Subjective and physiological effects, and expired carbon monoxide concentrations in frequent and occasional cannabis smokers following smoked, vaporized, and oral cannabis administration

The effect of cannabis edibles on driving and blood THC

BACKGROUND

Cannabis has been shown to impact driving due to changes produced by delta-9-tetrahydrocannabinol (THC), the psychoactive component of cannabis. Current legal thresholds for blood THC while driving are based predominantly on evidence utilizing smoked cannabis. It is known that levels of THC in blood are lower after eating cannabis as compared to smoking yet the impact of edibles on driving and associated blood THC has never been studied.

METHODS

Participants drove a driving simulator before and after ingesting their preferred legally purchased cannabis edible. In a counterbalanced control session, participants did not consume any THC or cannabidiol (CBD). Blood was collected for measurement of THC and metabolites as well as CBD. Subjective experience was also assessed.

RESULTS

Participants consumed edibles with, on average, 7.3 mg of THC, which is less than the maximum amount available in a single retail package in Ontario, providing an ecologically valid test of cannabis edibles. Compared to control, cannabis edibles produced a decrease in mean speed 2 h after consumption but not at 4 and 6 h. Under dual task conditions in which participants completed a secondary task while driving, changes in speed were not significant after the correction for multiple comparison. No changes in standard deviation of lateral position (SDLP; 'weaving'), maximum speed, standard deviation of speed or reaction time were found at any time point or under either standard or dual task conditions. Mean THC levels were significantly increased, relative to control, after consuming the edible but remained relatively low at approximately 2.8 ng/mL 2 h after consumption. Driving impairment was not correlated with blood THC. Subjective experience was altered for 7 h and participants were less willing/able to drive for up to 6 h, suggesting that the edible was intoxicating.

INTERPRETATION

This is the first study of the impact of cannabis edibles on simulated driving. Edibles were intoxicating as revealed by the results of subjective assessments (VAS), and there was some impact on driving. Detection of driving impairment after the use of cannabis edibles may be difficult.

Canada's THC unit: Applications for the legal cannabis market

The legalization of cannabis in Canada has accelerated the need for a standardized approach to measuring and communicating the amount of delta-9-tetrahydrocannabinol (THC) in cannabis products. This article offers an overview of the considerations associated with establishing and implementing a standard THC unit in the Canadian context. The article begins by discussing the applications of a standard THC unit, emphasizing its potential use in product labelling, consumer education, and product reporting and surveillance. The article then examines key considerations for identifying what a Canadian THC unit should be set at, specifically within the context of a country with a regulated commercial cannabis market. This is followed by a discussion of additional considerations related to the adoption of a Canadian THC unit, including its use across various product formats and modes of administration. A significant focus of this article is on prioritizing public health and safety and informed decision-making among adult consumers as the legal cannabis market evolves. Collaboration among various stakeholders, such as government agencies, industry, and public health professionals, is highlighted as crucial for a successful transition to the use of Canada's THC unit.

Cardiovascular and Respiratory Effects of Cannabis Use by Route of Administration: A Systematic Review

Aim: Knowledge of the cardiovascular and respiratory effects of cannabis use by route of administration is unclear. This evidence is necessary to increase clinical and public health awareness given the recent trend in cannabis legalization, normalization, and surge in the availability and usage of various forms of cannabis products. Methods: Search was conducted in Web of Science, ProQuest, Psych INFO, Scopus, Embase, and Medline databases, and subsequently in the references of retrieved articles. Peer-reviewed articles published between 2009 and 2023, that reported on cardiovascular and respiratory effects of cannabis use by route of administration were included. Studies with no report of the route of administration and combined use of other illicit substances were excluded. The review was guided by Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results: Of the 1873 articles retrieved, 42 met inclusion criteria encompassing six case reports, 21 reviews, and 15 empirical studies. Four administration routes were identified: smoking, vaping, oral ingestion, and dabbing. Smoking was the most common route of administration and was associated with both respiratory effects, such as bronchitis, dyspnea, and chronic obstructive lung disease, and cardiovascular effects including tachycardia, ventricular arrhythmias, and myocardial infarction. Cannabis edibles were associated with minimal respiratory effects. Tachycardia was the most common cardiovascular effect and was associated with all routes of administration. Conclusion: Cannabis use does cause cardiovascular and respiratory effects, but the conclusion remains tentative of the cardiovascular and respiratory effects by route of administration due to methodological limitations of the studies.

Tolerability of High-Dose Oral Δ9-THC: Implications for Human Laboratory Study Design

Background: Δ9-tetrahydrocannabinol (THC), the primary intoxicating compound in cannabis, has been tested extensively in controlled administration human studies. Some studies require a high THC dose that may induce adverse events (AEs), such as those testing novel treatments for cannabinoid overdose. Although there are ethical concerns related to administering high THC doses, there is no systematic analysis on studies utilizing these doses. In this review, we examine studies that administered oral THC doses ≥30 mg ("high-dose THC"), focusing on reported tolerability, subjective effects, and pharmacokinetics (PK), with the objective to inform the design of future studies. Methods: A comprehensive PubMed search was performed to identify studies meeting pre-specified criteria. Results: Our search identified 27 publications from 17 high-dose oral THC laboratory studies, with single doses up to 90 mg and multiple doses up to 210 mg per day. The maximum plasma THC concentration (Cmax) appeared to increase in a dose-proportional manner over this dose range. All high-dose THC studies enrolled participants with previous cannabis experience, although current use ranged from nonusers to regular cannabis users. High-dose THC was generally well tolerated with transient mild to moderate AE, including nausea and vomiting, anxiety, paranoia, and sedation. There were occasional participant withdrawals due to AEs, but there were no serious AE. Participants with frequent cannabis use tolerated high-dose THC best. Conclusion: Although based on limited data, THC was generally adequately tolerated with single oral doses of at least 50 mg in a controlled laboratory setting in healthy participants with past cannabis experience.

Vaporized D-limonene selectively mitigates the acute anxiogenic effects of Δ9-tetrahydrocannabinol in healthy adults who intermittently use cannabis

BACKGROUND

Cannabis contains hundreds of chemical constituents beyond delta-9-tetrahydrocannabinol (THC), which is believed to drive most of its acute pharmacodynamic effects. The entourage effect theory asserts that non-THC constituents can impact acute cannabis effects, but few empirical studies have systematically evaluated this theory in humans. This study assessed whether the cannabis terpenoid d-limonene mitigates the acute anxiogenic effects of THC.

METHODS

Twenty healthy adults completed nine, double-blind outpatient sessions in which they inhaled vaporized THC alone (15mg or 30mg), d-limonene alone (1mg or 5mg), the same doses of THC and d-limonene together, or placebo; a subset of participants (n=12) completed a tenth session in which 30mg THC+15mg d-limonene was administered. Outcomes included subjective drug effects, cognitive/psychomotor performance, vital signs, and plasma THC and d-limonene concentrations.

RESULTS

When d-limonene was administered alone, pharmacodynamic outcomes did not differ from placebo. Administration of 15mg and 30mg THC alone produced subjective, cognitive, and physiological effects typical of acute cannabis exposure. Ratings of anxiety-like subjective effects qualitatively decreased as d-limonene dose increased and concurrent administration of 30mg THC+15mg d-limonene significantly reduced ratings of "anxious/nervous" and "paranoid" compared with 30mg THC alone. Other pharmacodynamic effects were unchanged by d-limonene. D-limonene plasma concentrations were dose orderly, and concurrent administration of d-limonene did not alter THC pharmacokinetics.

CONCLUSIONS

D-limonene selectively attenuated THC-induced anxiogenic effects, suggesting this terpenoid could increase the therapeutic index of THC. Future research should determine whether this effect extends to oral dose formulations and evaluate the interactions between other cannabis terpenoids or cannabinoids and THC.

Amyotrophic Lateral Sclerosis and Pain: A Narrative Review from Pain Assessment to Therapy

Amyotrophic lateral sclerosis (ALS) is the most frequent neurodegenerative disease of the motor system that affects upper and lower motor neurons, leading to progressive muscle weakness, spasticity, atrophy, and respiratory failure, with a life expectancy of 2-5 years after symptom onset. In addition to motor symptoms, patients with ALS have a multitude of nonmotor symptoms; in fact, it is currently considered a multisystem disease. The purpose of our narrative review is to evaluate the different types of pain, the correlation between pain and the disease's stages, the pain assessment tools in ALS patients, and the available therapies focusing above all on the benefits of cannabis use. Pain is an underestimated and undertreated symptom that, in the last few years, has received more attention from research because it has a strong impact on the quality of life of these patients. The prevalence of pain is between 15% and 85% of ALS patients, and the studies on the type and intensity of pain are controversial. The absence of pain assessment tools validated in the ALS population and the dissimilar study designs influence the knowledge of ALS pain and consequently the pharmacological therapy. Several studies suggest that ALS is associated with changes in the endocannabinoid system, and the use of cannabis could slow the disease progression due to its neuroprotective action and act on pain, spasticity, cramps, sialorrhea, and depression. Our research has shown high patients' satisfaction with the use of cannabis for the treatment of spasticity and related pain. However, especially due to the ethical problems and the lack of interest of pharmaceutical companies, further studies are needed to ensure the most appropriate care for ALS patients.

Self-reported knowledge of tetrahydrocannabinol and cannabidiol concentration in cannabis products among cancer patients and survivors

PURPOSE

Cannabis use may introduce risks and/or benefits among people living with cancer, depending on product type, composition, and nature of its use. Patient knowledge of tetrahydrocannabinol (THC) or cannabidiol (CBD) concentration could provide information for providers about cannabis use during and after treatment that may aide in risk and benefit assessments. This study aimed to examine knowledge of THC or CBD concentration among patients living with cancer who consume cannabis, and factors associated with knowledge of cannabinoid concentrations.

METHODS

People living with cancer who consumed cannabis since their diagnosis (n = 343) completed an anonymous, mixed-mode survey. Questions assessed usual mode of delivery (MOD), knowledge of THC/CBD concentration, and how source of acquisition, current cannabis use, and source of instruction are associated with knowledge of THC/CBD concentration. Chi-square and separate binary logistic regression analyses were examined and weighted to reflect the Roswell Park patient population.

RESULTS

Less than 20% of people living with cancer had knowledge of THC and CBD concentration for the cannabis products they consumed across all MOD (smoking- combustible products, vaping- vaporized products (e-cigarettes), edibles-eating or drinking it, and oral- taking by mouth (pills)). Source of acquisition (smoking-AOR:4.6, p < 0.01, vaping-AOR:5.8, p < 0.00, edibles-AOR:2.6, p < 0.04), current cannabis use (edibles-AOR:5.4, p < 0.01, vaping-AOR: 11.2, p < 0.00, and oral-AOR:9.3, p < 0.00), and source of instruction (vaping only AOR:4.2, p < 0.05) were found to be variables associated with higher knowledge of THC concentration.

CONCLUSION

Self-reported knowledge of THC and CBD concentration statistically differed according to MOD, source of acquisition, source of instruction, and current cannabis use.

Stakeholders' Decisions and Preferences for the Provision and Use of Medicinal Cannabis: A Scoping Review

Background: The aim of this scoping review was to examine the extent that stakeholder's decisions about and preferences for the provision and use of medicinal cannabis (MC) had been investigated. We sought to identify which populations were examined, the methods used for eliciting preferences and exploring decisions, and the reported outcomes of studies. Methods: Electronic databases (PubMed, CINAHL, Embase, BSC and PsycINFO) and the reference lists of relevant articles were searched for studies published up to March 2022. Studies were included if stakeholder preferences for MC were (1) the primary focus of the research, or (2) an aspect of a larger preference focus. Studies that (3) described the decisions to use MC were also included. Results: Thirteen studies were reviewed. The population focus of these was primarily patient, with seven studies focused on general patient populations and five studies targeting specific patient populations such as cancer survivors, and people experiencing depression. Methods included health economics preference methods, qualitative interviews, and a single multicriteria decision-making study. Four categories of outcomes were defined and included comparisons of MC with a therapeutic alternative (n=5), preferences for MC attributes (n=5), administration preferences (n=4), and the decision process of users (n=2). Motivation differences in preference were found. Purely medicinal users and novice users place more importance on cannabidiol (CBD) than tetrahydrocannabinol. Overall, inhalation methods of administration were preferred due to quick onset of symptom relief. Price was the greatest influence on choice for recreational/medicinal users, whereas purely medicinal users were less price sensitive for products with higher CBD content. Conclusion: Studies examining public preferences for the provision and use of MC were absent. Revealed preference methods are a useful technique for understanding preferences for characteristics that are difficult to visibly assess such as cannabinoid or strain. The outcomes of symptom-specific multicriteria decision method studies that compare the benefit-safety profiles of commonly used treatments and MC may be a useful decision support tool for health practitioners. Studies with representative samples are needed to understand the impact of age, gender, and race on preferences for MC.

Parallel trajectories of vaping and smoking cannabis and their associations with mental and physical well-being among young adults

BACKGROUND

Vaping and smoking are common modes of using cannabis (THC) among young adults, but little is known about how patterns of cannabis vaping and smoking unfold over time or how using one or both types of products may differently affect mental and physical well-being. This study examines parallel processes of cannabis vaping and smoking over 5 years and mental and physical outcomes in a sample of young adults.

METHODS

Annual surveys were conducted between 2016 and 2022 with a mostly California-based cohort of 2428 young adults. Parallel process growth mixture models examined trajectories of past-month frequency of cannabis vaping and smoking from ages 20 - 25. Classes were extracted based on parallel trajectories of vaped and smoked product use. Models assessed differences in self-reported mental (anxiety, depression) and physical (ailments, subjective overall) well-being outcomes in young adulthood across classes, adjusting for demographic characteristics and mental and physical well-being at pre-baseline (average age 19).

RESULTS

Four cannabis vaping/smoking classes emerged: low use of cannabis (84.7%), decreasing smoking, low-moderate vaping (7.1%), stable moderate smoking, decreasing vaping (4.6%), and rapid increasing dual use (3.4%). Classes were similar on physical well-being indicators in young adulthood. The rapid increasing dual use class showed higher anxiety and depressive symptoms compared to other classes.

CONCLUSION

Progression to higher frequency of both vaping and smoking cannabis in young adulthood may contribute to poorer mental well-being compared to other use patterns. Targeted efforts to reduce dual vaping and smoking in young people who use cannabis may be needed.

Distress tolerance and problematic cannabis use: does the form of cannabis matter?

BACKGROUND

Low distress tolerance may result in greater vulnerability to problematic cannabis use. However, the role of the primary form of cannabis used has not been examined as a moderator of this association. While marijuana flower remains the preferred form of cannabis, the popularity of other forms of cannabis, including concentrates and edibles, is on the rise.

OBJECTIVES

We examined the association between distress tolerance and problematic cannabis use and whether the primary form of cannabis used moderates this relationship.

METHODS

Participants were 695 (67.6% male) past-month cannabis users who completed an online survey. Multiple linear regressions assessed whether distress tolerance, the primary form of cannabis used, and their interaction were related to problematic cannabis use while controlling for demographic variables and past 30-day alcohol and cannabis use frequency.

RESULTS

Lower tolerance for distress was associated with more problematic cannabis use. Endorsing concentrates as the primary form of cannabis used vs. marijuana flower was related to more problematic cannabis use while reporting edibles as the primary form of cannabis used vs. marijuana flower or concentrates was related to less problematic cannabis use. Individuals preferring marijuana flower or concentrates reported more problematic cannabis use at lower levels of distress tolerance.

CONCLUSIONS

Cannabis users exhibiting low distress tolerance or a preference for concentrates may be at greatest risk for experiencing negative consequences related to their cannabis use. Additionally, building tolerance for stressful situations, among both concentrates and marijuana flower users, may aid in minimizing problematic cannabis use.

The minor cannabinoid cannabigerol (CBG) is a highly specific blood biomarker of recent cannabis smoking

INTRODUCTION

The determination of recent cannabis use is of forensic interest in the investigation of automotive crashes, workplace incidents and other mishaps. Because Δ9-tetrahydrocannabinol may persist in blood after psychoactive effects of intoxication resolve, particularly in regular users, short-lived minor cannabinoids such as cannabigerol have merited examination as adjunct indicators of recent cannabis inhalation.

METHODS

As part of an observational cohort study, whole blood cannabinoids including cannabigerol were measured in whole blood by liquid chromatography with tandem mass spectrometry at baseline, and 30 minutes after initiation of a 15-minute supervised interval of ad libitum cannabis smoking in occasional (1-2 days/week over the past 30 days) (n = 24) and daily cannabis smokers (n = 32). Per protocol, subjects self-reported abstention from inhaling cannabis (>8 h) or ingesting cannabis (>12 h) prior to baseline measurement.

RESULTS

At baseline, none of the occasional users had detectable cannabigerol (limit of detection = 0.2 µg/L), whereas cannabigerol was detectable post-smoking in 7 of 24 (29%). Among daily cannabis users, 2 of 32 (6%) had detectable cannabigerol at baseline, increasing to 21 of 32 (66%) post-smoking. The odds ratio for recent cannabis smoking associated with a detectable cannabigerol was 27 (95% confidence interval: 6.6, 110.3). In this mixed cohort of occasional and daily cannabis users, receiver operator characteristic curve analysis indicated that whole blood cannabigerol concentration of ≥ 0.2 µg/L had 96% specificity, 50% sensitivity, and 73% accuracy for identifying a 15-minute interval of ad libitum cannabis smoking initiated 30 minutes earlier. Post smoking blood Δ9-tetrahydrocannabinol (median = 5.6 µg/L in occasional users, 21.3 µg/L in daily users) was significantly correlated with post-smoking cannabigerol (P < 0.0001).

CONCLUSION

Whole blood cannabigerol may have forensic utility as a highly specific albeit insensitive biomarker of recent cannabis smoking.

The effects of oral and vaporized cannabis alone, and in combination with alcohol, on driving performance using the STISIM driving simulator: A two-part, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory protocol

The legalization of cannabis for medicinal and non-medicinal purposes, and the corresponding increase in diversity of cannabis products, has resulted an urgent need for cannabis regulatory science. Among the most pressing needs is research related to impairment due to cannabis exposure, especially on driving performance. The present project was designed to evaluate the impact of oral and vaporized cannabis, when administered alone or in combination with alcohol, on simulated driving performance (STISIM driving simulator), cognitive/psychomotor ability, and field sobriety performance. Healthy adults will complete two, double-blind, double-dummy, placebo-controlled, randomized crossover clinical laboratory studies, one with oral cannabis (16 men/16 women) and the second with vaporized cannabis (16 men/16 women). In each study, participants will complete seven experimental sessions during which acute doses of placebo or high Δ9-THC cannabis containing 0, 10, or 25 mg Δ9-THC will be administered both alone and in combination with placebo or alcohol-containing beverages (target breath alcohol concentrations, BAC, of 0.0% or 0.05%). A positive control session (i.e., alcohol at target BAC of 0.08% with placebo cannabis) will also be completed. Simulated driving performance tests (available for download; see Methods), field sobriety assessments, subjective drug effect questionnaires, a mobile device impairment test (DRUID app), and collection of whole blood specimens will be completed repeatedly during each session. Linear mixed models will be used to test for differences across experimental conditions and a priori planned comparisons will be used to determine differences between conditions of interest (e.g., cannabis alone vs cannabis with alcohol). This research is designed to extend prior studies of cannabis and alcohol on driving performance by using oral and vaporized routes of cannabis administration. By increasing understanding of impairment associated with co-use of alcohol and these novel forms of cannabis, this research could inform impairment detection standards for cannabis and alcohol and have important implications for law enforcement, public policy decisions regarding accessibility of these substances, and education of the general population who may use cannabis and/or alcohol. Lastly, this manuscript provides interested researchers with access to the simulated driving scenarios and data extraction tools developed for this study as a means of facilitating future cross-study comparisons, which is important given the heterogeneity in methods used across laboratories in prior research.

Separate and combined effects of alcohol and cannabis on mood, subjective experience, cognition and psychomotor performance: A randomized trial

Co-use of alcohol and cannabis is associated with increased frequency and intensity of use and related problems. This study examined acute effects of alcohol and cannabis on mood, subjective experience, cognition, and psychomotor performance. Twenty-eight healthy cannabis users aged 19-29 years with recent history of binge drinking completed this within-subjects, double-blind, double-dummy, placebo-controlled, randomized clinical trial. Participants received: placebo alcohol and placebo cannabis (<0.1% THC); alcohol (target breath alcohol content [BrAC] 80 mg/dL) and placebo cannabis; placebo alcohol and active cannabis (12.5% THC); and active alcohol and cannabis over four sessions. Profile of Mood States (POMS), Addiction Research Centre Inventory (ARCI), verbal free recall (VFR), Digit Symbol Substitution Test (DSST), Continuous Performance Test (CPT), and grooved pegboard (GPB) task were administered before and approximately 75 min after drinking alcohol (1 h after smoking cannabis ad libitum). Significant effects of condition were found for the POMS (Tension-Anxiety, Confusion) and ARCI (MBG, LSD, PCAG, Euphoria, Sedation), predominantly with greater increases emerging after cannabis or alcohol-cannabis combined relative to placebo. Significant effects were found for VFR (immediate total and delayed recall, percent retained), DSST (trials attempted, trials correct, reaction time), and GPB (non-dominant hand) predominantly with greater declines in performance after alcohol and alcohol-cannabis combined relative to placebo and/or cannabis. Cannabis appeared to affect mood and subjective experience, with minimal impact on cognitive performance. Alcohol appeared to impair cognitive and psychomotor performance, with minimal impact on mood and subjective experience. Acute effects of alcohol and cannabis combined were additive at most.

Modes of cannabis administration in the year prior to conception among patients in Northern California

Cannabis use among individuals before and during pregnancy is increasing alongside the proliferation of new products with various modes of administration. Preconception cannabis use is a strong predictor of prenatal cannabis use. Yet little is known about how individuals administer cannabis during the preconception period, particularly in socioeconomically vulnerable populations. This study examined the prevalence and correlates of modes of cannabis administration (smoke, vape, blunts, edible/oral, dabs/wax, lotion/topical) during the year before conception, among patients who self-reported preconception cannabis use during universal screening in prenatal care. Descriptive statistics included sociodemographic characteristics, preconception cannabis use frequency, and modes of administration. Chi-square tests examined whether mode was associated with sociodemographic characteristics and use frequency. The sample (N = 11,936, screened from February 2020-May 2021) was 59.8% non-White and 26.1% were < 26 years old; 50.7% reported monthly or less, 21.8% weekly, and 27.4% daily preconception cannabis use; 69.7% smoked (any method), 34.5% smoked blunts, 53.4% used edibles/oral, 28.2% vaped, 9.9% used lotion/topical; 54.2% reported 1 mode, 30.4% reported 2 modes, 15.4% reported 3+ modes. Smoking was more common among daily users, younger patients, those with greater neighborhood deprivation, and Black and Hispanic patients, while edibles/oral were more common among ≤ monthly users, older patients, those with less neighborhood deprivation, and Asian patients. Use of other modes also varied by sociodemographic characteristics and use frequency. Research is needed to understand preconception cannabis use in vulnerable subpopulations, continuation of use during pregnancy, and whether health risks associated with preconception and prenatal cannabis use differ by administration mode.

Why Do Marijuana and Synthetic Cannabimimetics Induce Acute Myocardial Infarction in Healthy Young People?

The use of cannabis preparations has steadily increased. Although cannabis was traditionally assumed to only have mild vegetative side effects, it has become evident in recent years that severe cardiovascular complications can occur. Cannabis use has recently even been added to the risk factors for myocardial infarction. This review is dedicated to pathogenetic factors contributing to cannabis-related myocardial infarction. Tachycardia is highly important in this respect, and we provide evidence that activation of CB₁ receptors in brain regions important for cardiovascular regulation and of presynaptic CB₁ receptors on sympathetic and/or parasympathetic nerve fibers are involved. The prototypical factors for myocardial infarction, i.e., thrombus formation and coronary constriction, have also been considered, but there is little evidence that they play a decisive role. On the other hand, an increase in the formation of carboxyhemoglobin, impaired mitochondrial respiration, cardiotoxic reactions and tachyarrhythmias associated with the increased sympathetic tone are factors possibly intensifying myocardial infarction. A particularly important factor is that cannabis use is frequently accompanied by tobacco smoking. In conclusion, additional research is warranted to decipher the mechanisms involved, since cannabis use is being legalized increasingly and Δ⁹-tetrahydrocannabinol and its synthetic analogue nabilone are indicated for the treatment of various disease states.

A naturalistic study of orally administered vs. inhaled legal market cannabis: cannabinoids exposure, intoxication, and impairment

RATIONALE

Published studies examining the effects of cannabis have largely utilized forms of cannabis that are not representative of the legal market products currently available.

OBJECTIVES

The present study aimed to characterize naturalistic use of legal market flower and edible products by examining associations among blood cannabinoids and amount of THC consumed as well as physiological, cognitive, and subjective effects in users of edible and flower forms.

METHOD

Eighty-four participants who used cannabis at least 1 × /week (55 flower cannabis using participants; 29 edible cannabis using participants mean age = 31.95 years, 44% female) participated. At the experimental appointment in our mobile laboratory, participants completed a blood draw to assess plasma cannabinoids, measures of heart rate, subjective drug effects, and cognition both before and after ad libitum use of legal market flower or edible cannabis.

RESULTS

Average self-reported THC consumed was 15.97 mg (SD = 22.40) in edible users and 51.25 mg (SD = 45.23) in flower users. In the edible group, but not the flower group, strong correlations emerged between self-reported ad libitum THC consumed and plasma THC. Plasma THC was significantly higher after use of inhaled cannabis, but similar levels of plasma THC metabolites and similar levels of subjective intoxication and verbal memory impairment were observed in both flower and edible users.

CONCLUSIONS

Findings support strong correlations among ad libitum THC consumed and THC plasma levels after edible cannabis use and suggest few differences in intoxication and impairment between edible and flower cannabis users after ad libitum use. This novel study provides important preliminary data on the pharmacology and effects of legal market edible cannabis.

Effects of Marijuana Use on Smokers Switching to E-Cigarettes in a Randomized Clinical Trial

INTRODUCTION

Co-use of tobacco and marijuana is common, and research suggests that marijuana use may be a barrier to smoking cessation. Research to date has not evaluated how marijuana use affects e-cigarette switching behaviors and related outcomes in a harm reduction trial.

AIMS AND METHODS

This secondary analysis includes African American (48%) and Latinx (52%) adult smokers randomized to the e-cigarette group (N = 114) of a harm reduction clinical trial from 2018 to 2019. Participants were provided JUUL e-cigarettes and encouraged to make an exclusive switch for 6 weeks. Our primary outcome was cigarettes smoked per week. Secondary health outcomes were e-cigarette substitution (calculated by measuring e-cigarette pod use), expired carbon monoxide (CO), and respiratory symptoms. Marijuana products were recorded at three timepoints and coded for combustion.

RESULTS

Marijuana use during the study (n = 52, 46%) was not associated with week 6 cigarettes smoked or e-cigarette substitution, and combustible marijuana use was not associated with week 6 respiratory symptoms (ps > .05). After controlling for cigarettes smoked at week 6, combustible marijuana use was significantly associated with a 4.4 ppm increase in CO compared with no use of marijuana (p = .001).

CONCLUSIONS

Marijuana use was not a barrier to switching to e-cigarettes in this 6-week trial. Marijuana use contributed to elevated CO, reflecting greater exposure to toxic combustion products, beyond the effects of cigarette smoking. Marijuana co-use may increase risk of adverse health outcomes and may be a confounding factor when using CO as an endpoint to bioverify exclusive e-cigarette use.

IMPLICATIONS

This is the first known study to examine the effects of marijuana use on smokers switching to e-cigarettes. Marijuana use was not a barrier to cigarette reduction in a 6-week randomized clinical trial. Marijuana use uniquely contributed to higher carbon monoxide among cigarette smokers, indicating greater exposure to toxic combustion products, which could increase risk of adverse health outcomes. Furthermore, combustible marijuana use may be a confounding factor when CO is used as an endpoint to bioverify exclusive e-cigarette use.

A Clinical Framework for Assessing Cannabis-Related Impairment Risk

Clinicians play an important role in promoting safe and responsible medical cannabis use. One essential component to safe use is considering a patient's risk of neurocognitive impairment. However, there remains a lack of practical guidance on how clinicians can evaluate this risk for medical cannabis patients. Here, a practical framework is presented for clinicians to assess and stratify cannabis-associated impairment risk. The proposed framework is intended to practically guide healthcare providers in gaining a more comprehensive review of a patient's impairment-related factors. This framework can be used to assess impairment risk for patients currently using or considering medical cannabis and is recommended for all patients who perform safety-sensitive duties. Healthcare providers (HCP) managing patient's medical cannabis or those conducting assessments to determine risk of impairment for safety-sensitive workplaces can utilize this framework to stratify patients' risk of impairment. Such assessments can inform patient-specific needs for support, education, and guidance, to ensure cannabis is used safely and responsibly.

Lower-Risk Cannabis Use Guidelines (LRCUG) for reducing health harms from non-medical cannabis use: A comprehensive evidence and recommendations update

BACKGROUND

Cannabis use is common, especially among young people, and is associated with risks for various health harms. Some jurisdictions have recently moved to legalization/regulation pursuing public health goals. Evidence-based 'Lower Risk Cannabis Use Guidelines' (LRCUG) and recommendations were previously developed to reduce modifiable risk factors of cannabis-related adverse health outcomes; related evidence has evolved substantially since. We aimed to review new scientific evidence and to develop comprehensively up-to-date LRCUG, including their recommendations, on this evidence basis.

METHODS

Targeted searches for literature (since 2016) on main risk factors for cannabis-related adverse health outcomes modifiable by the user-individual were conducted. Topical areas were informed by previous LRCUG content and expanded upon current evidence. Searches preferentially focused on systematic reviews, supplemented by key individual studies. The review results were evidence-graded, topically organized and narratively summarized; recommendations were developed through an iterative scientific expert consensus development process.

RESULTS

A substantial body of modifiable risk factors for cannabis use-related health harms were identified with varying evidence quality. Twelve substantive recommendation clusters and three precautionary statements were developed. In general, current evidence suggests that individuals can substantially reduce their risk for adverse health outcomes if they delay the onset of cannabis use until after adolescence, avoid the use of high-potency (THC) cannabis products and high-frequency/-intensity of use, and refrain from smoking-routes for administration. While young people are particularly vulnerable to cannabis-related harms, other sub-groups (e.g., pregnant women, drivers, older adults, those with co-morbidities) are advised to exercise particular caution with use-related risks. Legal/regulated cannabis products should be used where possible.

CONCLUSIONS

Cannabis use can result in adverse health outcomes, mostly among sub-groups with higher-risk use. Reducing the risk factors identified can help to reduce health harms from use. The LRCUG offer one targeted intervention component within a comprehensive public health approach for cannabis use. They require effective audience-tailoring and dissemination, regular updating as new evidence become available, and should be evaluated for their impact.

A systematic review and meta-analysis of delay discounting and cannabis use

Delay discounting reflects the systematic reduction in the value of a consequence by delay to delivery. Theoretical and empirical work suggests that delay discounting is a key behavioral mechanism underlying substance use disorder. Existing work on cannabis use, however, is mixed with many studies reporting null results. The purpose of this review was to provide an in-depth assessment of the association between delay discounting and cannabis use. We conducted metaregression analyses to determine the omnibus correlation between delay discounting and cannabis use, and to evaluate task-based and sample-based moderators. Studies included evaluated an association between delay discounting and cannabis quantity-frequency or severity measures in human participants (27 studies, 61 effect sizes, 24,782 participants). A robust variance estimation method was used to account for dependence among effect sizes. A significant, but small, omnibus effect was observed (r = .082) in which greater cannabis use frequency or severity was associated with greater discounting. Incentive structure and outcome type were each significant moderators in a multiple moderator model such that incentivized tasks correlated with severity measures showed stronger associations (r = .234) than hypothetical tasks correlated with quantity-frequency measures (r = .029). Comparisons to historic effect size data supported the hypothesis that, at present, the relationship between cannabis use and delay discounting appears empirically smaller than for other substances. Future work should explore theoretical rationales explaining this modest relationship involving cannabis use and delay discounting, such as reflecting the smaller magnitude of perceived long-term clinical outcomes associated with cannabis compared to other substances. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Brain imaging of cannabinoid type I (CB1 ) receptors in women with cannabis use disorder and male and female healthy controls

Cannabis effects are predominantly mediated by pharmacological actions on cannabinoid type 1 (CB1 ) receptors. Prior positron emission tomography (PET) studies in individuals who use cannabis included almost exclusively males. PET studies in females are needed because there are sex differences in cannabis effects, progression to cannabis use disorder (CUD), and withdrawal symptom severity. Females with CUD (N = 10) completed two double-blind cannabis smoking sessions (Session 1: placebo; Session 2: active), and acute cannabis effects were assessed. After Session 2, participants underwent 3 days of monitored cannabis abstinence; mood, craving, and withdrawal symptoms were assessed and a PET scan (radiotracer: [11 C]OMAR) followed. [11 C]OMAR Distribution volume (VT ) from these participants was compared with VT of age/BMI-similar female non-users of cannabis ("healthy controls"; N = 10). VT was also compared between female and male healthy controls (N = 7). Females with CUD displayed significantly lower VT than female healthy controls in specific brain regions (hippocampus, amygdala, cingulate, and insula). Amygdala VT was negatively correlated with mood changes (anger/hostility) during abstinence, but VT was not correlated with other withdrawal symptoms or cannabis effects. Among healthy controls, females had significantly higher VT than males in all brain regions examined. Chronic cannabis use appears to foster downregulation of CB1 receptors in women, as observed previously in men, and there are inherent sex differences in CB1 availability. Future studies should elucidate the time course of CB1 downregulation among females who use cannabis and examine the relation between CB1 availability and cannabis effects among other populations (e.g., infrequent users; medicinal users).

Are vaporizers a lower-risk alternative to smoking cannabis?

Cannabis use is associated with various adverse physical and mental health outcomes as well as increased risk of motor vehicle collision. Many organizations and the "Lower-Risk Cannabis Use Guidelines" have recommended to use cannabis vaporizers instead of smoking to reduce the associated health risk. This commentary draws attention to the present evidence regarding harm reduction potential of cannabis vaping. Cannabis vaporizer use can reduce the emission of carbon monoxide, chronic respiratory symptoms, and exposure to several toxins while producing similar subjective effects and blood THC concentration compared with smoking cannabis, holding potential for harm reduction among habitual cannabis smokers. However, new cannabis users, regardless of method of administration of cannabis, may experience intense subjective effects and cognitive impairment with increased susceptibility to dependence. Hence, policy makers should consider limiting access to cannabis among young people and adopting strategies to reduce impaired driving under influence of cannabis. Future research should focus on impact of switching from cannabis smoking to dried herb vaping using cannabis vaporizers among chronic cannabis smokers, and long-term outcomes of medical cannabis vaping, and further explore association of vaping-associated lung injury with THC-containing e-liquids.

Assessment of cognitive and psychomotor impairment, subjective effects, and blood THC concentrations following acute administration of oral and vaporized cannabis

BACKGROUND

Cannabis legalization is expanding, but there are no established methods for detecting cannabis impairment.

AIM

Characterize the acute impairing effects of oral and vaporized cannabis using various performance tests.

METHODS

Participants (N = 20, 10 men/10 women) who were infrequent cannabis users ingested cannabis brownies (0, 10, and 25 mg Δ-9-tetrahydrocannabinol, THC) and inhaled vaporized cannabis (0, 5, and 20 mg THC) in six double-blind outpatient sessions. Cognitive/psychomotor impairment was assessed with a battery of computerized tasks sensitive to cannabis effects, a novel test (the DRiving Under the Influence of Drugs, DRUID^®), and field sobriety tests. Blood THC concentrations and subjective drug effects were evaluated.

RESULTS

Low oral/vaporized doses did not impair cognitive/psychomotor performance relative to placebo but produced positive subjective effects. High oral/vaporized doses impaired cognitive/psychomotor performance and increased positive and negative subjective effects. The DRUID^® was the most sensitive test to cannabis impairment, as it detected significant differences between placebo and active doses within both routes of administration. Women displayed more impairment on the DRUID^® than men at the high vaporized dose only. Field sobriety tests showed little sensitivity to cannabis-induced impairment. Blood THC concentrations were far lower after cannabis ingestion versus inhalation. After inhalation, blood THC concentrations typically returned to baseline well before pharmacodynamic effects subsided.

CONCLUSIONS

Standard approaches for identifying impairment due to cannabis exposure (i.e. blood THC and field sobriety tests) have severe limitations. There is a need to identify novel biomarkers of cannabis exposure and/or behavioral tests like the DRUID^® that can reliably and accurately detect cannabis impairment at the roadside and in the workplace.

Sex differences in the acute effects of oral and vaporized cannabis among healthy adults

Policy changes have increased access to cannabis for individuals with little or no prior exposure. Few studies have examined sex differences in cannabis effects among individuals with sporadic cannabis use or for nonsmoked routes of cannabis administration. Data from four double-blind, placebo-controlled studies were pooled to compare the acute pharmacodynamic effects of vaporized and oral cannabis in male (n = 27) and female (n = 23) participants who used cannabis infrequently (no use ≥30 days prior to randomization). Analyses compared peak change-from-baseline scores between male and female participants for subjective drug effects, cognitive/psychomotor performance, cardiovascular effects, and blood concentrations of Δ9-tetrahydrocannabinol (THC) and its primary metabolites (11-OH-THC, THC-COOH) after exposure to placebo cannabis or cannabis containing low-dose (5 or 10 mg) or high-dose THC (20 or 25 mg). Overall, cannabis elicited dose-orderly increases in subjective effects, impairment of cognitive/psychomotor performance, heart rate, and blood cannabinoid concentrations. Females exhibited greater peak blood 11-OH-THC concentrations and reported greater peak subjective ratings of "drug effect" that remained when controlling for body weight. When controlling for both body weight and peak blood cannabinoid concentrations, ratings of "anxious/nervous," "heart racing," and "restless" were significantly higher for females than males. Although additional research is needed to elucidate sex differences in responses to cannabis at a wider range of THC doses, other routes of administration, and products with diverse chemical composition, the current data indicate that public health messaging and clinical decision making around the use of cannabinoids should recommend lower starting doses for females and warnings about acute anxiogenic reactions.

The why behind the high: determinants of neurocognition during acute cannabis exposure

Acute cannabis intoxication may induce neurocognitive impairment and is a possible cause of human error, injury and psychological distress. One of the major concerns raised about increasing cannabis legalization and the therapeutic use of cannabis is that it will increase cannabis-related harm. However, the impairing effect of cannabis during intoxication varies among individuals and may not occur in all users. There is evidence that the neurocognitive response to acute cannabis exposure is driven by changes in the activity of the mesocorticolimbic and salience networks, can be exacerbated or mitigated by biological and pharmacological factors, varies with product formulations and frequency of use and can differ between recreational and therapeutic use. It is argued that these determinants of the cannabis-induced neurocognitive state should be taken into account when defining and evaluating levels of cannabis impairment in the legal arena, when prescribing cannabis in therapeutic settings and when informing society about the safe and responsible use of cannabis.

Human Laboratory Models of Cannabis Use: Applications for Clinical and Translational Psychiatry Research

Cannabis is increasingly used by individuals with mental health diagnoses and often purported to treat anxiety and various other psychiatric symptoms. Yet support for using cannabis as a psychiatric treatment is currently limited by a lack of evidence from rigorous placebo-controlled studies. While regulatory hurdles and other barriers make clinical trials of cannabis challenging to conduct, addiction researchers have decades of experience studying cannabis use in human laboratory models. These include methods to control cannabis administration, to delineate clinical and mechanistic aspects of cannabis use, and to evaluate potential treatment applications for cannabis and its constituents. In this paper, we review these human laboratory procedures and describe how each can be applied to study cannabis use in patients with psychiatric disorders. Because anxiety disorders are among the most common psychiatric illnesses affecting American adults, and anxiety relief is also the most commonly-reported reason for medicinal cannabis use, we focus particularly on applying human laboratory models to study cannabis effects in individuals with anxiety and related disorders. Finally, we discuss how these methods can be integrated to study cannabis effects in other psychiatric conditions and guide future research in this area.

Does how you use matter? The link between mode of use and cannabis-related risk

OBJECTIVES

With the recent legalization of cannabis there are more cannabis products available to consumers today than ever before. However, little is known about the relation of distinct modes of use to cannabis-related risks. The current study estimated the prevalence of different modes of use among a sample of university students, and quantified the magnitude of association between modes of use (type and number) and cannabis-related risks (i.e., dependence, negative consequences, simultaneous use with alcohol).

METHODS

The sample included 368 undergraduate students (71% female) who reported using cannabis in the last 6 months.

RESULTS

Joints were the most commonly reported primary mode (39%), followed by bongs/water pipes (33%), hand pipes (14%), edibles (7%) and vaporizers (5%). The majority of participants were multi-mode users (88%). On average, participants reported using 2.72 (sd = 1.04) modes of cannabis regularly. Bong users had more cannabis related harms (B = 1.85, p < .001), dependence symptoms (B = 1.87, p < .001) and were twice as likely to use alcohol and cannabis simultaneously (OR = 2.09; 95% CI: 1.17-3.74) compared to joint users. However, these associations were attenuated after adjusting for sex, age and cannabis frequency. Multi-modal users reported significantly more cannabis-related harms and misuse symptoms compared to single mode users.

CONCLUSION

Few differences in cannabis risks were found across modes of use. Frequency of use remains the most significant predictor of cannabis related risks. However, findings suggest that multimodal may be indicative of high risk cannabis use patterns and is an important target for screening and intervention.

A within-person comparison of the subjective effects of higher vs. lower-potency cannabis

BACKGROUND

Cannabis concentrates have much higher concentrations of THC than marijuana (flower) and are quickly gaining popularity in the United States. One hypothesis is that use of higher-THC cannabis (concentrates) might result in greater intoxication and more severe acute negative effects than lower-THC cannabis (marijuana), but few studies have compared the subjective effects of concentrates and marijuana.

METHODS

Current (past-year) cannabis users were recruited online to complete a survey about their cannabis use. Cannabis users who reported using both marijuana and concentrates (n = 574) answered questions about the subjective effects of marijuana and, subsequently, the subjective effects of concentrates. Subjective effects were obtained for the following domains: affect, cognitive function, psychotic-like experiences, physiological effects, and reduced consciousness.

RESULTS

Participants reported using marijuana between 5-6 times per week and concentrates slightly more than once per month. Within-person comparisons of the subjective effects of marijuana and concentrates showed that marijuana was rated as producing greater overall positive effects (Marijuana: M = 5.6, Concentrates: M = 4.5; Cohen's d = 0.75, paired t(561) = 14.67, p < .001), including greater positive affect and enhanced cognitive function. Negative effects of both marijuana and concentrates were minimal. Marijuana was selected over concentrates as the 'preferred type' of cannabis by 77.5 % of participants.

CONCLUSIONS

The main difference in the subjective effects of marijuana and concentrates is in terms of their positive effects, with marijuana producing greater positive effects than concentrates. Negative effects of marijuana and concentrates were small, suggesting that extreme negative effects are unlikely for regular cannabis users.

Bioactive Chemical Composition of Cannabis Extracts and Cannabinoid Receptors

Cannabis is widely used as a therapeutic drug, especially by patients suffering from psychiatric and neurodegenerative diseases. However, the complex interplay between phytocannabinoids and their targets in the human receptome remains largely a mystery, and there have been few investigations into the relationship between the chemical composition of medical cannabis and the corresponding biological activity. In this study, we investigated 59 cannabis samples used by patients for medical reasons. The samples were subjected to extraction (microwave and supercritical carbon dioxide) and chemical analyses, and the resulting extracts were assayed in vitro using the CB₁ and CB₂ receptors. Using a partial least squares regression analysis, the chemical compositions of the extracts were then correlated to their corresponding cannabinoid receptor activities, thus generating predictive models that describe the receptor potency as a function of major phytocannabinoid content. Using the current dataset, meaningful models for CB₁ and CB₂ receptor agonism were obtained, and these reveal the insignificant relationships between the major phytocannabinoid content and receptor affinity for CB₁ but good correlations between the two at CB₂ receptors. These results also explain the anomalies between the receptor activities of pure phytocannabinoids and cannabis extracts. Furthermore, the models for CB₁ and CB₂ agonism in cannabis extracts predict the cannabinoid receptor activities of individual phytocannabinoids with reasonable accuracy. Here for the first time, we disclose a method to predict the relationship between the chemical composition, including phytocannabinoids, of cannabis extracts and cannabinoid receptor responses.

'Standard THC units': a proposal to standardize dose across all cannabis products and methods of administration

BACKGROUND AND AIMS

Cannabis products are becoming increasingly diverse, and vary considerably in concentrations of ∆⁹ -tetrahydrocannabinol (THC) and cannabidiol (CBD). Higher doses of THC can increase the risk of harm from cannabis, while CBD may partially offset some of these effects. Lower Risk Cannabis Use Guidelines currently lack recommendations based on quantity of use, and could be improved by implementing standard units. However, there is currently no consensus on how units should be measured or standardized among different cannabis products or methods of administration.

ARGUMENT

Existing proposals for standard cannabis units have been based on specific methods of administration (e.g. joints) and these may not capture other methods, including pipes, bongs, blunts, dabbing, vaporizers, vape pens, edibles and liquids. Other proposals (e.g. grams of cannabis) cannot account for heterogeneity in THC concentrations among different cannabis products. Similar to alcohol units, we argue that standard cannabis units should reflect the quantity of primary active pharmacological constituents (dose of THC). On the basis of experimental and ecological data, public health considerations and existing policy, we propose that a 'standard THC unit' should be fixed at 5 mg THC for all cannabis products and methods of administration. If supported by sufficient evidence in future, consumption of standard CBD units might offer an additional strategy for harm reduction.

CONCLUSIONS

Standard ∆⁹ -tetrahydrocannabinol (THC) units can potentially be applied among all cannabis products and methods of administration to guide consumers and promote safer patterns of use.

Complex cannabis use patterns: Associations with cannabis consequences and cannabis use disorder symptomatology

BACKGROUND

Historically, cannabis researchers have assumed a single mode and product of cannabis (e.g., smoking plant). However, patterns of use, products (e.g., concentrates, edibles), and modes (e.g. blunts, vaporizers) are diversifying. This study sought to: 1) classify cannabis users into groups based on their use of the full range of cannabis products, and 2) examine user group differences on demographics, cannabis consequences and cannabis use disorder (CUD) symptomatology.

METHODS

In a sample of college students (data collected in Fall 2017), who used cannabis in the past year (N = 1390), latent class analysis (LCA) was used to characterize cannabis users. We then added demographic characteristics, cannabis consequences, and CUD symptomatology scores separately to LCA models to examine class differences.

RESULTS

Five unique classes emerged: high-frequency all-product users, high-frequency plant/moderate-frequency edible and concentrate users, low-frequency plant users, moderate-frequency plant and edible users, and low-frequency edible users. Demographic characteristics, cannabis consequences, and CUD symptomatology differed across classes characterized by frequency as well as product.

CONCLUSIONS

Results reflect the increasing variety of cannabis products, modes, and use patterns among college students. In this sample, frequency of use remains a strong predictor of cannabis-related consequences, in addition to type of product. As variation in cannabis use patterns continue to evolve, it is essential for researchers to conduct comprehensive assessments.

Pharmacodynamic effects of vaporized and oral cannabidiol (CBD) and vaporized CBD-dominant cannabis in infrequent cannabis users

INTRODUCTION

The use and availability of oral and inhalable products containing cannabidiol (CBD) as the principal constituent has increased with expanded cannabis/hemp legalization. However, few controlled clinical laboratory studies have evaluated the pharmacodynamic effects of oral or vaporized CBD or CBD-dominant cannabis.

METHODS

Eighteen healthy adults (9 men; 9 women) completed four, double-blind, double-dummy, drug administration sessions. Sessions were separated by ≥1 week and included self-administration of 100 mg oral CBD, 100 mg vaporized CBD, vaporized CBD-dominant cannabis (100 mg CBD; 3.7 mg THC), and placebo. Study outcomes included: subjective drug effects, vital signs, cognitive/psychomotor performance, and whole blood THC and CBD concentrations.

RESULTS

Vaporized CBD and CBD-dominant cannabis increased ratings on several subjective items (e.g., Like Drug Effect) relative to placebo. Subjective effects did not differ between oral CBD and placebo and were generally higher for CBD-dominant cannabis compared to vaporized CBD. CBD did not increase ratings for several items typically associated with acute cannabis/THC exposure (e.g., Paranoid). Women reported qualitatively higher ratings for Pleasant Drug Effect than men after vaporized CBD and CBD-dominant cannabis use. CBD-dominant cannabis increased heart rate compared to placebo. Cognitive/psychomotor impairment was not observed in any drug condition.

CONCLUSIONS

Vaporized CBD and CBD-dominant cannabis produced discriminable subjective drug effects, which were sometimes stronger in women, but did not produce cognitive/psychomotor impairment. Subjective effects of oral CBD did not differ from placebo. Future research should further elucidate the subjective effects of various types of CBD products (e.g., inhaled, oral, topical), which appear to be distinct from THC-dominant products.

The deleterious effects of cannabis during pregnancy on neonatal outcomes

OBJECTIVES

To evaluate whether cannabis use during pregnancy is associated with adverse neonatal outcomes that are independent of cigarette smoking.

DESIGN

Prospective cohort study.

SETTING

Adelaide (Australia), Auckland (New Zealand), Cork (Ireland), and Leeds, London and Manchester (United Kingdom).

PARTICIPANTS

5610 pregnant nulliparous women with low risk pregnancies recruited for the Screening for Pregnancy Endpoints (SCOPE) study, November 2004 - February 2011. At 14-16 weeks of pregnancy, women were grouped by self-reported cannabis use.

MAIN OUTCOME MEASURES

Infant birthweight, head circumference, birth length, gestational age, and severe neonatal morbidity or mortality.

RESULTS

314 women (5.6%) reported using cannabis in the 3 months before or during their pregnancy; 97 (31%) stopped using it before and 157 (50%) during the first 15 weeks of pregnancy, while 60 (19%) were still using cannabis at 15 weeks. Compared with babies of mother who had never used cannabis, infants of those who still used it at 15 weeks had lower mean values for birthweight (adjusted mean difference [aMD], -127 g; 95% CI, -238 to -17 g), head circumference (aMD, -0.5 cm; 95% CI, -0.8 to -0.1 cm), birth length (aMD, -0.8 cm; 95% CI, -1.4 to -0.2 cm), and gestational age at birth (aMD, -8.1 days; 95% CI, -12.1 to -4.0 days). The differences for all outcomes except gestational age were greater for women who used cannabis more than once a week than for those who used it less frequently.

CONCLUSIONS

Continuing to use cannabis during pregnancy is an independent risk factor for poorer neonatal outcomes.

Short- and Long-Term Effects of Cannabis on Headache and Migraine

Use of cannabis to alleviate headache and migraine is relatively common, yet research on its effectiveness remains sparse. We sought to determine whether inhalation of cannabis decreases headache and migraine ratings as well as whether gender, type of cannabis (concentrate vs flower), delta-9-tetrahydrocannabinol, cannabidiol, or dose contribute to changes in these ratings. Finally, we explored evidence for tolerance to these effects. Archival data were obtained from Strainprint, a medical cannabis app that allows patients to track symptoms before and after using different strains and doses of cannabis. Latent change score models and multilevel models were used to analyze data from 12,293 sessions where cannabis was used to treat headache and 7,441 sessions where cannabis was used to treat migraine. There were significant reductions in headache and migraine ratings after cannabis use. Men reported larger reductions in headache than women and use of concentrates was associated with larger reductions in headache than flower. Further, there was evidence of tolerance to these effects. PERSPECTIVE: Inhaled cannabis reduces self-reported headache and migraine severity by approximately 50%. However, its effectiveness appears to diminish across time and patients appear to use larger doses across time, suggesting tolerance to these effects may develop with continued use.

Vaporization of Marijuana Among Recreational Users: A Qualitative Study

OBJECTIVE

Vaporization of marijuana products, or "vaping," has become a prevalent mode of administration and is typically perceived to hold unique benefits compared to combustible administration methods. Such positive beliefs regarding marijuana vaporization may contribute to its abuse liability. This qualitative study examined cognitions pertaining to vaping among recreational marijuana users.

METHOD

Focus groups were conducted with frequent marijuana users (N = 31; five groups; six to seven per group; M = 5.0 days/week marijuana use). Three topic areas were queried during discussions with the goal of revealing factors that may contribute to the abuse liability of vaporization. These comprised differences between smoking and vaporizing marijuana products, perceived advantages of vaporization, and perceived disadvantages of vaporization. Focus groups lasted approximately 60 minutes and followed a semistructured agenda; the sessions were audio recorded and transcribed for an applied thematic analysis. An executive summary of each group was made and key themes pertaining to vaporization were summarized.

RESULTS

Several themes emerged, including differences between smoking and vaporizing marijuana, convenience, discretion, and efficiency of vaping, perceived health benefits, the absence of traditional smoking rituals, and the high cost of vaporization devices.

CONCLUSIONS

Several factors appear to promote marijuana vaporization, including device aspects (e.g., discreet, convenient), the subjective high, economical efficiency, and perceived harm-reducing and health-promoting effects. These qualitative data highlight unique cognitions about marijuana vaping that may substantially increase its abuse liability. Quantitative research is needed to examine the extent to which cognitions about marijuana vaporization contribute to actual use patterns and problematic behaviors.

Occupational Exposure to Secondhand Cannabis Smoke Among Law Enforcement Officers Providing Security at Outdoor Concert Events

Objectives

Numerous states within the USA have legalized cannabis for medical or non-medical (adult/recreational) use. With the increased availability and use of cannabis, occupational and environmental exposures to secondhand cannabis smoke (SHCS) raise concerns over whether non-users may be at risk for a ‘contact high’, impaired neurocognitive function, harm from irritants and carcinogens in smoke, or potentially failing a cannabis screening test. The extent of health effects from potential occupational exposure to SHCS is unknown. This is a study of occupational exposures to SHCS among law enforcement officers (LEOs) providing security at outdoor concerts on a college campus in a state where adult use of cannabis is legal.

Methods

Investigators evaluated a convenience sample of LEOs’ potential exposure to SHCS and symptoms experienced while providing security during two open-air stadium rock-n-roll concerts on consecutive days in July 2018. During each event, full-shift area and LEO personal air samples were collected for Δ9-tetrahydrocannabinol (Δ9-THC), the psychoactive component of cannabis. Urine (pre- and postevent; n = 58) and blood (postevent; n = 29) were also collected and analyzed for Δ9-THC and two of its metabolites [11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) and 11-nor-hydroxy-delta-9-tetrahydrocannabinol (OH-THC)]. Urine samples were analyzed using ultrahigh performance liquid chromatography coupled with positive electrospray ionization tandem mass spectrometry and results were compared with the Department of Transportation guidelines for urine screening for cannabis. Blood (postevent) samples were also collected and the plasma fraction was tested for Δ9-THC, THC-COOH, and OH-THC using high-performance liquid chromatography coupled with mass spectrometry. LEOs also completed a medical questionnaire asking about symptoms experienced during the concerts.

Results

Twenty-nine LEOs participated in the evaluation. Measurable amounts of Δ9-THC were found in area (concentrations ranged from non-detectable to 330 ng m−3) and personal air samples (53–480 ng m−3). Small amounts (&lt;1.0 ng ml−1) of a Δ9-THC metabolite (THC-COOH) were found in the postevent urine of 34% of LEOs. Neither Δ9-THC nor its metabolites were detected in any blood sample. LEOs reported experiencing non-specific symptoms during the concerts, such as burning, itchy, or red eyes (31%); dry mouth (21%); headache (21%); and coughing (21%).

Conclusions

Identification of Δ9-THC in the breathing zone for some LEOs indicates the potential for airborne exposure to the psychoactive component of cannabis. However, the magnitude of these exposures was small compared with those that would result in a dose of Δ9-THC associated with psychotropic effects. Similarly, THC-COOH was found in the postevent urine of some LEOs at concentrations that were orders of magnitude below active use cut-points used during a cannabis screening test (50 ng ml−1). Exposure to SHCS was not high enough to detect concentrations of THC, THC-COOH, to OH-THC in the blood, which could be due to differences between the limits of detection for the tests employed. The ocular and respiratory symptoms reported by LEOs may be related to irritants in SHCS. However, the health effects of SHCS remain unclear, and further research concerning occupational and environmental exposures is warranted.

Pharmacodynamic dose effects of oral cannabis ingestion in healthy adults who infrequently use cannabis

BACKGROUND

Prior controlled cannabis research has mostly focused on smoked cannabis and predominantly included frequent cannabis users. Oral cannabis products ("edibles") make up a large and growing segment of the retail cannabis market. This study sought to characterize the pharmacodynamic effects of oral cannabis among infrequent cannabis users.

METHODS

Seventeen healthy adults who had not used cannabis for at least 60 days completed four experimental sessions in which they consumed a cannabis-infused brownie that contained 0, 10, 25, or 50 mg THC. Subjective effects, vital signs, cognitive/psychomotor performance, and blood THC concentrations were assessed before and for 8 h after dosing.

RESULTS

Relative to placebo, the 10 mg THC dose produced discriminable subjective drug effects and elevated heart rate but did not alter cognitive/psychomotor performance. The 25 and 50 mg THC doses elicited pronounced subjective effects and markedly impaired cognitive and psychomotor functioning compared with placebo. For all active doses, pharmacodynamic effects did not manifest until 30-60 min after ingestion, and peak effects occurred 1.5-3 h post-administration. Blood THC levels were significantly correlated with some pharmacodynamic drug effects, but were substantially lower than what is typically observed after cannabis inhalation.

CONCLUSION

Ingestion of oral cannabis dose-dependently altered subjective drug effects and impaired cognitive performance. Unlike inhaled forms of cannabis for which acute effects occur almost immediately, effects of oral cannabis were considerably delayed. In an era of legalization, education about the time course of drug effects for cannabis edibles is needed to facilitate dose titration and reduce acute overdose incidents.

Effects of oral, smoked, and vaporized cannabis on endocrine pathways related to appetite and metabolism: a randomized, double-blind, placebo-controlled, human laboratory study

As perspectives on cannabis continue to shift, understanding the physiological and behavioral effects of cannabis use is of paramount importance. Previous data suggest that cannabis use influences food intake, appetite, and metabolism, yet human research in this regard remains scant. The present study investigated the effects of cannabis administration, via different routes, on peripheral concentrations of appetitive and metabolic hormones in a sample of cannabis users. This was a randomized, crossover, double-blind, placebo-controlled study. Twenty participants underwent four experimental sessions during which oral cannabis, smoked cannabis, vaporized cannabis, or placebo was administered. Active compounds contained 6.9 ± 0.95% (~50.6 mg) ∆9-tetrahydrocannabinol (THC). Repeated blood samples were obtained, and the following endocrine markers were measured: total ghrelin, acyl-ghrelin, leptin, glucagon-like peptide-1 (GLP-1), and insulin. Results showed a significant drug main effect (p = 0.001), as well as a significant drug × time-point interaction effect (p = 0.01) on insulin. The spike in blood insulin concentrations observed under the placebo condition (probably due to the intake of brownie) was blunted by cannabis administration. A significant drug main effect (p = 0.001), as well as a trend-level drug × time-point interaction effect (p = 0.08) was also detected for GLP-1, suggesting that GLP-1 concentrations were lower under cannabis, compared to the placebo condition. Finally, a significant drug main effect (p = 0.01) was found for total ghrelin, suggesting that total ghrelin concentrations during the oral cannabis session were higher than the smoked and vaporized cannabis sessions. In conclusion, cannabis administration in this study modulated blood concentrations of some appetitive and metabolic hormones, chiefly insulin, in cannabis users. Understanding the mechanisms underpinning these effects may provide additional information on the cross-talk between cannabinoids and physiological pathways related to appetite and metabolism.

Routes of cannabis administration among females in the year before and during pregnancy: Results from a pilot project

Use of cannabis during pregnancy is on the rise, yet little is known about how women administer cannabis during the perinatal period. This study examined self-reported modes of cannabis administration among women in the year before and during pregnancy, and their association with self-reported cannabis use frequency using data from 585 women screened in 2018-2019 for cannabis use during standard prenatal care in two medical centers in Northern California. The prevalence of cannabis use was 12% before pregnancy and 3% during pregnancy. Among the 71 women who reported cannabis use before pregnancy and the 19 women who reported cannabis use during pregnancy, smoking was the most common mode of administration (58% and 42%), followed by edibles (27% and 16%), vaping (23% and 16%), lotions (11% and 5%), and other (10% and 0%). In the year before pregnancy and during pregnancy, monthly or less use was most common (56% and 58%), followed by weekly use (24% and 26%) and daily use (20% and 16%). Among cannabis users, 43% used more than one mode before pregnancy compared to 15% during pregnancy. Daily cannabis use was most common among women who reported smoking only or smoking in combination with other modes. These novel results indicate that while smoking is the most common mode of cannabis administration during the perinatal period, there is variation in use and co-use of alternative modes. Future studies are needed to understand the relative health effects associated with individual and combined modes of cannabis administration during pregnancy.

Subjective effects of combustible, vaporized, and edible cannabis: Results from a survey of adolescent cannabis users

BACKGROUND

Data from controlled laboratory experiments in adults indicate that the subjective effects of cannabis vary by administration method (e.g., combustible, vaporized). Whether the subjective effects of cannabis experienced in the natural ecology and among adolescents differ by cannabis administration method is unknown. In this observational study, adolescents' retrospective reports of subjective effects after combustible, edible, and vaporized cannabis use were examined.

METHODS

Students from ten public schools in Los Angeles, CA, USA (M[SD] age = 16.1 [.43] years) who reported past 6-month use of combustible, edible, or vaporized cannabis (N = 584) were surveyed on subjective effects experienced after use (yes/no). They were provided with a 12 item self-report checklist of six positive (e.g., relaxed, energetic) and six negative (e.g., drowsy, lazy) subjective effects. For each method of administration, affirmative responses were summed in positive (range: 0-6) and negative (range: 0-6) effect composite scores.

RESULTS

Generalized estimating equations adjusted for demographics and recent cannabis use revealed a graded pattern of differences in positive subjective effects across products, with highest scores for combustible (M[SD] = 3.98[1.76]), followed by edible (M[SD] = 3.58 [2.04]) and vaporized (M[SD] = 3.11 [2.21]) cannabis (all pairwise cross-product contrasts p < .01). Mean negative effect score was highest for edible (M[SD] = 2.27 [1.95]), followed by combustible (M[SD] = 1.94 [1.66]), and vaporized (M[SD] = 1.34 [1.73]) cannabis, respectively (all pairwise contrasts p < .02).

CONCLUSION

Adolescents' reports of subjective effects varied across cannabis administration methods. Combustible cannabis' more desirable subjective effects profile might be indicative of higher abuse liability.

Beyond the Bud: Emerging Methods of Cannabis Consumption for Youth

Cannabis continues to be the most widely used illicit substance among youth, as many teens view the risks of cannabis consumption to be low. With cannabis laws becoming lax and dispensaries becoming more prevalent throughout the United States, highly concentrated Δ-9-tetrahydrocannibinol (THC) is becoming readily available. This article examines the available literature on consumption of concentrated THC, focusing on potential consequences of concentrate use among youth. Various methods for consuming concentrated THC, including ingestion of edibles, vaping, and dabbing, are discussed, along with associated risks of each consumption method. Recommendations for health professionals are provided.

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

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

A qualitative analysis of cannabis vaporization among medical users

Cannabis vaporization is a prevailing mode of administration among medical users for symptom relief. Limited research to date has considered factors that contribute to vaporization in medical users, although initial evidence suggests that vaporization may provide unique therapeutic advantages relative to other modes. This study aimed to provide an in-depth qualitative examination of vaping behavior and use preferences among medical cannabis users. Qualitative interviews were conducted with Rhode Island medical cannabis registration card holders (n = 25). Interviews followed a semistructured agenda and were audio-recorded and transcribed for applied thematic analysis. Key vaporization themes were summarized. Several themes emerged related to (a) medication dosing and administration (flexible timing of medication delivery; ease when traveling; type of device/cannabis formulation), (b) physical health advantages of vaping (general health benefits; better for medical condition; promoting tobacco cessation), (c) general advantages of vaping (portability, concealability, efficiency), and (d) disadvantages (weaker medication delivery; device cost; technology-use barriers). Various factors contribute to cannabis vaporization among medical users that are both general and medical-specific. Certain aspects of vaping may also interfere with effective delivery of cannabis, including technology aspects and device cost. These findings highlight the heterogeneity in vaporization behavior. Future work is needed to further identify factors that contribute to the therapeutic efficacy of cannabis and its modalities of use. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Methods to Assess Cannabis Consumption in Population Surveys: Results of Cognitive Interviewing

The Cannabis Act legalized the possession and sale of nonmedical cannabis in Canada on October 17, 2018. Evaluating the impact of cannabis legalization requires a more thorough understanding than is provided by most existing measures of cannabis use. The aim of this study was to pretest a range of cannabis consumption measures used in a population-based survey and to share insights gained in the process. Cognitive interviewing was conducted among 10 cannabis users aged ≥16 years. Comprehension and self-reporting of consumption types and amounts, sources of purchase, and cannabinoid levels were examined. Findings revealed areas for improvement in a number of survey items, including unclear wording and reference images. Identified issues were used to improve the survey for use in the International Cannabis Policy Study. The authors discuss important principles (e.g., use of visual cues, user-selected units, and time frames) that should be adopted when assessing cannabis use in population-based studies.

Delta-9-tetrahydrocannabinol intoxication is associated with increased prefrontal activation as assessed with functional near-infrared spectroscopy: A report of a potential biomarker of intoxication

The primary psychoactive compound in cannabis, Δ9-tetrahydrocannabinol (THC), binds to cannabinoid receptors (CB1) present in high concentrations in the prefrontal cortex (PFC). It is unknown whether the PFC hemodynamic response changes with THC intoxication. We conducted the first double-blind, placebo-controlled, cross-over study of the effect of THC intoxication on functional near infrared spectroscopy (fNIRS) measures of PFC activation. Fifty-four adult, regular (at least weekly) cannabis users received a single oral dose of synthetic THC (dronabinol; 5-50 mg, dose individually tailored to produce intoxication) and identical placebo on two visits at least one week apart. fNIRS recordings were obtained during a working memory task (N-Back) at three timepoints: before THC/placebo, at 100 min (when peak effects were expected), and at 200 min after THC/placebo administration. Functional data were collected using a continuous-wave NIRS device, with 8 sources and 7 detectors arrayed over the forehead, resulting in 20 channels covering PFC regions. Participants also completed frequent heart rate measures and subjective ratings of intoxication. Approximately half of participants reported significant intoxication. Intoxication ratings were not correlated with dose of THC. Increases in heart rate significantly correlated with intoxication ratings after THC dosing. Results indicated that 100 min after THC administration, oxygenated hemoglobin (HbO) response significantly increased from pre-dose HbO levels throughout the PFC in participants who reported significant intoxication. Changes in HbO response significantly correlated with self-reported intoxication at 100 min after THC administration. Among those who reported intoxication, HbO response decreased at 200 min after THC, when intoxication had largely resolved, compared to the peak THC time point. This study demonstrates that THC intoxication causes increased PFC activity, and fNIRS of the PFC can measure this effect. Increased neural activation in PFC represents a potential biomarker for cannabis intoxication.

Changing landscape of cannabis: novel products, formulations, and methods of administration

Laws regulating cannabis have changed radically in the U.S. and abroad. Historically, users smoked dried cannabis flowers that contained Δ9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, as the principal product constituent. Coincident with cannabis legalization and increased interest in medicinal use of the plant, there is now an expansive retail cannabis marketplace with novel cannabis products, formulations, and methods of administration. In this review, we describe emergent cannabis product chemotypes (e.g. THC-dominant, CBD-dominant, balanced or 'hybrid' with high concentrations of THC and CBD), product formulations (e.g. edibles, concentrates), and methods of administration (e.g. smoked, vaporized, orally ingested). Psychologists can play a pivotal role in studying the health impact of cannabis legalization and conducting research to inform product regulation.