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

State Medical Marijuana Laws and Associated Marijuana Use, Attitudes, and Perceived Social Norms among Adolescents in the U.S

Statewide medical marijuana laws (MMLs) in the U.S. may be associated with adolescent marijuana use behavior, attitudes toward marijuana use, and social norms. This study used data from the National Study on Drug Use and Health (2013-2016) to examine the associations of state MML with marijuana use, use frequency, and attitudes and perceived peer and parental social norms toward using marijuana. Propensity-score matching was used to reduce selection bias between states with and without MML (matched N = 50,000). Results showed that adolescents residing in states with MML had higher odds of using marijuana in the past month and past year (OR = 1.45 and 1.49; ps < .001), higher marijuana use frequencies in the past month (β = 0.12, p < .001), relatively more neutral attitudes toward marijuana use (β = - 0.06, p < .001), and weaker perception of peer and parental disapproval of marijuana use (β = - 0.04 and -0.02, ps < .001). Our findings suggested that for the states that have implemented MML, special efforts should be strengthened to prevent and reduce adolescent marijuana use. For the states that have not yet implemented MML, the associations between MML and adolescent marijuana use attitudes and perceived norms should be taken into account when legislating medical marijuana and designing prevention and intervention efforts.

Medical cannabis laws and medical and non-medical prescription stimulant use among a nationally representative sample of US Adults: Examining the role of sexual identity and gender

BACKGROUND

Medical marijuana laws (MMLs) can impact marijuana and opioid use, but the relationship between MMLs and other drugs, such as prescription stimulants, remains unexamined. Because lesbian, gay and bisexual (LGB) individuals report higher levels of prescription stimulant use than heterosexuals, we explored the relationship between MMLs and past-year medical and non-medical stimulant use by sexual identity and gender.

METHODS

We pooled 2015-2017 National Survey on Drug Use and Health data for adults (n = 126 463), and used survey-weighted multinomial logistic regression to estimate odds of past-year (a) medical prescription stimulant use, (b) non-medical prescription stimulant use and (c) non-medical versus medical stimulant use. We stratified by gender, adjusted for sociodemographic characteristics, and tested the interaction between MML state residence and sexual identity.

RESULTS

Bisexual men had higher medical (6.4% versus 4.1%; aROR=1.93[1.29-2.88]) and non-medical stimulant use 6.6% versus 2.4%; aROR=2.23[1.44-3.44]) than heterosexual men. Bisexual women had higher non-medical stimulant use (6.8% versus 1.6%; aROR=1.54[1.23-2.93] than heterosexual women. Female (aROR=0.70[0.62-0.78]) and male (aROR=0.74[0.66-0.82]) heterosexuals in MML states had lower odds of medical stimulant use than in non-MML states. Bisexual men in MML states had lower odds of medical (aROR=0.36[0.21-0.61]) and non-medical stimulant use (aROR=0.48[0.29-0.81]) than bisexual men in non-MML states. Similar patterns emerged for bisexual women's non-medical use (aROR=0.57[0.40-0.81]).

CONCLUSION

Prescription stimulant use was higher in non-MML states for most LGB subgroups. MMLs may differentially impact stimulant use, primarily for bisexual men and women. States enacting MMLs should consider potential impacts on drugs other than marijuana, especially among LGB populations.

U.S. Adults With Pain, a Group Increasingly Vulnerable to Nonmedical Cannabis Use and Cannabis Use Disorder: 2001-2002 and 2012-2013

OBJECTIVE

Given changes in U.S. marijuana laws, attitudes, and use patterns, individuals with pain may be an emerging group at risk for nonmedical cannabis use and cannabis use disorder. The authors examined differences in the prevalence of nonmedical cannabis use and cannabis use disorder among U.S. adults with and without pain, as well as whether these differences widened over time.

METHODS

Data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC, 2001-2002; N=43,093) and NESARC-III (2012-2013; N=36,309) were analyzed using logistic regression. Risk differences of past-year nonmedical cannabis use, frequent (at least three times a week) nonmedical use, and DSM-IV cannabis use disorder were estimated for groups with and without moderate to severe pain, and these risk differences were tested for change over time.

RESULTS

Any nonmedical cannabis use was more prevalent in respondents with than without pain (2001-2002: 5.15% compared with 3.74%; 2012-2013: 12.42% compared with 9.02%), a risk difference significantly greater in the 2012-2013 data than in the 2001-2002 data. The prevalence of frequent nonmedical cannabis use did not differ by pain status in the 2001-2002 survey, but was significantly more prevalent in those with than without pain in the 2012-2013 survey (5.03% compared with 3.45%). Cannabis use disorder was more prevalent in respondents with than without pain (2001-2002: 1.77% compared with 1.35%; 2012-2013: 4.18% compared with 2.74%), a significantly greater risk difference in the data from 2012-2013 than from 2001-2002.

CONCLUSIONS

The results suggest that adults with pain are a group increasingly vulnerable to adverse cannabis use outcomes, warranting clinical and public health attention to this risk. Psychiatrists and other health care providers treating patients with pain should monitor such patients for signs and symptoms of cannabis use disorder.

Assessing the public health impact of cannabis legalization in Canada: core outcome indicators towards an 'index' for monitoring and evaluation

The legalization of non-medical cannabis use and supply is impending in Canada. This constitutes a major policy change with the declared objective of improving public health outcomes, which requires rigorous monitoring and evaluation. While numerous different aspects associated with legalization will be examined, a focused perspective is required for effective policy evaluation purposes. To these ends, we have identified a set of 10 core indicators associated with cannabis-related risk/harm outcomes-based on current best evidence-that are expected to measure the primary impacts of legalization on public health outcomes. We briefly review these indicators, and their respective data availability in Canada. As ideally an integrated outcome assessment of cannabis legalization's impact on public health will be available, we further propose options to merge the individual indicators into an integrated, weighted 'index', considering their expected relative impact for public health. One possible approach to undertake this is 'multi-criteria decision analysis' as a method to weight the relative indicator impact on public health; alternative approaches are proposed. The integrated 'public health index' for cannabis legalization will allow for scientifically comprehensive, while focused, monitoring and evaluation of the effects of legalization in Canada for the benefits of science and evidence-based policy alike.

[Recreational use of cannabis: From effects to harm. Epidemiological data]

As the medical use of so-called "therapeutic cannabis" is in the process of being approved in France, the opening to its recreational use is the next logical step, as it has been always the chronology followed in all countries. Indeed, those who have legalized the drug have previously approved its therapeutic use. This "justifying a project phase" stage seems unavoidable. Therefore, it is appropriate to recall the effects and misdeeds of the drug during its recreational use. The general population surveys carried out in France for 25 years by public health France and the French Observatory of Drugs and Drug Addiction, have followed the evolution of psychoactive substances consumption. Particular attention was focused on cannabis use, which, in a context of wide dissemination for a quarter of a century, rose steadily higher among younger generations, but also among older adults. France is the European country with the highest prevalence of cannabis use among young people and adults. Last 25 years, its diffusion has continued to expand, and the experimentation rate multiplied by near 4. Estimated at 12.7% in 1992, it reached 44.8% in 2017. Moreover, 25% of users in the year aged from 18 to 64 years old were at high risk of problematic use or dependence in 2017. This figure is worrying because it is constantly increasing; it affects 3% of 18-64-year-old, just over a million people.

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.

Impact of Medical Marijuana Laws on State-Level Marijuana Use by Age and Gender, 2004-2013

In states that have passed medical marijuana laws (MMLs), marijuana use (MU) increased after MML enactment among people ages 26 and older, but not among ages 12-25. We examined whether the age-specific impact of MMLs on MU varied by gender. Data were obtained from the 2004-2013 restricted-use National Survey on Drug Use and Health, aggregated at the state level. The exposure was a time-varying indicator of state-level MML (0 = No Law, 1 = Before Law, 2 = After Law). Outcomes included past-month MU prevalence, daily MU prevalence among past-year users (i.e., 300+ days/year), and past-year marijuana use disorder (MUD) prevalence. Linear models tested the state-level MML effect on outcomes by age (12-17, 18-25, 26+) and gender. Models included a state-level random intercept and controlled for time- and state-level covariates. Past-month MU did not increase after enactment of MML in men or women ages 12-25. Among people 26+, past-month MU increased for men from 7.0% before to 8.7% after enactment (+ 1.7%, p < 0.001) and for women from 3.1% before to 4.3% after enactment (+ 1.1%, p = 0.013). Among users 26+, daily MU also increased after enactment in both genders (men 16.3 to 19.1%, + 2.8%, p = 0.014; women 9.2 to 12.7%, + 3.4%, p = 0.003). There were no statistically significant increases in past-year MUD prevalence for any age or gender group after MML enactment. Given the statistically significant increase in daily use among past-year users aged 26+ following enactment, education campaigns should focus on informing the public of the risks associated with regular marijuana use.

The Effect of Medical Marijuana Laws on Marijuana-Related Attitude and Perception Among US Adolescents and Young Adults

Marijuana liberalization policies are gaining momentum in the USA, coupled with limited federal interference and growing dispensary industry. This evolving regulatory landscape underscores the importance of understanding the attitudinal/perceptual pathways from marijuana policy to marijuana use behavior, especially for adolescents and young adults. Our study uses the restricted-access National Survey on Drug Use and Health (NSDUH) 2004-2012 data and a difference-in-differences design to compare the pre-policy, post-policy changes in marijuana-related attitude/perception between adolescents and young adults from ten states that implemented medical marijuana laws during the study period and those from the remaining states. We examined four attitudinal/perception pathways that may play a role in adolescent and young adult marijuana use behavior, including (1) perceived availability of marijuana, (2) perceived acceptance of marijuana use, (3) perceived wrongfulness of recreational marijuana use, and (4) perceived harmfulness of marijuana use. We found that state implementation of medical marijuana laws between 2004 and 2012 was associated with a 4.72% point increase (95% CI 0.15, 9.28) in the probability that young adults perceived no/low health risk related to marijuana use. Medical marijuana law implementation is also associated with a 0.37% point decrease (95% CI - 0.72, - 0.03) in the probability that adolescents perceived parental acceptance of marijuana use. As more states permit medical marijuana use, marijuana-related attitude/perception need to be closely monitored, especially perceived harmfulness. The physical and psychological effects of marijuana use should be carefully investigated and clearly conveyed to the public.

Guidelines for public health and safety metrics to evaluate the potential harms and benefits of cannabis regulation in Canada

ISSUES

Canada recently introduced a public health-based regulatory framework for non-medical cannabis. This review sought to identify a comprehensive set of indicators to evaluate the public health and safety impact of cannabis regulation in Canada, and to explore the ways in which these indicators may be expected to change in the era of legal non-medical cannabis.

APPROACH

Five scientific databases were searched to compile a list of cannabis-related issues of interest to public health and safety. A set of indicators was developed based on topics and themes that emerged. Preliminary evidence from other jurisdictions in the USA and Canada that have legalised medical and/or non-medical cannabis (e.g. Colorado, Washington) was summarised for each indicator, wherever possible.

KEY FINDINGS

In total, 28 indicators were identified under five broad themes: public safety; cannabis use trends; other substance use trends; cardiovascular and respiratory health; and mental health and cognition. Preliminary trends from other legalised jurisdictions reveal little consensus regarding the effect of cannabis legalisation on public health and safety harms and an emerging body of evidence to support potential benefits (e.g. reductions in opioid use and overdose).

IMPLICATIONS

In addition to indicators of commonly discussed challenges (e.g. cannabis-related hospitalisations, cannabis-impaired driving), this review led to the recommendation of several indicators to monitor for possible public health and safety improvements.

CONCLUSION

In preparing a comprehensive public health and safety monitoring and evaluation system for cannabis regulation, this review underscores the importance of not only measuring the possible risks but also the potential benefits.

The impact of decriminalization on marijuana and alcohol consumption in Jamaica

We examine whether marijuana decriminalization in Jamaica, a country that historically has had relatively widespread use of the drug, has led to an increase in its use, the frequency of use and the money spent on it. To this end, we use a national drug survey dataset with extensive information on people's use of, attitudes towards, access to marijuana. Our econometric analysis shows that awareness of the legislation has a positive correlation with the use of the substance. Worryingly, decriminalization positively correlates with the likelihood of first time and general use for youths. There is also some evidence that the legislation results in a substitution away from alcohol towards marijuana consumption for youths. From a policy perspective, a marijuana monitoring system can be implemented to follow the consumption patterns of youths. This should involve establishing school-level programmes that monitor students, and where potential drug users are identified, school officials should intervene to curb students' drug appetite before an escalated use of marijuana.

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.

A comparison of methods for health policy evaluation with controlled pre-post designs

Objective

To compare interactive fixed effects (IFE) and generalized synthetic control (GSC) methods to methods prevalent in health policy evaluation and re‐evaluate the impact of the hip fracture best practice tariffs introduced for hospitals in England in 2010.

Data Sources

Simulations and Hospital Episode Statistics.

Study Design

Best practice tariffs aimed to incentivize providers to deliver care in line with guidelines. Under the scheme, 62 providers received an additional payment for each hip fracture admission, while 49 providers did not. We estimate the impact using difference‐in‐differences (DiD), synthetic control (SC), IFE, and GSC methods. We contrast the estimation methods' performance in a Monte Carlo simulation study.

Principal Findings

Unlike DiD, SC, and IFE methods, the GSC method provided reliable estimates across a range of simulation scenarios and was preferred for this case study. The introduction of best practice tariffs led to a 5.9 (confidence interval: 2.0 to 9.9) percentage point increase in the proportion of patients having surgery within 48 hours and a statistically insignificant 0.6 (confidence interval: −1.4 to 0.4) percentage point reduction in 30‐day mortality.

Conclusions

The GSC approach is an attractive method for health policy evaluation. We cannot be confident that best practice tariffs were effective.

Association Between Recreational Marijuana Legalization in the United States and Changes in Marijuana Use and Cannabis Use Disorder From 2008 to 2016

IMPORTANCE

Little is known about changes in marijuana use and cannabis use disorder (CUD) after recreational marijuana legalization (RML).

OBJECTIVES

To examine the associations between RML enactment and changes in marijuana use, frequent use, and CUD in the United States from 2008 to 2016.

DESIGN, SETTING, AND PARTICIPANTS

This survey study used repeated cross-sectional survey data from the National Survey on Drug Use and Health (2008-2016) conducted in the United States among participants in the age groups of 12 to 17, 18 to 25, and 26 years or older.

INTERVENTIONS

Multilevel logistic regression models were fit to obtain estimates of before-vs-after changes in marijuana use among respondents in states enacting RML compared to changes in other states.

MAIN OUTCOMES AND MEASURES

Self-reported past-month marijuana use, past-month frequent marijuana use, past-month frequent use among past-month users, past-year CUD, and past-year CUD among past-year users.

RESULTS

The study included 505 796 respondents consisting of 51.51% females and 77.24% participants 26 years or older. Among the total, 65.43% were white, 11.90% black, 15.36% Hispanic, and 7.31% of other race/ethnicity. Among respondents aged 12 to 17 years, past-year CUD increased from 2.18% to 2.72% after RML enactment, a 25% higher increase than that for the same age group in states that did not enact RML (odds ratio [OR], 1.25; 95% CI, 1.01-1.55). Among past-year marijuana users in this age group, CUD increased from 22.80% to 27.20% (OR, 1.27; 95% CI, 1.01-1.59). Unmeasured confounders would need to be more prevalent in RML states and increase the risk of cannabis use by 1.08 to 1.11 times to explain observed results, indicating results that are sensitive to omitted variables. No associations were found among the respondents aged 18 to 25 years. Among respondents 26 years or older, past-month marijuana use after RML enactment increased from 5.65% to 7.10% (OR, 1.28; 95% CI, 1.16-1.40), past-month frequent use from 2.13% to 2.62% (OR, 1.24; 95% CI, 1.08-1.41), and past-year CUD from 0.90% to 1.23% (OR, 1.36; 95% CI, 1.08-1.71); these results were more robust to unmeasured confounding. Among marijuana users in this age group, past-month frequent marijuana use and past-year CUD did not increase after RML enactment.

CONCLUSIONS AND RELEVANCE

This study's findings suggest that although marijuana legalization advanced social justice goals, the small post-RML increase in risk for CUD among respondents aged 12 to 17 years and increased frequent use and CUD among adults 26 years or older in this study are a potential public health concern. To undertake prevention efforts, further studies are warranted to assess how these increases occur and to identify subpopulations that may be especially vulnerable.

Trends in Cannabis Treatment Admissions in Adolescents/Young Adults: Analysis of TEDS-A 1992 to 2016

OBJECTIVES

This study aims to evaluate changes in cannabis use patterns, referral sources, and admissions in adolescents and young adults (YAs). As the United States increasingly moves toward liberalization of cannabis laws, it is critical to have baseline information of use patterns in this population.

METHODS

Data were drawn from Treatment Episode Data Set-Admissions (TEDS-A) for adolescents (12-17 years) and young adults (18-24 years) entering treatment from 1992 to 2016 for primary cannabis use (N = 3,794,213). Rao-Scott chi-square tests were used to test for significant changes in proportions of individuals admitted to treatment for primary cannabis use and between 4-year increments from 1992 to 2016 (N = 1,052,724). Logistic regression assessed odds of admissions for primary cannabis use versus other substances.

RESULTS

Treatment admissions for cannabis among adolescents/YAs rose 3-fold from 1992 (49,996) to 1996 (125,858). The majority of referrals came from the criminal justice system (56%). Cannabis is increasingly the sole substance of use, with polysubstance use decreasing from 89% in 1992 to 59% in 2016. While alcohol-related treatment admissions were most common in 1992, admissions for treatment of cannabis use (followed by heroin and alcohol) were highest (38%) by 2016. Being an adolescent (odds ratio [OR] 3.1, 95% confidence interval [CI] 3.1-3.2), non-Hispanic black (OR 6.2, 95% CI 6.2-6.3), male (female OR 0.6, 95% CI 0.6-0.6) with co-occurring alcohol use (OR 25.9, 95% CI 25.7-26.1) was associated with admission for treatment of primary cannabis use as compared with other substances.

CONCLUSIONS

Public health efforts will be needed to ensure ongoing access and referral to treatment as the legal status of cannabis continues to change. Prevention and treatment efforts should target co-occurring alcohol and cannabis use.

Development of a Cannabis Assessment Tool (CAT-1) to measure current and lifetime marijuana use among older Veterans

OBJECTIVE

To develop a tool to assess current (past 30 days) and lifetime marijuana use in older Veterans.

SETTING

US Veteran's Affairs Healthcare System.

PARTICIPANTS

704 older Veterans were screened, 339 completed the initial survey, 100 completed the follow-up.

PRIMARY OUTCOME MEASURE

Pearson's correlation coefficient to assess strength of association between initial and follow-up survey on measures of current and lifetime marijuana use.

RESULTS

Both a 'gram-month' measure of marijuana smoked in the past 30 days (r=0.83) and a frequency-based measure assessing total number of times smoked in the past 30 days were reliable (r=0.89). Both a simple categorical measure of lifetime use (agreement=85%) and a continuous measure of lifetime use (r=0.82) were reliable.

CONCLUSIONS

The Cannabis Assessment Tool offers a reliable assessment of past 30 days and lifetime assessments of smoking cannabis in older adults.

The impact of cannabis access laws on opioid prescribing

While recent research has shown that cannabis access laws can reduce the use of prescription opioids, the effect of these laws on opioid use is not well understood for all dimensions of use and for the general United States population. Analyzing a dataset of over 1.5 billion individual opioid prescriptions between 2011 and 2018, which were aggregated to the individual provider-year level, we find that recreational and medical cannabis access laws reduce the number of morphine milligram equivalents prescribed each year by 11.8 and 4.2 percent, respectively. These laws also reduce the total days' supply of opioids prescribed, the total number of patients receiving opioids, and the probability a provider prescribes any opioids net of any offsetting effects. Additionally, we find consistent evidence that cannabis access laws have different effects across types of providers, physician specialties, and payers.

Cannabis legalization, tobacco prevention policies, and Cannabis use in E-cigarettes among youth

BACKGROUND

E-cigarettes are the most popular tobacco product among youth. As more states adopt cannabis legalization policies, youth cannabis use in e-cigarettes is a mounting concern.

METHODS

Data were from the 2016 and 2017 National Youth Tobacco Survey, a nationally-representative repeated cross-sectional survey administered to US middle and high school students. Ever use groups were categorized into e-cigarette ever users, cannabis in e-cigarette ever users, other tobacco ever users, and never users. Weighted multinomial logistic regression compared ever use groups, while controlling for state-level cannabis legalization and tobacco prevention polices, tobacco perceptions and exposures, and sociodemographic variables. Weighted prevalence of ever and current, or past 30 day, tobacco product use was determined by ever use groups.

RESULTS

Compared to e-cigarette ever users, cannabis in e-cigarette ever users increased (Adjusted Relative Risk Ratio (ARRR) = 1.65; p < 0.01) from 2016 to 2017. Medical-only and medical and recreational cannabis laws, and no e-cigarette minimum legal sales age (MLSA) and increased e-cigarette MLSA at 19 or 21 were positively associated with cannabis in e-cigarette ever users (ARRR = 1.34-1.85; p < 0.01, each). Ever and current use of all individual tobacco products was highest among cannabis in e-cigarette ever users compared to e-cigarette and other tobacco ever users.

CONCLUSIONS

Cannabis use in e-cigarettes has increased among youth, and these trends will likely continue as e-cigarettes continue to gain popularity and cannabis legalization policies proliferate. Targeted tobacco and cannabis prevention strategies are needed for youth, especially in states that have implemented cannabis 'medical and recreational laws.

Changes in alcohol and cigarette consumption in response to medical and recreational cannabis legalization: Evidence from U.S. state tax receipt data

BACKGROUND

Whether medical or recreational cannabis legalization impacts alcohol or cigarette consumption is a key question as cannabis policy evolves, given the adverse health effects of these substances. Relatively little research has examined this question. The objective of this study was to examine whether medical or recreational cannabis legalization was associated with any change in state-level per capita alcohol or cigarette consumption.

METHODS

Dependent variables included per capita consumption of alcohol and cigarettes from all 50 U.S. states, estimated from state tax receipts and maintained by the Centers for Disease Control and National Institute for Alcohol Abuse and Alcoholism, respectively. Independent variables included indicators for medical and recreational legalization policies. Three different types of indicators were separately used to model medical cannabis policies. Indicators for the primary model were based on the presence of active medical cannabis dispensaries. Secondary models used indicators based on either the presence of a more liberal medical cannabis policy ("non-medicalized") or the presence of any medical cannabis policy. Difference-in-difference regression models were applied to estimate associations for each type of policy.

RESULTS

Primary models found no statistically significant associations between medical or recreational cannabis legalization policies and either alcohol or cigarette sales per capita. In a secondary model, both medical and recreational policies were associated with significantly decreased per capita cigarette sales compared to states with no medical cannabis policy. However, post hoc analyses demonstrated that these reductions were apparent at least two years prior to policy adoption, indicating that they likely result from other time-varying characteristics of legalization states, rather than cannabis policy.

CONCLUSION

We found no evidence of a causal association between medical or recreational cannabis legalization and changes in either alcohol or cigarette sales per capita.

Changes in urban and rural cigarette smoking and cannabis use from 2007 to 2017 in adults in the United States

INTRODUCTION

Rural-urban differences in cigarette and cannabis use have traditionally shown higher levels of cigarette smoking in rural areas and of cannabis use in urban areas. To assess for changes in this pattern of use, we examined trends and prevalence of cigarette, cannabis, and co-use across urban-rural localities.

METHODS

Urban-rural trends in current cigarette and/or cannabis use was evaluated using 11 cohorts (2007-2017) of the National Survey on Drug Use and Health (NSDUH; N = 397,542). We used logistic regressions to model cigarette and cannabis use over time, adjusting for demographics (age, gender, race/ethnicity, income, education), in addition to assessing patterns of cannabis use among cigarette smokers and nonsmokers.

RESULTS

Despite decreases in cigarette smoking overall, between 2007 and 2017, the urban-rural disparity in cigarette smoking increased (AOR = 1.17), with less reduction in rural as compared to urban cigarette smokers. Cannabis use increased in general (AOR = 1.88 by 2017), with greater odds in urban than rural regions. Cannabis use increased more rapidly in non-cigarette smokers than smokers (AOR = 1.37 by 2017), with 219% greater odds of cannabis use in rural non-cigarette smokers in 2017 versus 2007.

CONCLUSIONS

Rurality remains an important risk factor for cigarette smoking in adults and the fastest-growing group of cannabis users is rural non-cigarette smokers; however, cannabis use is currently still more prevalent in urban areas. Improved reach and access to empirically-supported prevention and treatment, especially in rural areas, along with dissemination and enforcement of policy-level regulations, may mitigate disparities in cigarette use and slow the increase in rural cannabis use.

Trends of poly-substance use among Canadian youth

INTRODUCTION

Poly-substance use, increasingly understood as a behaviour with uniquely adverse consequences, is on the rise among Canadian youth. High levels of e-cigarette vaping and the recent legalization of recreational cannabis use may result in an acceleration of this trend. The aim of this work was to characterise changes in youth poly-substance use over time, generate baseline data for future investigations, and highlight areas of interest for policy action.

METHODS

Descriptive statistics and regression models explored patterns and trends in concurrent use of multiple substances (alcohol, cigarettes, cannabis, and e-cigarettes) among Canadian high school students taking part in the COMPASS prospective cohort study during Y2 (2013/2014; n = 45,298), Y3 (2014/2015, n = 42,355), Y4 (2015/2016; n = 40,436), Y5 (2016/2017; n = 37,060), and Y6 (2017/2018; n = 34,879).

RESULTS

Poly-substance use increased significantly over time, with over 50% of students who used substance reporting past-year use of multiple substances by 2017/2018. Male and Indigenous students were significantly more likely to report poly-substance use than female and white students respectively. E-cigarette vaping doubled from Y5 to Y6 and was included in all increasingly prevalent substance use combinations.

CONCLUSIONS

Youth poly-substance use, rising since 2012/2013, saw a particularly steep increase after 2016/2017. Differential effects were observed for distinct demographic subpopulations, indicating tailored interventions may be required. E-cigarette vaping surged in parallel with the observed increase, suggesting a key role for this behaviour in shaping youth poly-substance use.

A longitudinal examination of daily patterns of cannabis and alcohol co-use among medicinal and recreational veteran cannabis users

BACKGROUND

Prompted by the ongoing debate regarding whether cannabis serves as a complement to or substitute for alcohol, this study uses prospective data to examine daily associations between medicinal versus recreational cannabis and alcohol use in veterans.

METHODS

Three semi-annual waves of Timeline Followback Interview data were collected from a sample of veterans who reported co-using alcohol and cannabis on at least one day (N = 115; 56% medicinal users; 93% male; 62,100 observations). Linear mixed effects models were used to examine the association between daily cannabis use and number of drinks consumed across time for both medicinal and recreational users and to examine the frequency medicinal cannabis used to substitute for alcohol.

RESULTS

Compared to medicinal users, recreational users were more likely to drink more on cannabis use days relative to non-use days. Among medicinal users, those endorsing more frequent use of cannabis as a substitute for alcohol reported fewer number of drinks consumed on days when cannabis was used relative to non-use days.

CONCLUSIONS

Among veterans, recreational users are at greater risk for increased drinking when co-using cannabis at the daily level, an association that is stable over time. Medicinal users may be at lower risk for increased drinking on days when cannabis is also used, especially those who endorse using cannabis to substitute for alcohol. Findings help clarify the debate on cannabis-alcohol substitution or complementary associations in a sample of veterans and suggests that alcohol interventions should address cannabis use as a risk factor, especially for recreational users.

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

AIMS

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

DESIGN

Secondary data analysis.

SETTING

Los Angeles County, CA, USA.

PARTICIPANTS

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

MEASUREMENTS

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

FINDINGS

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

CONCLUSIONS

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

Modes of cannabis use: A secondary analysis of an intensive longitudinal natural history study

INTRODUCTION

There is a paucity of research on modes of cannabis use (e.g., joint vs. blunt), and further, little consensus on how to accurately assess both modes of use and route of administration. This secondary analysis used a longitudinal design with data collected daily to characterize mode of cannabis use.

METHODS

193 adult daily cannabis users who were considering quitting at some point enrolled in the study. No treatment was provided. Each day for 84 days, participants reported on mode of cannabis use (i.e., joints, blunts, pipes/vaporizer and food) using an interactive voice response system. We report on single and poly-use of modes across study days and weeks and examine characteristics associated with different modes of use.

RESULTS

White participants were most likely to use pipes/vaporizer, with use on 57% of study days, while Black participants were most likely to use blunts with use on 53% of days. Thus, joint use was less common in both groups. Poly-use of different modes within the same week was very common (i.e., 56% of weeks among White participants and 60% of weeks in Black participants). Age, gender, race, cannabis dependence, presence of others during cannabis use, and alcohol use were associated with different modes of use.

CONCLUSIONS

The major limitation of this study was use of a convenience sample and lack of detailed data on vaporizer use. Joint use is no longer the most common mode of use in either White or Black participants and exclusive use of a single modality is uncommon.

State-level marijuana policies and marijuana use and marijuana use disorder among a nationally representative sample of adults in the United States, 2015-2017: Sexual identity and gender matter

BACKGROUND

Research demonstrates an association between state-level medical marijuana laws (MMLs) and increased marijuana use (MU) and MU disorder (MUD) among adults, but has yet to explore this association among lesbian, gay and bisexual (LGB) individuals, including gender differences.

METHODS

We pooled the 2015-2017 National Survey on Drug Use and Health data for adults (n = 126,463) and used gender-stratified adjusted multivariable logistic regression to model the odds of past-year MU, past-year medical MU, daily/near-daily MU, and MUD; we also tested the interaction between MML state residence and sexual identity.

RESULTS

Bisexual women had higher past-year MU (40% versus 10.3%; aOR = 2.9[2.4-3.4]), daily/near-daily MU (9.8% versus 1.5%; aOR = 4.6[3.3-6.2]), and medical MU ((5.5% versus 1.2%) aOR = 5.5[3.8-8.1]) than heterosexual women. Gay/lesbian women also had higher past-year MU (26.1% versus 10.3%; aOR = 2.8[2.2-3.7]), daily/near-daily MU (5.6% versus 1.5%; aOR = 2.9[1.8-4.6]), and medical MU (4.7% versus 1.2%; aOR = 3.0(1.4-6.6]) than heterosexual women. Bisexual women in MML states had higher past-year MU ((44.4% vs. 34.1%); aOR = 1.8[1.5-2.1]) and medical use (7.1% vs. 3.3% (aOR = 2.5[1.5-3.9]) than bisexual women in non-MML states. The odds of any past-year medical MU for bisexual versus heterosexual women was different in MML versus non-MML states (Exponentiated β = 0.53, p = 0.01). Gay men in MML states had higher past year MU (31.2% versus 25.7%; aOR = 1.6[1.1-2.5] and medical MU (6.4% vs 1.7%; aOR = 5.0[4.2-6.1]) than gay men in non-MML states.

CONCLUSIONS

Results suggest that MMLs may differentially impact MU for sexual minority individuals-particularly bisexual women. Findings demonstrate the need for states enacting MMLs to consider potential differential impacts on LGB populations.

Fatal crashes in the 5 years after recreational marijuana legalization in Colorado and Washington

Colorado and Washington legalized recreational marijuana in 2012, but the effects of legalization on motor vehicle crashes remains unknown. Using Fatality Analysis Reporting System data, we performed difference-in-differences (DD) analyses comparing changes in fatal crash rates in Washington, Colorado and nine control states with stable anti-marijuana laws or medical marijuana laws over the five years before and after recreational marijuana legalization. In separate analyses, we evaluated fatal crash rates before and after commercial marijuana dispensaries began operating in 2014. In the five years after legalization, fatal crash rates increased more in Colorado and Washington than would be expected had they continued to parallel crash rates in the control states (+1.2 crashes/billion vehicle miles traveled, CI: -0.6 to 2.1, p = 0.087), but not significantly so. The effect was more pronounced and statistically significant after the opening of commercial dispensaries (+1.8 crashes/billion vehicle miles traveled, CI: +0.4 to +3.7, p = 0.020). These data provide evidence of the need for policy strategies to mitigate increasing crash risks as more states legalize recreational marijuana.

Is There Less Opioid Abuse in States Where Marijuana Has Been Decriminalized, Either for Medicinal or Recreational Use? A Clin-IQ

Opioid use, abuse, and associated mortality have reached an epidemic level. In some states, cannabis is being used to treat chronic pain. To examine the hypothesis that medical marijuana legislation may reduce adverse opioid-related outcomes if patients substitute cannabis for opioids for pain management, we conducted a clinical inquiry (Clin-IQ). We searched Ovid MEDLINE, Ovid MEDLINE In-Process, and Embase for studies using the search terms marijuana, cannabis, legal, marijuana smoking, medical marijuana, opioid-related disorders, cannabis use, medical cannabis, legal aspect, and opiate addiction. We included population-based articles published from January 1, 2012, through December 5, 2018, that assessed the relationship between marijuana use and decriminalization and the aforementioned opioid-related outcomes. Ten peer-reviewed studies met the inclusion criteria; 3 cross-sectional studies, 6 ecologic studies (ie, using aggregate data), and 1 retrospective cohort study. Eight studies reported associations between policies decriminalizing marijuana and reduced prescription opioid use, 1 study was inconclusive, and the retrospective cohort study reported an increase in adverse opioid-related outcomes. These results should be interpreted with caution given limitations associated with the studies' design. Results demonstrating association between marijuana decriminalization and opioid-related outcomes are mixed. Longitudinal studies are needed, and further analysis of this policy should continue to be tracked.

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.

Mapping regulatory models for medicinal cannabis: a matrix of options

Objective The aim of the present study was to develop a framework for assessing regulatory options for medicinal cannabis in Australia. Methods International regulatory regimes for medicinal cannabis were reviewed with a qualitative policy analysis approach and key policy features were synthesised, leading to a conceptual framework that facilitates decision making across multiple dimensions. Results Two central organising dimensions of medicinal cannabis regulation were identified: cannabis supply and patient authorisation (including patient access). A number of the different supply options can be matched with a number of different patient authorisation options, leading to a matrix of possible regulatory regimes. Conclusions The regulatory options, as used internationally, involve different forms of cannabis (synthetic and plant-based pharmaceutical preparations or herbal cannabis) and the varying extent to which patient authorisation policies and procedures are stringently or more loosely defined. The optimal combination of supply and patient authorisation options in any jurisdiction that chooses to make medicinal cannabis accessible will depend on policy goals. What is known about the topic? Internationally, regulation of medicinal cannabis has developed idiosyncratically, depending on formulations that were made available and local context. There has been no attempt to date in the scientific literature to systematically document the variety of regulatory possibilities for medicinal cannabis. What does this paper add? This paper presents a new conceptual schema for considering options for the regulation of medicinal cannabis, across both supply and patient authorisation aspects. What are the implications for practitioners? The design of regulatory systems in Australia, whether for pharmaceutical or herbal products, is a vital issue for policy makers right now as federal and state and territory governments grapple with the complexities of medicinal cannabis regulation. The conceptual schema presented herein provides a tool for more systematic thinking about the options.

The effect of cannabis laws on opioid use

BACKGROUND

Many Americans rely on opioids at varying dosages to help ameliorate their suffering. However, empirical evidence is mounting that opioids are ineffective at controlling non-cancer related chronic pain, and many argue the strategies meant to relieve patient suffering are contributing to the growing opioid epidemic. Concurrently, several states now allow the use of medical cannabis to treat a variety of medical conditions, including chronic pain. Needing more exploration is the impact of cannabis laws on general opioid reliance and whether chronic pain sufferers are opting to use cannabis medicinally instead of opioids.

METHODS

This study investigates the effect of Medical Marijuana Laws (MML)s on opioid use and misuse controlling for a number of relevant factors using data from several years of the National Survey on Drug Use and Health and multivariate logistic regression and longitudinal analysis strategies.

RESULTS

Results provide evidence that MMLs may be effective at reducing opioid reliance as survey respondents living in states with medical cannabis legislation are much less apt to report using opioid analgesics than people living in states without such laws, net other factors. Results further indicate that the presence of medicinal cannabis legislation appears to have no influence over opioid misuse.

CONCLUSION

MMLs may ultimately serve to attenuate the consequences of opioid overreliance.

Age Differences in Daily and Nondaily Cannabis Use in the United States, 2002-2014

OBJECTIVE

Adult cannabis use has increased in the United States since 2002, particularly after 2007, contrasting with stable/declining trends among youth. We investigated whether specific age groups disproportionately contributed to changes in daily and nondaily cannabis use trends.

METHOD

Participants ages 12 and older (N = 722,653) from the 2002-2014 National Survey on Drug Use and Health reported past-year cannabis use frequency (i.e., daily = ≥300 days/year; nondaily = 1-299 days/year; none). Multinomial logistic regression was used to model change in past-year daily and nondaily cannabis use prevalence by age group (i.e., 12-17, 18-25, 26-34, 35-49, 50-64, ≥65), before and after 2007. Multinomial logistic regressions estimated change in relative odds of cannabis use frequency over time by age, adjusting for other sociodemographics.

RESULTS

Daily cannabis use prevalence decreased in ages 12-17 before 2007 and increased significantly across adult age categories only after 2007. Increases did not differ significantly across adult ages 18-64 and ranged between 1 and 2 percentage points. Nondaily cannabis use decreased among respondents ages 12-25 and 35-49 before 2007 and increased across adult age categories after 2007, particularly among adults 26-34 (i.e., 4.5 percentage points). Adjusted odds of daily versus nondaily cannabis use increased after 2007 for ages 12-64.

CONCLUSIONS

Increases in daily and nondaily cannabis use prevalence after 2007 were specific to adult age groups in the context of increasingly permissive cannabis legislation, attitudes, and lower risk perception. Although any cannabis use may be decreasing among teens, relative odds of more frequent use among users increased in ages 12-64 since 2007. Studies should assess not only any cannabis use, but also frequency of use, to target prevention efforts of adverse effects of cannabis that are especially likely among frequent users.

State marijuana laws and opioid overdose mortality

Background

The opioid epidemic in the United States is a national public health crisis. In recent years, marijuana legalization has been increasingly adopted by state governments as a policy intervention to control the opioid epidemic under the premise that marijuana and opioids are substitutive substances. The purpose of this systematic review is to synthesize the empirical evidence regarding the impact of state marijuana laws on opioid overdose mortality and other opioid-related health outcomes.

Method

A comprehensive search of the research literature in 18 bibliographic databases returned 6640 records, with 5601 abstracts reviewed, 29 full text articles screened for eligibility, and 16 eligible studies included in the systematic review. Comprehensive Meta-Analysis software was used to generate summary estimates, forest plots, funnel plots, and heterogeneity statistics.

Results

Of the 16 eligible studies, 4 assessed the association of state marijuana law status with opioid overdose mortality, 7 with prescription opioids dispensed, and the remaining with nonmedical use and opioid-related hospitalizations. Random effects modeling based on pooled data revealed that legalizing marijuana for medical use was associated with a statistically non-significant 8% reduction in opioid overdose mortality (95% confidence interval: − 0.21 to 0.04; p = 0.201) and a 7% reduction in prescription opioids dispensed (95% confidence interval: − 0.13 to − 0.01; p = 0.017). Legalizing marijuana for recreational use was associated with an additional 7% reduction in opioid overdose mortality in Colorado and 6% reduction in opioid prescriptions among fee-for-service Medicaid and managed care enrollees.

Conclusions

Legalizing marijuana might contribute to a modest reduction in opioid prescriptions. Evidence about the effect of marijuana legalization on opioid overdose mortality is inconsistent and inconclusive. If any, the effectiveness of state marijuana laws in reducing opioid overdose mortality appears to be rather small and limited to states with operational marijuana dispensaries. It remains unclear whether the presumed benefit of legalizing marijuana in reducing opioid-related harms outweighs the policy’s externalities, such as its impact on mental health and traffic safety.

Medical marijuana laws are associated with increases in substance use treatment admissions by pregnant women

BACKGROUND AND AIMS

Between 2002 and 2014, past-month marijuana use among pregnant women in the United States increased 62%, nearly twice the growth of the general population. This growth coincides with the proliferation of state medical marijuana laws (MMLs) authorizing physicians to recommend marijuana for approved conditions. We estimated the association between MMLs and substance use treatment utilization among pregnant and non-pregnant women of reproductive age. We also examined whether the association varied across MML provisions, age groups and treatment referral sources to clarify potential pathways.

DESIGN

Nation-wide administrative data from the 2002-14 Treatment Episodes Data Set Admissions, and a difference-in-differences design that exploited the staggered implementation of MMLs to compare changes in outcomes before and after implementation between MML and non-MML states.

SETTING

Twenty-one MML and 27 non-MML US states.

PARTICIPANTS

Pregnant and non-pregnant women aged 12-49 admitted to publicly funded specialty substance use treatment facilities.

MEASUREMENTS

The primary outcome variable was the number of treatment admissions per 100 000 women aged 12-49, aggregated at the state-year level (n = 606). Admissions for marijuana, alcohol, cocaine and opioids were considered. The primary independent variable was an indicator of MML implementation in a state.

FINDINGS

Among pregnant women, the rate of marijuana treatment admissions increased by 4.69 [95% confidence interval (CI) = 1.32, 8.06] in MML states relative to non-MML states. This growth was accompanied by increases in treatment admissions involving alcohol (β = 3.19; 95% CI = 0.97, 5.410 and cocaine (β = 2.56; 95% CI = 0.34, 4.79), was specific to adults (β = 5.50; 95% CI = 1.52, 9.47) and was largest in states granting legal protection for marijuana dispensaries (β = 6.37; 95% CI = -0.97, 13.70). There was no statistically significant association between MMLs and treatment admissions by non-pregnant women.

CONCLUSIONS

Medical marijuana law implementation in US states has been associated with greater substance use treatment utilization by pregnant adult women, especially in states with legally protected dispensaries.

The Association Between Cannabis Use and Aberrant Behaviors During Chronic Opioid Therapy for Chronic Pain

Objective

Health care providers are likely to see an increase in the concomitant use of cannabis and opioids, particularly with the increased liberalization and ongoing research into the possible role of medical marijuana for chronic pain. Recent literature reports a prevalence of concurrent use ranging from 8.9% to 31.8%. The primary aim of this study was to determine the relationship between cannabis use and aberrant drug behaviors in noncancer pain patients receiving chronic opioid therapy.

Design

Retrospective chart review.

Setting

Community-based, interdisciplinary pain management center.

Subjects

Data from 209 patients who were evaluated for a medication management program between October 1, 2011, and January 1, 2014, and met inclusion criteria. Forty-four were positive for cannabis in their initial random urine drug toxicology.

Methods

Data from electronic health records, including demographics, urine drug toxicology, disability, opioid dose, opioid risk assessment data, and pain severity were analyzed to examine differences among cannabis users and noncannabis users.

Results

Subjects with cannabis in their initial urine drug toxicology were more likely to have a future occurrence of an opioid-related aberrancy (P < 0.001), be male (P = 0.047), have a history of substance abuse (P = 0.013), and be enrolled into a higher level of clinical monitoring of opioid medication use (P = 0.008). No other associations with demographic and clinical variables reached statistical significance.

Conclusions

Concurrent use of cannabis and opioids by patients with chronic pain appears to indicate higher risk for opioid misuse. Closer monitoring for opioid-related aberrancy is indicated for this group of patients.

Impact of Medical Marijuana Legalization on Opioid Use, Chronic Opioid Use, and High-risk Opioid Use

OBJECTIVE

To determine the association of medical marijuana legalization with prescription opioid utilization.

METHODS

A 10% sample of a nationally representative database of commercially insured population was used to gather information on opioid use, chronic opioid use, and high-risk opioid use for the years 2006-2014. Adults with pharmacy and medical benefits for the entire calendar year were included in the population for that year. Multilevel logistic regression analysis, controlling for patient, person-year, and state-level factors, were used to determine the impact of medical marijuana legalization on the three opioid use measures. Sub-group analysis among cancer-free adults and cancer-free adults with at least one chronic non-cancer pain condition in the particular year were conducted. Alternate regression models were used to test the robustness of our results including a fixed effects model, an alternate definition for start date for medical marijuana legalization, a person-level analysis, and a falsification test.

RESULTS

The final sample included a total of 4,840,562 persons translating into 15,705,562 person years. Medical marijuana legalization was found to be associated with a lower odds of any opioid use: OR = 0.95 (0.94-0.96), chronic opioid use: OR = 0.93 (0.91-0.95), and high-risk opioid use: OR = 0.96 (0.94-0.98). The findings were similar in both the sub-group analyses and all the sensitivity analyses. The falsification tests showed no association between medical marijuana legalization and prescriptions for antihyperlipidemics (OR = 1.00; CI 0.99-1.01) or antihypertensives (OR = 1.00; CI 0.99-1.01).

CONCLUSIONS

In states where marijuana is available through medical channels, a modestly lower rate of opioid and high-risk opioid prescribing was observed. Policy makers could consider medical marijuana legalization as a tool that may modestly reduce chronic and high-risk opioid use. However, further research assessing risk versus benefits of medical marijuana legalization and head to head comparisons of marijuana versus opioids for pain management is required.

The Effects of Marijuana Use on Transitions through Stages of Alcohol Involvement for Men and Women in the NESARC I and II

Background: With the changing context of marijuana use, it is critical to identify effects of use. We extend previous work by examining whether marijuana use influences progression and remission through alcohol involvement stages for men and women. Methods: Data come from Waves I and II of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC, n = 34,432). We assess the potential influence of marijuana use at Wave 1 on transitions across three latent statuses of alcohol involvement between waves. We apply propensity score weighting to account for shared risk factors. Results: Marijuana use was associated cross-sectionally and longitudinally with alcohol involvement statuses for both sexes. After propensity score adjustment, men with marijuana histories were 3.50 times as likely as men without such histories to transition from no to severe problems across waves relative to staying in the same status (p < .001). Women with marijuana histories were 1.74 times as likely as women without such histories to transition from no problems at Wave 1 to moderate problems at Wave 2 (p = .030) and 0.13 times as likely as women without such histories to transition from severe problems to no problems (p = .006). Conclusions: Results suggest that marijuana use impacts progression to more serious stages of alcohol involvement for both men and women, as well as hinders remission among women. Findings point to the importance of screening those with marijuana histories for alcohol problems, as well as the need to understand the mechanism of why marijuana use may increase the risk of alcohol problems.

Impacts of Medical Marijuana Laws on Young Americans Across the Developmental Spectrum

Introduction State legalization of marijuana for medical purposes could increase illicit marijuana use among young people. Medical marijuana laws may boost the availability of marijuana and reduce perceptions of its harmfulness, leading more young people to try it. Prior studies report little evidence that these laws are impacting marijuana consumption by young Americans, and none have systematically compared developmentally distinct age groups. Methods We performed multilevel, serial cross-sectional analyses on ten annual waves of U.S. National Survey on Drug Use and Health, from 2004 to 2013, comparing young people in states with and without medical marijuana laws. Disaggregated analyses compared multiple measures of marijuana use across approximately 450,300 individuals in early adolescence (12-14 years), late adolescence (15-17 years) and young adulthood (18-25 years). Results Dwelling in a state that had legalized medical marijuana was not associated with marijuana consumption in the past month among early adolescents, late adolescents or young adults. However, young adults living in medical marijuana states were significantly more likely to have initiated first use in the past year. Conclusions Medical marijuana laws increase the likelihood that young adults will start using marijuana but do not affect more vulnerable developmental groups in early and late adolescence. Delaying the age of first use into young adulthood can reduce the risk of a drug use disorder later in life. Young adults are in the peak years of engagement with illicit drugs and state medical marijuana laws appear to be leading larger numbers to try the drug.

Children's Health Insurance Program Expansions: What Works for Families?

We examine the impact of Children’s Health Insurance Program (CHIP) eligibility expansions 1999 to 2012 on child and joint parent/child insurance coverage. We use changes in state CHIP income eligibility levels and data from the Current Population Survey Annual Social and Economic Supplement to create child/parent dyads. We use logistic regression to estimate marginal effects of eligibility expansions on coverage in families with incomes below 300% federal poverty level (FPL) and, in turn, 150% to 300% FPL. The latter is the income range most expansions targeted. We find CHIP expansions increased public coverage among children in families 150% to 300% FPL by 2.5 percentage points (pp). We find increased joint parent/child coverage of 2.3 pp (P = .055) but only in states where the public eligibility levels for parent and child are within 50 pp. In these states, the CHIP expansion increased the probability that both parent/child are publicly insured (2.5 pp) among insured dyads, but where the eligibility levels are further apart (51-150 pp; >150 pp), CHIP expansions increase the probability of mixed coverage—one public, one private—by 0.9 to 1.5 pp. Overall, families made decisions regarding coverage that put the child first but parents took advantage of joint parent/child coverage when eligibility levels were close. Joint public parent/child coverage can have positive care-seeking effects as well as reduced financial burdens for low-income families.

Prelegalisation patterns and trends of cannabis use among Canadian youth: results from the COMPASS prospective cohort study

OBJECTIVE

Canada federally legalised recreational cannabis use among adults in October 2018. The impact this will have on Canadian youth is cause for concern. The current study examined changes in youth cannabis use over the time prior to legalisation to explore the impact of the beginning federal discourse around legalisation during the 2016/2017 school year.

DESIGN

COMPASS, a prospective cohort study based on annual self-administered questionnaires.

SETTING

Ontario and Alberta during the first 6 years of the COMPASS study (2012/2013 to 2017/2018).

PARTICIPANTS

Canadian grade 9-12 students attending secondary schools participating in COMPASS. In total, 2 30 404 questionnaires were included in the analysis (Y1: 2012/2013, n=24 173; Y2: 2013/2014, n=45 298; Y3: 2014/2015, n=42 355, Y4: 2015/2016, n=40 436; Y5: 2016/2017, n=37 060; Y6: 2017/2018, n=34 897).

PRIMARY AND SECONDARY OUTCOME MEASURES

Lifetime cannabis use, past-year cannabis use, weekly cannabis use, ease of access to cannabis and age at first cannabis use.

RESULTS

Cannabis never-use decreased between Y5 and Y6. Changes in age at first cannabis use mirrored this trend, with male students consistently starting younger. Cannabis access rates increased from Y4, mainly led by female students. Lifetime and past-year use rates were lowest in Y4 then increased in Y5 and Y6 due to a rise in the occasional use more common among female students, who reported use increases first. Non-white students were more likely use cannabis, with black and Aboriginal students the only two groups consistently reporting more weekly than occasional use, though with opposing trajectories. Overall, Aboriginal students had the highest odds of reporting lifetime, past-year and weekly use among the demographic groups examined.

CONCLUSION

After a steady decrease in patterns of cannabis among youth over several years, it appears that there has been a gradual increase in cannabis use among youth following the start of discourse around cannabis legalisation, with some populations of youth being at greater risk.

Time trends in US cannabis use and cannabis use disorders overall and by sociodemographic subgroups: a narrative review and new findings

Background: Due to significant comorbidity and impairment associated with cannabis use and cannabis use disorder, understanding time trends in cannabis use and cannabis use disorder is an important public health priority.Objectives: To identify trends in cannabis use and cannabis use disorder overall, and by sociodemographic subgroup.Methods: Narrative review of published findings on trends in cannabis use and cannabis use disorders in data from repeated cross-sectional US general population surveys. In addition, in National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; 2002-2002) and NESARC-III (2012-2013) data, logistic regression was used to examine whether trends differed between subgroups of adults.Results: The review showed that in adults, cannabis use increased over the past decade overall and within sociodemographic subgroups (gender, age, race/ethnicity, income, education, marital status, urbanicity, region, pregnancy status, disability status), with greater increases in men and disabled adults. Most sources also indicated significant increases in cannabis use disorders. New analysis showed significantly greater increases in adult cannabis use and cannabis use disorder in men (p ≤ .0001); young adults (p < .05); Blacks (vs. Whites, p < .01); low income groups (p < .001); never-married p ≤ .0001), and urban residents (p < .05). In adolescents, cannabis use generally decreased, although recent increases were observed in older and non-White adolescents.Conclusion: Cannabis use and cannabis use disorder are increasing in adults, with specific sociodemographic groups at higher risk, and may be increasing in some adolescent subgroups. Studies should determine mechanisms for differential trends to provide information to policymakers and enable informed decisions on cannabis legalization and service planning.

Medical marijuana legalization and associated illicit drug use and prescription medication misuse among adolescents in the U.S

BACKGROUND

Use of illicit drugs and misuse of prescription medications among U.S. adolescents have been major public health issues. As over half of the states have implemented medical marijuana laws (MMLs), it is unclear if MML implementation is associated with use of illicit drugs and misuse of prescription medications among adolescents.

METHODS

This study used data from the 2013-2014 National Survey of Drug Use and Health and included adolescents aged 12-18 with a total of 26,826 participants after the propensity-score matching used to reduce selection bias between states that had and had not implemented MML. Seven logistic regressions were conducted to examine MML implementation and associated use of illicit drugs (including cocaine/crack, heroin, hallucinogens, and inhalants) and misuse of prescription medications (including pain relievers, tranquilizers/sedatives, and stimulants), controlling for sociodemographics and use of cigarettes, alcohol, and marijuana.

RESULTS

Adolescents residing in the states that had legalized medical marijuana were more likely to use cocaine/crack and heroin in the past 12 months (OR = 1.63, 2.61, respectively; both ps < 0.05). However, MML implementation was not associated with the likelihood of using other illicit drugs or misusing prescription medications.

CONCLUSIONS

The study findings suggest that for the states that have implemented MML, policy and educational interventions should as well be implemented to prevent not only marijuana use but also use of other harder drugs such as cocaine/crack and heroin among adolescents. States that have yet implemented MML should consider the possible associations between MML implementation and use of other illicit drugs when legislating MML.

Commentary on Jones J, Jones KN and Peil J (2018) The impact of the legalization of recreational marijuana on college students. Addictive Behaviors 77: 255-259, https://doi.org/10.1016/j.addbeh.2017.08.015

With the broadening legislative changes surrounding legalized recreational marijuana in the United States, tracking the impact of such changes is imperative. As such, in a recent article published in Addictive Behaviors, we identified several emerging trends in the first state to legalize recreational marijuana, Colorado. Since our publication, similar research from other states that have legalized recreational marijuana (Oregon and Washington) has emerged. Here, we attempt to expand on our findings and identify patterns across the research, by comparing and contrasting our results to research in other states with legalized recreational marijuana. We identified several trends including, but not limited to, the rates of marijuana use rising after decriminalization, but not the retail sale of recreational marijuana; recreational marijuana legalization leading to a decrease in the relationship between marijuana and alcohol use; and the identification of binge drinkers as a high-risk population for marijuana use after recreational legalization. We also explore the complicated relationship between marijuana use and academic performance, and point out areas where future research is needed.

Higher average potency across the United States is associated with progression to first cannabis use disorder symptom

OBJECTIVE

To determine if higher potency cannabis is associated with earlier progression to regular cannabis use, daily cannabis use, and cannabis use disorder symptom onset.

METHODS

Data sources were the Michigan Longitudinal Study, an ongoing prospective, high-risk family study investigating the course and predictors for substance use disorders among youth beginning prior to school entry and time-parallel national average trends in delta-9-tetrahydrocannabinol (i.e., psychoactive compound in cannabis). The national average trends in delta-9-tetrahydrocannabinol were used to estimate potency level for the individual. Only cannabis users were included in analyses (n = 527).

RESULTS

Cox regression showed an increased risk of progression from cannabis initiation to cannabis use disorder symptom onset by 1.41 times (p < .001) for each unit increase in national average delta-9-tetrahydrocannabinol as compared to those not endorsing CUD symptom onset, adjusting for sex, regular use, and cohort effects. Accounting for regular use, individuals initiating cannabis at national average 4.9% delta-9-tetrahydrocannabinol were at 1.88 times (p = .012) higher risk for cannabis use disorder symptom onset within one year compared to those who did not endorse CUD symptom onset, while those initiating cannabis at national average 12.3% delta-9-tetrahydrocannabinol were at 4.85 times (p = .012) higher risk within one year.

CONCLUSIONS

This study provides prospective evidence suggesting higher potency cannabis, on average in the U.S., increases risk for onset of first cannabis use disorder symptom. Development of guidelines regarding cannabis potency is critical for reducing the costs associated with negative health outcomes.

Associations between state-level policy liberalism, cannabis use, and cannabis use disorder from 2004 to 2012: Looking beyond medical cannabis law status

BACKGROUND

Medical cannabis laws (MCL) have received increased attention as potential drivers of cannabis use (CU), but little work has explored how the broader policy climate, independent of MCL, may impact CU outcomes. We explored the association between state-level policy liberalism and past-year cannabis use (CU) and cannabis use disorder (CUD).

METHODS

We obtained state-level prevalence of past-year CU and CUD among past year cannabis users for ages 12-17, 18-25, and 26+ from the 2004-2006 and 2010-2012 National Surveys on Drug Use and Health. States were categorized as liberal, moderate, or conservative based on state-level policy liberalism rankings in 2005 and 2011. Linear models with random state effects examined the association between policy liberalism and past-year CU and CUD, adjusting for state-level social and economic covariates and medical cannabis laws.

RESULTS

In adjusted models, liberal states had higher average past-year CU than conservative states for ages 12-17 (+1.58 percentage points; p = 0.03) and 18-25 (+2.96 percentage points; p = 0.01) but not for 26+ (p = 0.19). CUD prevalence among past year users was significantly lower in liberal compared to conservative states for ages 12-17 (-2.87 percentage points; p = 0.045) and marginally lower for ages 26+ (-2.45 percentage points; p = 0.05).

CONCLUSION

Liberal states had higher past-year CU, but lower CUD prevalence among users, compared to conservative states. Researchers and policy makers should consider how the broader policy environment, independent of MCL, may contribute to CU outcomes.

Marijuana and Cardiac Arrhythmias: A Scoping Study

With increasing legalization, marijuana has become the most commonly abused substance in the United States. Together with the introduction of more potent marijuana products over the years, more adverse events are being reported and clinically characterized. Delta-9-tetrahydrocannabinol (THC) is the active psychotropic component of marijuana, which acts mainly on G-protein cannabinoid receptors CB1 and CB2. Multiple isolated cases of arrhythmias associated with marijuana use have been published. In this manuscript we conduct a scoping study of a total of 27 cases of arrhythmia associated with marijuana. Most cases were reported in young males (81%) with a mean age of 28 ± 10.6 years. Atrial fibrillation (26%) and ventricular fibrillation (22%) were the most common arrhythmias reported. Brugada pattern was reported in 19% of the patients. Marijuana associated arrhythmia resulted in a high mortality rate of 11 %. While the exact mechanisms of arrhythmias associated with marijuana are not clear, several hypothesis have been introduced including the effect of marijuana on cardiac ion channels as well as its effects on the central nervous system. In this paper we discuss the possible mechanisms of marijuana induced arrhythmia citing the evidence available to-date.

PERCEPTION OF DAMAGE AND BENEFITS ASSOCIATED TO THE USE OF MARIJUANA IN ADOLESCENTS, VIÑA DEL MAR, CHILE

ABSTRACT Objective: analyze the perception of harm and benefits, and its association with the use of marijuana in high school students, as well as the intention to use it in a context of regulatory changes. Method: a quantitative, exploratory, cross-sectional study was designed, applying a self-administered questionnaire to 268 high school students. Results: The results showed that the declared consumption in the sample is higher than that obtained in previous studies in Chile, which had already warned of the increase in prevalence, compared to previous measurements. There is a low perception of risk associated with consumption and insecurity regarding benefits. In the framework of regulatory changes, no change was observed in the intention of use. Adolescent consumers would continue to do so as before, while those who have not consumed it, 25% would try it, and 60% would still not use it. Conclusions: The current discussion in the country has focused on the effect that the change in the law would have, by itself, on adolescent consumption, however, it is relevant to direct efforts towards the perceptions of risk and benefits that they have, in order to stop the observed increasing in consumption in the country, in the latest studies.

Correct knowledge of medical cannabis legal status in one's own state: Differences between adolescents and adults in the United States, 2004-2013

BACKGROUND

Studies have found age-specific effects of medical cannabis laws (MCLs), particularly affecting adult cannabis use but not adolescent use. We examined whether age differences in MCL knowledge are in accordance with age differences in MCL effects on cannabis use.

METHODS

Data from the 2004-2013 repeated cross-sectional National Surveys on Drug Use and Health included people ages 12 and older in the United States. State-aggregated MCL knowledge was the proportion of people that correctly identified living in a state that did not allow medical cannabis prior to MCL enactment, or that allowed medical cannabis after MCL enactment. We regressed state-aggregated MCL knowledge on time-varying MCL enactment (i.e., no MCL by 2015, before MCL, after MCL), testing associations by age strata (12-17, 18-25, 26+), open dispensary status, and adjusting for time and state-level demographics.

RESULTS

Model-based MCL knowledge was significantly lower among adolescents than adults; after enactment, 36.8% of ages 12-17, 48.8% of ages 18-25, and 45.4% of ages 26+ were aware of their state's MCL status. Correct MCL status knowledge decreased across all age groups after MCL enactment (i.e., low knowledge of MCL changes at the time they occurred). Open cannabis dispensaries significantly increased correct MCL knowledge, with a 7.7-point increase for adolescents and a 17.5-point increase for adults 26 + .

CONCLUSIONS

Lower MCL knowledge among adolescents than adults was in accordance with MCL effects on cannabis use previously observed among adults only. Studies should assess whether MCL knowledge is a consequence or predictor of individual-level cannabis use across age groups.

Challenges in studying statewide pedestrian injuries and drug involvement

BACKGROUND

Increasing U.S. rates of pedestrian injuries could be attributable in part to changing policies and attitudes towards drugs and associated increases in use, yet drug use has not been investigated widely as a risk factor for pedestrian injury. This study details challenges to investigating drug-involved pedestrian crashes using existing surveillance systems.

METHODS

Using California police reports from 2004 to 2016, we performed simple linear regression with the proportion of data that was missing by year for drug and alcohol use as the outcome of interest. We also explored differences in the relative proportion of missing data across sex, race, and age groups through simple logistic regression. Finally, we compared missing data for alcohol and drug use indicators for pedestrians and drivers.

RESULTS

From 2004 to 2016, 182,278 pedestrians were involved in crashes across California. Only 1.22% (n = 2219) of records indicated drug use, and 98% had missing data for drug use; the proportion of missing data did not change over time (b = - 0.040, p = 0.145, 95% CI = (- 0.095, 0.016)). The proportion of missing values for alcohol use increased each year (b = 0.49, 95% CI = (0.26, 0.72), p = 0.001). Driver drug and alcohol use indictors showed similar data missingness, and missing data did not show significant variation over time. Hispanics were more likely to have missing data for drug use compared to Whites (OR = 0.61, p < 0.001, 95% CI = (0.56, 0.67)), and Blacks were more likely to have missing data for alcohol use compared to Whites (OR = 0.87, p < 0.0001, 95% CI = (0.84, 0.91)).

CONCLUSIONS

Drug use may be a key contributing factor to pedestrian injury, but drug use remains consistently and largely unmeasured in existing surveillance systems. Without better collection of drug and alcohol data, monitoring trends in drug-involved pedestrian injury will not be feasible.

Marijuana use is associated with alcohol use and consequences across the first 2 years of college

College entry is associated with marijuana initiation, and co-use of alcohol and marijuana is associated with problematic outcomes, including alcohol-related consequences. The present study explored if: (a) use of marijuana on a given day would be associated with greater alcohol use within the same day; (b) use of marijuana within a given week would be associated with increased alcohol-related consequences in that same week; and (c) the association between marijuana use and alcohol consumption and consequences varies across time or by precollege level of problematic alcohol use. Participants (N = 488 college student drinkers, 59% female) completed assessments of marijuana use, alcohol use, and alcohol consequences across 2 years. Analyses revealed: (a) daily marijuana use predicted greater number of daily drinks and estimated breath alcohol concentration; (b) weekly marijuana use predicted more weekly positive and negative alcohol consequences; (c) the effect of daily marijuana use on alcohol use strengthened over time, while the effect of weekly marijuana use on positive alcohol consequences reduced over time; and (d) precollege level of problematic alcohol use moderated the association between daily marijuana and alcohol use and weekly marijuana use and negative consequences. This study provides the first longitudinal evidence of the association between marijuana use and greater alcohol use and consequences in college students. Future research examining event-level measurement of alcohol and marijuana co-use is important for the prevention of alcohol-related consequences. (PsycINFO Database Record (c) 2018 APA, all rights reserved).