The Effect of Medical Marijuana Laws on Body Weight

Medical marijuana laws and mental health in the United States

The consequences of legal access to medical marijuana for individuals' well-being are controversially assessed. We contribute to the discussion by evaluating the impact of the introduction of medical marijuana laws across US states on self-reported mental health considering different motives for cannabis consumption. Our analysis is based on BRFSS survey data from close to eight million respondents between 1993 and 2018 that we combine with information from the NSDUH to estimate individual consumption propensities. We find that eased access to marijuana through medical marijuana laws reduce the reported number of days with poor mental health for individuals with a high propensity to consume marijuana for medical purposes and for those individuals who likely suffer from frequent pain.

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.

Have recreational marijuana laws undermined public health progress on adult tobacco use?

Public health experts caution that legalization of recreational marijuana may normalize smoking and undermine the decades-long achievements of tobacco control policy. However, very little is known about the impact of recreational marijuana laws (RMLs) on adult tobacco use. Using newly available data from the Population Assessment of Tobacco and Health (PATH) and dynamic difference-in-differences and discrete-time hazard approaches, we find that RML adoption increases prior-month marijuana use among adults ages 18-and-older by 2-percentage-points, driven by an increase in marijuana initiation among prior non-users. However, this increase in adult marijuana use does not extend to tobacco use. Rather, we find that RML adoption is associated with a lagged reduction in electronic nicotine delivery systems (ENDS) use, consistent with the hypothesis that ENDS and marijuana are substitutes. Moreover, auxiliary analyses from the National Survey on Drug Use and Health (NSDUH) show that RML adoption is associated with a reduction in adult cigarette smoking. We conclude that RMLs may generate tobacco-related health benefits.

Recreational marijuana laws and the misuse of prescription opioids: Evidence from National Survey on Drug Use and Health microdata

Several studies have concluded that legalizing medical marijuana can reduce deaths from opioid overdoses. Drawing on micro data from the National Survey on Drug Use and Health, a survey uniquely suited to assessing patterns of substance use, we examine the relationship between recreational marijuana laws (RMLs) and the misuse of prescription opioids. Using a standard difference-in-differences (DD) regression model, we find that RML adoption reduces the likelihood of frequently misusing prescription opioids such as OxyContin, Percocet, and Vicodin. However, using a two-stage procedure designed to account for staggered treatment and dynamic effects, the DD estimate of relationship between RML adoption and the likelihood of frequently misusing prescription opioids becomes positive. Although event study estimates suggest that RML adoption leads to a decrease in the frequency of prescription opioid abuse, this effect appears to dissipate after only 2 or 3 years.

Relationships between sales of legal medical cannabis and alcohol in Canada. Health Policy 2023;128:28-33. [PMID: 36443110 DOI: 10.1016/j.healthpol.2022.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The extent to which legalizing cannabis use might lead to increased or decreased alcohol use has important implications for public health, economic growth, and government policy. This study analyzed Canada's monthly per capita sales of alcohol and legal medical cannabis using fixed effect panel data linear regressions. The data covered seven Canadian regions from January 2011 to September 2018, and controlled for changing levels of retail activity, alcohol prices, tertiary education, unemployment, and impaired driving penalties. The analysis estimated that each dollar of legal medical cannabis sold was associated with an average alcohol sales decrease of roughly $0.74 to $0.84. This suggests that medical cannabis was an economic substitute for alcohol in Canada, and that the country's 2017-2018 alcohol sales were roughly 1.8% lower than they would have been without legal medical cannabis. The results therefore indirectly imply that reduced alcohol consumption might have partly offset cannabis legalization's health and economic impacts.

The impact of Medicare shared savings program participation on hospital financial performance: An event-study analysis

OBJECTIVE

To evaluate the impact of hospitals' participation in the Medicare Shared Savings Program (MSSP) on their financial performance.

DATA SOURCES

Centers for Medicare & Medicaid Services Hospital Cost Reports and MSSP Accountable Care Organizations (ACO) Provider-Level Research Identifiable File from 2011 to 2018.

STUDY DESIGN

We used an event-study design to estimate the temporal effects of MSSP participation on hospital financial outcomes and compared within-hospital changes over time between MSSP and non-MSSP hospitals while controlling for hospital and year fixed effects and organizational and service-area characteristics. The following financial outcomes were evaluated: outpatient revenue, inpatient revenue, net patient revenue, Medicare revenue, operating margin, inpatient revenue share, Medicare revenue share, and allowance and discount rate.

DATA COLLECTION/EXTRACTION METHODS

Secondary data linked at the hospital level.

PRINCIPAL FINDINGS

Controlling for trends in non-MSSP hospitals, MSSP participation was associated with differential increases in net patient revenue by $3.28 million (p < 0.001), $3.20 million (p < 0.01), and $4.20 million (p < 0.01) in the second, third, and fourth year and beyond after joining MSSP, respectively. Medicare revenue differentially increased by $1.50 million (p < 0.05), $2.24 million (p < 0.05), and $4.47 million (p < 0.05) in the first, second, and fourth year and beyond. Inpatient revenue share differentially increased by 0.29% (p < 0.05) in the second year and 0.44% (p < 0.05) in the fourth year and beyond. Medicare revenue share differentially increased by 0.17% (p < 0.01), 0.25% (p < 0.01), 0.32% (p < 0.01), and 0.41% (p < 0.01) in consecutive years following MSSP participation. MSSP participation was associated with 0.33% (p < 0.05) and 0.39% (p < 0.05) differential reduction in allowance and discount rate in the second and third years.

CONCLUSIONS

MSSP participation was associated with differential increases in net patient revenue, Medicare revenue, inpatient revenue share, and Medicare revenue share, and a differential reduction in allowance and discount rate.

Cloudy with a chance of munchies: Assessing the impact of recreational marijuana legalization on obesity

Obesity in the US arguably constitutes the most significant health epidemic over the past century. Recent legislative changes allowing for recreational marijuana use further create a need to better understand the relationship between marijuana use and health choices, leading to obesity. We examine this relationship by using a synthetic control approach to examine the impact of legalized recreational marijuana access on obesity rates by comparing Washington State to a synthetically constructed counterfactual. We find that recreational marijuana's introduction did not lead to increased obesity rates and may have led to decreases in obesity.

Association of Recreational Cannabis Legalization With Alcohol Use Among Adults in the US, 2010 to 2019

Importance

In the US, cannabis use has nearly doubled during the past decade, in part because states have implemented recreational cannabis laws (RCLs). However, it is unclear how legalization of adult-use cannabis may affect alcohol consumption.

Objective

To estimate the association between implementation of state RCLs and alcohol use among adults in the US.

Design, Settings, and Participants

This was a cross-sectional study of 4.2 million individuals who responded to the Behavioral Risk Factor Surveillance System in 2010 to 2019. A difference-in-differences approach with demographic and policy controls was used to estimate the association between RCLs and alcohol use, overall and by age, sex, race and ethnicity, and educational level. Data analyses were performed from June 2021 to March 2022.

Exposures

States with RCLs, as reported by the RAND-University of Southern California Schaeffer Opioid Policy Tools and Information Center.

Main Outcomes and Measures

Past-month alcohol use, binge drinking, and heavy drinking.

Results

Of 4.2 million respondents (median age group, 50-64 years; 2 476 984 [51.7%] women; 2 978 467 [58.3%] non-Hispanic White individuals) in 2010 through 2019, 321 921 individuals lived in state-years with recreational cannabis laws. Recreational cannabis laws were associated with a 0.9 percentage point (95% CI, 0.1-1.7; P = .02) increase in any alcohol drinking but were not significantly associated with binge or heavy drinking. Increases in any alcohol use were primarily among younger adults (18-24 years) and men, as well as among non-Hispanic White respondents and those without any college education. A 1.4 percentage point increase (95% CI, 0.4-2.3; P = .006) in binge drinking was also observed among men, although this association diminished over time.

Conclusions and Relevance

This cross-sectional study and difference-in-differences analysis found that recreational cannabis laws in the US may be associated with increased alcohol use, primarily among younger adults and men.

Medical cannabis and automobile accidents: Evidence from auto insurance

While many states have legalized medical cannabis, many unintended consequences remain under-studied. We focus on one potential detriment-the effect of cannabis legalization on automobile safety. We examine this relationship through auto insurance premiums. Employing a modern difference-in-differences framework and zip code-level premium data from 2014 to 2019, we find that premiums declined, on average, by $22 per year following medical cannabis legalization. The effect is more substantial in areas near a dispensary and in areas with a higher prevalence of drunk driving before legalization. We estimate that existing legalization has reduced health expenditures related to auto accidents by almost $820 million per year with the potential for a further $350 million reduction if legalized nationally.

Weight stability in adults with obesity initiating medical marijuana treatment for other medical conditions

Few studies have evaluated weight change in patients who initiate medical marijuana treatment to address diagnosed health concerns. The objective of this study was to examine whether patients initiating medical marijuana use for a qualifying health condition experienced changes in health and biopsychosocial functioning over time, including weight gain or loss. Specifically, this observational, longitudinal study evaluated changes in the body mass index (BMI) of adults with co-morbid obesity (body mass index [BMI] ≥ 30 kg/m²) and severe obesity (BMI ≥ 40 kg/m²) who were starting medical marijuana treatment for any of the 23 qualifying medical conditions at one of three dispensaries in Pennsylvania. Height and weight measurements were collected at baseline (prior to medical marijuana use) and then 90 days (± 14 days) later. Participants included in analyses (n = 52, M = 55.0 ± 13.6 years, 59.6% female) had a mean baseline BMI of 36.2 ± 5.4 kg/m² and the majority sought medical marijuana for chronic pain (73.1%). No significant change in BMI was observed from baseline to month three (p > 0.05) in the sample. Additionally, no significant change in BMI was observed in the subset of patients with severe obesity (n = 12, p > 0.05). Our findings are limited by low follow-up rates and convenience sampling methodology but may help to mitigate weight gain concerns in the context of medical marijuana use.

Relationships of Cannabis Policy Liberalization With Alcohol Use and Co-Use With Cannabis: A Narrative Review

PURPOSE

The liberalization of cannabis policies has the potential to affect the use of other substances and the harms from using them, particularly alcohol. Although a previous review of this literature found conflicting results regarding the relationship between cannabis policy and alcohol-related outcomes, cannabis policies have continued to evolve rapidly in the years since that review.

SEARCH METHODS

The authors conducted a narrative review of studies published between January 1, 2015, and December 31, 2020, that assessed the effects of cannabis policies on the use of alcohol in the United States or Canada.

SEARCH RESULTS

The initial search identified 3,446 unique monographs. Of these, 23 met all inclusion criteria and were included in the review, and five captured simultaneous or concurrent use of alcohol and cannabis.

DISCUSSION AND CONCLUSIONS

Associations between cannabis policy liberalization and alcohol use, alcohol-related outcomes, and the co-use of alcohol and cannabis were inconclusive, with studies finding positive associations, no associations, and negative associations. Although several studies found that cannabis policy liberalization was associated with decreases in alcohol use measures, these same studies showed no impact of the cannabis policy on cannabis use itself. The lack of a consistent association was robust to subject age, outcome measure (e.g., use, medical utilization, driving), and type of cannabis policy; however, this may be due to the small number of studies for each type of outcome. This paper discusses several notable limitations of the evidence base and offers suggestions for improving consistency and comparability of research going forward, including a stronger classification of cannabis policy, inclusion of measures of the alcohol policy environment, verification of the impact of cannabis policy on cannabis use, and consideration of mediation effects.

Repeal of state laws permitting denial of health claims resulting from alcohol impairment: Impact on treatment utilization

BACKGROUND

Many states in the U.S. still have Alcohol Exclusion Laws (AELs), which allow insurance companies to deny health claims resulting from alcohol impairment. There are concerns that this form of structural stigmatization affects alcohol treatment-seeking behaviors. We examined the effects of AEL repeal on treatment admissions for alcohol use disorder (AUD).

METHODS

Data on alcohol treatment admissions from 1992 to 2017 were obtained from the Treatment Episode Data Set. The state-level aggregate number of treatment admissions was derived, including healthcare professional referrals only, self-referrals only, and both self-referral and healthcare professional referrals. The number of treatment admissions by health insurance status (private, public, and uninsured) was also calculated. The study used a difference-in-differences (DID) quasi-experimental design.

RESULTS

The DID analysis showed that the number of admissions for alcohol treatment from healthcare professional referrals increased 16% in the AEL repeal states compared to states with AELs or that never had AELs (IRR=1.16, 95% CI=1.07, 1.25). These results were consistent for analysis by payment sources. In particular, treatment admissions from healthcare professional referrals for patients covered by private insurance increased about 38% in states with AEL repeal (IRR=1.38, 95% CI=1.17, 1.64) compared to states without AEL repeal. However, the findings were no longer significant when the state-specific time trends were taken into account.

CONCLUSIONS

This study documented that AEL repeal may have had a significant impact on the number of treatment admissions for AUD. These findings suggest that AELs function as a barrier to treatment-seeking behavior.

Heterogeneous health effects of medical marijuana legalization: Evidence from young adults in the United States

Legalizing marijuana for medical purposes is a longstanding debate. However, evidence of marijuana's health effects is limited, especially for young adults. We estimate the health impacts of medical marijuana laws (MML) in the U.S. among young adults aged 18-29 years using the difference-in-differences method and data from the Behavioral Risk Factors Surveillance System. We find that having MMLs with strict regulations generate health gains, but not in states with lax regulations. Our heterogeneity analysis results indicate that individuals with lower education attainments, with lower household income and without access to health insurance coverage gain more health benefits from MML with strict regulations than from MML with lax regulations. The findings suggest greater net health gains under strict controls concerning marijuana supply and access.

Clinical Characteristics and Quality of Life in Adults Initiating Medical Marijuana Treatment

INTRODUCTION

Despite the rising availability and use of medical marijuana (MM) in the USA, little is known about the demographics, clinical characteristics, or quality of life of MM patients. This study describes the demographic characteristics and health-related quality of life (HRQoL) of MM patients who are initiating treatment in Pennsylvania.

METHODS

Two-hundred adults naive to MM and referred for any of the 23 state-approved qualifying conditions were recruited at three MM dispensaries in Pennsylvania between September 2020 and March 2021. All participants consented to the study; completed semi-structured interviews that included demographic questionnaires, the Short Form-36 (SF-36), and Generalized Anxiety Disorder-7 (GAD-7); provided height and weight measurements; and allowed access their dispensary medical records.

RESULTS

Participants had a mean age of 48.5 ± 15.6 years, predominantly identified as female (67.5%), and were most commonly referred for chronic pain (63.5%) and/or anxiety (58.5%). Additionally, 46.0% were living with obesity as determined by BMI. Relative to a normative sample, participants reported diminished HRQoL in several domains, most notably in role limitations due to physical health (M = 46.0 ± 42.0), role limitations due to emotional problems (M = 52.5 ± 42.3), energy and fatigue (M = 39.8 ± 20.2), and pain (M = 49.4 ± 26.0).

DISCUSSION/CONCLUSION

Patients initiating MM treatment experienced low HRQoL in multiple domains. Future studies could evaluate the relationship between HRQoL and patients' decisions to pursue MM treatment, as well as changes in HRQoL with MM use over time.

The effects of graduated driver licensing on teenage body weight

The graduated driver licensing (GDL) program requires teenage drivers to pass through an intermediate stage, which contains specific driving restrictions such as a night curfew or a limit on the number of teen passengers to be carried, before earning full driving privileges. Using individual data from the 1999 to 2017 biennial Youth Risk Behavior Surveillance System (YRBS) combined with state-level GDL policy variations, we estimate the effects of GDL on teenage body weight in the United States. We find that the presence of GDL raises adolescents' body mass index Z-score and their likelihood of being overweight or obese. Among the restrictions imposed, a night curfew implemented together with a passenger restriction makes the most significant impact. These estimated effects are concentrated among states with more restrictive GDL policies. We also find that the presence of GDL reduces adolescent physical activity and heavy smoking, while increasing their time spent watching TV and milk intake, perhaps contributing to youth weight gain. An event study analysis reveals that the effects of GDL on adolescent weight increase may be transitory.

Marijuana legalization and household spending on food and alcohol

Utilizing the Consumer Expenditure Interview Survey from 2005 to 2019, I study spending on food and alcohol following recreational marijuana law (RML). Exploiting differences in the timing of the passage of RMLs and employing two-way fixed-effects methods, I find that households located in states adopting these laws increase their quarterly spending on food, which is driven mainly by spending on food consumed away from home. Legalization of recreational marijuana also leads to increased quarterly spending on alcohol. These findings suggest a complementarity between food, alcohol, and marijuana.

Recreational marijuana laws and junk food consumption

We use retail scanner data on purchases of high calorie food to study the causal relationship between recreational marijuana laws (RMLs) and consumption of high calorie food. To do this we exploit differences in the timing of introduction of recreational marijuana laws among states and find that they are complements. Specifically, in counties located in RML states monthly sales of high calorie food increased by 3.2 percent when measured by sales and 4.5 percent when measured by volume when using our preferred identification strategy. Results are robust to including placebo effective dates for RMLs in treated states and products as well as when using Synthetic Control Methods as an alternative methodology.

Do-It-Yourself medicine? The impact of light cannabis liberalization on prescription drugs

Governments worldwide are increasingly concerned about the booming use of CBD (cannabidiol) products. However, we know little about the impact of their liberalization. We study a unique case of unintended liberalization of a CBD-based product (light cannabis) that occurred in Italy in 2017. Using unique and high-frequency data on prescription drug sales and by exploiting the staggered local availability of the new product in each Italian province, we document a significant substitution effect between light cannabis and anxiolytics, sedatives, opioids, anti-depressants and anti-psychotics. Results are informative for regulators and suggest that bans on light cannabis use would disregard the needs of patients to seek effective reliefs of their symptoms.

Does cannabis complement or substitute alcohol consumption? A systematic review of human and animal studies

BACKGROUND

Whether alcohol and cannabis complement or substitute each other has been studied for over two decades. In the changing cannabis policy landscape, debates are moving rapidly and spill-over effects on other substances are of interest.

AIMS

update and extend a previous systematic review, by: (a) identifying new human behavioural studies reporting on substitution and/or complementarity of alcohol and cannabis, and (b) additionally including animal studies.

METHODS

We replicated the search strategy of an earlier systematic review, supplemented with a new search for animal studies. Search results were crossed checked against the earlier review and reference lists were hand searched. Findings were synthesised using a narrative synthesis.

RESULTS

Sixty-five articles were included (64 in humans, one in animals). We synthesised findings into categories: patterns of use, substitution practices, economic relationship, substance use disorders, policy evaluation, others and animal studies. Overall, 30 studies found evidence for substitution, 17 for complementarity, 14 did not find evidence for either, and four found evidence for both.

CONCLUSIONS

Overall, the evidence regarding complementarity and substitution of cannabis and alcohol is mixed. We identified stronger support for substitution than complementarity, though evidence indicates different effects in different populations and to some extent across different study designs. The quality of studies varied and few were designed specifically to address this question. Dedicated high-quality research is warranted.

Altered States or Much to Do About Nothing? A Study of When Cannabis Is Used in Relation to the Impact It Has on Performance

As more local, state, and national governments change laws regarding the legality of cannabis use, it is essential for organizations to understand how the workplace may be influenced by these changes. The current study begins to answer this question by examining the relationship between three temporal-based cannabis measures and five forms of workplace performance. Using data from 281 employees and their direct supervisors, our results indicate that cannabis use before and during work negatively relate to task performance, organization-aimed citizenship behaviors, and two forms of counterproductive work behaviors. At the same time, after-work cannabis use was not related (positively or negatively) to any form of performance as rated by the user’s direct supervisor. We discuss methodological, theoretical, and practical implications for researchers, organizations, and governmental agencies concerned with cannabis use.

Medical marijuana and workers' compensation claiming

We study the effect of state medical marijuana laws (MMLs) on workers' compensation (WC) claiming among adults. Medical marijuana is plausibly related to WC claiming by allowing improved symptom management, and thus reduced need for the benefit, among injured or ill workers. We use data on claiming drawn from the Annual Social and Economic supplement to the Current Population Survey over the period 1989 to 2012, coupled with a differences-in-differences design to provide the first evidence on this relationship. Our estimates show that, post MML, WC claiming declines, both the propensity to claim and the level of income from WC. These findings suggest that medical marijuana can allow workers to better manage symptoms associated with workplace injuries and illnesses and, in turn, reduce need for WC. However, the reductions in WC claiming post MML are very modest in size.

Sex, marijuana and baby booms

We study the behavioral changes caused by marijuana use on sexual activity, contraception, and birth counts by applying a differences-in-differences approach that exploits the variation in timing of the introduction of medical marijuana laws (MMLs) among states. We find that MMLs cause an increase in sexual activity, a reduction in contraceptive use conditional on having sex, and an increase in number of births. There is also suggestive evidence on temporary increases in the state-year gonorrhea rate. These changes may be attributed to behavioral responses including increased attention to the immediate hedonic effects of sexual contact, increased sexual frequency, as well as delayed discounting and ignoring the future costs associated with sex. Our findings on births suggest that behavioral factors can counteract the physiological changes from marijuana use that tend to decrease fertility. Our findings are robust to a broad set of tests.

Medical Marijuana Users are More Likely to Use Prescription Drugs Medically and Nonmedically

OBJECTIVES

Previous studies have found a negative population-level correlation between medical marijuana availability in US states, and trends in medical and nonmedical prescription drug use. These studies have been interpreted as evidence that use of medical marijuana reduces medical and nonmedical prescription drug use. This study evaluates whether medical marijuana use is a risk or protective factor for medical and nonmedical prescription drug use.

METHODS

Simulations based upon logistic regression analyses of data from the 2015 National Survey on Drug Use and Health were used to compute associations between medical marijuana use, and medical and nonmedical prescription drug use. Adjusted risk ratios (RRs) were computed with controls added for age, sex, race, health status, family income, and living in a state with legalized medical marijuana.

RESULTS

Medical marijuana users were significantly more likely (RR 1.62, 95% confidence interval [CI] 1.50-1.74) to report medical use of prescription drugs in the past 12 months. Individuals who used medical marijuana were also significantly more likely to report nonmedical use in the past 12 months of any prescription drug (RR 2.12, 95% CI 1.67-2.62), with elevated risks for pain relievers (RR 1.95, 95% CI 1.41-2.62), stimulants (RR 1.86, 95% CI 1.09-3.02), and tranquilizers (RR 2.18, 95% CI 1.45-3.16).

CONCLUSIONS

Our findings disconfirm the hypothesis that a population-level negative correlation between medical marijuana use and prescription drug harms occurs because medical marijuana users are less likely to use prescription drugs, either medically or nonmedically. Medical marijuana users should be a target population in efforts to combat nonmedical prescription drug use.

The Impact of Medical Marijuana Laws and Dispensaries on Self-Reported Health

Growing evidence suggests that medical marijuana laws have harm reduction effects across a variety of outcomes related to risky health behaviors. This study investigates the impact of medical marijuana laws on self-reported health using data from the Behavioral Risk Factor Surveillance System from 1993 to 2013. In our analyses we separately identify the effect of a medical marijuana law and the impact of subsequent active and legally protected dispensaries. Our main results show surprisingly limited improvements in self-reported health after the legalization of medical marijuana and legally protected dispensaries. Subsample analyses reveal strong improvements in health among non-white individuals, those reporting chronic pain, and those with a high school degree, driven predominately by whether or not the state had active and legally protected dispensaries. We also complement the analysis by evaluating the impact on risky health behaviors and find that the aforementioned demographic groups experience large reductions in alcohol consumption after the implementation of a medical marijuana law.

Early evidence of the impact of cannabis legalization on cannabis use, cannabis use disorder, and the use of other substances: Findings from state policy evaluations

Background: The past decade has seen unprecedented shifts in the cannabis policy environment, and the public health impacts of these changes will hinge on how they affect patterns of cannabis use and the use and harms associated with other substances.Objectives: To review existing research on how state cannabis policy impacts substance use, emphasizing studies using methods for causal inference and highlighting gaps in our understanding of policy impacts on evolving cannabis markets.Methods: Narrative review of quasi-experimental studies for how medical cannabis laws (MCLs) and recreational cannabis laws (RCLs) affect cannabis use and use disorders, as well as the use of or harms from alcohol, opioids, and tobacco.Results: Research suggests MCLs increase adult but not adolescent cannabis use, and provisions of the laws associated with less regulated supply may increase adult cannabis use disorders. These laws may reduce some opioid-related harms, while their impacts on alcohol and tobacco use remain uncertain. Research on RCLs is just emerging, but findings suggest little impact on the prevalence of adolescent cannabis use, potential increases in college student use, and unknown effects on other substance use.Conclusions: Research on how MCLs influence cannabis use has advanced our understanding of the importance of heterogeneity in policies, populations, and market dynamics, but studies of how MCLs relate to other substance use often ignore these factors. Understanding effects of cannabis laws requires greater attention to differences in short- versus long-term effects of the laws, nuances of policies and patterns of consumption, and careful consideration of appropriate control groups.

The effects of e-cigarette minimum legal sale age laws on youth substance use

We use difference-in-differences models and individual-level data from the national and state Youth Risk Behavior Surveillance System from 2005 to 2015 to examine the effects of e-cigarette minimum legal sale age (MLSA) laws on youth cigarette smoking, alcohol consumption, and marijuana use. Our results suggest that these laws increased youth smoking participation by about one percentage point and approximately half of the increased smoking participation could be attributed to smoking initiation. We find little evidence of higher cigarette smoking persisting beyond the point at which youth age out of the laws. Our results also show little effect of the laws on youth drinking, binge drinking, and marijuana use. Taking these together, our findings suggest a possible unintended effect of e-cigarette MLSA laws-rising cigarette use in the short term while youth are restricted from purchasing e-cigarettes.

Theoretical Explanation for Reduced Body Mass Index and Obesity Rates in Cannabis Users

Introduction: Obesity is treatment-resistant, and is linked with a number of serious, chronic diseases. Adult obesity rates in the United States have tripled since the early 1960s. Recent reviews show that an increased ratio of omega-6 to omega-3 fatty acids contributes to obesity rates by increasing levels of the endocannabinoid signals AEA and 2-AG, overstimulating CB₁R and leading to increased caloric intake, reduced metabolic rates, and weight gain. Cannabis, or THC, also stimulates CB₁R and increases caloric intake during acute exposures. Goals: To establish the relationship between Cannabis use and body mass index, and to provide a theoretical explanation for this relationship. Results: The present meta-analysis reveals significantly reduced body mass index and rates of obesity in Cannabis users, in conjunction with increased caloric intake. Theoretical explanation: We provide for the first time a causative explanation for this paradox, in which rapid and long-lasting downregulation of CB₁R following acute Cannabis consumption reduces energy storage and increases metabolic rates, thus reversing the impact on body mass index of elevated dietary omega-6/omega-3 ratios.

Medical marijuana laws and workplace fatalities in the United States

AIMS

The aim of this research was to determine the association between legalizing medical marijuana and workplace fatalities.

DESIGN

Repeated cross-sectional data on workplace fatalities at the state-year level were analyzed using a multivariate Poisson regression.

SETTING

To date, 29 states and the District of Columbia have legalized the use of marijuana for medicinal purposes. Although there is increasing concern that legalizing medical marijuana will make workplaces more dangerous, little is known about the relationship between medical marijuana laws (MMLs) and workplace fatalities.

PARTICIPANTS

All 50 states and the District of Columbia for the period 1992-2015.

MEASUREMENTS

Workplace fatalities by state and year were obtained from the Bureau of Labor Statistics. Regression models were adjusted for state demographics, the unemployment rate, state fixed effects, and year fixed effects.

FINDINGS

Legalizing medical marijuana was associated with a 19.5% reduction in the expected number of workplace fatalities among workers aged 25-44 (incident rate ratio [IRR], 0.805; 95% CI, .662-.979). The association between legalizing medical marijuana and workplace fatalities among workers aged 16-24, although negative, was not statistically significant at conventional levels. The association between legalizing medical marijuana and workplace fatalities among workers aged 25-44 grew stronger over time. Five years after coming into effect, MMLs were associated with a 33.7% reduction in the expected number of workplace fatalities (IRR, 0.663; 95% CI, .482-.912). MMLs that listed pain as a qualifying condition or allowed collective cultivation were associated with larger reductions in fatalities among workers aged 25-44 than those that did not.

CONCLUSIONS

The results provide evidence that legalizing medical marijuana improved workplace safety for workers aged 25-44. Further investigation is required to determine whether this result is attributable to reductions in the consumption of alcohol and other substances that impair cognitive function, memory, and motor skills.

The impact of child welfare legislation on domestic violence-related homicide rates

State-specific statutes providing legal consequences for perpetrating domestic violence in the presence of a child have been enacted across the United States between 1996 and 2012. This paper examines the impact of this child welfare legislation, using a difference-in-differences approach. We find a significant drop in domestic violence-related homicide rates, when considering a wide range of victim-offender relationships. However, this result does not hold for marital homicides, suggesting that for this subpopulation, the risk of reprisal and consequent reduction in reporting may be counterbalancing the hypothesized deterrent impacts of the legislation.

Substance Use Treatment Provider Behavior and Healthcare Reform: Evidence from Massachusetts

We examine the impact of the 2006 Massachusetts healthcare reform on substance use disorder (SUD) treatment facilities' provision of care. We test the impact of the reform on treatment quantity and access. We couple data on the near universe of specialty SUD treatment providers in the USA with a synthetic control method approach. We find little evidence that the reform lead to changes in treatment quantity or access. Reform effects were similar among for-profit and non-profit facilities. In an extension, we show that the reform altered the setting in which treatment is received, the number of offered services, and the number of programs for special populations. These findings may be useful in predicting the implications of major health insurance expansions on the provision of SUD treatment. Copyright © 2017 John Wiley & Sons, Ltd.

How Medical Marijuana Smoothed the Transition to Marijuana Legalization in the United States

Public support for legalizing marijuana use increased from 25% in 1995 to 60% in 2016, rising in lockstep with support for same-sex marriage. Between November 2012 and November 2016, voters in eight states passed ballot initiatives to legalize marijuana sales for nonmedical purposes-covering one-fifth of the US population. These changes are unprecedented but are not independent of the changes in medical marijuana laws that have occurred over the past 20 years. This article suggests five ways in which the passage and implementation of medical marijuana laws smoothed the transition to nonmedical legalization in the United States: (a) They demonstrated the efficacy of using voter initiatives to change marijuana supply laws, (b) enabled the psychological changes needed to destabilize the "war on drugs" policy stasis, (c) generated an evidence base that could be used to downplay concerns about nonmedical legalization, (d) created a visible and active marijuana industry, and (e) revealed that the federal government would allow state and local jurisdictions to generate tax revenue from marijuana.