Recreational Cannabis - Minimizing the Health Risks from Legalization

Alcohol and cannabis use and co-use among Whites and Hispanics on and off the U.S./Mexico border in California

This paper examines self-reported rates of drinking and cannabis use and co-use among White and Hispanic adults randomly selected in four counties in California: Imperial on the border; and Kern, Tulare, and Madera in California's Central Valley. Co-use was significantly higher among the U.S. born than among those born abroad, and in the Central Valley than on the border. Co-users were heavier drinkers, had higher rates of alcohol use disorder, other alcohol problems, and a positive history of illicit drug use than drinkers only.

The impact of recreational cannabis markets on motor vehicle accident, suicide, and opioid overdose fatalities

In the U.S., an increasing number of states are legalizing regulated commercial markets for recreational cannabis, which allows private industry to produce, distribute, and sell marijuana to those 21 and older. The health impacts of these markets are not fully understood. Preliminary evidence suggests recreational markets may be associated with increased use among adults, which indicates there may be downstream health impacts on outcomes related to cannabis use. Three causes of death that are linked to cannabis use are motor vehicle accidents, suicide, and opioid overdose. Drawing on data from U.S. death certificates from 2009 to 2019, we conducted a difference-in-differences analysis to estimate the impact of recreational markets on fatalities from motor vehicle accidents, suicide, and opioid overdose in seven states: Colorado, Washington, Oregon, Alaska, Nevada, California, and Massachusetts. States with comprehensive medical cannabis programs with similar pre-trends in deaths were used as comparisons. For each outcome, a pooled estimate was generated with a meta-analysis using random effects models. The results revealed substantial increases in crash fatalities in Colorado, Oregon, Alaska, and California of 16%, 22%, 20%, and 14%, respectively. Based on estimates from all seven states, recreational markets were associated with a 10% increase in motor vehicle accident deaths, on average. This study found no evidence that recreational markets impacted suicides. Most states saw a relative reduction in opioid overdose death that ranged between 3 and 28%. On average, recreational markets were associated with an 11% reduction in opioid overdose fatalities.

Association of cannabis use disorder with cardiovascular diseases: A two-sample Mendelian randomization study

Background

The use of cannabis has increased globally due to more regions decriminalizing marijuana use for therapeutic and recreational aims. Several observational studies have revealed that cannabis use is associated with an increased risk of adverse cardiovascular pathologies and diseases. Nevertheless, the causal associations between cannabis use and cardiovascular diseases remain unclear. Hence, we performed single-variable and multivariable Mendelian randomization (MR) to evaluate the association between cannabis use disorder and various cardiovascular diseases.

Materials and methods

Summary statistics were collected from the largest-to-date genome-wide association studies (GWAS) of cannabis use disorder. The 12 SNPs for cannabis use disorder were used as instrumental variables in this study. MR estimates were pooled using a random-effects inverse-variance weighted (IVW) method. Simple median and weighted median methods were conducted as sensitivity analyses.

Results

The genetic liability to cannabis use disorder was associated with an augmented risk of coronary artery disease, myocardial infarction, atrial fibrillation, heart failure, deep venous thrombosis, pulmonary embolism, and stroke. Except for stroke, the results were inconsistent in the sensitivity analyses. The overall patterns for the associations of cannabis use disorder with atrial fibrillation, heart failure, pulmonary embolism and stroke remained in multivariable MR analyses adjusting for potential mediators, including smoking, alcohol, body mass index, blood lipid, type 2 diabetes, hypertension, and depression. However, the association with coronary artery disease, myocardial infarction, and deep venous thrombosis did not persist in multivariable MR analyses. Mediation analysis demonstrated that smoking, body mass index, low-density lipoprotein, hypertension, and depression have more significant mediation effects, which suggests that these factors partly mediate the link from cannabis use disorder to coronary artery disease, myocardial infarction, and deep venous thrombosis.

Conclusion

The genetic liability to cannabis use disorder was associated with a higher risk of atrial fibrillation, heart failure, pulmonary embolism, and stroke. The evidence for the association between cannabis use disorder, coronary artery disease, myocardial infarction, and deep venous thrombosis was weak. Hence, future use of cannabis for therapeutic and recreational aims should consider its potential impact on cardiovascular diseases.

Impact of cannabis legalization on healthcare utilization for psychosis and schizophrenia in Colorado

BACKGROUND

Emergency department (ED) visits involving psychosis and schizophrenia have increased at a rate exceeding population growth in the United States over the past decade. Research shows a strong dose-response relationship between chronic use of high-potency cannabis and odds of developing symptoms of psychosis. The aim of this study was to evaluate the impact of cannabis legalization on psychosis and schizophrenia-related ED visits in Colorado.

METHODS

Using administrative data from Colorado Hospital Association (CHA) on county-level quarterly ED visits between January 1, 2013, and December 31, 2018, we applied a difference-in-difference analysis to examine how new exposure to recreational cannabis dispensaries after 2014 differentially influenced the rate of ED visits for psychosis and schizophrenia, comparing counties with no prior medical cannabis dispensary exposure to counties with low or high medical dispensary exposure.

RESULTS

As recreational dispensaries per 10,000 residents increased, there was no significant association with the rate of schizophrenia ED visits per capita (incidence rate ratio or IRR: 0.95, 95% CI [0.69, 1.30]) while the rate of psychosis visits increased 24% (IRR: 1.24, 95% CI [1.02, 1.49]). Counties with no previous medical dispensaries experienced larger increases in schizophrenia ED visits than counties already exposed to a low level of medical dispensaries, but this effect was not significant. Counties with low baseline medical exposure had lower increases in rates of psychosis visits than counties with high baseline medical exposure (IRR 0.83, 95% CI [0.69, 0.99]).

CONCLUSIONS

There was a positive association between the number of cannabis dispensaries and rates of psychosis ED visits across all counties in Colorado. Although it is unclear whether it is access to products, or the types of products that may be driving this association, our findings suggest there is a potential impact on the mental health of the local population that is observed after cannabis legalization.

Coping Motives Mediate the Association of Trauma History with Problematic Cannabis Use in Young Adult Medical Cannabis Patients and Non-Patient Cannabis Users

Background: Despite evidence of the contribution of childhood trauma to the development of problematic cannabis use, its mediating pathways are largely unknown. Given the link between cannabis motives with trauma and problematic cannabis use, motives of use may represent a construct through which trauma impacts problematic cannabis use. Methods: A sample of 339 medical cannabis patient and non-patient young adult users from the Los Angeles area were sampled at baseline and one year later. The current study examined the impact of childhood trauma on problematic use through a variety of cannabis use motives. Results: Controlling for age, socioeconomic status, perceived stress, and baseline problematic use, endorsing the use of cannabis to cope with distress at baseline uniquely mediated the associations between different childhood trauma types (e.g., physical abuse, neglect, sexual trauma) and problematic use one year later. Experience of any childhood trauma was positively associated with coping motives, whereas emotional and physical abuse were positively associated with pain motives, and sexual abuse was positively associated with sleep motives. Using cannabis for coping and increasing attention/focus were also positively associated with higher problematic use, whereas using cannabis for sleep was inversely associated with problematic use one year later. Conclusions: The motives of coping with distress and inattention may represent intermediate constructs through which trauma leads to later problematic cannabis use. Results highlight the need to clarify the pathways between health and non-health-oriented motives and cannabis use over time.

Marijuana use and high-risk health behaviors among diverse college students post- legalization of recreational marijuana use

Objectives

This study examined high-risk health behaviors in marijuana-users among a diverse college population in Southern California, post legalization of marijuana for recreational use.

Study design

A cross-sectional research design was employed utilizing existing data via the 2018 National College Health Assessment (NCHA) from a large Minority-Serving Institution (MSI) population [n = 1345 (Hispanic/Latino/a, n = 456; White, n = 353; Asian Pacific Islander (API), n = 288; Multiracial/Biracial, n = 195; Other, n = 53)].

Methods

Chi square and t-tests assessed differences in descriptive characteristics (age, gender, race/ethnicity and GPA) and high-risk behaviors (alcohol, tobacco and sexual behaviors) among marijuana users and non-users. Logistic regression analyses examined the relationship between race/ethnicity and high-risk behaviors with marijuana use (dependent variable).

Results

Among marijuana-users, significant (p = 0.004) differences were observed between race/ethnicity with Whites reporting using most (32.7%), followed by Hispanics (27.6%) and then APIs (17.8%). Marijuana-users compared with non-users consistently reported high-risk alcohol behaviors (p < 0.0001), were more likely to smoke tobacco (p < 0.0001) and engaged in more high-risk sexual behaviors (p < 0.0001). Logistic regression showed after adjusting for demographic characteristics and high-risk behaviors, race/ethnicity was borderline significantly associated with marijuana use, specifically for Whites (OR = 1.53; 95% CI: (−0.01, 0.86), p = 0.06) and the Other race/ethnicity category (OR = 2.32; 95% CI: (0.12, 1.56), p = 0.02) compared with APIs.

Conclusion

Our findings clearly demonstrate deleterious high-risk behaviors such as alcohol use, tobacco use, and certain sexual behaviors occur more among marijuana-users compared to non-users, post legalization of marijuana for recreational use. Further, race-ethnic differences were observed. Therefore, continued examination of marijuana use trends and high-risk behaviors is critical in monitoring the implications of marijuana policy changes, specifically in diverse populations.

Racial and Ethnic Differences in Cannabis Use Following Legalization in US States With Medical Cannabis Laws

IMPORTANCE

Little is known about changes in cannabis use outcomes by race and ethnicity following the enactment of recreational cannabis laws (RCLs).

OBJECTIVES

To examine the association between enactment of state RCLs and changes in cannabis outcomes by race and ethnicity overall and by age groups in the US.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used restricted use file data from the National Surveys of Drug Use and Health between 2008 and 2017, which were analyzed between September 2019 and March 2020. National survey data included the entire US population older than 12 years.

MAIN OUTCOMES AND MEASURES

Self-reported past-year and past-month cannabis use and, among people that used cannabis, daily past-month cannabis use and past-year Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) cannabis use disorder. Multi-level logistic regressions were fit to estimates changes in cannabis use outcomes by race and ethnicity overall and by age between respondents in states with and without enacted RCLs, controlling for trends in states with medical cannabis laws or no cannabis laws.

RESULTS

A total of 838 600 participants were included for analysis (mean age, 43 years [range, 12-105 years]; 434 900 women [weighted percentage, 51.5%]; 511 900 participants (weighted percentage, 64.6%) identified as non-Hispanic White, 99 000 (11.9%) as non-Hispanic Black, 78 400 (15.8%) as Hispanic, and 149 200 (7.6%) as other (including either Native American, Pacific Islander, Asian, or more than 1 race or ethnicity). Compared with the period before RCL enactment, the odds of past-year cannabis use after RCL enactment increased among Hispanic (adjusted odds ratio [aOR], 1.33; 95% CI, 1.15-1.52), other (aOR, 1.31; 95% CI, 1.12-1.52), and non-Hispanic White (aOR, 1.21; 95% CI, 1.12-1.31) populations, particularly among those aged 21 years or more. Similarly, the odds of past-month cannabis use increased among Hispanic (aOR, 1.43; 95% CI, 1.22-1.69), other (aOR, 1.43; 95% CI, 1.20-1.70), and non-Hispanic White (aOR, 1.24; 95% CI, 1.13-1.35) populations after RCL enactment. No increases were found in the odds of past-year or past-month cannabis use post-RCL enactment among non-Hispanic Black individuals or among individuals aged 12 to 20 years for all race and ethnicity groups. In addition, among people who used cannabis, while no increases were found in past-month daily cannabis in any racial or ethnic group, the odds of cannabis use disorder increased post-RCL among individuals categorized as other overall (aOR, 1.45; 95% CI, 1.07-1.95), but no increases were found by age group.

CONCLUSIONS AND RELEVANCE

Changes in cannabis use by race and ethnicity that may be attributable to policy enactment and variations in recreational policy provisions should be monitored. To ensure that the enactment of recreational cannabis laws truly contributes to greater equity in outcomes and adheres to antiracist policies, monitoring unintended and intended consequences that may be attributable to recreational cannabis use and similar policies by race and ethnicity is needed.

Dual trajectories of cannabis and alcohol use among young adults in a state with legal nonmedical cannabis

BACKGROUND

Understanding the nature of the association between cannabis and alcohol use within individuals over time in the era of legalized cannabis is of crucial importance for assessing the public health consequences of increasing cannabis use. An important unanswered question is whether cannabis and alcohol use substitute for one another. Specifically, is greater use of one substance associated with less use of the other substance (i.e., a negative association) or are the substances complementary and their association positive?

METHODS

We used 24 consecutive months of data on a young adult sample (n = 774; 56% female, age 18-25 during the study) who drank alcohol in the year prior to enrollment. The sample was recruited in Washington State in 2015/2016 (after legalization of nonmedical cannabis) using media advertisements and community flyers and outreach. Using parallel process latent growth curve models, we assessed three types of association between cannabis and alcohol use across the 24-month period: (1) an association between average levels of cannabis and alcohol use; (2) an association between rates of change in cannabis and alcohol use; and (3) correlations between shorter-term deviations/fluctuations off of longer-term trajectories of level and change in cannabis and alcohol use.

RESULTS

We found a positive association between the average frequency of cannabis and alcohol use; individuals who used cannabis more frequently on average also drank alcohol more frequently on average. Change over time in cannabis use was positively associated with change in alcohol use. There was also a contemporaneous positive association between fluctuations in cannabis and alcohol use.

CONCLUSIONS

Overall, we found no evidence of substitution. Rather, the results suggest a complementary relationship between cannabis and alcohol use, such that the use of cannabis and alcohol rises and falls together.

Trends over time in adult cannabis use: A review of recent findings

In the United States, policies regarding the medical and nonmedical use of cannabis are changing rapidly. In 2021, a total of 34 US states have legalized cannabis for adult medical use, and 15 of these states have legalized adult non-medical use. These changing policies have raised questions about increasing prevalences of cannabis use, changing perceptions regarding frequent use, and potentially related outcomes such as comorbid psychiatric illness or driving under the influence of cannabis. Research regarding the correlates of any and frequent cannabis use is also developing quickly. This article reviews recent empirical studies concerning (1) adult trends in cannabis use, (2) state cannabis laws and related outcomes, and (3) emerging evidence regarding how the global coronavirus 19 pandemic may impact cannabis use patterns. We summarize recent findings and conclude with suggestions to address unanticipated effects of rapidly changing cannabis laws and policies.

Factors associated with health-related cannabis use intentions among a community sample of people who inject drugs in Los Angeles and San Francisco, CA 2016 to 2018

OBJECTIVE

Cannabis motivations have been studied extensively among patients of medicinal cannabis dispensaries, but less is known about motivations in community samples of opioid-using people who inject drugs. Our objective is to describe cannabis use motivations associated with self-treatment of physical pain, emotional issues, and as an opioid substitute.

METHODS

Data come from 6-month follow-up interviews with people who inject drugs who participated in a study on the efficacy of an injection initiation prevention intervention in Los Angeles and San Francisco, California from 2016-18. The analytic sample consists of 387 people who inject drugs who reported past-month cannabis use. We developed multivariable logistic regression models by reported cannabis use motivations: physical pain relief, emotional problems, and opioid substitute.

RESULTS

The most common cannabis use motivations reported by people who inject drugs was to "get high," relieve physical pain and emotional problems, and reduce opioid use. In separate multivariate models, using cannabis for physical pain relief was associated with higher odds of using cannabis as a substitute for opioids; cannabis for emotional problems was associated with being diagnosed with depression; and cannabis as a substitute for opioids was associated with non-prescribed, non-injection methadone use.

CONCLUSION

People who inject drugs reported using cannabis for health-related motivations. This motivation aligns with health needs and suggests the acceptability of cannabis use for health reasons in this population. Studies to determine the medical effectiveness of cannabis products for these common health and mental health needs among people who inject drugs are needed.

Relationship Between Cannabis Use and Erectile Dysfunction: A Systematic Review and Meta-Analysis

Globally, there is increasing usage and legalization of cannabis. In addition to its reported therapeutic effects, cannabis has several health risks which are not clearly defined. Erectile dysfunction (ED) is the most common male sexual disorder and there are plausible mechanisms linking cannabis use to ED. No attempt has been made to collate the literature on this topic. The aim of this review was to summarize the prevalence and risk of ED in cannabis users compared to controls.

A systematic review of major databases from inception to January 1, 2019, without language restriction, was undertaken to identify studies investigating cannabis use and presence of ED. The analysis compared the prevalence of ED in cannabis users versus controls. Consequently, the odds ratio (OR) with 95% confidence intervals (CI) was calculated, applying a random-effect model.

Five case–control studies were included with data from 3,395 healthy men, 1,035 using cannabis (smoking) and 2,360 nonusers. The overall prevalence of ED in cannabis users was 69.1% (95% CI: 38.0–89.1), whilst the correspondent figure in controls was 34.7% (95% CI: 20.3–52.7). The OR of ED in cannabis users was almost four times that of controls (OR = 3.83; 95% CI: 1.30–11.28; p = .02), even if characterized by high heterogeneity (I² = 90%) and the prediction intervals overlapped 1.00 (95% CI: 0.35–7.26).

Data suggest that ED is twice as high in cannabis users compared to controls. Future longitudinal research is needed to confirm/refute this and explore if a dose–response relationship between cannabis and ED may be evident.

Medical marijuana laws and driving under the influence of marijuana and alcohol

AIMS

Medical marijuana law (MML) enactment in the United States has been associated with increased cannabis use but lower traffic fatality rates. We assessed the possible association of MML and individual-level driving under the influence of cannabis (DUIC) and also under the influence of alcohol (DUIA).

DESIGN AND SETTING

Three cross-sectional U.S. adult surveys: The National Longitudinal Alcohol Epidemiologic Survey (NLAES; 1991-1992), the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; 2001-2002), and the NESARC-III (2012-2013).

PARTICIPANTS

The total n was 118 497: 41 764, 41 184, and 35 549 from NLAES, NESARC, and NESARC-III, respectively.

MEASUREMENTS

Across the three surveys, similar questions in the Alcohol Use Disorder and Associated Disabilities Interview Schedule assessed DUIC and DUIA. Ever-MML states enacted MML between 1991-1992 and 2012-2013 (overall period). Early-MML states enacted MML between 1991-1992 and 2001-2002 (early period). Late-MML states enacted MML between 2001-2002 and 2012-2013 (late period). MML effects on change in DUIC and DUIA prevalence were estimated using a difference-in-differences specification to compare changes in MML and other states.

FINDINGS

From 1991-1992 to 2012-2013, DUIC prevalence nearly doubled (from 1.02% to 1.92%), increasing more in states that enacted MML than other states (difference-in-differences [DiD] = 0.59%; 95% CI = 0.06%-1.12%). Most change in DUIC prevalence occurred between 2001-2002 and 2012-2013. DUIC prevalence increased more in states that enacted MML 2001-2002 to 2012-2013 than in never-MML states (DiD = 0.77%; 95% CI = -0.05%-1.59%), and in two early-MML states, California (DiD = 0.82; 95% CI = 0.06-1.59) and Colorado (DiD = 1.32; 95% CI = 0.11-2.53). In contrast, DUIA prevalence appeared unrelated to MML enactment.

CONCLUSIONS

Medical marijuana law enactment in US states appears to have been associated with increased prevalence of driving under the influence of cannabis, but not alcohol.

What is the prevalence and risk of cannabis use disorders among people who use cannabis? a systematic review and meta-analysis

BACKGROUND AND AIMS

We aim to quantify the prevalence and risk of having a cannabis use disorder (CUD), cannabis abuse (CA) or cannabis dependence (CD) among people in the general population who have used cannabis.

METHOD

We conducted a systematic review of epidemiological cross-sectional and longitudinal studies on the prevalence and risks of CUDs among cannabis users. We identified studies published between 2009 and 2019 through PubMed, the Global Burden Disease (GBD) Database, and supplementary searches up to 2020. The outcomes of interest were CUDs based on DSM or ICD criteria. Estimates were synthesized using random-effects meta-analyses, followed by meta-regression of study characteristics on effect sizes.

RESULTS

From 1383 records identified, 21 studies were included. Meta-analyses showed that among people who used cannabis, 22% (18-26%) have CUD, 13% (8-18%) have CA, and 13% (10-15%) have CD. Estimates from cohort studies, showed that the risk of developing CD increased to 33% (22-44%) among young people who engaged in regular (weekly or daily) use of cannabis. There was a lack of data from cohort studies to estimate the risk of CUD or CA among regular cannabis users.

CONCLUSIONS

Cannabis users need to be informed about the risks of developing CUDs and the higher risks among those who initiate early and use frequently during adolescence. Future studies are needed to examine how changes in cannabis policies may affect the risks of CUDs in the population.

Persistent cannabis use as an independent risk factor for violent behaviors in patients with schizophrenia

Although recent studies have shown a moderately strong association between cannabis use and violence among people with severe mental disorders, the direction of this association has not been investigated prospectively in a population with schizophrenia. Therefore, this study aims to determine, using cross-lag models, whether a temporal relationship between cumulative cannabis use and violence exists in a population with schizophrenia. The authors reported findings covering an 18-month period from a randomized, double-blind clinical trial of antipsychotic medications for schizophrenia treatment. Among the 1460 patients enrolled in the trial, 965 were followed longitudinally. Although persistent cannabis use predicted subsequent violence, violence did not predict cannabis use. The relationship was therefore unidirectional and persisted when controlling for stimulants and alcohol use. Finally, a significant body of evidence suggests a link between persistent cannabis use and violence among people with mental illnesses. Studies to further investigate the mechanisms underlying this association should be conducted.

Genome-wide DNA methylation analysis of heavy cannabis exposure in a New Zealand longitudinal cohort

Cannabis use is of increasing public health interest globally. Here we examined the effect of heavy cannabis use, with and without tobacco, on genome-wide DNA methylation in a longitudinal birth cohort (Christchurch Health and Development Study, CHDS). A total of 48 heavy cannabis users were selected from the CHDS cohort, on the basis of their adult exposure to cannabis and tobacco, and DNA methylation assessed from whole blood samples, collected at approximately age 28. Methylation in heavy cannabis users was assessed, relative to non-users (n = 48 controls) via the Illumina Infinium® MethylationEPIC BeadChip. We found the most differentially methylated sites in cannabis with tobacco users were in the AHRR and F2RL3 genes, replicating previous studies on the effects of tobacco. Cannabis-only users had no evidence of differential methylation in these genes, or at any other loci at the epigenome-wide significance level (P < 10^-7). However, there were 521 sites differentially methylated at P < 0.001 which were enriched for genes involved in neuronal signalling (glutamatergic synapse and long-term potentiation) and cardiomyopathy. Further, the most differentially methylated loci were associated with genes with reported roles in brain function (e.g. TMEM190, MUC3L, CDC20 and SP9). We conclude that the effects of cannabis use on the mature human blood methylome differ from, and are less pronounced than, the effects of tobacco use, and that larger sample sizes are required to investigate this further.

Toward a Typology of Normative Drug Users Based on Levels of Functioning, Justifications and Types of Use

The study explores 29 individuals who described themselves as functioning normatively while using drugs on a regular basis. They defined their use as intensive, constant, and playing a significant part in their normative lives. The content analysis revealed a typology consisting of four different types of normative users: the socially connected users, the better coping users, the ambivalent users, and the recovering users. This typology was created on the basis of three axes: level of functioning, justification of use, style of use. Our typology highlights the differences between normative users with varying patterns of drug usage and levels of functioning, ranging from users who claim that drug use causes them no harm to those who acknowledge that drug use has significantly damaged their functioning. This typology places particular emphasis on normative users who are experiencing a range of difficulties and need specific forms of therapy to preserve their normative lives.

Association Between Cannabis Use and Complications Related to Crohn's Disease: A Retrospective Cohort Study

BACKGROUND

Crohn's disease is an idiopathic inflammatory process that is occasionally associated with complications, which cause significant morbidity and mortality. The anti-inflammatory effect of cannabis in intestinal inflammation has been shown in several experimental models; it is unknown whether this correlates with fewer complications in Crohn's disease patients.

AIMS

To compare the prevalence of Crohn's disease-related complications among cannabis users and non-users in patients admitted with a primary diagnosis of Crohn's disease or a primary diagnosis of Crohn's related complication and a secondary diagnosis of Crohn's disease between 2012 and 2014.

METHODS

We used data from the Healthcare Cost and Utilization Project-National Inpatient Sample. Cannabis users (615) were compared directly after propensity score match to non-users, in aspects of various complications and clinical end-points.

RESULTS

Among matched cohorts, Cannabis users were less likely to have the following: active fistulizing disease and intra-abdominal abscess (11.5% vs. 15.9%; aOR 0.68 [0.49 to 0.94], p = 0.025), blood product transfusion (5.0% vs. 8.0%; aOR 0.48 [0.30 to 0.79], p = 0.037), colectomy (3.7% vs. 7.5%; aOR 0.48 [0.29-0.80], p = 0.004), and parenteral nutrition requirement (3.4% vs. 6.7%, aOR 0.39 [0.23 to 0.68], p = 0.009).

CONCLUSION

Cannabis use may mitigate several of the well-described complications of Crohn's disease among hospital inpatients. These effects could possibly be through the effect of cannabis in the endocannabinoid system.

Perception of Benefits and Harms of Medical Cannabis among Seriously Ill Patients in an Outpatient Palliative Care Practice

Introduction: Patients with serious illness often have pain, uncontrolled symptoms, and poor quality of life. Evidence continues to evolve regarding the role of cannabis to treat chronic pain, nausea, and anorexia. Little is known about how patients with serious illness perceive its benefits and harms. Given that an increasing number of clinicians across the United States are treating patients with medical cannabis, it is important for providers to understand patient beliefs about this modality. We assessed patient perceptions of benefits and harms of cannabis who obtained a medical cannabis card within an ambulatory palliative care (APC) practice. Methods: We recruited patients with a medical cannabis card, allowing for legal possession of cannabis oil, from an APC practice in Georgia. All participants reported using cannabis products. Patients completed an online survey that included questions about their cannabis use, concurrent opiate or controlled medication use, and perceptions of benefits and harms of cannabis. Results: All 101 patients invited to participate completed the survey. A majority had cancer (76%) and were married (61%), disabled or retired (75%), older than 50 years of age (64%), and men (56%). Most patients ingested (61%) or vaporized (49%) cannabis products. A majority of respondents perceived cannabis to be important for their pain (96%) management. They reported that side effects were minimally bothersome, and drowsiness was the most commonly reported bothersome harm (28%). A minority of patients reported cannabis withdrawal symptoms (19%) and concerns for dependency (14%). The majority of patients were using concurrent prescription opioids (65%). Furthermore, a majority of cancer patients reported cannabis as being important for cancer cure (59%). Conclusion: Patients living with serious illnesses who use cannabis in the context of a multidisciplinary APC practice use cannabis for curative intent and for pain and symptom control. Patients reported improved pain, other symptoms, and a sense of well-being with few reported harms.

Time Trends in the Co-use of Cannabis and the Misuse of Tranquilizers, Sedatives and Sleeping Pills among Young Adults in Spain between 2009 and 2015

The aims of this study were: (a) to estimate time trends in the prevalence of the co-use of cannabis and other cannabis-based products (CBP) with the misuse of tranquilizers, sedatives, and sleeping pills (TSSp) between 2009 and 2015; and (b) to identify the factors associated with the probability of the co-use of CBP with TSSp misuse during this period among Spanish younger adults (15–34 years old). We analyzed data collected from the Spanish National Surveys on Alcohol and Other Drugs (EDADES) in 2009, 2011, 2013, and 2015. CBP co-use with TSSp misuse were the dependent variables. We also analyzed sociodemographic features, self-perceived health status, lifestyle habits, perceived health risk of consumption, and perceived availability of substance using logistic regression models. The prevalence of CBP co-use with TSSp misuse has decreased in Spain. The factors associated with co-use were a lack of education (OR 2.34), alcohol (OR 7.2), tobacco (OR 6.3) and other illicit psychoactive drug (OR 6.5) consumption, perceived non-health risk for the consumption of CBP and TSSp (OR 3.27), and perceived availability of CBP (OR 2.96). Our study identified several factors that appear to affect CBP and TSSp co-use in younger adults, with potential implications for healthcare providers.

International Perspectives on the Implications of Cannabis Legalization: A Systematic Review & Thematic Analysis

The legality, recreational and medical use of cannabis varies widely by country and region but remains largely prohibited internationally. In October 2018, Canada legalized the recreational use of cannabis—a move many viewed as controversial. Proponents of legalization have emphasized the potential to eradicate the marijuana black market, improve quality and safety control, increase tax revenues, improve the availability of medical cannabis, and lower gang-related drug violence. Conversely, opponents of legalization have stressed concerns about cannabis’ addictive potential, second-hand cannabis exposure, potential exacerbation of underlying and established mental illnesses, as well as alterations in perception that affect safety, particularly driving. This systematic review synthesizes recent international literature on the clinical and public health implications of cannabis legalization.

Cannabis Associated "High" Cardiovascular Morbidity and Mortality: Marijuana Smoke Like Tobacco Smoke? A Déjà Vu/Déjà Vécu Story?

BACKGROUND

Cannabis use has increased over the past several years as some countries have legalized its use for the treatment of certain medical conditions and/or for recreational use. Thus, concerns have risen about potential adverse health effects. Increasing number of reports have associated cannabis use with serious cardiovascular (CV) complications. Furthermore, there appears to be a likeness in the harmful health effects, especially on the CV and respiratory systems, of cannabis smoking to those of tobacco smoking.

OBJECTIVE

To review the CV effects of cannabis use and compare them with those of tobacco use.

METHODS

Articles were reviewed that were published in English literature reporting on cannabis and cannabinoid pharmacology and their effects on the CV system and their consequences. Emphasis was also placed on articles reporting on cannabis use in adolescents, exposure to secondhand smoke, its effect on exercise and finally its inter-relationship and similarities with tobacco use.

RESULTS

With growing cannabis use, an increasing number of reports have emerged associating marijuana use with serious and life-threatening CV complications, including acute coronary syndromes, potentially lethal cardiac arrhythmias and ischemic strokes. There are certain similarities of the deleterious CV and respiratory effects of cannabis smoking with those of tobacco smoking. Despite the difference in the active ingredients (tetrahydrocannabinol vs. nicotine), each substance produces a plethora of chemicals when smoked and these are largely identical; furthermore, due to different modes of smoking, cannabis chemicals are retained in the body for a longer time. Of course, concomitant tobacco and cannabis smoking is a perplexing factor in isolating damages specifically pertaining to cannabis use, while the health risk is additive. Although the mechanisms producing CV harm may be somewhat different between these two substances, the outcome appears similar, or even worse, as the effects may emerge at a younger age.

CONCLUSION

There is an increasing concern that, apart from the mental health problem with cannabis smoking, societies may be facing another wave of a déjà vu/déjà vécu phenomenon similar to the tobacco smoking story.

The impacts of potency, warning messages, and price on preferences for Cannabis flower products

BACKGROUND

Recreational cannabis has been legalized in 11 states and Washington DC in the US. However, little is known about individual preferences for legal cannabis products. This study estimated the impacts of tetrahydrocannabinol (THC), cannabidiol (CBD), warning messages, and price on preferences for cannabis flowers.

METHODS

A cross-sectional online survey with discrete choice experiments was implemented in October 2017. A sample of 2400 adults aged 21 years or older were recruited from 6 US states with recreational cannabis legalization, consisting of 1200 past-year nonusers and 1200 past-year users. Each respondent was randomly assigned to 12 discrete choice scenarios, each asking them to choose from an opt-out option and 3 cannabis flower products with varying levels in THC, CBD, warning messages, and price. The impacts of product attributes on individual choices were analyzed with nested logit regressions.

RESULTS

Both cannabis nonusers and users preferred higher CBD and lower price. Users also preferred higher THC. The results on warning messages were mixed: graphic warning on drugged driving and text warning message had positive impacts on nonusers' and users' preferences for cannabis flowers, respectively, whereas FDA disapproval disclaimer had negative impacts on nonusers' preferences. Heterogeneities in preferences were revealed among nonusers by former use status and among users by reason of use. Particularly, medical cannabis users were not as responsive to THC as recreational cannabis users or dual users were. Regarding relative importance of the attributes, all respondents but medical cannabis users perceived price as the most important attribute (relative importance 51-64%), whereas medical cannabis users perceived CBD as the most important attribute (relative importance 47%).

CONCLUSION

The findings indicated that product characteristics may have influences on US adults' choices of legal cannabis flower products and may deserve consideration for cannabis regulatory framework.

Association between cannabis use and complications related to ulcerative colitis in hospitalized patients: A propensity matched retrospective cohort study

Ulcerative colitis (UC) is a chronic inflammatory process that is occasionally associated with complications that cause significant morbidity and mortality. Studies in experimental animal models have demonstrated a beneficial effect of cannabis on intestinal inflammation. It is however unknown if this corresponds to fewer complications for patients with Ulcerative Colitis.We aimed to compare the prevalence of UC related complications and certain key clinical endpoints among cannabis users and nonusers hospitalized with a primary diagnosis of UC, or primary diagnosis of a UC-related complication with a secondary diagnosis of UC.Using data from the Healthcare Cost and Utilization Project-National Inpatient Sample (NIS) during 2010-2014, a total of 298 cannabis users with UC were compared to a propensity score matched group of nonusers with UC. We evaluated several UC-related complications and clinical endpoints.Within our matched cohort, prevalence of partial or total colectomy was lower in cannabis users compared to nonusers (4.4% vs 9.7%, P = .010) and there was a trend toward a lower prevalence of bowel obstruction (6.4% vs 10.7%, P = .057). Cannabis users had shorter hospital length-of-stay (4.5 vs 5.7 days P < .007) compared to their nonuser counterparts.Cannabis use may mitigate some of the well described complications of UC among hospitalized patients. Our findings need further evaluation, ideally through more rigorous clinical trials.

The Australian drug harms ranking study

BACKGROUND/AIM

The aim of the current study was to review drug harms as they occur in Australia using the Multi-criteria Decision Analysis (MCDA) methodology adopted in earlier studies in other jurisdictions.

METHOD

A facilitated workshop with 25 experts from across Australia, was held to score 22 drugs on 16 criteria: 9 related to harms that a drug produces in the individual and 7 to harms to others. Participants were guided by facilitators through the methodology and principles of MCDA. In open discussion, each drug was scored on each criterion. The criteria were then weighted using a process of swing weighting. Scoring was captured in MCDA software tool.

RESULTS

MCDA modelling showed the most harmful substances to users were fentanyls (part score 50), heroin (part score 45) and crystal methamphetamine (part score 42). The most harmful substances to others were alcohol (part score 41), crystal methamphetamine (part score 24) and cigarettes/tobacco (part score 14). Overall, alcohol was the most harmful drug when harm to users and harm to others was combined. A supplementary analysis took into consideration the prevalence of each substance in Australia. Alcohol was again ranked the most harmful substance overall, followed by cigarettes, crystal methamphetamine, cannabis, heroin and pharmaceutical opioids.

CONCLUSIONS

The results of this study make an important contribution to the emerging international picture of drug harms. They highlight the persistent and pervasive harms caused by alcohol. Policy implications and recommendations are discussed. Policies to reduce harm from alcohol and methamphetamine should be a priority.

Traffic fatalities within US states that have legalized recreational cannabis sales and their neighbours

BACKGROUND AND AIMS

A growing body of evidence suggests that cannabis impairs driving ability. We used mortality data to investigate whether the commercial sale of cannabis for recreational use affected traffic fatality rates both in states that legalized it and in neighbouring jurisdictions.

DESIGN

Interrupted time-series of traffic fatality rates adjusted for seasonality and autocorrelation. Changes are reported as step and trend effects against a comparator of states that had not implemented medicinal or recreational cannabis during the study period (2009-16). Sensitivity analyses added a 6-month 'phase-in' to account for lags in production. Meta-analyses were used to derive pooled results.

SETTING

Three states that legalized recreational cannabis sales [Colorado (January 2014), Washington State (June 2014) and Oregon (October 2015] and nine neighbouring jurisdictions [Kansas, Nebraska, New Mexico, Oklahoma and Utah (Colorado neighbours); British Columbia and Oregon (Washington neighbours); and California and Nevada (Oregon neighbours)].

MEASUREMENTS

Monthly traffic fatalities rates per million residents using mortality data from CDC WONDER and RoadSafetyBC and census data.

FINDINGS

There was a pooled step increase of 1.08 traffic fatalities per million residents followed by a trend reduction of -0.06 per month (both P < 0.001), although with significant heterogeneity between sites (step: I²  = 73.7%, P < 0.001; trend: I²  = 68.4%; P = 0.001). Effects were similar in both legalizing (step: 0.90, P < 0.001; trend: -0.05, P = 0.007) and neighbouring sites (step: 1.15, P = 0.005; trend: -0.06, P = 0.001). The 6-month phase-in produced similar if larger effects (step: 1.36, P = 0.006; trend: -0.07, P < 0.001).

CONCLUSIONS

The combination of step increases and trend reductions suggests that in the year following implementation of recreational cannabis sales, traffic fatalities temporarily increased by an average of one additional traffic fatality per million residents in both legalizing US states of Colorado, Washington and Oregon and in their neighbouring jurisdictions.

Adolescent E-Cigarette, Hookah, and Conventional Cigarette Use and Subsequent Marijuana Use

: media-1vid110.1542/5799875103001PEDS-VA_2017-3616Video Abstract OBJECTIVES: Noncigarette tobacco products may confer a risk of marijuana use similar to combustible cigarettes. We examined whether adolescent electronic cigarette (e-cigarette), hookah, or combustible cigarette use is associated with initiating and currently using marijuana as well as using both tobacco and marijuana concurrently.

METHODS

Adolescents from 10 public schools in Los Angeles, California, completed in-classroom surveys at baseline (fall 2013, ninth grade) and at a 24-month follow-up (fall 2015, 11th grade). Among adolescents who never used marijuana at baseline (N = 2668), associations of baseline e-cigarette, hookah, or combustible cigarette use with ever marijuana use (initiation), current marijuana use (past 30 days), and current dual use of marijuana and these tobacco products at the 24-month follow-up were examined.

RESULTS

Baseline ever versus never e-cigarette use was associated with initiation (odds ratio [OR] 3.63; 95% confidence interval [CI] 2.69-4.90) and current (OR 3.67; 95% CI 2.51-5.36) marijuana use 24 months later. Ever versus never hookah use was associated with initiation (OR 3.55; 95% CI 2.49-5.08) and current (OR 4.10; 95% CI 2.69-6.25) marijuana use 24 months later. Similar associations were observed for combustible cigarette smoking and initiation (OR 4.30; 95% CI 2.79-6.63) and current use of marijuana (OR 1.97; 95% CI 1.05-3.68). Current use of any of these tobacco products at baseline was associated with current use of both tobacco and marijuana (OR 2.28; 95% CI 1.47-3.55) 24 months later.

CONCLUSIONS

The association between tobacco use and subsequent marijuana use across adolescence extends to multiple tobacco products.

Marijuana Regulatory Frameworks in Four US States: An Analysis Against a Public Health Standard

The movement to legalize and regulate retail marijuana is growing. We examined legislation and regulations in the first 4 states to legalize recreational marijuana (Colorado, Washington, Oregon, and Alaska) to analyze whether public health best practices from tobacco and alcohol control to reduce population-level demand were being followed. Only between 34% and 51% of policies followed best practices. Marijuana regulations generally followed US alcohol policy regarding conflict of interest, taxation, education (youth-based and problematic users), warning labels, and research that does not seek to minimize consumption and the associated health effects. Application of US alcohol policies to marijuana has been challenged by some policy actors, notably those advocating public health policies modeled on tobacco control. Reversing past decisions to regulate marijuana modeled on alcohol policies will likely become increasingly difficult once these processes are set in motion and a dominant policy framework and trajectory becomes established. Designing future marijuana legislation to prioritize public health over business would make it easier to implement legalization of recreational marijuana in a way that protects health.

Medical Marijuana: Current Concepts, Pharmacological Actions of Cannabinoid Receptor Mediated Activation, and Societal Implications

PURPOSE OF REVIEW

The purpose of the following review is to summarize the history and current policies related to marijuana use and prevalence, basic and clinical science pharmacological literature regarding efficacy, subpopulations of concern, and varying policies regarding its use at present.

RECENT FINDINGS

With the increasingly widespread utilization of marijuana, there is also a growing complexity of public health policy, regulation, and necessity to further assess the medical indications and adverse long-term effects of marijuana use. Health care providers as well as the general public must be prepared to become familiar and up-to-date with medical literature, legislation, and educational material regarding medical marijuana.

US Epidemiology of Cannabis Use and Associated Problems

This review provides an overview of the changing US epidemiology of cannabis use and associated problems. Adults and adolescents increasingly view cannabis as harmless, and some can use cannabis without harm. However, potential problems include harms from prenatal exposure and unintentional childhood exposure; decline in educational or occupational functioning after early adolescent use, and in adulthood, impaired driving and vehicle crashes; cannabis use disorders (CUD), cannabis withdrawal, and psychiatric comorbidity. Evidence suggests national increases in cannabis potency, prenatal and unintentional childhood exposure; and in adults, increased use, CUD, cannabis-related emergency room visits, and fatal vehicle crashes. Twenty-nine states have medical marijuana laws (MMLs) and of these, 8 have recreational marijuana laws (RMLs). Many studies indicate that MMLs or their specific provisions did not increase adolescent cannabis use. However, the more limited literature suggests that MMLs have led to increased cannabis potency, unintentional childhood exposures, adult cannabis use, and adult CUD. Ecological-level studies suggest that MMLs have led to substitution of cannabis for opioids, and also possibly for psychiatric medications. Much remains to be determined about cannabis trends and the role of MMLs and RMLs in these trends. The public, health professionals, and policy makers would benefit from education about the risks of cannabis use, the increases in such risks, and the role of marijuana laws in these increases.

Variation in cannabis potency and prices in a newly legal market: evidence from 30 million cannabis sales in Washington state

AIMS

To (1) assess trends and variation in the market share of product types and potency sold in a legal cannabis retail market and (2) estimate how potency and purchase quantity influence price variation for cannabis flower.

DESIGN

Secondary analysis of publicly available data from Washington State's cannabis traceability system spanning 7 July 2014 to 30 September 2016. Descriptive statistics and linear regressions assessed variation and trends in cannabis product variety and potency. Hedonic regressions estimated how purchase quantity and potency influence cannabis flower price variation.

SETTING

Washington State, USA.

PARTICIPANTS

(1) A total of 44 482 176 million cannabis purchases, including (2) 31 052 123 cannabis flower purchases after trimming price and quantity outliers.

MEASUREMENTS

Primary outcome measures were (1) monthly expenditures on cannabis, total delta-9-tetrahydrocannabinol (THC) concentration and cannabidiol (CBD) concentration by product type and (2) excise tax-inclusive price per gram of cannabis flower. Key covariates for the hedonic price regressions included quantity purchased, THC and CBD.

FINDINGS

Traditional cannabis flowers still account for the majority of spending (66.6%), but the market share of extracts for inhalation increased by 145.8% between October 2014 and September 2016, now comprising 21.2% of sales. The average THC-level for cannabis extracts is more than triple that for cannabis flowers (68.7% compared to 20.6%). For flower products, there is a statistically significant relationship between price per gram and both THC [coefficient = 0.012; 95% confidence interval (CI) = 0.011-0.013] and CBD (coefficient = 0.017; CI = 0.015-0.019). The estimated discount elasticity is -0.06 (CI = -0.07 to -0.05).

CONCLUSIONS

In the state of Washington, USA, the legal cannabis market is currently dominated by high-THC cannabis flower, and features growing expenditures on extracts. For cannabis flower, both THC and CBD are associated with higher per-gram prices, and there are small but significant quantity discounts.

Cannabis use, attitudes, and legal status in the U.S.: A review

Cannabis is widely used among adolescents and adults. In the U.S., marijuana laws have been changing, and Americans increasingly favor legalizing cannabis for medical and recreational uses. While some can use cannabis without harm, others experience adverse consequences. The objective of this review is to summarize information on the legal status of cannabis, perceptions regarding cannabis, prevalence and time trends in use and related adverse consequences, and evidence on the relationship of state medical (MML) and recreational (RML) marijuana laws to use and attitudes. Twenty-nine states now have MMLs, and eight of these have RMLs. Since the early 2000s, adult and adolescent perception of cannabis use as risky has decreased. Over the same time, the prevalence of adolescent cannabis use has changed little. However, adult cannabis use, disorders, and related consequences have increased. Multiple nationally representative studies indicate that MMLs have had little effect on cannabis use among adolescents. However, while MML effects have been less studied in adults, available evidence suggests that MMLs increase use and cannabis use disorders in adults. While data are not yet available to evaluate the effect of RMLs, they are likely to lower price, increase availability, and thereby increase cannabis use. More permissive marijuana laws may accomplish social justice aims (e.g., reduce racial disparities in law enforcement) and generate tax revenues. However, such laws may increase cannabis-related adverse health and psychosocial consequences by increasing the population of users. Dissemination of balanced information about the potential health harms of cannabis use is needed.

BDNF overexpression prevents cognitive deficit elicited by adolescent cannabis exposure and host susceptibility interaction

Cannabis abuse in adolescence is associated with increased risk of psychotic disorders. Δ-9-tetrahydrocannabinol (THC) is the primary psychoactive component of cannabis. Disrupted-In-Schizophrenia-1 (DISC1) protein is a driver for major mental illness by influencing neurodevelopmental processes. Here, utilizing a unique mouse model based on host (DISC1) X environment (THC administration) interaction, we aimed at studying the pathobiological basis through which THC exposure elicits psychiatric manifestations. Wild-Type and dominant-negative-DISC1 (DN-DISC1) mice were injected with THC (10 mg/kg) or vehicle for 10 days during mid-adolescence-equivalent period. Behavioral tests were conducted to assess exploratory activity (open field test, light-dark box test) and cognitive function (novel object recognition test). Electrophysiological effect of THC was evaluated using acute hippocampal slices, and hippocampal cannabinoid receptor type 1 and brain-derived neurotrophic factor (BDNF) protein levels were measured. Our results indicate that THC exposure elicits deficits in exploratory activity and recognition memory, together with reduced short-term synaptic facilitation and loss of BDNF surge in the hippocampus of DN-DISC mice, but not in wild-type mice. Over-expression of BDNF in the hippocampus of THC-treated DN-DISC1 mice prevented the impairment in recognition memory. The results of this study imply that induction of BDNF following adolescence THC exposure may serve as a homeostatic response geared to maintain proper cognitive function against exogenous insult. The BDNF surge in response to THC is perturbed in the presence of mutant DISC1, suggesting DISC1 may be a useful probe to identify biological cascades involved in the neurochemical, electrophysiological, and behavioral effects of cannabis related psychiatric manifestations.