US Epidemiology of Cannabis Use and Associated Problems

Design of Small Non-Peptidic Ligands That Alter Heteromerization between Cannabinoid CB1 and Serotonin 5HT2A Receptors

Activation of cannabinoid CB1 receptors (CB1R) by agonists induces analgesia but also induces cognitive impairment through the heteromer formed between CB1R and the serotonin 5HT2A receptor (5HT2AR). This side effect poses a serious drawback in the therapeutic use of cannabis for pain alleviation. Peptides designed from the transmembrane helices of CB1R, which are predicted to bind 5HT2AR and alter the stability of the CB1R-5HT2AR heteromer, have been shown to avert CB1R agonist-induced cognitive impairment while preserving analgesia. Using these peptides as templates, we have now designed nonpeptidic small molecules that prevent CB1R-5HT2AR heteromerization in bimolecular fluorescence complementation assays and the heteromerization-dependent allosteric modulations in cell signaling experiments. These results provide proof-of-principle for the design of optimized ligand-based disruptors of the CB1R-5HT2AR heteromer, opening new perspectives for in vivo studies.

Intraperitoneal delivery of cannabidiol (CBD) and Δ9-tetrahydocannabinol (THC) promotes papillomavirus infections in athymic nude mice

We used our mouse papillomavirus (MmuPV1) model to test the hypothesis that two primary psychoactive ingredients of marijuana, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), promote papillomavirus persistence in the oral mucosa of infected mice. We conducted intraperitoneal (ip) injections of a moderate dose (3 mg/kg) of either CBD and/or THC in both male and female athymic nude mice and followed the mice up to 20 weeks post-infection. These doses are comparable to what is estimated for human conventional cannabis consumption. All mice were infected with MmuPV1 in the oral cavity at week 4 post-ip delivery of CBD, THC, or a combination of THC and CBD (T + C). THC and CBD were detected in the blood of treated mice for up to 72 h after ip injection. Significantly higher levels of viral DNA were detected in males from both CBD and T + C-treated groups compared to those in the control group at 9- 10-and 12-weeks post infection. A marginally increased viral RNA was also detected in the infected tongues of males in all tested groups compared to that in males in the vehicle control group; the opposite was observed in females. We detected significantly higher levels of dermal dendritic cells (CD205+CD11c+), granulocytes (Ly6G+), but macrophages (F4-80+) recruited to the infected tongues of CBD-treated females. Our findings suggest that CBD may play a role in promoting MmuPV1 persistence in the oral cavity.

Cannabinoid Hyperemesis Syndrome (CHS) - An emerging gastrointestinal disorder and clinical challenge

Nausea and vomiting are not uncommon symptoms resulting in emergency department (ED) or primary care visits. One of the emerging etiologies - Cannabinoid Hyperemesis Syndrome (CHS) remains significantly under-diagnosed, often resulting in unnecessary repeat ED visits and testing. This is in part due to lack of experience with and knowledge about CHS by health care professionals. Characterized by cyclic vomiting, often severe and intractable, it is frequently associated with a form of self-treatment; the compulsive need to take hot showers, and in the context of chronic cannabis use. With increased legalization and resultant accessibility to cannabis containing products, the risk of adverse events is significantly rising. Lack of clinical familiarity with the range of potential deleterious physical and mental health effects associated with cannabis leads to delays in appropriate diagnosis and effective treatment of CHS. Moreover, commonly utilized anti-emetics, such as ondansetron, and similar 5 HT drugs may not fully attenuate symptoms of CHS, and other interventions may be necessary; ultimately abstinence being the most effective long term clinical preventive approach. The objective of this review article is to assist the clinician in identifying the specific clinical characteristics of CHS, distinguishing it from other causes of CVS or nausea and vomiting, to facilitate more rapid, effective interventions. Collaboration with substance use professionals should also be considered during CHS treatment.

A Matched Design for Causal Inference With Survey Data: Evaluation of Medical Marijuana Legalization in Kentucky and Tennessee

A concern surrounding marijuana legalization is that driving after marijuana use may become more prevalent. Survey data are valuable for estimating policy effects, however their observational nature and unequal sampling probabilities create challenges for causal inference. To estimate population-level effects using survey data, we propose a matched design and implement sensitivity analyses to quantify how robust conclusions are to unmeasured confounding. Both theoretical justification and simulation studies are presented. We found no support that marijuana legalization increased tolerant behaviors and attitudes toward driving after marijuana use, and these conclusions seem moderately robust to unmeasured confounding.

School Nurse Perspectives of Medical Cannabis Policy in K-12 Schools: An Exploratory Descriptive Study

As states legalize medical cannabis, school nurses face increased parent questions about administration at school. Although school nurses frequently collaborate on the development and implementation of medication administration policies, their perceptions of barriers to school-based medical cannabis administration are not well-documented. To explore these perceptions, we surveyed school nurses (n = 379) in sixteen states about their beliefs related to school-based medical cannabis administration policy development. Findings revealed school nurses from states completely legalizing cannabis expressed significantly fewer concerns about the safety, stigma, and federal status of medical cannabis than their peers in more restrictive states. Implications for practice include (a) education of key stakeholders, (b) collaboration with stakeholders to formulate medication administration policy; and (c) development of state-level guidance for school professionals.

Associations between college enrollment and trends in substance use among young adults in the US from 2015 to 2019

Background: Substance use among college students has negative academic and health outcomes. Identifying substances that are more commonly used by students than non-students can reveal specific risks in the college environment.Objectives: To examine associations between college enrollment and prevalence and trends of use of a comprehensive list of substances.Methods: The sample included 2015-2019 participants in the National Survey on Drug Use and Health who were aged 18 to 22 and who were full-time enrolled or not enrolled in college. Prevalence of substance use was calculated for four subgroups: college males (n = 6,707), college females (n = 8,284), non-college males (n = 10,019), and non-college females (n = 9,266). Multivariate logistic regression was used to model the relationships between enrollment and substance use. Temporal trends in substance use prevalence were calculated for each subgroup.Results: College enrollment was associated with prescription stimulant misuse (aOR 1.50, 95% CI: 1.35-1.67), alcohol use (aOR 1.36, 95% CI: 1.27-1.47), and binge drinking (aOR 1.22, 95% CI: 1.15-1.30). From 2015 to 2019, the only substance whose use significantly increased among any subgroup was cannabis. The increase occurred among females only (+4.7% in college females and +5.6% in non-college females; both p < .01).Conclusions: College enrollment is most strongly associated with prescription stimulant misuse, suggesting that colleges should consider explicitly including stimulant misuse prevention in their health promotion strategies. The increasing use of cannabis among females warrants clinicians' attention to routine screening for use and provision of information about the mental health impacts of cannabis.

US State Recreational and Medical Cannabis Delivery Laws, 2024

Objectives. To provide a legal epidemiology review of state-level policies that regulate the direct delivery of recreational and medical cannabis in the United States. Methods. We conducted a comprehensive review to identify all relevant policies as of July 1, 2024. Specifically, we developed a coding scheme to capture laws governing (1) direct delivery of recreational cannabis, (2) licensing for direct delivery of recreational cannabis, (3) direct delivery of medical cannabis to qualifying patients, and (4) medical cannabis delivery solely from caregivers to qualified patients. Results. Fourteen states authorized the direct delivery of recreational cannabis to adults. Twenty-six states and the District of Columbia permitted the direct delivery of medical cannabis to qualifying patients. Twelve states allowed the delivery of medical cannabis to patients exclusively through caregivers. There were numerous variations in the licensing and authorization of recreational and medical cannabis delivery. Conclusions. States varied in how the delivery of cannabis was regulated. Public Health Implications. A comprehensive review of state-level policies on cannabis delivery highlights the diverse approaches and their implications for recreational and medical cannabis access. (Am J Public Health. Published online ahead of print November 14, 2024:e1-e13. https://doi.org/10.2105/AJPH.2024.307874).

Cannabis Use and Cannabis Use Disorder Among U.S. Adults with Psychiatric Disorders: 2001-2002 and 2012-2013

BACKGROUND

Rates of cannabis use disorder (CUD) have increased disproportionately among Veterans Administration (VA) patients with psychiatric disorders compared to patients with no disorder. However, VA patient samples are not representative of all U.S. adults, so results on disproportionate increases in CUD prevalence could have been biased. To address this concern, we investigated whether disproportionate increases in the prevalence of cannabis outcomes among those with psychiatric disorders would replicate in nationally representative samples of U.S. adults.

METHODS

Data came from two national surveys conducted in 2001-2002 (n = 43,093) and 2012-2013 (n = 36,309). Outcomes were any past-year non-medical cannabis use, frequent non-medical use (≥3 times weekly), and DSM-IV CUD. Psychiatric disorders included mood, anxiety and antisocial personality disorders. Logistic regression was used to generate predicted prevalences of the outcomes, prevalence differences calculated and additive interactions compared differences between those with and without psychiatric disorders.

RESULTS

Cannabis outcomes increased more among those with psychiatric disorders. The difference in prevalence differences included any past-year non-medical cannabis use, 2.45% (95%CI = 1.29-3.62); frequent non-medical cannabis use, 1.58% (95%CI = 0.83-2.33); CUD, 1.40% (95%CI = 0.58-2.21). For most specific disorders, prevalences increased more among those with the disorder.

CONCLUSIONS

In the U.S. general population, rates of cannabis use and CUD increased more among adults with psychiatric disorders than other adults, similar to findings from VA patient samples. Results suggest that although VA patients are not representative of all U.S. adults, findings from this important patient group can be informative. Greater clinical and policy attention to CUD is warranted for adults with psychiatric disorders.

Event-level associations among THC, CBD, social context, and subjective effects during Cannabis use episodes

BACKGROUND

Limited research considers the quantity and potency of cannabis products along with social context on the subjective effects of real-world cannabis use.

AIMS

This study examined the subjective effects of acute use as a function of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) doses and social context during cannabis use episodes.

METHOD

Ninety-six participants (43.75% male, Mage = 35.73) reporting weekly cannabis use completed a baseline self-report battery assessing cannabis use. Then, THC and CBD potency and quantity of the cannabis product, social context, and subjective experience were assessed through self-initiated surveys after cannabis use episodes during a 14-day ecological momentary assessment (EMA).

RESULTS

Greater feeling high and liking were significantly associated with a higher THC dose than one's average (b = 0.03, p < 0.001; b = 0.02, p < 0.001) and social use (b = 0.38, p < 0.001; b = 0.20, p = 0.01). A higher CBD dose than one's average (b = 0.01, p = 0.04) was significantly associated with greater liking. A significant interaction effect of THC dose and social context (b = 0.01, p = 0.02) was observed such that solitary use had a negative association between THC dose and disliking (b = -0.01, p = 0.04), and social use had a null association (b = 0.003, p = 0.25). Individuals with greater cannabis problems reported lower liking (b = -0.18, p = 0.03) and higher disliking (b = 0.08, p = 0.02), but not feeling high, on average, across the EMA protocol.

CONCLUSION

Social context plays an important role in the subjective experience of cannabis use. Interventions targeting cannabis problems could highlight the evidence that individuals with greater cannabis problems might experience less liking but more disliking in general across use episodes to effectively challenge expectancies/motives of use.

Conceptualizing problematic use of medicinal Cannabis: Development and preliminary validation of a brief screening questionnaire

The use of Medicinal Cannabis (MC) for treating chronic pain is increasing, globally, yet the definition of problematic MC use remains unclear. Defining problematic use of cannabis in medical and non-medical contexts may be fundamentally different since individuals prescribed MC often experience physical dependence, which do not necessarily imply pathology. We aimed to conceptualize problematic use of MC and develop a brief questionnaire for identifying and quantifying problematic MC use. Content validation used a broad definition of problematic substance use, adapting and compiling an initial list of 36 items from various sources: (a) screening tools for assessing problematic prescription opioid medication use; (b) screening tools for problematic recreational cannabis use and (c) qualitative interviews with MC patients. 390 American self-identified chronic pain patients holding a MC card rated each item from the initial list on a 5-point frequency scale and filled out questionnaires assessing various clinical outcomes. Following initial item titration, a multi-group measurement invariance comparison strategy, using two external indicators: alcohol-related problems and depression, resulted a final eight-item list that met fit quality in a baseline model, presented excellent internal consistency reliability (α = 0.929), and significantly correlated with anxiety and low quality of life. Items in the final list related predominantly to negative consequences of MC use. Problematic use of MC is characterized by negative physiological, social, emotional and functional consequences. The final eight-item list was named the Medicinal Cannabis Negative Consequences Scale (MCNCS), emerging as a brief measure for problematic MC use and demonstrating preliminary reliability and validity, which could aid clinicians and researchers.

Association of Cannabis Use Reduction With Improved Functional Outcomes: An Exploratory Aggregated Analysis From Seven Cannabis Use Disorder Treatment Trials to Extract Data-Driven Cannabis Reduction Metrics

OBJECTIVE

This exploratory analysis sought to determine whether decreases in cannabis use are associated with improvements in cannabis-related problems and functional outcomes, and if so, what percentage decrease is associated with improvement.

METHODS

Data were aggregated from seven cannabis use disorder treatment trials conducted in the United States (N=920; ages 13 years and older; mean age, 25 years; 30% female, 7% Black, 11% Hispanic/Latinx). Outcome measures included the patient-reported Marijuana Problems Scale (MPS), Health-Related Quality of Life scale (HRQOL), and Pittsburgh Sleep Quality Index and the clinician-rated Clinical Global Impressions (CGI) severity and improvement scales (CGI-S and CGI-I). Generalized estimating equations tested the association between changes in 4-week cannabis use and improvements in functional outcomes. Classification and regression tree (CART) models were developed to determine what reductions in cannabis use could be used as classifiers of improvement.

RESULTS

Decreases in the amount and frequency of cannabis use were significantly associated with improvements in MPS severity and total scores as well as improvements on the CGI-I and in sleep quality, but not improvements on the HRQOL. CART models performed best for CGI-I scores (72%-75% correct classification), while other outcome measures did not perform as well (40%-62% correct classification). CART models showed improvements on the CGI at 74% reduction in use amounts and 47% reduction in use days.

CONCLUSIONS

Reductions in cannabis use (∼50% reduction in use days and ∼75% reduction in use amounts) were associated with clinician-assessed improvement, which suggests that cannabis use reduction may yield benefit among individuals with cannabis use disorder. These exploratory results extract a data-driven metric to inform future studies, clinicians, patients, and policy recommendations.

Abnormal developmental of hippocampal subfields and amygdalar subnuclei volumes in young adults with heavy cannabis use: A three-year longitudinal study

BACKGROUND

Differences in the volumes of the hippocampus and amygdala have consistently been observed between young adults with heavy cannabis use relative to their non-using counterparts. However, it remains unclear whether the subfields of these functionally and structurally heterogenous regions exhibit similar patterns of change in young adults with long-term heavy cannabis use disorder (CUD).

OBJECTIVES

This study aims to investigate the effects of long-term heavy cannabis use in young adults on the subregional structures of the hippocampus and amygdala, as well as their longitudinal alterations.

METHODS

The study sample comprised 20 young adults with heavy cannabis use and 22 matched non-cannabis using healthy volunteers. All participants completed the Cannabis Use Disorder Identification Test (CUDIT) and underwent two T1-structural magnetic resonance imaging (MRI) scans, one at baseline and another at follow-up 3 years later. The amygdala, hippocampus, and their subregions were segmented on T1-weighted anatomical MRI scans, using a previously validated procedure.

RESULTS

At baseline, young adults with heavy CUD exhibited significantly larger volumes in several hippocampal (bilateral presubiculum, subiculum, Cornu Ammonis (CA) regions CA1, CA2-CA3, and right CA4-Dentate Gyrus (DG)) and amygdala (bilateral paralaminar nuclei, right medial nucleus, and right lateral nucleus) subregions compared to healthy controls, but these differences were attenuated at follow-up. Longitudinal analysis revealed an accelerated volumetric decrease in these subregions in young adults with heavy CUD relative to controls. Particularly, compared to healthy controls, significant accelerated volume decreases were observed in the right hippocampal subfields of the parasubiculum, subiculum, and CA4-DG. In the amygdala, similar trends of accelerated volumetric decreases were observed in the left central nucleus, right paralaminar nucleus, right basal nucleus, and right accessory basal nucleus.

CONCLUSIONS

The current findings suggest that long-term heavy cannabis use impacts maturational process of the amygdala and hippocampus, especially in subregions with high concentrations of cannabinoid type 1 receptors (CB1Rs) and involvement in adult neurogenesis.

Cannabis, cannabinoids and health: a review of evidence on risks and medical benefits

The legalization of cannabis for medical and recreational purposes has progressed internationally. Cannabis and cannabinoids are advocated for a plethora of medical indications. An increasing number of medical and nonmedical users regularly consume large doses of delta-9-Tetrahydrocannabinol (THC), the main active component of cannabis. Aim: to summarize the evidence on (1) risks of recreational cannabis use and (2) effectiveness and safety of medicinal cannabis. Findings on recreational use: Cannabis is mostly used to experience its acute rewarding effects. Regular use of high THC products can produce addiction (cannabis use disorder or CUD). Acute consumption of high THC doses (including unintentionally) can cause time-limited mental, gastrointestinal, and cardiovascular problems and motor vehicle accidents. Chronic patterns of cannabis use have been associated with multiple adverse outcomes that are of particular concern among adolescents and young adults, such as, disrupted learning, impaired cognitive performance, reduced educational attainment and an increased risk of CUD, psychosis/schizophrenia, mood and anxiety disorders and suicidal behaviors. There is debate about the extent to which cannabis use is a cause of these adverse outcomes. Physical health risks (e.g., respiratory and cardiovascular, prematurity and restricted fetal growth, hyperemesis syndrome among others) have also been linked with repeated consumption of cannabis with a high THC content. Findings on medical cannabis use: Herbal cannabis, medicines from extracted or synthetized cannabinoids-often used as adjuvants to standard medicines-may produce small to modest benefits. This is primarily the case in treating chronic pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and refractory epilepsy (in the case of cannabidiol, CBD). The evidence is inconclusive on their value in treating mental disorders and other medical conditions. Safety: Cannabis-based medicine is generally well tolerated. There is a risk of mild to moderate adverse effects and CUD.

Prevalence of and trends in current cannabis use among US youth and adults, 2013-2022

Introduction

Cannabis use is increasing due to several factors including the adoption of laws legalizing its use across the United States (US). We examined changes in current cannabis use among US youth and adults and by key sociodemographic groups.

Methods

Using data from the 2013-2022 National Survey on Drug Use and Health (n=543,195), we estimated the prevalence of (2013-2019, 2020, 2021-2022) and trends in (2013-2019, 2021-2022) current (i.e., past 30-day) cannabis use among US youth (aged 12-17) and adults (aged 18+) overall and by age, gender, race and ethnicity, educational attainment, and total annual family income. We also examined sociodemographic factors associated with use from 2013 to 2019, in 2020, and from 2021 to 2022.

Results

Cannabis use increased from 7.59 % to 11.48 % in 2013-2019, was 11.54 % in 2020, and increased again from 13.13 % to 15.11 % in 2021-2022. Among youth, cannabis use remained constant from 2013 to 2019 and 2021-2022. In 2022, use was highest among aged 18-34, male, non-Hispanic multiracial, and generally lower SES adults. From 2021-2022, cannabis use increased among several groups such as adults who were aged 35-49 (14.25-17.23 %), female (11.21-13.00 %), and Hispanic (10.42-13.50 %). Adults who were aged 18-25, male, non-Hispanic multiracial, some college educated, and of lower annual family income had consistently higher odds of current cannabis use from 2013 to 2019, in 2020, and from 2021 to 2022.

Conclusions

Cannabis use is increasing overall and among certain sociodemographic groups. Our findings inform prevention and harm reduction efforts aimed at mitigating the prevalence of cannabis use in the US.

A Bivariate Twin Study of Lifetime cannabis Initiation and Lifetime Regular Tobacco Smoking Across Three Different Countries

Regular cigarette smoking and cannabis consumption are strongly positively related to each other, yet few studies explore their underlying variation and covariation. We evaluated the genetic and environmental decomposition of variance and covariance of these two traits in twin data from three countries with different social norms and legislation. Data from the Netherlands Twin Register, FinnTwin12/16, and the Minnesota Center for Twin Family Research (total N = 21,617) were analyzed in bivariate threshold models of lifetime regular smoking initiation (RSI) and lifetime cannabis initiation (CI). We ran unstratified models and models stratified by sex and country. Prevalence of RSI was lowest in the Netherlands and prevalence of CI was highest in Minnesota. In the unstratified model, genetic (A) and common environmental factors (C) contributed substantially to the liabilities of RSI (A = 0.47, C = 0.34) and CI (A = 0.28, C = 0.51). The two liabilities were significantly phenotypically (rP = 0.56), genetically (rA = 0.74), and environmentally correlated in the unstratified model (rC = 0.47and rE = 0.48, representing correlations between common and unique environmental factors). The magnitude of phenotypic correlation between liabilities varied by country but not sex (Minnesota rP ~ 0.70, Netherlands rP ~ 0.59, Finland rP ~ 0.45). Comparisons of decomposed correlations could not be reliably tested in the stratified models. The prevalence and association of RSI and CI vary by sex and country. These two behaviors are correlated because there is genetic and environmental overlap between their underlying latent liabilities. There is heterogeneity in the genetic architecture of these traits across country.

An examination of cannabis use motives among couples with intimate partner violence and alcohol use disorder

BACKGROUND AND OBJECTIVES

Cannabis use is highly prevalent among individuals with a history of intimate partner violence (IPV) and among people who drink alcohol. Motives for cannabis use are important correlates of consumption and problem severity. However, no research has examined cannabis use motives among couples with IPV. The goals of the study were to examine (1) the associations between a person and their partner's cannabis use motives; and (2) examine the extent to which each partners' cannabis use motives are related to their own and their partner's cannabis consumption.

METHODS

Participants were 100 couples (n = 92 different-sex couples, n = 8 same-sex couples) who reported physical IPV in their current relationship.

RESULTS

Certain cannabis motives (coping and conformity) and behaviors (cannabis use frequency, quantity and drug-related problems) were positively associated between intimate partners. One's own higher coping motives were associated with greater frequency of cannabis consumption; higher conformity motives were associated with less quantity of consumption; higher social motives were associated with greater quantity of cannabis consumption; and one's partner's social motives were associated with less quantity of cannabis consumption. DISCUSSION AND CONCLUSIONS: Findings suggest that couples report similar motives for cannabis use, and that one's own and their partner's motives may differentially influence frequency and quantity of use.

SCIENTIFIC SIGNIFICANCE

This study provides novel information on congruency between cannabis use motives and behaviors between intimate partners, as well as how both an individual and their partner's motives for use can influence an individual's cannabis use behaviors.

Association of semaglutide with reduced incidence and relapse of cannabis use disorder in real-world populations: a retrospective cohort study

Cannabis is the most frequently used illicit drug in the United States with more than 45 million users of whom one-third suffer from a cannabis use disorder (CUD). Despite its high prevalence, there are currently no FDA-approved medications for CUD. Patients treated with semaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA) approved for treating type 2 diabetes (T2D) and for weight management have reported reduced desire to drink and smoke. Preclinical studies have shown that semaglutide decreased nicotine and alcohol consumption. Preclinical and preliminary clinical evidence of semaglutide's potential beneficial effects on various substance use disorders led us to evaluate if it pertained to CUD. In this retrospective cohort study of electronic health records (EHRs) from the TriNetX Analytics Network, a global federated health research network of approximately 105.3 million patients from 61 large healthcare organizations in the US, we aimed to assess the associations of semaglutide with both incident and recurrent CUD diagnosis compared to non-GLP-1RA anti-obesity or anti-diabetes medications. Hazard ratio (HR) and 95% confidence intervals (CI) of incident and recurrent CUD were calculated for 12-month follow-up by comparing propensity-score matched patient cohorts. The study population included 85,223 patients with obesity who were prescribed semaglutide or non-GLP-1RA anti-obesity medications, with the findings replicated in 596,045 patients with T2D. In patients with obesity (mean age 51.3 years, 65.6% women), semaglutide compared with non-GLP-1RA anti-obesity medications was associated with lower risk for incident CUD in patients with no prior history CUD (HR: 0.56, 95% CI: 0.42-0.75), and recurrent CUD diagnosis in patients with a prior history CUD (HR: 0.62, 95% CI: 0.46-0.84). Consistent reductions were seen for patients stratified by gender, age group, race and in patients with and without T2D. Similar findings were replicated in the study population with T2D when comparing semaglutide with non-GLP-1RA anti-diabetes medications for incident CUD (HR: 0.40, 95% CI: 0.29-0.56) and recurrent CUD (HR: 0.66, 95% CI: 0.42-1.03). While these findings provide preliminary evidence of the potential benefit of semaglutide in CUD in real-world populations, further preclinical studies are warranted to understand the underlying mechanism and randomized clinical trials are needed to support its use clinically for CUD.

The influence of drug class on reward in substance use disorders

In the United States, the societal costs associated with drug use surpass $500 billion annually. The rewarding and reinforcing properties that drive the use of these addictive substances are typically examined concerning the neurobiological effects responsible for their abuse potential. In this review, terms such as "abuse potential," "drug," and "addictive properties" are used due to their relevance to the methodological, theoretical, and conceptual framework for understanding the phenomenon of drug-taking behavior and the associated body of preclinical and clinical literature. The use of these terms is not intended to cast aspersions on individuals with substance use disorders (SUD). Understanding what motivates substance use has been a focus of SUD research for decades. Much of this corpus of work has focused on the shared effects of each drug class to increase dopaminergic transmission within the central reward pathways of the brain, or the "reward center." However, the precise influence of each drug class on dopamine signaling, and the extent thereof, differs considerably. Furthermore, the aforementioned substances have effects on several neurobiological targets that mediate and modulate their addictive properties. The current manuscript sought to review the influence of drug class on the rewarding effects of each of the major pharmacological classes of addictive drugs (i.e., psychostimulants, opioids, nicotine, alcohol, and cannabinoids). Our review suggests that even subtle differences in drug effects can result in significant variability in the subjective experience of the drug, altering rewarding and other reinforcing effects. Additionally, this review will argue that reward (i.e., the attractive and motivational property of a stimulus) alone is not sufficient to explain the abuse liability of these substances. Instead, abuse potential is best examined as a function of both positive and negative reinforcing drug effects (i.e., stimuli that the subject will work to attain and stimuli that the subject will work to end or avoid, respectively). Though reward is central to drug use, the factors that motivate and maintain drug taking are varied and complex, with much to be elucidated.

Latent Trajectories of Persistence of Cannabis Use Across Four Decades in 329 Men From the San Diego Prospective Study

OBJECTIVE

These analyses use data from a 40-year prospective study to extend information into the sixth and seventh decades of life regarding latent trajectory classes of cannabis use and predictors of those classes.

METHOD

Data from the San Diego Prospective Study were analyzed for 329 men of European and Hispanic ethnicity who had used cannabis at about age 23 at study entry (Time 1) and who were interviewed about every 5 years through about age 60 to 70. Latent classes of cannabis use trajectories were evaluated using latent class growth analyses, baseline predictors of class membership were determined, and significant predictors of each class were established using logistic regression analyses.

RESULTS

Four latent classes were identified ranging from 12.5% with cannabis use at every follow-up to 25.8% with no use after Time 1. Eight of 14 Time 1 predictors differed significantly across the trajectory classes, including five (age, marital status, religious identity, intensity of cannabis use, and sensation seeking) that significantly contributed to regression analyses when all significant predictors were considered together.

DISCUSSION

Forty-two percent of participants continued using cannabis long-term, including one in eight who used it at every follow-up. Predictors of continued use and identification of those most likely to stop required gathering information on a range of demographic, prior substance use, and personality characteristics.

CONCLUSIONS

Considering the potential enhanced dangers of cannabis use in later life, the high rate of continued use over four decades implies that clinicians should ask all older patients about recent cannabis use, especially if they had used it in their 20s.

Randomized Laboratory Study of Single-Dose Cannabis, Dronabinol, and Placebo in Patients With Schizophrenia and Cannabis Use Disorder

BACKGROUND AND HYPOTHESIS

Up to 43% of people with schizophrenia have a lifetime cannabis use disorder (CUD). Tetrahydrocannabinol (THC) has been shown to exacerbate psychosis in a dose-dependent manner, but little research has assessed its effects on schizophrenia and co-occurring CUD (SCZ-CUD). In this double-dummy, placebo-controlled trial (total n = 130), we hypothesized that a modest dose of THC would worsen cognitive function but not psychosis.

STUDY DESIGN

Effects of single-dose oral THC (15 mg dronabinol) or smoked 3.5% THC cigarettes vs placebo in SCZ-CUD or CUD-only on positive and negative symptoms of schizophrenia (only for SCZ-CUD), cognition, and drug experiences assessed several hours after drug administration. SCZ-only and healthy control participants were also assessed.

STUDY RESULTS

Drug liking was higher in THC groups vs placebo. Neither smoked THC nor oral dronabinol predicted positive or negative symptom subscale scores 2 and 5 h, respectively, after drug exposure in SCZ-CUD participants. The oral dronabinol SCZ-CUD group, but not smoked THC SCZ-CUD group, performed worse than placebo on verbal learning (B = -9.89; 95% CI: -16.06, -3.18; P = .004) and attention (B = -0.61; 95% CI: -1.00, -0.23; P = .002). Every 10-point increment in serum THC + THCC ng/ml was associated with increased negative symptoms (0.40 points; 95% CI: 0.15, 0.65; P = .001; subscale ranges 7-49) and trends were observed for worse positive symptoms and performance in verbal learning, delayed recall, and working memory.

CONCLUSIONS

In people with SCZ-CUD, a modest single dose of oral THC was associated with worse cognitive functioning without symptom exacerbation several hours after administration, and a THC dose-response effect was seen for negative symptoms.

Structure-based identification of a G protein-biased allosteric modulator of cannabinoid receptor CB1

Cannabis sativa is known for its therapeutic benefit in various diseases including pain relief by targeting cannabinoid receptors. The primary component of cannabis, Δ9-tetrahydrocannabinol (THC), and other agonists engage the orthosteric site of CB1, activating both Gi and β-arrestin signaling pathways. The activation of diverse pathways could result in on-target side effects and cannabis addiction, which may hinder therapeutic potential. A significant challenge in pharmacology is the design of a ligand that can modulate specific signaling of CB1. By leveraging insights from the structure-function selectivity relationship (SFSR), we have identified Gi signaling-biased agonist-allosteric modulators (ago-BAMs). Further, two cryoelectron microscopy (cryo-EM) structures reveal the binding mode of ago-BAM at the extrahelical allosteric site of CB1. Combining mutagenesis and pharmacological studies, we elucidated the detailed mechanism of ago-BAM-mediated biased signaling. Notably, ago-BAM CB-05 demonstrated analgesic efficacy with fewer side effects, minimal drug toxicity and no cannabis addiction in mouse pain models. In summary, our finding not only suggests that ago-BAMs of CB1 provide a potential nonopioid strategy for pain management but also sheds light on BAM identification for GPCRs.

Cannabis Use Reported by Patients Receiving Primary Care in a Large Health System

Importance

Despite the changing legal status of cannabis and the potential impact on health, few health systems routinely screen for cannabis use, and data on the epidemiology of cannabis use, and especially medical cannabis use among primary care patients, are limited.

Objective

To describe the prevalence of, factors associated with, and reasons for past-3 month cannabis use reported by primary care patients.

Design, Setting, and Participants

This cross-sectional study used electronic health record data from patients aged 18 years and older who had an annual wellness visit between January 2021 and May 2023 from a primary care clinic within a university-based health system in Los Angeles, California.

Exposures

Factors of interest included age, race and ethnicity, sex, employment status, and neighborhood Area Deprivation Index (ADI).

Main Outcomes and Measures

Cannabis use was assessed using the Alcohol Substance Involvement Screening Test (ASSIST). Patients were also asked about reasons for use, symptoms for which they used cannabis, and mode of use.

Results

Among the 175 734 patients screened, the median (range) age was 47 (18-102) years; 101 657 (58.0%) were female; 25 278 (15.7%) were Asian, 21 971 (13.7%) were Hispanic, and 51 063 (31.7%) were White. Cannabis use was reported by 29 898 (17.0%), with 10 360 (34.7%) having ASSIST scores indicative of moderate to high risk for cannabis use disorder (CUD). Prevalence of cannabis use was higher among male patients than female patients (14 939 [20.0%] vs 14 916 [14.7%]) and younger patients (18-29 years, 7592 [31.0%]; ≥60 years, 4200 [8.5%]), and lower among those who lived in the most disadvantaged neighborhoods (ADI decile 9-10, 189 [13.8%]; ADI decile 1-2, 12 431 [17.4%]). The most common modes of use included edibles (18 201 [61.6%]), smoking (15 256 [51.7%]), and vaporizing (8555 [29.0%]). While 4375 patients who reported using cannabis (15.6%) did so for medical reasons only, 21 986 patients (75.7%) reported using cannabis to manage symptoms including pain (9196 [31.7%]), stress (14 542 [50.2%]), and sleep (16 221 [56.0%]). The median (IQR) number of symptoms managed was 2 (1-4), which was higher among patients who were at moderate to high risk for CUD (4 [2-6] symptoms).

Conclusions and Relevance

In this study, cannabis use and risk of CUD were common, and more than three-quarters of patients who reported any cannabis use reported doing so to manage a health-related symptom. These findings suggest that integration of information regarding cannabis use for symptom management could help provide a crucial point-of-care opportunity for clinicians to understand their patients' risk for CUD.

Exploring the effects of cannabis health warnings on protective health intentions among US adults in legal recreational states

BACKGROUND

As cannabis policy trends toward liberalization, assessing cannabis health warning effects becomes increasingly important. This study investigated underlying mechanisms accounting for the effectiveness of cannabis health warnings on protective health intentions.

METHOD

A sample of 1,095 adults (21+) living in legal recreational US states who reported using cannabis in the past 12 months participated in an online experiment. Participants were randomly assigned to view cannabis health warnings that described risks of impaired driving, mental health, and smoke exposure and varied pictures and text (vs. text-only) attributes in warnings. Outcomes were message reactions (cognitive elaboration, fear, and hope), attitudes and beliefs (perceived severity of cannabis harms and perceived susceptibility to cannabis harms, and perceived response and self-efficacy to prevent cannabis harms), and protective health intentions (information-seeking about cannabis health effects and having interpersonal discussions about cannabis harms with family, friends, and medical professionals).

RESULTS

MANCOVA results showed no significant differences between text-only vs. pictorial attributes on protective health intentions; thus, warning conditions were controlled and analyzed using structural equation modeling (SEM). SEM results showed that attention to cannabis health warnings (text-only or pictorial) elicited higher cognitive elaboration, fear, and hope-an emotion associated with coping actions that motivate positive expectations of future events. These outcomes, in turn, were associated with greater perceived severity and susceptibility and greater perceived response efficacy, respectively. Hope, perceived severity, and perceived response and self-efficacy were independently associated with greater intentions to seek information about cannabis health effects and to discuss cannabis health harms.

CONCLUSION

Attention to warnings impacted emotions, attitudes, and protective health intentions. Fear is commonly associated with health warning effects, and our results suggest that hope is also an important factor. This research contributes to understanding the effects of cannabis health warnings and can inform regulatory agencies that mandate warnings on cannabis products.

The effects of simultaneous alcohol and cannabis use on subjective drug effects: A narrative review across methodologies

Over 75% of young adults who use cannabis also report drinking alcohol, leading to increased risks that include impaired cognition, substance use disorders, and more heavy and frequent substance use. Studies suggest that subjective responses to either alcohol or cannabis can serve as a valuable indicator for identifying individuals at risk of prolonged substance use and use disorder. While laboratory studies show additive effects when alcohol and cannabis are used together, the impact of co-using these substances, specifically with respect to cannabidiol, on an individual's subjective experience remains unclear. This narrative review explores the effects of simultaneous alcohol and cannabis (SAM) use on subjective drug effects, drawing from qualitative research, laboratory experiments, and naturalistic studies. Experimental findings are inconsistent regarding the combined effects of alcohol and cannabis, likely influenced by factors such as dosage, method of administration, and individual substance use histories. Similarly, findings from qualitative and naturalistic studies are mixed regarding subjective drug effects following SAM use. These discrepancies may be due to recall biases, variations in assessment methods, and the measurement in real-world contexts of patterns of SAM use and related experiences. Overall, this narrative review highlights the need for more comprehensive research to understand more fully subjective drug effects of SAM use in diverse populations and settings, emphasizing the importance of frequent and nuanced assessment of SAM use and subjective responses in naturalistic settings.

Cannabidiol Exposure During Rat Pregnancy Leads to Labyrinth-Specific Vascular Defects in the Placenta and Reduced Fetal Growth

Introduction: Cannabis use is increasing among pregnant people, and cannabidiol (CBD), a constituent of cannabis, is often perceived as "natural" and "safe" as it is non-intoxicating. In utero, cannabis exposure is associated with negative health outcomes, including fetal growth restriction (FGR). The placenta supplies oxygen and nutrients to the fetus, and alterations in placental development can lead to FGR. While there has been some investigation into the effects of Δ9-THC, there has been limited investigation into the impacts of in utero gestational CBD exposure on the placenta. Methods: This study used histological and transcriptomic analysis of embryonic day (E)19.5 rat placentas from vehicle and CBD (3 mg/kg intraperitoneal injection) exposed pregnancies (E6.5-18.5). Results: The study revealed that pups from CBD-exposed pregnancies were 10% smaller, with the placentae displaying a decreased fetal blood space perimeter-to-area ratio. The transcriptomic analysis supported compromised angiogenesis and blood vessel formation with downregulated biological processes, including tube morphogenesis, angiogenesis, blood vessel morphogenesis, blood vessel development and vasculature development. Further, the CBD-exposed placentas displayed changed expression of glucose transporters (decreased GLUT1 and GR expression and increased GLUT3 expression). Transcriptomic analysis further revealed upregulated biological processes associated with metabolism. Finally, histological and transcriptomic analysis revealed altered cell populations within the placenta, specifically to syncytiotrophoblast layer II and endothelial cells. Conclusion: Together these results suggest that the structural changes in CDB-exposed placentae, including the altered expression of nutrient transporters and the changes to the placental fetal vasculature, may underlie the reduced fetal growth.

Trends in Adolescent Comorbid Cannabis Use Disorder and Postoperative Complications

BACKGROUND

Increasing legalization and widespread misinformation about the dangers of cannabis use have contributed to the rising prevalence of cannabis use disorder (CUD) among adolescents. Our objective was to determine the prevalence of CUD in adolescent surgical patients and evaluate its association with postoperative complications.

METHODS

We performed a retrospective, 1:1 propensity-matched cohort study of adolescents (aged 10-17 years) with and without CUD who underwent inpatient operations at US hospitals participating in the Pediatric Health Information System from 2009 to 2022. The primary outcome was the trend in prevalence of CUD. Secondary outcomes included postoperative complications. Using a Bonferroni correction, we considered a P value < .008 to be significant.

RESULTS

Of 558 721 adolescents undergoing inpatient surgery from 2009 to 2022, 2604 (0.5%) were diagnosed with CUD (2483 were propensity matched). The prevalence of CUD increased from 0.4% in 2009 to 0.6% in 2022 (P < .001). The adjusted odds of respiratory complications, ICU admission, mechanical ventilation, and extended hospital stay were significantly higher in adolescents with CUD (respiratory complications: odds ratio [OR], 1.52; 95% confidence interval [CI], 1.16-2.00; P = .002; ICU admission: OR, 1.78; 95% CI, 1.61-1.98; P < .001; mechanical ventilation: OR, 2.41; 95% CI, 2.10-2.77; P < .001; extended hospital stay: OR, 1.96; 95% CI, 1.74-2.20; P < .001). The propensity score-adjusted odds of postoperative mortality or stroke for adolescents with CUD were not significantly increased (mortality: OR, 1.40; 95% CI, 0.87-2.25; P = .168; stroke: OR, 2.46; 95% CI, 1.13-5.36; P = .024).

CONCLUSIONS

CUD is increasing among adolescents scheduled for surgery. Given its association with postoperative complications, it is crucial to screen adolescents for cannabis use to allow timely counseling and perioperative risk mitigation.

Warning Labels as a Public Health Intervention: Effects and Challenges for Tobacco, Cannabis, and Opioid Medications

Warning labels help consumers understand product risks, enabling informed decisions. Since the 1966 introduction of cigarette warning labels in the United States, research has determined the most effective message content (health effects information) and format (brand-free packaging with pictures). However, new challenges have emerged. This article reviews the current state of tobacco warning labels in the United States, where legal battles have stalled pictorial cigarette warnings and new products such as electronic cigarettes and synthetic nicotine products pose unknown health risks. This article describes the emerging research on cannabis warnings; as more places legalize recreational cannabis, they are adopting lessons from tobacco warnings. However, its uncertain legal status and widespread underestimation of harms impede strict warning standards. The article also reviews opioid medication warning labels, suggesting that lessons from tobacco could help in the development of effective and culturally appropriate FDA-compliant opioid warning labels that promote safe medication use and increased co-dispensing of naloxone.

Cannabis Use Characteristics Associated with Self-Reported Cognitive Function in a Nationally Representative U.S. sample

BACKGROUND

With increases in cannabis use and potency, there is a need to improve our understanding of the impact of use on cognitive function. Previous research indicates long-term cannabis use may have a negative effect on executive function. Few studies have examined persistence of it in protracted abstinence, and there is limited evidence of predictors of worse cognitive function in current and former users. In this study, we aim to evaluate the associations between cannabis use status (current, former, and never use) and self-report cognition. Further, we investigate if cannabis use characteristics predict self-report cognitive function.

METHODS

Cross-sectional cannabis use data from the National Epidemiological Survey on Alcohol and Related Conditions-III (NESARC-III), a national survey (N = 36,309) conducted in the USA between 2012 and 2013 were used alongside the Executive Function Index scales. The data were analyzed by using Ordinary Least Squares regression.

RESULTS

Current (N = 3,681, Female = 37.7%) and former users (N = 7,448, Female = 45.4%) reported poorer cognition than never users (N = 24,956, Female = 56.6%). Self-reported cognition of former users was in-between that of current and never users. Several cannabis use characteristics were associated with self-reported cognition in current and former users.

CONCLUSION

While prospective studies are required to confirm, findings suggest cannabis use is linked to worse cognition. There may be some limited recovery of cognition in former users and some cannabis use characteristics predict impairment. These findings add to our understanding of the cognitive impact of cannabis use. As worse cognitive function may impact relapse, findings have implications for personalization of cannabis use disorder treatment.

"Everything is kind of the same except my mind is with me": exploring cannabis substitution in a sample of adults in early recovery from an opioid or stimulant addiction

BACKGROUND

Recovery from addiction is frequently equated with abstinence. However, some individuals who resolve an addiction continue to use substances, including via substitution (i.e., increased use of one substance after eliminating/ reducing another). Substitution may play a distinct role during early recovery (≤ 1 year), as this period is marked by dramatic change and adjustment. Cannabis is one of the most used substances and is legal for medical and recreational use in an increasing number of states. Consequently, cannabis an increasingly accessible substitute for substances, like fentanyl, heroin, cocaine and methamphetamine, with higher risk profiles (e.g., associated with risk for withdrawal, overdose, and incarceration).

METHODS

Fourteen participants reported that they had resolved a primary opioid or stimulant addiction and subsequently increased their cannabis use within the previous 12 months. Using grounded theory, the interviewer explored their experiences of cannabis use during early recovery. Data were analyzed in three stages: line by line coding for all text related to cannabis use and recovery, focused coding, and axial coding to generate a theory about recovery with cannabis substitution. The motivational model of substance use provided sensitizing concepts.

RESULTS & DISCUSSION

The final sample included eight men and six women ranging in age from 20 to 50 years old. Three participants resolved an addiction to methamphetamine and the remaining 11, an addiction to opioids. Participants explained that cannabis was appealing because of its less harmful profile (e.g., no overdose risk, safe supply, few side effects). Participants' primary motives for cannabis use included mitigation of psychiatric symptoms, withdrawal/ cravings, and boredom. While cannabis was effective toward these ends, participants also reported some negative side effects (e.g., decreased productivity, social anxiety). All participants described typical benefits of recovery (e.g., improved self-concept, better relationships) while continuing to use cannabis. Their experiences with and beliefs about substitution suggest it can be an effective strategy for some individuals during early recovery.

CONCLUSIONS

Cannabis use may benefit some adults who are reducing their opioid or stimulant use, especially during early recovery. The addiction field's focus on abstinence has limited our knowledge about non-abstinent recovery. Longitudinal studies are needed to understand the nature of substitution and its impact on recovery over time.

State cannabis laws and cannabis positivity among fatally injured drivers

BACKGROUND

As of November 8, 2023, 24 states and the District of Columbia have legalized cannabis for both recreational and medical use (RMCL-states), 14 states have legalized cannabis for medical use only (MCL-states) and 12 states have no comprehensive cannabis legislation (NoCL-states). As more states legalize cannabis for recreational use, it is critical to understand the impact of such policies on driving safety.

METHODS

Using the 2019 and 2020 Fatality Analysis Reporting System data, we performed multivariable logistic regression modeling to explore the association between state level legalization status and cannabis positivity using toxicological testing data for 14,079 fatally injured drivers. We performed a sensitivity analysis by including multiply imputed toxicological testing data for the 14,876 eligible drivers with missing toxicological testing data.

RESULTS

Overall, 4702 (33.4%) of the 14,079 fatally injured drivers tested positive for cannabis use. The prevalence of cannabis positivity was 30.7% in NoCL-states, 32.8% in MCL-states, and 38.2% in RMCL-states (p < 0.001). Compared to drivers fatally injured in NoCL-states, the adjusted odds ratios of testing positive for cannabis were 1.09 (95% confidence interval: 0.99, 1.19) for those fatally injured in MCL-states and 1.54 (95% confidence interval: 1.34, 1.77) for those fatally injured in RMCL-states. Sensitivity analysis yielded similar results.

CONCLUSIONS

Over one-third of fatally injured drivers tested positive for cannabis use. Drivers fatally injured in states with laws permitting recreational use of cannabis were significantly more likely to test positive for cannabis use than those in states without such laws. State medical cannabis laws had little impact on the odds of cannabis positivity among fatally injured drivers.

Cannabis use and mood disorders: a systematic review

Background

Problematic cannabis use is highly prevalent among people with mood disorders. This underscores the need to understand the effects of cannabis and cannabinoids in this population, especially considering legalization of recreational cannabis use.

Objectives

We aimed to (1) systematically evaluate cross-sectional and longitudinal studies investigating the interplay between cannabis use, cannabis use disorder (CUD), and the occurrence of mood disorders and symptoms, with a focus on major depressive disorder (MDD) and bipolar disorder (BD) and; (2) examine the effects of cannabis on the prognosis and treatment outcomes of MDD and BD.

Methods

Following PRISMA guidelines, we conducted an extensive search for English-language studies investigating the potential impact of cannabis on the development and prognosis of mood disorders published from inception through November 2023, using EMBASE, PsycINFO, PubMed, and MEDLINE databases.

Results

Our literature search identified 3,262 studies, with 78 meeting inclusion criteria. We found that cannabis use is associated with increased depressive and manic symptoms in the general population in addition to an elevated likelihood of developing MDD and BD. Furthermore, we observed that cannabis use is linked to an unfavorable prognosis in both MDD or BD.

Discussion

Our findings suggest that cannabis use may negatively influence the development, course, and prognosis of MDD and BD. Future well-designed studies, considering type, amount, and frequency of cannabis use while addressing confounding factors, are imperative for a comprehensive understanding of this relationship.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023481634.

Age differences in patterns of cannabis use among an online US sample of adults who consume cannabis frequently

Background: Cannabis use is increasing among middle-aged and older US adults, populations that are particularly vulnerable to the adverse effects of cannabis. Risks for adverse effects differ by cannabis use patterns, which have become increasingly heterogeneous. Nevertheless, little is known about age differences in such patterns.Objective: To investigate age differences in cannabis use patterns, comparing younger (age 18-49), middle-aged (age 50-64), and older adults (age ≥65).Methods: A total of 4,151 US adults with past 7-day cannabis consumption completed an online survey (35.1% male; 60.1% female; 4.8% identified as "other"). Regression models examined age differences in cannabis use patterns.Results: Compared to younger adults, middle-aged and older adults were more likely to consume cannabis during evening hours (50-64: adjusted odds ratio [aOR] = 2.98, 95% CI 2.24-3.96; ≥65: aOR = 4.23, 95 CI 2.82-6.35); by only one method (50-64: aOR = 1.67, 95% CI 1.34-2.09; ≥65: aOR = 3.38, 95 CI 2.24-5.09); primarily by smoking as the only method (50-64: aOR = 1.52, 95% CI 1.29-1.78; ≥65: aOR = 2.12, 95 CI 1.64-2.74); but less likely to consume concentrated cannabis products (concentrates) with extremely high %THC (50-64: aOR = 0.71, 95% CI 0.54-0.93; ≥65: aOR = 0.30, 95 CI 0.16-0.55). Age differences in cannabis use patterns were also observed between middle-aged and older adults.Conclusion: Findings suggest that middle-aged and older adults may engage in less risky cannabis use patterns compared to younger groups (e.g. lower likelihood of consuming highly potent concentrates). However, findings also underscore the importance of recognizing risks unique to these older demographics, such as smoking-related health events. Consequently, prevention strategies targeting such use patterns are needed.

Genome-wide DNA methylation analysis of cannabis use disorder in a veteran cohort enriched for posttraumatic stress disorder

Cannabis use has been increasing over the past decade, not only in the general US population, but particularly among military veterans. With this rise in use has come a concomitant increase in cannabis use disorder (CUD) among veterans. Here, we performed an epigenome-wide association study for lifetime CUD in an Iraq/Afghanistan era veteran cohort enriched for posttraumatic stress disorder (PTSD) comprising 2,310 total subjects (1,109 non-Hispanic black and 1,201 non-Hispanic white). We also investigated CUD interactions with current PTSD status and examined potential indirect effects of DNA methylation (DNAm) on the relationship between CUD and psychiatric diagnoses. Four CpGs were associated with lifetime CUD, even after controlling for the effects of current smoking (AHRR cg05575921, LINC00299 cg23079012, VWA7 cg22112841, and FAM70A cg08760398). Importantly, cg05575921, a CpG strongly linked to smoking, remained associated with lifetime CUD even when restricting the analysis to veterans who reported never smoking cigarettes. Moreover, CUD interacted with current PTSD to affect cg05575921 and cg23079012 such that those with both CUD and PTSD displayed significantly lower DNAm compared to the other groups. Finally, we provide preliminary evidence that AHRR cg05575921 helps explain the association between CUD and any psychiatric diagnoses, specifically mood disorders.

Differential disruption of response alternation by precipitated Δ9-THC withdrawal and subsequent Δ9-THC abstinence in mice

In addition to overt somatic symptoms, cannabinoid withdrawal can also manifest as disruptions in motivation and attention. Experimental animal models using operant-conditioning approaches reveal these differences, in either antagonist-precipitated or spontaneous withdrawal models. However, these processes have yet to be characterized in the same subjects simultaneously. To differentiate between motivational and attentional processes disrupted in cannabinoid withdrawal, the current study used a response alternation task in which a fixed-ratio (FR) schedule repeatedly alternated between two spatially distinct response options throughout daily training sessions. This task yielded traditional measures of motivation (e.g., response latency) as well as attention (e.g., responses to the incorrect side). After two weeks of training, male and female C57BL/6 J mice either received vehicle or Δ9-THC (10 mg/kg, s.c.) twice daily for 5 days. On the 6th day, all mice received their final injection of vehicle or Δ9-THC followed 30 min later by injection of the CB1 receptor selective inverse agonist rimonabant (2 mg/kg, i.p.) to precipitate withdrawal. Testing continued for 3 days post-rimonabant to assess how THC abstinence impacted task performance. Whereas rimonabant decreased response rates to equal degrees in THC-treated and vehicle-treated mice, THC-treated mice showed longer session times, longer response latencies, and more errors per reinforcer. Only THC-treated mice showed a longer latency to switch after committing an error reflecting that precipitated withdrawal impacted measures of both motivation and attention. During the 3-day abstinence window, performance of vehicle-treated mice returned to baseline, but THC-treated mice continued to show disruptions in motivational measures. Importantly, attentional measures (errors and latency to switch after an error) were unaffected by THC abstinence. These data suggest that precipitated and "spontaneous" cannabinoid withdrawal may be qualitatively and quantitatively distinct withdrawal conditions with precipitated withdrawal disrupting both attentional and motivational processes, while abstinence may only affect motivation.

Adjuvant Novel Nanocarrier-Based Targeted Therapy for Lung Cancer

Lung cancer has the lowest survival rate due to its late-stage diagnosis, poor prognosis, and intra-tumoral heterogeneity. These factors decrease the effectiveness of treatment. They release chemokines and cytokines from the tumor microenvironment (TME). To improve the effectiveness of treatment, researchers emphasize personalized adjuvant therapies along with conventional ones. Targeted chemotherapeutic drug delivery systems and specific pathway-blocking agents using nanocarriers are a few of them. This study explored the nanocarrier roles and strategies to improve the treatment profile's effectiveness by striving for TME. A biofunctionalized nanocarrier stimulates biosystem interaction, cellular uptake, immune system escape, and vascular changes for penetration into the TME. Inorganic metal compounds scavenge reactive oxygen species (ROS) through their photothermal effect. Stroma, hypoxia, pH, and immunity-modulating agents conjugated or modified nanocarriers co-administered with pathway-blocking or condition-modulating agents can regulate extracellular matrix (ECM), Cancer-associated fibroblasts (CAF),Tyro3, Axl, and Mertk receptors (TAM) regulation, regulatory T-cell (Treg) inhibition, and myeloid-derived suppressor cells (MDSC) inhibition. Again, biomimetic conjugation or the surface modification of nanocarriers using ligands can enhance active targeting efficacy by bypassing the TME. A carrier system with biofunctionalized inorganic metal compounds and organic compound complex-loaded drugs is convenient for NSCLC-targeted therapy.

Cannabinoid hyperemesis syndrome: prevalence and management in an era of cannabis legalization

As more states legalize cannabinoid products for recreational use and medicinal purposes, the prevalence of cannabinoid hyperemesis syndrome has become increasingly common. Yet, it remains unrecognized to many healthcare providers along with the most efficacious treatments. Cannabinoid hyperemesis syndrome most often presents with episodic vomiting secondary to chronic daily cannabis use over several months to years. Patients often complain of nausea and abdominal pain that is improved by taking hot showers or baths. Symptoms are alleviated with the cessation of cannabis use over a period of 6-12 months. Treatment for acute attacks often consists of parenteral benzodiazepines in the inpatient setting. Long-term management and prevention of further attacks are aided by tricyclic antidepressants such as amitriptyline with a dose range of 50-200 mg/d. Once a patient is in remission, amitriptyline can be tapered slowly. As cannabis becomes more widely available and accepted in the continental United States, so must education on the diagnosis of cannabinoid hyperemesis syndrome and treatment strategies.

Marijuana-induced ST-elevation myocardial infarction in adolescents and young adults: A case report and comprehensive review of literature

As per the Centers for Disease Control and Prevention (CDC), the incidence of myocardial infarction (MI) is reported to be 805,000 cases annually in the United States (US). Although commonly occurring in elderly individuals with underlying cardiovascular comorbidities or younger generations with familial predispositions serving as risk factors, it is extremely rare for an isolated event to occur in teenagers with a history of marijuana use. In this article, we report a rare case of ST-elevation myocardial infarction (STEMI) in a 19-year-old male with no past medical history that was attributed to marijuana use. This case report and review of literature depict a potential association between marijuana use and STEMI. We also highlight potential clinical implications to aid healthcare professionals in making an early diagnosis and achieving a timely management strategy.

A Systematic Review of the Molecular and Cellular Alterations Induced by Cannabis That May Serve as Risk Factors for Bipolar Disorder

BACKGROUND

Cannabis use is a risk factor of psychiatric illness, such as bipolar disorder type-I (BDI). Indeed, cannabis use strongly influences the onset and clinical course of BDI, although the biological mechanisms underlying this interaction remain unknown. Therefore, we have reviewed the biological mechanisms affected by cannabis use that may trigger BD.

METHODS

A systematic review was carried out of articles in which gene expression was studied in cannabis users or human-derived cells exposed to tetrahydrocannabinol (THC) or cannabidiol (CBD). A second systematic review was then performed to identify articles in which gene expression was studied in BDI samples, highlighting those that described alterations to the same molecular and cellular mechanisms affected by cannabis/THC/CBD.

RESULTS

The initial search identified 82 studies on cannabis and 962 on BDI. After removing duplicates and applying the inclusion/exclusion criteria, 9 studies into cannabis and 228 on BDI were retained. The molecular and cellular mechanisms altered by cannabis use or THC/CBD exposure were then identified, including neural development and function, cytoskeletal function, cell adhesion, mitochondrial biology, inflammatory related pathways, lipid metabolism, the endocannabinoid system, the hypocretin/orexin system, and apoptosis. Alterations to those activities were also described in 19 of 228 focused on BDI.

CONCLUSIONS

The biological mechanisms described in this study may be good candidates to the search for diagnostic biomarkers and therapeutic targets for BDI. Because cannabis use can trigger the onset of BD, further studies would be of interest to determine whether they are involved in the early development of the disorder, prompting early treatment.

Abnormal developmental of structural covariance networks in young adults with heavy cannabis use: a 3-year follow-up study

Heavy cannabis use (HCU) exerts adverse effects on the brain. Structural covariance networks (SCNs) that illustrate coordinated regional maturation patterns are extensively employed to examine abnormalities in brain structure. Nevertheless, the unexplored aspect remains the developmental alterations of SCNs in young adults with HCU for three years, from the baseline (BL) to the 3-year follow-up (FU). These changes demonstrate dynamic development and hold potential as biomarkers. A total of 20 young adults with HCU and 22 matched controls were recruited. All participants underwent magnetic resonance imaging (MRI) scans at both the BL and FU and were evaluated using clinical measures. Both groups used cortical thickness (CT) and cortical surface area (CSA) to construct structural covariance matrices. Subsequently, global and nodal network measures of SCNs were computed based on these matrices. Regarding global network measures, the BL assessment revealed significant deviations in small-worldness and local efficiency of CT and CSA in young adults with HCU compared to controls. However, no significant differences between the two groups were observed at the FU evaluation. Young adults with HCU displayed changes in nodal network measures across various brain regions during the transition from BL to FU. These alterations included abnormal nodal degree, nodal efficiency, and nodal betweenness in widespread areas such as the entorhinal cortex, superior frontal gyrus, and parahippocampal cortex. These findings suggest that the topography of CT and CSA plays a role in the typical structural covariance topology of the brain. Furthermore, these results indicate the effect of HCU on the developmental changes of SCNs in young adults.

Cannabis Use Disorder Is Associated With Longer In-Hospital Lengths of Stay, Higher Rates of Medical Complications, and Costs of Care Following Primary 1- to 2-Level Lumbar Fusion

STUDY DESIGN

Retrospective case-control study.

OBJECTIVES

The purpose of this study is to assess whether cannabis use disorder (CUD) patients undergoing primary 1- to 2-level lumbar fusion (1-2LF) for the treatment of degenerative lumbar spine disorders have higher rates of: (1) in-hospital lengths of stay (LOS), (2) medical complications, and (3) healthcare expenditures.

MATERIALS AND METHODS

A retrospective case-control study of the MSpine dataset of the PearlDiver claims from January 2007 to March 2018 was performed. Patients with CUD undergoing 1-2LF were queried and matched to a comparison group in a 1:5 ratio by age, sex, and various medical comorbidities yielding 22, 815 patients within the study (CUD = 3805; control = 19 010). Outcomes analyzed included LOS, 90-day medical complications, and costs. A P-value less than .004 was considered significant.

RESULTS

This study found CUD patients undergoing primary 1-2LF experience longer in-hospital LOS (4- vs. 3-days, P < .0001). Additionally, CUD patients were found to have significantly higher frequency and odds-ratios (OR) (31.88 vs. 18.01% OR: 1.41, P < .0001) of adverse events within ninety days following their procedure. CUD patients also had significantly higher day of surgery ($18,946.79 vs. $15,691.02, P < .0001) and 90 days healthcare expenditures ($21,469.01 vs. $19,556.71, P < .0001).

CONCLUSION

Patients with CUD can prepare for increased LOS, complications, and costs following primary 1-2LF. The study can be used to educate these patients of the potential outcomes following their procedure.

Perceptions, Attitudes, and Knowledge of Cannabis and its Use: A Qualitative Study among Herbal Heart Study Young Adult Cannabis Consumers in South Florida

Growing cannabis use among young adults in the United States surpasses research and public understanding, raising health concerns despite potential benefits. Limited research focuses on their knowledge, attitudes, risks, and motivations, especially in states with limited legalization. This study explores cannabis knowledge and attitudes among healthy young adult cannabis consumers to understand their risk and benefit perceptions. Data include a subsample of participants in the Herbal Heart Study, a cohort to examine subclinical cardiovascular risk among healthy young adult (18-35 years old) cannabis consumers and non-consumers. A qualitative thematic analysis of the interviews was performed using a deductive approach driven by the theory of the Health Belief Model to generate categories and codes. Dedoose was used to organize transcripts and coding. A total of 22 young adult cannabis consumers (M age = 25.3, SD = 4.4) were interviewed between May 5, 2021- September 23, 2022. Participants were predominantly female (n = 13) and Hispanic (n = 9) or non-Hispanic Black (n = 7). Five themes were identified: perceived health benefits and risks associated with cannabis use, motivation for cannabis use, knowledge of cannabis, and perceived barriers to cannabis use. Participants discussed knowledge, positive/negative attitudes toward cannabis, and perceived risks/benefits based on personal experience and gathered information. Some showed knowledge deficits, and most wanted more health-related cannabis research. Given the current climate of rising cannabis legalization, availability of novel cannabis products, and societal acceptance, further research and evidence-based cannabis literacy for young adults are essential to keep pace with liberalization trends.

A systematic review of cannabis health warning research

Background

Cannabis legalization provides an opportunity to communicate with consumers through mandated health warnings on cannabis packaging. However, research on cannabis health warnings is a nascent field. Therefore, a review is needed to synthesize cannabis health warning research and inform ongoing policy discussions.

Methods

This paper used systematic review guidelines to search online databases, including PubMed Central, Scopus, Web of Science, Jstor, Communication and Mass Media Complete, Medline, PsycINFO, and Google Scholar. Search strings combined the terms "cannabis" or "marijuana" with "health warning" or "health warning message" or "warning label" or "health warning label" or "health information label." Results were synthesized narratively.

Results

The search identified 90 research articles. After screening, 17 studies on the impact of cannabis health warnings were retained. Retained studies focused on the hypothetical effects of cannabis health warnings (n = 11; 64.7 %) and "real world" effects of implementing warnings post-legalization (n = 6; 35.3 %). Evidence indicated mandated cannabis health warnings improved noticing and recall of health warning content. Cannabis health warnings describing risks of addiction were consistently rated the least effective. Pictorial cannabis health warnings generally outperformed text-only warnings when displayed on their own, while experiments with warnings on products had mixed results. Cannabis health warnings decreased product appeal, mainly when package branding was minimized.

Conclusions

Health warnings on cannabis packaging are an important strategy to communicate risk to consumers. Mandating warnings increased notice, recall, and health knowledge. Warnings with pictures and describing specific risks were most effective, as was showing warnings without product branding.

Cannabis use and social anxiety disorder in emerging adulthood: Results from a nationally representative sample

Cannabis use and social anxiety disorder (SAD) are prevalent during emerging adulthood. Previous work has demonstrated that SAD is related to cannabis use in adults; however, less is known about what correlates relate to this association in emerging adults. A subsample of individuals ages 18-25 years old from the NESARC-III (N = 5194) was used to (a) evaluate the association between cannabis use and SAD and (b) examine what correlates may be associated with cannabis use and SAD in emerging adulthood. Weighted cross-tabulations assessed sociodemographics and lifetime psychiatric disorder prevalence estimates among the emerging adult sample. Multinomial logistic regressions examined associations between sociodemographics and psychiatric disorders and four groups (i.e., no cannabis use or SAD; cannabis use only; SAD only; cannabis use + SAD). The prevalence of co-occurring cannabis use and SAD was 1.10%. Being White, a part-time student, or not a student were associated with increased odds of having co-occurring cannabis use + SAD (OR range: 2.26-3.09). Significant associations also emerged between major depressive disorder, bipolar I disorder, generalized anxiety disorder, specific phobia, agoraphobia, and panic disorder and co-occurring cannabis use + SAD (AOR range: 3.03-19.05). Results of this study may have implications for better identifying and screening emerging adults who are at risk of co-occurring cannabis use and SAD.

Accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking

INTRODUCTION

Cannabis intoxication may increase the risk of motor vehicle crashes. However, reliable methods of assessing cannabis intoxication are limited. The presence of eyelid tremors is among the signs of cannabis use identified under the Drug Evaluation and Classification Program of the International Association of Chiefs of Police. Our objectives were to assess the accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking using a blinded, controlled study design.

METHODS

Adult subjects (N = 103) were recruited into three groups based on their cannabis use history: daily, occasional, and no current cannabis use. Participants' closed eyelids were video recorded for 30 seconds by infrared videography goggles before and at a mean ± standard deviation time of 71.4 ± 4.6 minutes after the onset of a 15-minute interval of ad libitum cannabis flower smoking or vaping. Three observers with expertise in neuro-ophthalmology and medical toxicology were trained on exemplar videos of eyelids to reach a consensus on how to grade eyelid tremor. Without knowledge of subjects' cannabis use history or time point (pre- or post-smoking), observers reviewed each video for eyelid tremor graded as absent, slight, moderate, or severe. During subsequent data analysis, this score was further dichotomized as a consensus score of absent (absent/slight) or present (moderate/severe).

RESULTS

Kappa and intraclass correlation coefficient statistics demonstrated moderate agreement among the coders, which ranged from 0.44-0.45 and 0.58-0.61, respectively. There was no significant association between recent cannabis use and the observers' consensus assessment that eyelid tremor was present, and cannabis users were less likely to have tremors (odds ratio: 0.75; 95 percent confidence interval: 0.25, 2.40). The assessment of eyelid tremor as an indicator of recent cannabis smoking had a sensitivity of 0.86, specificity of 0.18, and accuracy of 0.64.

DISCUSSION

Eyelid tremor has fair sensitivity but poor specificity and accuracy for identification of recent cannabis use. Inter-rater reliability for assessment of eyelid tremor was moderate for the presence and degree of tremor. The weak association between recent cannabis use and eyelid tremor does not support its utility in identifying recent cannabis use.

LIMITATIONS

Videos were recorded at only one time point after cannabis use. Adherence to abstinence could not be strictly supervised. Due to regulatory restrictions, we were unable to control the cannabis product used or administer a fixed Δ9-tetrahydrocannabinol dose. Participants were predominately non-Hispanic and White.

CONCLUSIONS

In a cohort of participants with a range of cannabis use histories, acute cannabis smoking was not associated with the presence of eyelid tremor, regardless of cannabis use history, at 70 minutes post-smoking. Additional research is needed to identify the presence of eyelid tremor accurately, determine the relationship between cannabis dose and timeline in relation to last cannabis use to eyelid tremor, and determine how it should be, if at all, utilized for cannabis Drug Recognition Evaluator examinations.

Associations between Adolescent Marijuana Use, Driving after Marijuana Use and Recreational Retail Sale in Colorado, USA

OBJECTIVE

We investigated associations between the retail distribution of recreational marijuana in Colorado and (i) past 30-day marijuana use and (ii) driving after marijuana use (DAMU) among a representative sample of public high school students using four waves of data from a state surveillance system.

METHODS

Past 30-day marijuana use was assessed among all sampled students (n = 85,336). DAMU was assessed among students 15 years or older who indicated driving (n = 47,518). Modified Poisson regression with robust variance estimates was used to estimate prevalence ratios (PR) comparing the pre-distribution (2013) and post-distribution (2015, 2017, 2019) periods for marijuana-related behaviors. Frequency of behavioral engagement was assessed using a multinomial approach.

RESULTS

An estimated 20.3% of students engaged in past 30-day marijuana use and 10.5% of student drivers engaged in DAMU. Retail distribution of recreational marijuana was not significantly associated with the prevalence of any marijuana use or DAMU. However, it was associated with 1.16 (95% CI: 1.04-1.29) times the prevalence of using marijuana one or two times in the last 30 days, 1.27 (1.03, 1.55) times the prevalence of DAMU one time, and 0.82 (0.69, 0.98) times the prevalence of DAMU six or more times. No significant associations were observed for the remaining frequency categories.

CONCLUSIONS

Approximately 1 in 10 students who drive reported DAMU. Varying prevalence in the frequency of past 30-day marijuana use and DAMU was observed following the retail distribution of recreational marijuana in Colorado. Care should be taken to properly educate adolescent drivers regarding the dangers of DAMU.

"I've smoked weed with my daughter": Cannabis Use within Families Affected by Parental Opioid Misuse

Youth with parents who use opioids are more likely to engage in early substance use, especially cannabis use. The purpose of this study was to describe the context of cannabis use among families affected by parental opioid misuse. We conducted 25 in-depth interviews with families affected by parental opioid misuse. Participants were parents with a history of opioid misuse and young adults (ages 18-24) who had parents with a history of opioid misuse. Interviews were digitally recorded and professionally transcribed. Data were analyzed inductively using a qualitative content analytic approach. Familial cannabis use was common among young people and their parents. Participants described familial cannabis use as a bonding activity that felt safe and lightened the mood. Additional research is needed to understand the complex role that cannabis use may play in families affected by opioid misuse. Strategies for intergenerational substance use prevention are discussed.

The relationship between medical marijuana use and prescription pain reliever use among U.S. adults: A retrospective analysis utilizing the 2015-2019 National Survey on Drug Use and Health (NSDUH)

Background

Despite a number of states in the U.S. enacting medical marijuana policies, there is currently a lack of research outlining the role that individual-level factors play in predicting medical marijuana use, especially regarding use and misuse of prescription pain relievers. The overall aim of this study was to assess the prevalence of medical marijuana use in the U.S. and to identify clinical, social, and demographic predictors.

Methods

A retrospective secondary database analysis was conducted utilizing five years of the National Survey on Drug Use and Health (NSUDH). A multivariable logistic regression model assessed the association between prescription pain reliever use and medical marijuana in the adult U.S. population while adjusting for substance use factors, psychiatric factors, and demographic characteristics.

Results

Within the U.S. adult population from 2015 to 2019, medical marijuana use increased from 1.6% to 2.4%, while appropriate prescription pain reliever use decreased from 33.4% to 27.5%, and prescription pain reliever misuse decreased from 4.7% to 3.7%. Of all marijuana users, 15.1% resided within non-medical marijuana states. Medical marijuana users are more likely to have a serious mental illness (14.0% vs. 4.4%) and a non-marijuana related substance dependence (5.3% vs. 1.2%). Past-year medical marijuana use was significantly more likely to be reported among appropriate users of prescription pain relievers (OR = 1.99, p < .001) and misusers (OR = 1.94, p < .001) (relative to nonusers).

Conclusions

Prescription pain reliever appropriate use and misuse were associated with higher odds of medical marijuana use. This study identified a potential treatment gap among individuals residing in states with no medical marijuana availability. These study findings highlight the potential benefits of medical marijuana legalization that future research can build on to guide policy making decisions.

Cannabis use in context: Relations among impulsive personality traits, context, and cannabis problems

INTRODUCTION

Impulsive personality traits are associated with cannabis problems. Person-Environment Transactions Theory suggests that highly impulsive individuals behave differently in certain contexts, however little research has focused on the context in which cannabis is used. Therefore, the current study tested whether impulsive traits moderated relations between cannabis use contexts (social vs. solitary) and cannabis problems.

METHOD

In this cross-sectional study, college student who use cannabis (N = 435; 60.7% female) reported on their impulsive traits (i.e., negative urgency, positive urgency, premeditation, perseverance, and sensation seeking), typical cannabis use context (i.e., alone, with friends), typical cannabis use frequency, and past 30-day cannabis problems.

RESULTS

Both solitary cannabis use and negative urgency were associated with more cannabis problems. There were significant interactions between negative urgency and solitary cannabis use and lack of perseverance and solitary cannabis use, such that high and mean (but not low) levels of both negative urgency and lack of perseverance were associated with more cannabis problems the more frequently an individual used cannabis alone. There was also a significant interaction between sensation seeking and social cannabis use, such that high and mean (but not low) levels of sensation seeking were associated with cannabis problems for individuals who used cannabis more socially.

CONCLUSIONS

Findings suggest that impulsivity may potentiate risk for cannabis problems depending on the context in which cannabis is used. Prevention efforts may benefit from targeting protective strategy use in certain cannabis use contexts based upon an individual's personality traits.

Health, safety, and socioeconomic impacts of cannabis liberalization laws: An evidence and gap map

Background

Globally, cannabis laws and regulations are rapidly changing. Countries are increasingly permitting access to cannabis under various decriminalization, medicalization, and legalization laws. With strong economic, public health, and social justice incentives driving these domestic cannabis policy reforms, liberalization trends are bound to continue. However, despite a large and growing body of interdisciplinary research addressing the policy-relevant health, safety, and socioeconomic consequences of cannabis liberalization, there is a lack of robust primary and systematic research that comprehensively investigates the consequences of these reforms.

Objectives

This evidence and gap map (EGM) summarizes the empirical evidence on cannabis liberalization policies. Primary objectives were to develop a conceptual framework linking cannabis liberalization policies to relevant outcomes, descriptively summarize the empirical evidence, and identify areas of evidence concentration and gaps.

Search Methods

We comprehensively searched for eligible English-language empirical studies published across 23 academic databases and 11 gray literature sources through August 2020. Additions to the pool of potentially eligible studies from supplemental sources were made through November 2020.

Selection Criteria

The conceptual framework for this EGM draws upon a legal epidemiological perspective highlighting the causal effects of law and policy on population-level outcomes. Eligible interventions include policies that create or expand access to a legal or decriminalized supply of cannabis: comprehensive medical cannabis laws (MCLs), limited medical cannabidiol laws (CBDLs), recreational cannabis laws (RCLs), industrial hemp laws (IHLs), and decriminalization of cultivations laws (DCLs). Eligible outcomes include intermediate responses (i.e., attitudes/behaviors and markets/environments) and longer-term consequences (health, safety, and socioeconomic outcomes) of these laws.

Data Collection and Analysis

Both dual screening and dual data extraction were performed with third person deconfliction. Primary studies were appraised using the Maryland Scientific Methods Scale and systematic reviews were assessed using AMSTAR 2.

Main Results

The EGM includes 447 studies, comprising 438 primary studies and nine systematic reviews. Most research derives from the United States, with little research from other countries. By far, most cannabis liberalization research focuses on the effects of MCLs and RCLs. Studies targeting other laws-including CBDLs, IHLs, and DCLs-are relatively rare. Of the 113 distinct outcomes we documented, cannabis use was the single most frequently investigated. More than half these outcomes were addressed by three or fewer studies, highlighting substantial evidence gaps in the literature. The systematic evidence base is relatively small, comprising just seven completed reviews on cannabis use (3), opioid-related harms (3), and alcohol-related outcomes (1). Moreover, we have limited confidence in the reviews, as five were appraised as minimal quality and two as low quality.

Authors’ Conclusions

More primary and systematic research is needed to better understand the effects of cannabis liberalization laws on longer-term-and arguably more salient-health, safety, and socioeconomic outcomes. Since most research concerns MCLs and RCLs, there is a critical need for research on the societal impacts of industrial hemp production, medical CBD products, and decriminalized cannabis cultivation. Future research should also prioritize understanding the heterogeneous effects of these laws given differences in specific provisions and implementation across jurisdictions.