cannabis Products in California Adolescents

PURPOSE

Cannabis use among adolescents may have detrimental effects and use among this age group is increasing. It is important to understand how expansion of laws permitting cannabis sales may impact adolescent use. Much of the current research has explored how state-level policy decisions may impact adolescents' use behaviors; however, there is a gap in the understanding of how differences in local jurisdictional policies may also influence underage cannabis use.Procedures: The present study cross-sectionally assesses local variation in cannabis policies to explore the potential effects of local policy on underage use behaviors. Data were collected from (N = 1,573) adolescents representing 120 different localities across California, collected as a part of Project Cal Teens. Linear regression models were used to assess associations between local jurisdiction's allowance of retail sale of cannabis for adult-use and past 30-day use of non-medical (adult use) cannabis and perceived access to cannabis products.

FINDINGS

Local policy allowing cannabis retail was associated with adolescents' significantly higher past 30-day use of cannabis (β = 0.25 95% CI = 0.08, 0.42) and perceived access (β = 0.60 95% CI = 0.27, 0.94).

CONCLUSIONS

Results highlight the impact of local cannabis policies on adolescent cannabis use and perception. Considering the effects of cannabis use on adolescent development, this is an important public health concern because 14 states have already legalized recreational retail sales and growing numbers of local jurisdictions are allowing the retail sale of recreational cannabis.

Trends in Adolescent Cannabis-Related Hospitalizations by State Legalization Laws, 2008-2019

PURPOSE

Adolescent cannabis use is associated with adverse health outcomes. The impact of cannabis legalization on adolescent cannabis-related hospitalizations remains unknown. We sought to assess whether state cannabis legalization is associated with adolescent cannabis-related hospitalizations.

METHODS

We conducted a retrospective cohort study of adolescent (11-17 years) hospitalizations at children's hospitals between January 1, 2008 and December 31, 2019 using the Inpatient Essentials database. We investigated differences in adolescent cannabis-related diagnosis during a hospitalization by state cannabis legalization status, including states with no legal use to medical cannabis laws (MCLs) and states with MCLs to nonmedical (>21 years old) cannabis laws (NMCLs).

RESULTS

Of 1,898,432 adolescent hospitalizations in 18 states and Washington, DC, there were 37,562 (2%) hospitalizations with a cannabis-related diagnosis, with 8,457 (23%) in states with no legal use, 20,444 (54%) in MCL states, and 8,661 (23%) in NMCL states. There was an increase in adjusted odds of a cannabis-related hospitalization in MCL (odds ratio 1.05, 95% confidence interval 1.04-1.06) and NMCL states (odds ratio 1.03, 95% confidence interval 1.02-1.03) between 2008 and 2019. Characteristics associated with the greatest increase in adjusted odds of a cannabis-related hospitalization postpolicy change included adolescents without an underlying mental health or other substance use disorder in MCL and NMCL states (p < .001) and younger age in NMCL states (13 vs. 16 and 17 years old, p = .02 and p = .02).

CONCLUSIONS

Cannabis-related adolescent hospitalizations at children's hospitals are increasing, with a disproportionate increase postlegalization in states with NMCLs. Interventions are warranted to increase cannabis use identification and treatment among at-risk adolescents in the hospital-based setting.

Trends and Factors Related to Blunt Use in Middle and High School Students, 2010-2020

BACKGROUND AND OBJECTIVES

Blunt use is a popular mode of marijuana consumption among adolescents in the United States, but little is known about how its prevalence has changed over time or factors associated with its use. With this study, we assessed trends and correlates of past (ever used but not in the past 30 days) and current (used in past 30 days) blunt use among adolescents in Florida.

METHODS

We analyzed data from 2010-2020 cross-sectional, statewide representative Florida Youth Tobacco Surveys that comprised 461 706 middle and high schoolers using Joinpoint to calculate annual percentage change (APC) in the weighted prevalence of past and current blunt use. A weighted multivariable regression model was developed by using 2019-2020 Florida Youth Tobacco Survey data to examine the factors associated with past and current blunt use.

RESULTS

Whereas the prevalence of past (APC = -5.32%) and current (APC = -5.28%) blunt use significantly decreased from 2010 to 2015, an increasing trend in current use prevalence (APC = 14.91%) was observed from 2015 to 2018 and has been approximately constant ever since. Similar increasing trends were observed in current blunt use among female students (APC = 14.92%), middle schoolers (19.57%), and non-Hispanic (NH) white students (APC = 11.12%) from 2016 to 2020. Several factors were consistently associated with greater odds of both past and current blunt use for both middle and high schoolers, including older age, being NH Black (versus NH white), past and current use of cigarettes, electronic cigarettes, hookah, cigars, and ever vaping marijuana.

CONCLUSIONS

Although blunt use among Florida youth decreased from 2010 to 2015, substantial increases were observed since 2015, suggesting that existing tobacco control programs should incorporate marijuana (and blunt) modules into existing tobacco and nicotine prevention programs.

Association between county level cannabis dispensary counts and opioid related mortality rates in the United States: panel data study

OBJECTIVE

To examine county level associations between the prevalence of medical and recreational cannabis stores (referred to as dispensaries) and opioid related mortality rates.

DESIGN

Panel regression methods.

SETTING

812 counties in the United States in the 23 states that allowed legal forms of cannabis dispensaries to operate by the end of 2017.

PARTICIPANTS

The study used US mortality data from the Centers for Disease Control and Prevention combined with US census data and data from Weedmaps.com on storefront dispensary operations. Data were analyzed at the county level by using panel regression methods.

MAIN OUTCOME MEASURE

The main outcome measures were the log transformed, age adjusted mortality rates associated with all opioid types combined, and with subcategories of prescription opioids, heroin, and synthetic opioids other than methadone. The associations of medical dispensary and recreational dispensary counts with age adjusted mortality rates were also analyzed.

RESULTS

County level dispensary count (natural logarithm) is negatively related to the log transformed, age adjusted mortality rate associated with all opioid types (β=-0.17, 95% confidence interval -0.23 to -0.11). According to this estimate, an increase from one to two storefront dispensaries in a county is associated with an estimated 17% reduction in all opioid related mortality rates. Dispensary count has a particularly strong negative association with deaths caused by synthetic opioids other than methadone (β=-0.21, 95% confidence interval -0.27 to -0.14), with an estimated 21% reduction in mortality rates associated with an increase from one to two dispensaries. Similar associations were found for medical versus recreational storefront dispensary counts on synthetic (non-methadone) opioid related mortality rates.

CONCLUSIONS

Higher medical and recreational storefront dispensary counts are associated with reduced opioid related death rates, particularly deaths associated with synthetic opioids such as fentanyl. While the associations documented cannot be assumed to be causal, they suggest a potential association between increased prevalence of medical and recreational cannabis dispensaries and reduced opioid related mortality rates. This study highlights the importance of considering the complex supply side of related drug markets and how this shapes opioid use and misuse.

Examining Associations Between Licensed and Unlicensed Outlet Density and Cannabis Outcomes From Preopening to Postopening of Recreational Cannabis Outlets

BACKGROUND AND OBJECTIVES

To expand on epidemiologic studies examining associations between the legalization of recreational cannabis and use among young adults, we examined the associations between licensed and unlicensed cannabis outlet density and cannabis outcomes.

METHODS

A total of 1097 young adults aged 21 and older living in Los Angeles County were surveyed before licensed recreational cannabis outlets opened (Time 1: July to December 2017) and after (Time 2: July 2018 to June 2019). Using a database of open licensed and unlicensed cannabis retailers to calculate individual-level cannabis outlet density measures, we examined associations between outlet density within a 4-mile radius of participants' residences with Time 2 outcomes of any past-month use, daily use, intentions to use, quantity used, consequences, and cannabis use disorder (CUD) symptoms.

RESULTS

After controlling for demographic factors and cannabis outcomes at a time point prior to their opening (Time 1), licensed cannabis outlets were associated with young adults' cannabis use, heavy use, and intentions, and unlicensed outlets were associated with young adults' heavy cannabis use and CUD symptoms.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

This study expands beyond studies of outlet prevalence to find that, after controlling for outcomes 1 year prior, licensed and unlicensed outlets were associated with young adults' cannabis outcomes. The current study is among the first to find associations between cannabis use outcomes and density of cannabis outlets among young adults using data from two time points: preopening and postopening of recreational cannabis retailers. Findings can inform policies around the density and placement of cannabis outlets. (Am J Addict 2020;00:00-00).

Validation of secondary data sources for enumerating marijuana dispensaries in a state commercializing marijuana

OBJECTIVES

To assess 1) the validity of online crowdsourcing platforms in enumerating licensed brick-and-mortar marijuana dispensaries and 2) the validity of state licensing directory and online crowdsourcing platforms in enumerating active brick-and-mortar marijuana dispensaries in California.

METHODS

We obtained business lists from California Bureau of Cannabis Control (BCC) licensing directory and three online crowdsourcing platforms (Weedmaps, Leafly, and Yelp) in May 2019. Calls were made to verify street address, operation status, dispensary category (recreational-only, medical-only, recreational & medical), and presence of storefronts in May-July 2019. Validity measures, including sensitivity, specificity, positive predictive value, and negative predictive value, were calculated when applicable.

RESULTS

In identifying licensed dispensaries in BCC, Leafly had the highest sensitivity (.66) and Yelp had the highest specificity (.87). The dispensary category posted on online crowdsourcing platforms in over 25 % licensed dispensaries and the dispensary category claimed in call verification in over 10 % licensed dispensaries disagreed with the approved category in BCC. There were 2121 businesses combined from BCC and online crowdsourcing platforms, among which 826 were verified to be active brick-and-mortar dispensaries. Weedmaps had the highest sensitivity (.80) and Yelp had the highest negative predictive value (.74) in identifying verified dispensaries. Weedmaps overall had the highest sensitivity in all three dispensary categories. Weedmaps had the highest sensitivity in more populated counties whereas BCC had the highest sensitivity in less populated counties.

CONCLUSIONS

Each secondary data source has strengths and limitations. The findings inform surveillance and research regarding how to best strategize data use when resources are limited.

Youth's Proximity to Marijuana Retailers and Advertisements: Factors Associated with Washington State Adolescents' Intentions to Use Marijuana

The current study explored the influences of advertising exposure, numbers of marijuana retailers, distance to retailers, and constructs from the integrative model of behavioral prediction, including outcome beliefs, perceived norms, and efficacy, on youth's intentions to use marijuana in a state in which the use of recreational marijuana is legal. A state-wide online cross-sectional survey of 350 adolescents ages 13-17, residing in Washington state, was conducted in June 2018. The results of the regression analysis suggest that exposure to marijuana advertising, positive and negative outcome beliefs, and perceived peer norms were associated with intention to use marijuana. Distances to retailers moderated the relationships between exposure to advertising and intentions, as well as between positive outcome beliefs and intentions. States that have legalized recreational marijuana should continue considering the location of retailers in relation to neighborhoods and advertising regulations to reduce the appeal to youth. Additionally, prevention efforts could aim to influence outcome beliefs and norms in an attempt to reduce adolescents' intentions to use recreational marijuana.

Marijuana Legalization and Youth

Various states have legalized marijuana for medical purposes and/or decriminalized recreational marijuana use. These changes coincide with a decrease in perceived harmfulness of the drug and an increase in its use among youth. This change is of critical concern because of the potential harmful impact of marijuana exposure on adolescents. Marijuana use has been associated with several adverse mental health outcomes, including increased incidence of addiction and comorbid substance use, suicidality, and new-onset psychosis. Negative impacts on cognition and academic performance have also been observed. As the trend toward legalization continues, the pediatric community will be called on to navigate the subsequent challenges that arise with changing policies. Pediatricians are uniquely positioned to provide innovative care and educate youth and families on the ever-evolving issues pertaining to the impact of marijuana legalization on communities. In this article, we present and analyze the most up-to-date data on the effects of legalization on adolescent marijuana use, the effects of adolescent use on mental health and cognitive outcomes, and the current interventions being recommended for use in pediatric office settings.

Locating Medical and Recreational Cannabis Outlets for Research Purposes: Online Methods and Observational Study

Background

An increasing number of states have laws for the legal sale of recreational and medical cannabis out of brick-and-mortar storefront locations. Given the proliferation of cannabis outlets and their potential for impact on local economies, neighborhood structures, and individual patterns of cannabis use, it is essential to create practical and thorough methods to capture the location of such outlets for research purposes. However, methods used by researchers vary greatly between studies and often do not include important information about the retailer’s license status and storefront signage.

Objective

The aim of this study was to find methods for locating and observing cannabis outlets in Los Angeles County after the period when recreational cannabis retailers were granted licenses and allowed to be open for business.

Methods

The procedures included searches of online cannabis outlet databases, followed by methods to verify each outlet’s name, address, license information, and open status. These procedures, conducted solely online, resulted in a database of 531 outlets. To further verify each outlet’s information and collect signage data, we conducted direct observations of the 531 identified outlets.

Results

We found that 80.9% (430/531) of these outlets were open for business, of which 37.6% (162/430) were licensed to sell cannabis. Unlicensed outlets were less likely to have signage indicating the store sold cannabis, such as a green cross, which was the most prevalent form of observed signage. Co-use of cannabis and tobacco/nicotine has been found to be a substantial health concern, and we observed that 40.6% (175/430) of cannabis outlets had a tobacco/nicotine outlet within sight of the cannabis outlet. Most (350/430, 81.4%) cannabis outlets were located within the City of Los Angeles, and these outlets were more likely to be licensed than outlets outside the city.

Conclusions

The findings of this study suggest that online searches and observational methods are both necessary to best capture accurate and detailed information about cannabis outlets. The methods described here can be applied to other metropolitan areas to more accurately capture the availability of cannabis in an area.

Associations between young adult marijuana outcomes and availability of medical marijuana dispensaries and storefront signage

AIMS

We investigated associations between the density of medical marijuana dispensaries (MMDs) around young adults' homes and marijuana use outcomes.

DESIGN

Secondary data analysis.

SETTING

Los Angeles County, CA, USA.

PARTICIPANTS

A total of 1887 participants aged 18-22 years, surveyed online in 2016-17.

MEASUREMENTS

Outcomes were past-month marijuana use (number of days used, number of times each day), positive expectancies and perceived peer use. Density was measured as the total number of MMDs and number of MMDs with storefront signage indicative of marijuana sales, within 4 miles of respondents' homes.

FINDINGS

Eighty-four per cent of respondents had 10 or more MMDs within 4 miles of their homes. Multiple linear regression analyses that adjusted for individual-level socio-demographic characteristics and neighborhood socio-economic status indicated that living near a higher number of MMDs was associated with greater number of days used in the past month [β = 0.025; 95% confidence interval (CI) = 0.001, 0.049; P = 0.04] and higher positive marijuana expectancies (β = 0.003; 95% CI = 0.001, 0.007; P = 0.04). Living near more MMDs with storefront signage had a four- to six-fold larger effect on number of times used per day and positive expectancies, respectively, compared with associations with the total MMD count. Adjusting for medical marijuana card ownership attenuated the association with number of days used in the past month and positive expectancies, and an unexpected association emerged between higher MMD density and fewer number of times used each day (β = -0.005; 95% CI = -0.009, -0.001; P = 0.03).

CONCLUSIONS

For young adults in Los Angeles County, living near more medical marijuana dispensaries (MMDs) is positively associated with more frequent use of marijuana within the past month and greater expectations of marijuana's positive benefits. MMDs with signage show stronger associations with number of times used each day and positive expectancies.

The Associations of Neighborhood Availability of Marijuana Dispensaries and DATA-2000 Waivered Providers with Hospital Stays Related to Opioids

Background: Evidence is emerging on how state-wide marijuana legalization and increased supply of DATA-2000 waivered providers may be associated with outcomes related to opioids. It is unknown whether such associations remain at the neighborhood level. Objectives: This study examined the associations of neighborhood availability of marijuana dispensaries and DATA-2000 waivered providers with opioid-related hospital stays. Methods: Discharge-level records of inpatient (N = 264,013) and observation stays (N = 12,621) were obtained from the Washington Comprehensive Hospital Abstract Reporting System from January through June 2016. Outcomes were indicators for inpatient stays related to opioid use disorder (OUD), inpatient stays related to opioid overdose, and observation stays related to OUD. Primary predictors were the density of marijuana dispensaries and DATA-2000 waivered providers at the zip code level. Multilevel logistic regressions with random intercepts were used to examine the cross-sectional associations, controlling for other patient and neighborhood characteristics. Results: Patients living in neighborhoods with one more recreational marijuana dispensaries per square mile were more likely (OR = 1.54, p = .017) to be diagnosed with OUD in inpatient stays. Living in neighborhoods with increased density of medical marijuana dispensaries or DATA-2000 waivered providers was not associated with being diagnosed with OUD or opioid overdose in inpatient or observation stays. Conclusions: Recreational and medical marijuana dispensaries were differentially associated with opioid-related hospital stays. Further investigations are warranted to explore the causal pathways of the findings.

Density of Medical Marijuana Dispensaries and Current Marijuana Use among Young Adult Marijuana Users in Los Angeles

Background: While tobacco and alcohol studies have focused on density of outlets as a determinant of consumption, research has begun examining the effects of medical marijuana (MM) dispensaries on marijuana use. Objectives: Examine the relationship between density of MM dispensaries and frequency of marijuana use among young adult medical marijuana patients (MMP) and nonpatient users (NPU). Methods: Young adult marijuana users (n = 329) aged 18- to 26-year old were sampled in Los Angeles in 2014-2015 and separated into MMP (n = 198) and NPU (n = 131). In 2014, 425 operational MM dispensaries were identified within the City of Los Angeles. Sequential multilevel Poisson random effect models examined density of MM dispensaries per square mile and 90 d marijuana use among MMP and NUP at the ZIP code level while controlling for demographic, behavioral, and community characteristics. Results: Density of MM dispensaries was not related to 90 d use of marijuana (days of use or hits per day) among either MMP or NPU. MMP reported significantly greater days of marijuana use in the past 90 d compared to NPU but no differences were found for hits per day. African-Americans reported significantly greater hits per day compared to whites. Hispanics reported significantly fewer hits per day compared to non-Hispanics. Conclusion: Concentration of MM dispensaries surrounding young adult marijuana users in Los Angeles was unrelated to days of marijuana use irrespective of having a MM recommendation or not. Rather, individual factors related to consumer choices and behaviors were more important in determining recent marijuana use among MMP and NPU.

Adolescent Marijuana Use, Marijuana-Related Perceptions, and Use of Other Substances Before and After Initiation of Retail Marijuana Sales in Colorado (2013-2015)

Due to the recentness of changes to marijuana policies in a number of states, the effect on adolescent use and perceptions is not yet well understood. This study examines change in adolescent marijuana use and related perceptions in Colorado, before and after the implementation of legal commercial sale of recreational marijuana for adults starting on January 1, 2014. The data are from a repeated cross-sectional survey of a representative sample of Colorado high school students, with separately drawn samples surveyed in fall 2013 (prior to implementation) and fall 2015 (18 months after implementation). We examined change in the prevalence of adolescent marijuana use, measured by lifetime use, past 30-day use, frequent use, and use on school property. To consider the possibility of heterogeneity in the change in marijuana use, we examined change in past 30-day marijuana use by demographic characteristics (sex, grade, race/ethnicity), school characteristics (poverty, percent minority), urbanicity of the school district, and whether the city or county permitted retail marijuana stores. There was an absence of significant effects for change in lifetime or past 30-day marijuana use. Among those reporting past 30-day use, frequent use and use on school property declined. There was a significant decline in the perceived harm associated with marijuana use, but we did not find a significant effect for perceived wrongfulness, perceived ease of access, or perceived parental disapproval. We did not find significant variability in past 30-day use by demographic characteristics or by school and community factors from 2013 to 2015. We did not find a significant effect associated with the introduction of legal sales of recreational marijuana to adults in Colorado on adolescent (illegal) use, but ongoing monitoring is warranted, including consideration of heterogeneity in the effects of marijuana policies.

Medical Marijuana Availability, Price, and Product Variety, and Adolescents' Marijuana Use

PURPOSE

We aimed to examine the availability of medical marijuana dispensaries, price of medical marijuana products, and variety of medical marijuana products in school neighborhoods and their associations with adolescents' use of marijuana and susceptibility to use marijuana in the future.

METHODS

A representative sample of 8th, 10th, and 12th graders (N = 46,646) from 117 randomly selected schools in California participated in the cross-sectional 2015-2016 California Student Tobacco Survey (CSTS). Characteristics of medical marijuana dispensaries in California were collected and combined with school locations to compute availability, price, and product variety of medical marijuana in school neighborhoods. Multilevel logistic regressions with random intercepts at school level were conducted to test the associations, accounting for individual and school socioeconomic characteristics.

RESULTS

The distance from school to the nearest medical marijuana dispensary (within 0- to 1-mi and 1- to 3-mi bands) was not associated with adolescents' use of marijuana in the past month or susceptibility to use marijuana in the future, nor was the weighted count of medical marijuana dispensaries within the 3-mi band of school. Neither the product price nor the product variety in the dispensary nearest to school was associated with marijuana use or susceptibility to use. The results were robust to different specifications of medical marijuana measures.

CONCLUSIONS

There was no evidence supporting the associations of medical marijuana availability, price, or product variety around school with adolescents' marijuana use and susceptibility to use.

Heterogeneity of state medical marijuana laws and adolescent recent use of alcohol and marijuana: Analysis of 45 states, 1991-2011

OBJECTIVE

To assess associations between enactment of state medical marijuana laws (MMLs), MML restrictiveness, and past-30-day youth alcohol use overall, and in relation to marijuana use.

METHOD

This quasi-experimental difference-in-difference designed study used state-level Youth Risk Behavior Survey data of 9th-12th grade students in 45 states from 1991-2011 (N D 715,014). We conducted bivariate (unadjusted) and multivariable (adjusted for state, year, individual characteristics) logistic regression analyses to examine the effect of MML enactment (yes/no) and less restrictive vs. more restrictive MMLs on five varying measures of past 30-day alcohol use (i.e., any use or binge) and alcohol and marijuana use behaviors.

RESULTS

In the final adjusted analyses, MML enactment was associated with lower odds of adolescent past 30-day (1) alcohol use (OR D 0.92, [0.87, 0.97], p < .01) and (2) use of both alcohol and marijuana (OR D 0.93, [0.87, 0.99], p < .05). States with less restrictive MMLs had lower odds of past 30-day (1) alcohol use (OR D 0.94, [0.92, 0.97], p < .001), (2) binge drinking (OR D 0.96, [0.93, 0.97], p < .05), (3) alcohol use without any marijuana use (OR D 0.96, [0.93, 0.99], p < .01), and (4) use of both alcohol and marijuana (OR D 0.96, [0.92, 0.99], p < .05).

CONCLUSIONS

This study found that enactment of any MML, and of less restrictive MMLs, was associated with lower odds of past 30-day adolescent alcohol use among adolescents. With continued change in state marijuana laws, it is important to monitor the effect of their enactment and implementation, as well as their specific provisions (e.g. dispensaries, home cultivation), which may differentially affect adolescent behaviors.

Understanding Rates of Marijuana Use and Consequences Among Adolescents in a Changing Legal Landscape

PURPOSE OF REVIEW

There is not one answer to address whether marijuana use has increased, decreased, or stayed the same given changes in state legalization of medical and non-medical marijuana in the USA.

RECENT FINDINGS

Evidence suggests some health benefits for medical marijuana; however, initiation of marijuana use is a risk factor for developing problem cannabis use. Though use rates have remained stable over recent years, about one in three 10th graders report marijuana use, most adolescents do not view the drug as harmful, and over 650,000 youth aged 12 to 17 struggle with cannabis use disorder.

SUMMARY

Although the health benefits of medical marijuana are becoming better understood, more research is needed. Intervention and prevention programs must better address effects of marijuana, acknowledging that while there may be some benefits medically, marijuana use can affect functioning during adolescence when the brain is still developing.

State and National Contexts in Evaluating Cannabis Laws: A Case Study of Washington State

As of January 2016, 23 U.S. states and the District of Columbia have legalized medical or nonmedical cannabis, with more likely to follow. This dynamic policy context represents a substantial challenge for policy evaluation. Part I of this article provides a summary of state-level cannabis policy components across states and federal action regarding state-level policies. Part II presents a detailed history of cannabis policies in Washington State from 1998 to 2015 and analyzes the potential impacts of the policy changes on cannabis supply and demand. As an early adopter of both medical and nonmedical cannabis policies, Washington State provides an excellent example of the key elements to be considered in evaluating the relationship between policy changes and cannabis use. We highlight the importance of the interplay of federal enforcement priorities and previously adopted state-level cannabis regimes in interpreting the potential impacts of new cannabis policies.

State-level medical marijuana laws, marijuana use and perceived availability of marijuana among the general U.S. population

BACKGROUND

Little is known on how perceived availability of marijuana is associated with medical marijuana laws. We examined the relationship between medical marijuana laws (MML) and the prevalence of past-month marijuana use, with perceived availability of marijuana.

METHODS

Data were from respondents included in the National Survey of Drug Use and Health restricted use data portal 2004-2013. Multilevel logistic regression of individual-level data was used to test differences between MML and non-MML states and changes in prevalence of past-month marijuana use and perceived availability from before to after passage of MML among adolescents, young adults and older adults controlling for demographics.

RESULTS

Among adults 26+, past-month prevalence of marijuana use increased from 5.87% to 7.15% after MML passage (Adjusted Odds Ratio (AOR): 1.24 [1.16-1.31]), but no change in prevalence of use was found for 12-17 or 18-25 year-olds. Perceived availability of marijuana increased after MML was enacted among those 26+ but not in younger groups. Among all age groups, prevalence of marijuana use and perception of it being easily available was higher in states that would eventually pass MML by 2013 compared to those that had not. Perceived availability was significantly associated with increased risk of past-month marijuana use in all age groups.

CONCLUSION

Evidence suggests perceived availability as a driver of change in use of marijuana due to MML. To date, this has only occurred in adults 26+ and different scenarios that could explain this change need to be further explored.