The effects of medical marijuana laws on illegal marijuana use

Recreational marijuana legalization and college student use: Early evidence

We analyze marijuana use by college undergraduates before and after legalization of recreational marijuana. Using survey data from the National College Health Assessment, we show that students at Washington State University experienced a significant increase in marijuana use after legalization. This increase is larger than would be predicted by national trends. The change is strongest among females, Black students, and Hispanic students. The increase for underage students is as much as for legal-age students. We find no corresponding changes in the consumption of tobacco, alcohol, or other drugs.

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No literature has yet assessed the impact of recreational legalization on college students’ marijuana use.

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Probability of marijuana use by students increased after recreational legalization.

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Frequency of marijuana use by students increased after recreational legalization.

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Increase is especially large for females and for Black and Hispanic students.

Prevalence and correlates of treatment utilization among adults with cannabis use disorder in the United States

BACKGROUND

The increase in cannabis potency may have treatment implications for cannabis use disorder (CUD). Given the reported increase in prevalence of cannabis use among adults, there is a need to understand substance use treatment needs for CUD.

METHODS

We examined demographics and behavioral health indicators of adults aged ≥18 years that met criteria for past-year CUD (n=10,943) in the 2005-2013 National Surveys on Drug Use and Health. We determined prevalence and correlates of past-year treatment use for alcohol/drug, any drug, and cannabis use related problems, to inform treatment efforts for CUD.

RESULTS

The majority of adults with past-year CUD were young adults aged 18-25 or men, had low income, and did not attend college. Two-thirds of adults with CUD met criteria for cannabis dependence, which was comparatively common among younger adults, women, low-income or publicly insured adults, and college-educated adults. Nicotine dependence (40.92%) and alcohol (44.07%) or other drug use disorder (19.70%) were prevalent among adults with CUD. Overall, less than 13% of adults with CUD had received alcohol/drug use treatment the past year; only 7.8% received cannabis-specific treatment. There was no significant yearly variation in treatment use prevalence over 9 years. In particular, Asian-Americans, women, and college-educated adults underutilized cannabis-specific treatment.

CONCLUSIONS

This large sample of adults with CUD reveals pervasive underutilization of cannabis-related treatment, especially in women, married adults, and those with college education, despite a high proportion of comorbid behavioral health problems.

Medical marijuana policies and hospitalizations related to marijuana and opioid pain reliever

OBJECTIVES

Twenty-eight states in the U.S have legalized medical marijuana, yet its impacts on severe health consequences such as hospitalizations remain unknown. Meanwhile, the prevalence of opioid pain reliever (OPR) use and outcomes has increased dramatically. Recent studies suggested unintended impacts of legalizing medical marijuana on OPR, but the evidence is still limited. This study examined the associations between state medical marijuana policies and hospitalizations related to marijuana and OPR.

METHODS

State-level annual administrative records of hospital discharges during 1997-2014 were obtained from the State Inpatient Databases (SID). The outcome variables were rates of hospitalizations involving marijuana dependence or abuse, opioid dependence or abuse, and OPR overdose in 1000 discharges. Linear time-series regressions were used to assess the associations of implementing medical marijuana policies to hospitalizations, controlling for other marijuana- and OPR-related policies, socioeconomic factors, and state and year fixed effects.

RESULTS

Hospitalizations related to marijuana and OPR increased sharply by 300% on average in all states. Medical marijuana legalization was associated with 23% (p=0.008) and 13% (p=0.025) reductions in hospitalizations related to opioid dependence or abuse and OPR overdose, respectively; lagged effects were observed after policy implementation. The operation of medical marijuana dispensaries had no independent impacts on OPR-related hospitalizations. Medical marijuana polices had no associations with marijuana-related hospitalizations.

CONCLUSION

Medical marijuana policies were significantly associated with reduced OPR-related hospitalizations but had no associations with marijuana-related hospitalizations. Given the epidemic of problematic use of OPR, future investigation is needed to explore the causal pathways of these findings.

Irish general practitioner attitudes toward decriminalisation and medical use of cannabis: results from a national survey

Background

Governmental debate in Ireland on the de facto decriminalisation of cannabis and legalisation for medical use is ongoing. A cannabis-based medicinal product (Sativex®) has recently been granted market authorisation in Ireland. This unique study aimed to investigate Irish general practitioner (GP) attitudes toward decriminalisation of cannabis and assess levels of support for use of cannabis for therapeutic purposes (CTP).

Methods

General practitioners in the Irish College of General Practitioner (ICGP) database were invited to complete an online survey. Anonymous data yielded descriptive statistics (frequencies, percentages) to summarise participant demographic information and agreement with attitudinal statements. Chi-square tests and multi-nominal logistic regression were included.

Results

The response rate was 15% (n = 565) which is similar to other Irish national GP attitudinal surveys. Over half of Irish GPs did not support the decriminalisation of cannabis (56.8%). In terms of gender, a significantly higher proportion of males compared with females (40.6 vs. 15%; p < 0.0001) agreed or strongly agreed with this drug policy approach. A higher percentage of GPs with advanced addiction specialist training (level 2) agreed/strongly agreed that cannabis should be decriminalised (54.1 vs. 31.5%; p = 0.021). Over 80% of both genders supported the view that cannabis use has a significant effect on patients’ mental health and increases the risk of schizophrenia (77.3%). Over half of Irish GPs supported the legalisation of cannabis for medical use (58.6%). A higher percentage of those who were level 1-trained (trained in addiction treatment but not to an advanced level) agreed/strongly agreed cannabis should be legalised for medical use (p = 0.003). Over 60% agreed that cannabis can have a role in palliative care, pain management and treatment of multiple sclerosis (MS). In the regression response predicator analysis, females were 66.2% less likely to agree that cannabis should be decriminalised, 42.5% less likely to agree that cannabis should be legalised for medical use and 59.8 and 37.6% less likely to agree that cannabis has a role in palliative care and in the treatment of multiple sclerosis (respectively) than males.

Conclusions

The majority of Irish GPs do not support the present Irish governmental drug policy of decriminalisation of cannabis but do support the legalisation of cannabis for therapeutic purposes. Male GPs and those with higher levels of addiction training are more likely to support a more liberal drug policy approach to cannabis for personal use. A clear majority of GPs expressed significant concerns regarding both the mental and physical health risks of cannabis use. Ongoing research into the health and other effects of drug policy changes on cannabis use is required.

How does state marijuana policy affect US youth? Medical marijuana laws, marijuana use and perceived harmfulness: 1991-2014

AIMS

To test, among US students: (1) whether perceived harmfulness of marijuana has changed over time, (2) whether perceived harmfulness of marijuana changed post-passage of state medical marijuana laws (MML) compared with pre-passage; and (3) whether perceived harmfulness of marijuana statistically mediates and/or modifies the relation between MML and marijuana use as a function of grade level.

DESIGN

Cross-sectional nationally representative surveys of US students, conducted annually, 1991-2014, in the Monitoring the Future study.

SETTING

Surveys conducted in schools in all coterminous states; 21 states passed MML between 1996 and 2014.

PARTICIPANTS

The sample included 1 134 734 adolescents in 8th, 10th and 12th grades.

MEASUREMENTS

State passage of MML; perceived harmfulness of marijuana use (perceiving great or moderate risk to health from smoking marijuana occasionally versus slight or no risk); and marijuana use (prior 30 days). Data were analyzed using time-varying multi-level regression modeling.

FINDINGS

The perceived harmfulness of marijuana has decreased significantly since 1991 (from an estimated 84.0% in 1991 to 53.8% in 2014, P < 0.01) and, across time, perceived harmfulness was lower in states that passed MML [odds ratio (OR) = 0.86, 95% confidence interval (CI) = 0.75-0.97]. In states with MML, perceived harmfulness of marijuana increased among 8th graders after MML passage (OR = 1.21, 95% CI = 1.08-1.36), while marijuana use decreased (OR = 0.81, 95% CI = 0.72-0.92). Results were null for other grades, and for all grades combined. Increases in perceived harmfulness among 8th graders after MML passage was associated with ~33% of the decrease in use. When adolescents were stratified by perceived harmfulness, use in 8th graders decreased to a greater extent among those who perceived marijuana as harmful.

CONCLUSIONS

While perceived harmfulness of marijuana use appears to be decreasing nationally among adolescents in the United States, the passage of medical marijuana laws (MML) is associated with increases in perceived harmfulness among young adolescents and marijuana use has decreased among those who perceive marijuana to be harmful after passage of MML.

Evaluating the public health impacts of legalizing recreational cannabis use in the United States

BACKGROUND AND AIMS

Since 2012 four US states have legalized the retail sale of cannabis for recreational use by adults, and more are likely to follow. This report aimed to (1) briefly describe the regulatory regimes so far implemented; (2) outline their plausible effects on cannabis use and cannabis-related harm; and (3) suggest what research is needed to evaluate the public health impact of these policy changes.

METHOD

We reviewed the drug policy literature to identify: (1) plausible effects of legalizing adult recreational use on cannabis price and availability; (2) factors that may increase or limit these effects; (3) pointers from studies of the effects of legalizing medical cannabis use; and (4) indicators of cannabis use and cannabis-related harm that can be monitored to assess the effects of these policy changes.

RESULTS

Legalization of recreational use will probably increase use in the long term, but the magnitude and timing of any increase is uncertain. It will be critical to monitor: cannabis use in household and high school surveys; cannabis sales; the number of cannabis plants legally produced; and the tetrahydrocannabinol (THC) content of cannabis. Indicators of cannabis-related harms that should be monitored include: car crash fatalities and injuries; emergency department presentations; presentations to addiction treatment services; and the prevalence of regular cannabis use among young people in mental health services and the criminal justice system.

CONCLUSIONS

Plausible effects of legalizing recreational cannabis use in the United States include substantially reducing the price of cannabis and increasing heavy use and some types of cannabis-related harm among existing users. In the longer term it may also increase the number of new users.

Why it is probably too soon to assess the public health effects of legalisation of recreational cannabis use in the USA

The citizens of four US states-Alaska, Colorado, Oregon, and Washington-have voted to legalise the sale of cannabis to adults for recreational purposes, and more states look likely to follow. Experience with alcohol and tobacco suggests that a for-profit legal cannabis industry will increase use by making cannabis more socially acceptable to use, making it more readily available at a cheaper price, and increasing the number of users and frequency of their use. We argue that it is too early to see the full effects of legalised cannabis policies on use and harm because several factors could delay the full commercialisation of a legal cannabis industry. These factors include restrictions on various licensed producers and sellers, and legal conflicts between Federal and State laws that might provide a brake on the speed and scale of commercialisation in states that have legalised cannabis. Any increases in cannabis use and harm could be minimised if governments introduced public health policies that limited the promotional activities of a legal cannabis industry, restricted cannabis availability to adults, and maintained cannabis prices at a substantial fraction of the black market price. So far, no states have chosen to implement these policies.

Determinants of Public Support for Marijuana Legalization in Uruguay, the United States, and El Salvador

What are the determinants of public support for marijuana legalization? In the last 3 years, Uruguay and the states of Colorado and Washington have legalized the production, sale, and consumption of recreational marijuana. Although Uruguay and the United States have followed different paths toward legalization, these cases provide an excellent opportunity to explore the relationship between drug policy implementation and public opinion in different political contexts. Using logistic regressions on data from the 2014 AmericasBarometer cross-national surveys conducted in Uruguay, the United States, and El Salvador, this article examines citizen views toward marijuana regulation and the individual determinants of support for legalization in a comparative fashion. Results underline the role of political socialization variables in those countries in which legalization is being debated. Across countries, some of the most important factors for predicting positive attitudes toward marijuana regulation are related to political tolerance, ideology, and the views toward the government.

Trends in cannabis use disorders among racial/ethnic population groups in the United States

BACKGROUND

Minority groups generally experience more disparities than whites in behavioral healthcare use. The population of racial/ethnic groups is growing faster than whites. Given increased concerns of cannabis use (CU) and its associations with health conditions, we examined national trends in cannabis use disorder (CUD) among adults aged ≥18 by race/ethnicity.

METHODS

Data were from the 2005-2013 National Surveys on Drug Use and Health (N=340,456). We compared CU patterns and the conditional prevalence of CUD among cannabis users by race/ethnicity to understand racial/ethnic variations in CUD.

RESULTS

Approximately 1.5% of adults met criteria for a CUD in the past year. Regardless of survey year, cannabis dependence was more common than cannabis abuse, representing 66% of adults with a CUD. Across racial/ethnic groups, the prevalence of cannabis abuse and dependence remained stable during 2005-2013. In the total adult sample, the odds of weekly CU, monthly CU, and cannabis dependence were greater among blacks, native-Americans, and mixed-race adults than whites. Among cannabis users, the odds of cannabis abuse and dependence were greater among blacks, native-Americans, and Hispanics than whites. Logistic regression controlling for age, sex, education, and survey year indicated an increased trend in monthly CU and weekly CU in the total sample and among past-year cannabis users. Younger age, male sex, and low education were associated with increased odds of cannabis dependence.

CONCLUSIONS

The large sample provides robust information that indicates a need for research to monitor CUD and identify culturally appropriate interventions especially for targeting minority populations.

Influence of legal status on the uptake of cannabis in young people

PURPOSE OF REVIEW

Policies that limit young people's access to cannabis may reduce early onset of use and minimize health-related harm. This review article provides an update of recent research examining the influence of the cannabis policy frameworks on the use of cannabis by young people.

RECENT FINDINGS

There are significant concerns that ongoing policy changes in favour of legalization will increase the uptake of cannabis by young people. Evidence to support a causal effect of cannabis policy changes on increased uptake by young people is lacking; more time may be needed to assess the impact because the policies are still evolving. Policy changes in favour of legalization were associated with reduced risk perception although this may be a cause or consequence. The need to situate the impact of these policies in the context of specific policy features, social norms and perceptions about cannabis has been highlighted.

SUMMARY

A more nuanced understanding of the impact of the legal status of cannabis on young people is needed to build evidence for future policy options. The impact of these policies may not be immediately apparent but limiting young people's access to cannabis must be prioritized during policy deliberations.

Medical Marijuana Laws Reduce Prescription Medication Use In Medicare Part D

Legalization of medical marijuana has been one of the most controversial areas of state policy change over the past twenty years. However, little is known about whether medical marijuana is being used clinically to any significant degree. Using data on all prescriptions filled by Medicare Part D enrollees from 2010 to 2013, we found that the use of prescription drugs for which marijuana could serve as a clinical alternative fell significantly, once a medical marijuana law was implemented. National overall reductions in Medicare program and enrollee spending when states implemented medical marijuana laws were estimated to be $165.2 million per year in 2013. The availability of medical marijuana has a significant effect on prescribing patterns and spending in Medicare Part D.

Cannabis consumption patterns among frequent consumers in Uruguay

BACKGROUND

In 2013, Uruguay became the first country to fully regulate the cannabis market, which now operates under state control. Cannabis can be legally acquired in three ways: growing it for personal use (self-cultivation), cannabis club membership, and from pharmacies (not yet implemented). Users must be entered into a confidential official registry to gain access.

METHODS

This article presents findings of a Respondent Driven Sample survey of 294 high-frequency cannabis consumers in the Montevideo metropolitan area.

RESULTS

Frequent consumers resort to more than one method for acquiring cannabis, with illegal means still predominating after 1 year of the new regulation law. Cannabis users overwhelmingly support the current regulation, but many of them are reluctant to register.

CONCLUSIONS

Some of the attitudes and behaviors of the high-frequency consumers pose a challenge to the success of the cannabis law. Individuals relying on more than one method of access defy the single access clause, a prerequisite for legal use, while the maximum amount of cannabis individuals can access monthly seems too high even for most frequent consumers, which might promote the emergence of a grey market. Reluctance to register among a significant proportion of high-frequency consumers raises doubts about the law's ability to achieve its stated objectives.

Attempts to stop or reduce daily cannabis use: An intensive natural history study

We attempted to replicate and add to our prior study of attempts to stop or reduce cannabis use among daily cannabis users trying to change on their own, by observing a larger sample and adding further clinically relevant outcomes. Daily users (n = 193) who intended to stop or reduce sometime in the next 3 months called an Interactive Voice Response system each morning for 3 months to report on cannabis use, attempts to stop or reduce, withdrawal symptoms, and so forth, on the prior day. This study replicated our prior findings that (a) cannabis users trying to change make many, and often rapid, transitions among use as usual, reduction, and abstinence; (b) reduction attempts are more common than abstinence attempts; (c) quit and reduction attempts are short-lived and few participants achieve long-term abstinence; (d) alcohol and drug use are not greater on abstinence days; and (e) few users seek treatment. Novel findings included (f) a greater number of days of abstinence or intentional reduction predicted a greater decline in cannabis dependence, (g) most users do not prepare before their quit attempt, (h) coping outcomes during abstinence predict increased duration of abstinence, (i) tobacco use is less common on days of abstinence, and (j) withdrawal symptoms occur even with short quit attempts. Replication tests in more generalizable samples and of longer duration are indicated. Further natural history studies are likely to provide information to help improve the content of psychological treatments for cannabis use. (PsycINFO Database Record

Impacts of Changing Marijuana Policies on Alcohol Use in the United States

BACKGROUND

Marijuana policies are rapidly evolving. In the United States, recreational use of marijuana is now legal in 4 states and medical marijuana is legal in 23 states. Research evaluating such policies has focused primarily on how policies affect issues of price, access to, use, and consequences of marijuana. Due to potential spillover effects, researchers also need to examine how marijuana policies may impact use and consequences of alcohol.

METHODS

The current paper is a critical review of articles evaluating alcohol outcomes associated with marijuana decriminalization, medical marijuana legalization, and nonmedical or recreational marijuana legalization. We identified articles and reports through (1) online searches of EBSCO host database including Academic Search Premier, Econlit, Legal Collection, Medline, PsycARTICLES, and PsycINFO, as well as PubMed and Google Scholar databases; (2) review of additional articles cited in papers identified through electronic searches; and (3) targeted searches of state and local government records regarding marijuana law implementation. We reviewed studies with respect to their data sources and sample characteristics, methodology, and the margin of alcohol and marijuana use, timing of policy change, and the aspects of laws examined.

RESULTS

The extant literature provides some evidence for both substitution (i.e., more liberal marijuana policies related to less alcohol use as marijuana becomes a substitute) and complementary (i.e., more liberal marijuana policies related to increases in both marijuana and alcohol use) relationships in the context of liberalization of marijuana policies in the United States.

CONCLUSIONS

Impact of more liberal marijuana policies on alcohol use is complex, and likely depends on specific aspects of policy implementation, including how long the policy has been in place. Furthermore, evaluation of marijuana policy effects on alcohol use may be sensitive to the age group studied and the margin of alcohol use examined. Design of policy evaluation research requires careful consideration of these issues.

Borders Up in Smoke: Marijuana Enforcement in Nebraska After Colorado’s Legalization of Medicinal Marijuana

With the passage of Amendments 20 (2000) and 64 (2012), Colorado legalized the medicinal and recreational use of marijuana. Nebraskan law enforcement in border counties subsequently reported increases in arrests and reductions in jail space. In response, the Nebraska state legislature passed LR-520 to study the potential increased costs incurred by criminal justice agencies in border counties. To investigate this situation, we compare trends in drug arrests and jail occupancy across three areas: border counties, those that contain Interstate 80 (I-80) as a major transportation route, and the remaining counties in the state of Nebraska from 2000 through 2013. We found that border counties, but not necessarily those along the I-80 corridor, experienced significant growth in marijuana-related arrests and jail admissions after the expansion of the medical marijuana program in Colorado. Implications for research and policy are discussed.

The effect of medical marijuana laws on adolescent and adult use of marijuana, alcohol, and other substances

We estimate the effect of medical marijuana laws (MMLs) in ten states between 2004 and 2012 on adolescent and adult use of marijuana, alcohol, and other psychoactive substances. We find increases in the probability of current marijuana use, regular marijuana use and marijuana abuse/dependence among those aged 21 or above. We also find an increase in marijuana use initiation among those aged 12-20. For those aged 21 or above, MMLs further increase the frequency of binge drinking. MMLs have no discernible impact on drinking behavior for those aged 12-20, or the use of other psychoactive substances in either age group.

The Impact of Legalizing and Regulating Weed: Issues with Study Design and Emerging Findings in the USA

Evaluations of the impact of medical and recreational marijuana laws rely on quasi- or natural experiments in which researchers exploit changes in the law and attempt to determine the impact of these changes on outcomes. This chapter reviews three key issues of causal inference in observational studies with respect to estimating of impact of medical or recreational laws on marijuana use-intervention definition, outcome measurement, and random assignment of study participants. We show that studies tend to use the same statistical approach (differences-in-differences) and yet find differential impacts of medical marijuana laws on adult use in particular. We demonstrate that these seemingly conflicting findings may be due to different years of analysis, ages of the study sample in each year, and assignment of jurisdictions to the control group versus treatment group.