Recreational Marijuana Legalization Research Articles

A National Survey of Marijuana Use Among U.S. Adults According to Obesity Status, 2016-2022.

Background and Objective: Research has linked marijuana use with lower body mass index (BMI). The current study explores the correlation between marijuana use on BMI in the general U.S. population. It reports the prevalence of marijuana in adults in relation to BMI, overall and across the levels of important variables. Materials and Methods: This study used a probability sample of U.S. adults 18 years of age and older from the 2016 through 2022 Behavioral Risk Factor Surveillance System, a telephone-administered survey. The survey collects data from a representative sample regarding health-related risk behaviors, chronic health conditions, and use of preventive services. The primary outcome variables are current (at least once in the last 30 days) and daily (at least 20 of the last 30 days) marijuana use. Results: The study sample consists of 735,921 participants in the surveys that completed the optional module on marijuana use. Prevalence of marijuana use in adults doubled during the study period (7.48% to 14.91%). The increase directly corresponds with a shift toward legalization of medical and recreational marijuana. On average, the prevalence of use is 9% higher when medical marijuana is legal and 81% higher when recreational marijuana is legal (vs. not legal). For obese individuals, prevalence of current marijuana use is 35% lower than for nonobese individuals on average. Lower prevalence of marijuana use in obese individuals is consistently observed across the levels of certain demographic variables, employment status, tobacco smoking history, marijuana legalization status, and certain medical conditions (asthma, arthritis, and depression). In 2022, the adjusted odds of current or daily marijuana use are significantly lower and similar among obese (vs. non-obese) (0.68, 0.69, respectively), such that reduced obesity does not require daily use. Similarly, the adjusted odds of current marijuana use decrease in similar fashion to daily marijuana use with higher BMI weight classification. Conclusion: Marijuana use is correlated with lower BMI. As legalization and prevalence of the drug in the U.S. increases, the prevalence of obesity may decline. However, clinicians should view this outcome along with the known health risks associated with marijuana use.

Religiosity Influences Legalization of Marijuana among Chaldean Americans.

The purpose of this study was to evaluate Chaldean American perspectives towards legalization and moral acceptability of recreational and medicinal marijuana in the state of Michigan. An online survey was created and distributed through various social media groups, churches, and Chaldean organizations which resulted in a total of 637 respondents following the removal of respondents who did not meet criteria. The survey was open from March 20th, 2022 to April 20th, 2022. The independent variable was level of religiosity. The dependent variables were moral acceptability, opinion towards legalization of recreational and medicinal marijuana, and risk of cannabis use disorder. Logistic regression was used to estimate the strength of the association between the independent and dependent variables. Approximately 64% of the sample was female and 54.6% were between the ages of 21 to 29. Almost 80% of respondents reported high religiosity and 83.4% strongly or somewhat supported the legalization of medicinal marijuana. In addition, 85.8% felt medicinal marijuana was morally acceptable and 58.9% believed recreational marijuana was morally wrong. In the fully adjusted models, individuals who reported high religiosity (compared to low/moderate) were more likely to oppose legalization of recreational marijuana (OR = 2.80; 95% CI = 1.46, 5.39) and believed that marijuana was morally wrong (OR = 2.36; 95% CI = 1.16, 4.78). This trend was not observed with medicinal marijuana. These findings have important implications in better understanding a traditionally conservative ethnic minority group in their attitudes towards marijuana and how religion influences their perspectives. Additional studies are needed to examine any changes in opinion overtime as this is the first study of its kind.

From high school to higher education: Is recreational marijuana a consumption amenity for US college students?

AbstractThis paper examines how recreational marijuana legalization (RML) affects first‐time college enrollment in the US using a unique college‐level dataset and various estimation methods such as difference‐in‐differences and event study. I find that RML increases enrollments by approximately up to 9%, without compromising degree completion or graduation rate, and it boosts college competitiveness by offering a positive amenity, as evidenced by the rise in out‐of‐state enrollments relative to neighboring states. In addition, I find no evidence that RML affects college prices, quality, or in‐state enrollment. This effect is stronger for non‐selective public colleges in early‐adopting RML states.

Perceptions About Marijuana Use in Pregnancy Among Pregnant Users and Nonusers in a State Without Legalized Recreational Cannabis [ID 2683513

INTRODUCTION: Cannabis use in pregnancy is rising. The objective of this study is to compare attitudes regarding marijuana use among pregnant users and nonusers. METHODS: This was a prospective study (IRB #262700) in which a 35-question, anonymous survey was distributed to pregnant patients at outpatient prenatal visits across gestation. Questions included topics regarding marijuana use in pregnancy, perceived risks, and provider–patient education. RESULTS: 408/460 (88.7%) approached pregnant patients completed the survey. Self-reported rate of marijuana use during pregnancy: 11.8% (48/408). There were no ethnic differences in users and the most common age for use was 18–24 years (24/48). 79% (38/48) reported use two to three times weekly or greater. Average response score (Likert scale) for participants using marijuana compared to those who did not to the following statements were statistically significant and positive towards prenatal use: belief that pregnant patients should refrain from marijuana use: 2.31 versus 3.53 (<.001); acceptability of medical marijuana: 3.68 versus 2.82 (<.001); minimal health risk: 4.15 versus 2.96 (<.001); support for legalization of recreational marijuana: 4.58 versus 3.51 (<.001). Lack of counseling on cessation and risk of cannabis use in pregnancy were reported by 82% and 84% of participants with 74% of current users reporting lack of counseling. 54% of users desired more information regarding cannabis-related pregnancy complications. CONCLUSION: Higher-than-expected self-reported marijuana use during pregnancy. Lack of counseling on risks of marijuana use and importance of cessation highlight an important opportunity for counseling and intervention supporting current ACOG guidelines of SBIRT (screening, brief intervention, and treatment referral).

Recreational marijuana: Ethical positions and consumption status in explaining attitudes, perceived law ethicalness, and perceived corporate social responsibility

AbstractDrawing from the Ethics Position theory and the Theory of Planned Behavior, this study was conducted with a comprehensive four‐part goal. It seeks to explore the moderating influences of the consumption status and ethical positions in elucidating (i) individuals' attitude toward recreational marijuana consumption, (ii) individuals' perceived ethical stance regarding recreational marijuana legalization, (iii) individuals' CSR perception of firms operating within the marijuana industry often deemed as morally contentious, and (iv) the interrelationships among the aforementioned variables. Based on a sample of 411 Canadians and two grouping variables, ANOVA tests and a structural Equation Modeling were used to test the research hypotheses. The results show that individuals' attitudes toward the consumption of marijuana, perceived ethicalness of legalizing it, and perceived CSR significantly vary across the three groups of consumption status (i.e., non‐consumer, occasional, and regular) and the four groups of ethical positions (i.e., absolutism, exceptionism, situationism, and subjectivism). The SEM results, however, show that, except for a few cases, there were no notable variations in the model's path coefficients among the identified groups. This study has intriguing implications for academicians, practitioners, politicians, managers, social welfare activists, and other stakeholders.

United States marijuana legalization and opioid mortality trends before and during the first year of the COVID-19 pandemic.

To determine if marijuana legalization was associated with reduced opioid mortality. The United States (US) opioid mortality trend during the 2010-2019 decade was compared in states and District of Columbia (jurisdictions) that had implemented marijuana legalization with states that had not. Acceleration of opioid mortality during 2020, the first year of the coronavirus disease 2019 (COVID-19) pandemic, was also compared in recreational and medicinal-only legalizing jurisdictions. Joinpoint methodology was applied to the Centers for Disease Control and Prevention WONDER data. Trends in legalizing jurisdictions were cumulative aggregates. The overall opioid and fentanyl death rates and the percentage of opioid deaths due to fentanyl increased more during 2010-2019 in jurisdictions that legalized marijuana than in those that did not (pairwise comparison p = 0.007, 0.05, and 0.006, respectively). By 2019, the all-opioid and fentanyl death rates were 44 and 50 percent greater in the legalizing than in the nonlegalizing jurisdictions, respectively. When the COVID-19 pandemic hit in 2020, jurisdictions that implemented recreational marijuana legalization before 2019 had significantly greater increases in both overall opioid and fentanyl death rates than jurisdictions with medicinal-only legalization. For all-opioids, the mean (95 percent confidence interval) 2019-to-2020 increases were 46.5 percent (36.6, 56.3 percent) and 29.1 percent (20.2, 37.9 percent), respectively (p = 0.02). For fentanyl, they were 115.6 percent (80.2, 151.6 percent) and 55.4 percent (31.6, 79.2 percent), respectively (p = 0.01). During the past decade, marijuana legalization in the US was associated at the jurisdiction level with a greater acceleration in opioid death rate. An even greater increase in opioid mortality occurred in recreational-legalizing jurisdictions with the onset of the COVID-19 pandemic. Marijuana legalization is correlated with worsening of the US opioid epidemic.

Adolescent Δ8-THC and Marijuana Use in the US

Gummies, flavored vaping devices, and other cannabis products containing psychoactive hemp-derived Δ8-tetrahydrocannabinol (THC) are increasingly marketed in the US with claims of being federally legal and comparable to marijuana. National data on prevalence and correlates of Δ8-THC use and comparisons to marijuana use among adolescents in the US are lacking. To estimate the self-reported prevalence of and sociodemographic and policy factors associated with Δ8-THC and marijuana use among US adolescents in the past 12 months. This nationally representative cross-sectional analysis included a randomly selected subset of 12th-grade students in 27 US states who participated in the Monitoring the Future Study in-school survey during February to June 2023. Self-reported sex, race, ethnicity, and parental education; census region; state-level adult-use (ie, recreational) marijuana legalization (yes vs no); and state-level Δ8-THC policies (regulated vs not regulated). The primary outcome was self-reported Δ8-THC and marijuana use in the past 12 months (any vs no use and number of occasions used). In the sample of 2186 12th-grade students (mean age, 17.7 years; 1054 [48.9% weighted] were female; 232 [11.1%] were Black, 411 [23.5%] were Hispanic, 1113 [46.1%] were White, and 328 [14.2%] were multiracial), prevalence of self-reported use in the past 12 months was 11.4% (95% CI, 8.6%-14.2%) for Δ8-THC and 30.4% (95% CI, 26.5%-34.4%) for marijuana. Of those 295 participants reporting Δ8-THC use, 35.4% used it at least 10 times in the past 12 months. Prevalence of Δ8-THC use was lower in Western vs Southern census regions (5.0% vs 14.3%; risk difference [RD], -9.4% [95% CI, -15.2% to -3.5%]; adjusted risk ratio [aRR], 0.35 [95% CI, 0.16-0.77]), states in which Δ8-THC was regulated vs not regulated (5.7% vs 14.4%; RD, -8.6% [95% CI, -12.9% to -4.4%]; aRR, 0.42 [95% CI, 0.23-0.74]), and states with vs without legal adult-use marijuana (8.0% vs 14.0%; RD, -6.0% [95% CI, -10.8% to -1.2%]; aRR, 0.56 [95% CI, 0.35-0.91]). Use in the past 12 months was lower among Hispanic than White participants for Δ8-THC (7.3% vs 14.4%; RD, -7.2% [95% CI, -12.2% to -2.1%]; aRR, 0.54 [95% CI, 0.34-0.87]) and marijuana (24.5% vs 33.0%; RD, -8.5% [95% CI, -14.9% to -2.1%]; aRR, 0.74 [95% CI, 0.59-0.94]). Δ8-THC and marijuana use prevalence did not differ by sex or parental education. Δ8-THC use prevalence is appreciable among US adolescents and is higher in states without marijuana legalization or existing Δ8-THC regulations. Prioritizing surveillance, policy, and public health efforts addressing adolescent Δ8-THC use may be warranted.

Mathematical model for the dynamics of alcohol-marijuana co-abuse

A mathematical model for the dynamics of alcohol-marijuana coabuse is presented in this work. In the past years legalization of recreational marijuana in several states in the United States has added a new layer to alcohol addiction. Much research has been done for alcohol addiction or drug abuse independently, but few include the incidence of marijuana use for alcohol users. A compartmental epidemiological model is used, and results such as the existence and boundedness of solutions, the basic reproduction number using the next-generation method, the disease-free equilibrium, and an analytical expression for the endemic equilibrium are included. Numerical simulations with parameters obtained from data in the United States are performed for different compartments of the population as well as the reproduction number for the alcohol and marijuana sub-models. The model can be adapted for different regions worldwide using appropriate data. This work contributes to understanding the dynamics of the co-abuse of addictive substances. Even though alcohol and marijuana are both legal, they can be of great harm to the brain of the individual when combined, having tremendous consequences for society as a whole. Creating awareness of a public health concern with facts based on scientific research is the ultimate goal of this work.

Associations between simultaneous use of alcohol and cannabis and cannabis-related problems in 2014–2016: evidence from the Washington panel survey

BackgroundTo address the research question of how simultaneous users of alcohol and cannabis differ from concurrent users in risk of cannabis use problems after the recreational marijuana legalization in Washington State.MethodsWe used generalized estimating equations with a Poisson distribution to analyze the association between simultaneous use of alcohol and marijuana (SAM) and cannabis-related problems compared to concurrent use. The data is a longitudinal sample of drinkers and cannabis users (n = 257, 47% female) aged 18 years and older from Washington State in 2014–2016. We adjusted for survey weights to account for differential probability of selection and response rates. The primary outcome is the past-six-month CUDIT problem subscale (ranging from 0 to 28), which is the total score for seven CUDIT problem items, after excluding the three items that covered marijuana use frequency. Covariates include marijuana use frequency (daily/near daily use, regular use, or infrequent use), marijuana daily quantity, alcohol daily volume, panel survey cycle, medical marijuana recommendation, driving time to nearest marijuana outlet, age of marijuana use onset, and other demographics.ResultsAfter adjusting for covariates, we found that compared to concurrent use, SAM was significantly positively associated with CUDIT problem subscale (IRR = 1.68, 95% CI: 1.25–2.27, p < 0.001); daily/near daily use of marijuana was strongly significantly associated with CUDIT problem subscale compared with infrequent use (IRR = 5.1, 2.71–9.57, p < 0.001) or regular use (IRR = 3.05, 1.91–4.85, p < 0.001). Secondary analyses using CUDIT total score as the outcome also showed a significant positive association with SAM compared to concurrent use (IRR = 1.17, 1.02–1.34, p < 0.05).ConclusionsThis study highlighted the importance of SAM, in addition to cannabis use frequency for predicting cannabis-related problems.

Recreational Marijuana Legalization and Workplace Injuries Among Younger Workers

This case-control study uses state-by-year workplace injury data to assess recreational marijuana legalization adoption and workplace injuries among younger workers aged 20 to 34 years.

The effect of place on voting behavior: The case of the Arizona proposition to legalize recreational marijuana

AbstractIn 2020, Arizonans approved Proposition 207, the Smart and Safe Arizona Act, which legalized recreational marijuana sales. Previous research has typically used non‐spatial survey data to understand marijuana legalization voting patterns. However, voting behavior can, in part, be shaped by geographic context, or place, which is unaccounted for in aspatial survey data. We use multiscale geographically weighted regression to analyze how place shaped Proposition 207 voting behavior, independently of demographic variations across space. We find significant spatial variability in the sensitivity of voting for Proposition 207 to changes in several of the predictor variables of opposition and support for recreational marijuana legalization. We argue that local statistical modeling approaches provide a more in‐depth understanding of ballot measure voting behavior than the current use of global models.Related ArticlesBranton, Regina, and Ronald J. McGauvran. 2018. “Mary Jane Rocks the Vote: The Impact of Climate Context on Support for Cannabis Initiatives.” Politics &amp; Policy 46(2): 209–32. https://doi.org/10.1111/polp.12248.Brekken, Katheryn C., and Vanessa M. Fenley. 2020. “Part of the Narrative: Generic News Frames in the U.S. Recreational Marijuana Policy Subsystem.” Politics &amp; Policy 49(1): 6–32. https://doi.org/10.1111/polp.12388.Fisk, Jonathan M., Joseph A. Vonasek, and Elvis Davis. 2018. “‘Pot'reneurial Politics: The Budgetary Highs and Lows of Recreational Marijuana Policy Innovation.” Politics &amp; Policy 46(2): 189–208. https://doi.org/10.1111/polp.12246.

Legalization and retail availability of recreational marijuana and adolescent use in schools.

Legalization of use and retail sales of recreational marijuana in U.S. states and the associated potential increase in access to marijuana and normalization of its use by adults could lead to increased use by adolescents. Studies have found that states with legal recreational marijuana have higher rates of adolescent use and frequency of use compared to states without legal use. We examined changes in student office discipline referrals (ODRs) for substance use offenses in Oregon middle and high schools before and after the legalization of recreational marijuana relative to comparison schools in other states. We found that rates of substance use related ODRs in middle schools increased by 0.14 per 100 students (30% of the mean) with legalization relative to comparison schools. This increase was moderated by the presence of a marijuana outlet within one mile of the school. We found no statistically discernible changes in high school ODRs. Marijuana use in adolescence has been linked to negative health and social consequences, including academic problems, mental health issues, and impaired driving. Potential adverse impact on adolescents and investments in school-based prevention programs could be important considerations for policymakers and public health officials when evaluating marijuana legalization.

A-328 Urine Toxicology Screening: Tetrahydrocannabinol Positivity Patterns at an U.S. Urban Tertiary Care Children's Hospital

Abstract Background Given the recent legalization of recreational and medical marijuana in different states, there is an increasing exposure of children and teenagers to marijuana products which has led to an increase in health care visits and hospitalizations. Our drug testing algorithm uses an immunoassay test for initial urinary drug screening (UDS) followed by an automatic confirmatory test only when a positive UDS result is obtained. The immunoassay test is performed in-house and detects the major metabolites of delta9- tetrahydrocannabinol (THC), the main psychoactive component of marijuana. In contrast, the liquid chromatography-tandem mass spectrometry (LC-MS/MS) confirmatory test is more specific towards THC and is carried out in an external lab. In light of the ongoing trend of marijuana exposure cases and the fact that immunoassay cross-reactivity with non-cannabinoid compounds is uncommon, we aim to assess the necessity of automatic confirmatory tests in our patient population and evaluate its impact on patient management. Methods We conducted a retrospective study to assess the trends in cannabinoid hospital-related encounters by age, gender, and incidence with other drugs, in our population among the main campus and satellites (November 2021–October 2022). The UDS tests that were positive for cannabinoids were further evaluated to assess their agreement with the confirmatory testing. Results Cannabinoid positive tests account for 62.0% (504/813) of all positive UDS tests in all our locations and 84% (425/504) of the cases did not test positive for other drug classes. Among this population, 92.7% (467/504) are in the adolescent age (≥13 years), whereas 7.3% (37/504) were children (&amp;lt;13 years). Female population comprises 56.0% (217/504) of the cases whereas male, 43% (271/504) of the cases. The true positive rate for the immunoassay test was 99.6% (465/467) and 94.6% (35/37) for adolescents and children, respectively. Clinical decisions were made after a positive immunoassay result and before the confirmatory test as this is a send out test and takes a few days to receive the result. Conclusion Our evidence-based approach demonstrates unnecessary confirmatory testing for the adolescent group in our population due to a high positivity rate (99.6%). Discontinuing automatic confirmatory testing for this group will eliminate workload and reduce healthcare costs. On the other hand, automatic confirmatory testing in children will continue as these exposures are mainly considered unintentional and require more investigation.

Variation in Hospital Practices Regarding Marijuana Use in Pregnancy and Lactation.

Background and Objectives: Evidence is lacking on the safety of marijuana (MJ) exposure on the fetus and neonate, and current guidelines vary across professional organizations. We examined variation in hospital practices regarding use of mother's own milk (MOM) in the setting of perinatal MJ exposure based on hospital location and state MJ legal designation. Methods: We conducted a cross-sectional electronic survey of U.S. perinatal health care workers on hospital policies and clinical practice regarding maternal MJ use from November 2021 to April 2022. We analyzed responses from those working in states with legal recreational MJ (REC), MJ legal for medical use only (MED), and illegal MJ (NON), based on legalization status as of 2021. Results: Two thousand six hundred eighty-three surveys were analyzed from 50 states and the District of Columbia, with 1,392 respondents from REC states, 524 from NON states, and 668 from MED states. Hospital policies and practices showed significant differences between facilities from REC and NON states. REC states were more likely to have policies allowing use of MOM from mothers using MJ after delivery and less likely to routinely include cannabinoids in toxicology testing. Hospital policies also varied within individual hospitals between well baby nurseries and neonatal intensive care units. Conclusions: Hospital practices vary widely surrounding provision of MOM in the presence of maternal MJ use, based on state legalization status and hospital unit of care. Clear guidelines across professional organizations regarding perinatal MJ exposure, regardless of legality, are warranted to improve consistency of care and patient education.

Association Between Marijuana Laws and Suicide Among 12- to 25-Year-Olds in the United States From 2000 to 2019

Cannabis use is associated with suicide-related outcomes in both adolescents and adults, and may be increasing amid shifting cannabis policies. However, little is known about the impact of medical marijuana legalization (MML) and recreational marijuana legalization (RML) policies on youth suicide. Using 20 years of national data, we examined associations between MML, RML, and suicide-related mortality among US individuals aged 12 to 25 years, and assessed whether they varied based on age and sex. Suicide deaths (N= 113,512) from the 2000-2019 National Vital Statistics System Multiple Cause of Death files for age groups 12 to 13, 14 to 16, 17 to 19, 20 to 22, and 23 to 25 years were examined in relation to time-varying cannabis law status using a staggered adoption difference-in-difference (DiD) approach with a negative binomial regression to determine associations between MML, RML, and suicide rates, controlling for individual- and state-level covariates and accounting for the varying effective dates of MML and RML by state. The overall unadjusted annual suicide rate was 10.93/100,000, varying from 9.76 (states without marijuana laws (ML)) to 12.78 (MML states) to 16.68 (RML states). In multivariable analysis, both MML (incidence rate ratio [IRR]= 1.10, 95% CI: 1.05-1.15) and RML (IRR= 1.16, 95% CI: 1.06-1.27) were associated with higher suicide rates among female youth compared to those in states without ML. Youth aged 14 to 16 years had higher rates of suicide in states with RML compared to states with MML (IRR= 1.14, 95% CI: 1.00-1.30) and states without ML (IRR= 1.09, 95% CI: 1.00-1.20). Findings were consistent across sensitivity analyses. MML and RML were associated with increased suicide-related mortality in female youth and 14- to- 16-year-old individuals of both sexes. Mechanisms through which cannabis policies are related to increased youth suicide warrant further study and should inform legislative reform.

In Case You Haven't Heard…

New York's legal recreational marijuana industry is not going well. The huge state has opened only 12 dispensaries. The black market is rampant. Farmers who replanted their food crops with marijuana now have more product than they know what to do with. Last year's harvest is still waiting to be sold, and it's time for another harvest. Farmer's markets may be the next best option. It's not only New York — other states have the same problem. But in New York, dispensaries were only going to be awarded to people who could show they had been jailed for marijuana possession, which took time, so even though recreational use was legal, there was no legal dispensary. “Unlicensed shops rushed in to fill the void,” Fortune magazine reported last week. Now, it's a losing battle for farmers, as last year's “flower” may soon become too old to even sell. For the Fortune magazine article, go to https://fortune.com/2023/06/05/pot‐farmers‐going‐broke‐growing‐new‐york‐legal‐weed‐market‐not‐taking‐off/.

Collisions and cannabis: Measuring the effect of recreational marijuana legalization on traffic crashes in Washington State

Objective Washington State was among the first states in the US to legalize recreational consumption and retail sales of marijuana. Recreational use of cannabis was legalized December 6, 2012, following the passage of Initiative 502 30 days prior. Roughly 19 months later the first retail cannabis stores opened their doors for public sales (“commercialization”). I measure the impact of cannabis legalization and commercialization on traffic collisions in Washington State. Methods With county-level vehicle crash data from the Washington State Department of Transportation collected monthly, I utilize an interrupted time-series framework with Poisson estimation to compare traffic collisions with recreational retail cannabis sales revenue from 2011 (three years pre-commercialization) through 2017 (three years post-commercialization). First, I measure the shift in collisions brought about by Washington’s 2012 cannabis legalization. Then, I compare retail cannabis sales—a measure of commercialization—to traffic collisions based on severity of injury (fatal, severe injury, minor injury, non-injury, and all). Results After controlling for confounding factors, evidence suggests that recreational cannabis legalization led to fewer fatal and serious injury collisions. Retail cannabis sales generally correlate with more traffic collisions, particularly for less severe (minor injury) crashes. These findings are robust to the inclusion of additional control variables pertaining to county-level cannabis usage and driving behavior while intoxicated. Conclusions Cannabis legalization led to fewer fatal, serious, and minor injury collisions. Commercialization (cannabis sales) correlated with an increase in less severe crashes. Although cannabis use generally increased in Washington State following legalization/commercialization, survey data suggest that driving behavior while under the influence of cannabis did not change significantly over the post-commercialization period. Future research should focus on measuring the dose-dependent impact of cannabis consumption on traffic collisions. This should include recognition of the importance of cannabis dosing, timing, and route of consumption. Lastly, the dangers of poly-drug driving—particularly cannabis and alcohol—are well established and should be high priority for further research.

Recreational Marijuana Legalization, Local Retail Availability, and Alcohol and Marijuana Use and Co-Use Among California High School Students.

This study examined whether recreational marijuana legalization (RML) and local retail availability were associated with marijuana and alcohol use and co-use among adolescents. We investigated associations between RML and past-30-day marijuana and alcohol use and co-use, and moderating effects of retail availability of marijuana and alcohol, using data from the 2010-2011 to 2018-2019 California Healthy Kids Surveys (CHKS) of 9th and 11th grade students in 38 California cities. Multilevel mixed-effects logistic regression analyses were conducted, controlling for secular trends and student and city demographics. Additional analyses examined associations of RML and retail availability with co-use among subgroups of drinkers and marijuana users. For the full sample, RML was inversely associated with alcohol use but was not significantly associated with marijuana use or co-use with alcohol. However, significant interactions between RML and marijuana outlet density showed that there were increases in marijuana and alcohol co-use and alcohol following legalization in cities with higher densities of marijuana outlets. RML was positively associated with co-use among non-heavy and heavy drinkers, but inversely related to co-use among occasional and frequent marijuana users. A significant positive interaction between RML and marijuana outlet density indicated that RML was associated with increases in co-use for occasional marijuana users in cities with higher densities of marijuana outlets. RML was associated with increases in marijuana and alcohol co-use and alcohol use among California high school students, particularly those in cities with higher densities of retail cannabis stores, although this varied across alcohol and marijuana use subgroups.

Revisiting the effect of recreational marijuana on traffic fatalities

This study examines the effect of retail recreational marijuana legalization on traffic fatalities using the most current data available and recent advancements in difference-in-difference estimation methods proposed by Callaway and Sant'Anna, (2021). A modified difference-in-difference (CS-DID) is used to estimate the effect of recreational marijuana legalization on traffic fatalities reported in the Fatality Analysis Reporting System (FARS). Difference-in-difference regression models are run at the state-year level, using data from 2007 through 2020, and compared to estimates using traditional two-way-fixed-effects (TWFE) models. Consistent with past studies, results from conventional TWFE suggest traffic fatalities increase at a rate of 1.2 per billion vehicle miles traveled (BVMT) after retail of recreational marijuana begins. However, using the CS-DID model, we find slightly larger average total treatment effects (∼2.2 fatalities per BVMT). Moreover, the size of the effect changes across time, where cohorts "treated" earlier have substantially higher increases than those who more recently legalized. Traffic fatalities increase by 2.2 per billion miles driven after retail legalization, which may account for as many as 1400 traffic fatalities annually. States who legalized earlier experienced larger traffic fatality increases. TWFE methods are inadequate for policy evaluation and do not capture heterogeneous effects across time.

Did Michigan’s Legalization of Recreational Marijuana and Ohio’s Legalization of Medical Marijuana Increase Marijuana OVI Arrests in Ohio?

Did Michigan’s Legalization of Recreational Marijuana and Ohio’s Legalization of Medical Marijuana Increase Marijuana OVI Arrests in Ohio?