It Is Past Time to Consider Cannabis in Vaping Research

Dual-Vaping of Nicotine and Cannabis Among Adults Who Currently Use Tobacco Products in Five New England States

INTRODUCTION

Current measures of vaping behaviors in the U.S. do not distinguish what substances participants are vaping and to what extent they are dual-vaping nicotine and cannabis. This study describes the use of new survey questions that more specifically ask whether participants who vape are vaping nicotine, cannabis, cannabidiol (CBD), or another substance.

AIMS AND METHODS

Adults, who reported any past 30-day tobacco use, from five New England states participated in an online survey from April 2021 to July 2022. Participants who vaped were asked, "Have you used any of the following vape substances in the past 30 days?" with the possible responses of nicotine, cannabis, CBD, other, and "don't know." Dual use of both nicotine and cannabis was defined as the vaping of both nicotine and cannabis and/or CBD in the past 30 days, operationalized as a dichotomous outcome. Data were collected in monthly, repeated cross-sectional waves. Multinomial logistic regression was used to examine correlates of dual-vaping.

RESULTS

The analytic sample included 1547 adults who reported past 30-day tobacco use (mean age 42.9 years, 62.8% female, 85.4% White, 48.5% income of less than $50 000). Over one-quarter (26.1%) reported dual-vaping in the past 30 days. Identifying as male (p = .002) and self-rated anxiety (p = .043) were associated with a higher odds of dual-vaping.

CONCLUSIONS

Our findings show that a sizable proportion of a sample of New England adults who have used tobacco in the past 30 days are dual-vaping nicotine and cannabis. Adequate survey measures for assessing the vaping of multiple substances can help in better screening and characterization of health behaviors around dual-use.

IMPLICATIONS

This study addresses a key gap in adequate survey measures for assessing vaping of multiple substances. We found that among adults with past 30-day tobacco use, dual-vaping was prevalent and associated with different correlates, such as self-reported anxiety and education level, compared to sole-vaping of nicotine or cannabis. Our findings may help in characterizing and targeting future population-level surveillance and intervention efforts for multiple substance use behaviors.

The Relationship between Vaping Cannabis and Frequency of Cannabis Use and Cannabis-Related Problems among Urban High School Students

Background: Vaping, including vaping cannabis, is increasing among adolescents. In this longitudinal study, we examined the relationship between vaping cannabis and frequency of cannabis use and related problems over 6 months among adolescents. Material and Methods: Data were from 233 participants (46.8% male, 93.1% African American, mean age = 16.4 years) reporting cannabis use. The Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) assessed frequency of past 30-day cannabis use and cannabis-related problems at baseline, 3- and 6-months post-baseline. We used latent growth curve modeling to compare vaping to non-vaping adolescents on trends in cannabis use frequency and ASSIST cannabis scores. Results: Adolescents who vaped cannabis (11.7%) had higher past 30-day frequency (mean = 17.89 days, SD = 10.49) of cannabis use at baseline compared to adolescents who had not vaped (mean = 12.1 days, SD = 10.93), but reported a significantly sharper decline in frequency of cannabis use (b = -0.34, p = 0.017). A significantly steeper decrease existed in the mean cannabis ASSIST scores for the vaping group than for the non-vaping group (b = -0.34, p = 0.014). Mean ASSIST scores on the cannabis subscale between the two groups were significantly different at 6-month follow-up (Vape mean = 6.00, SD = 8.12 vs. Non-vape mean = 9.6, SD = 9.39; p < 0.021). Conclusions: In a sample of cannabis-using adolescents, adolescents with experience vaping cannabis, compared to adolescents without vaping experience, on average reported sharper decreases in frequency of cannabis use and cannabis-related problems such as health or social problems.

Prevalence and correlates of past 30-day dual-vaping of nicotine and cannabis among adolescents in five New England states

SIGNIFICANCE

Adolescent vaping behavior includes vaping of multiple substances, including both nicotine and cannabis (dual-vaping). This study describes the prevalence and the sociodemographic correlates of past 30-day dual-vaping.

METHODS

We recruited adolescents ages 13-17 from five New England states (Massachusetts, Connecticut, Rhode Island, Vermont, New Hampshire) through the Prodege online survey panel from April 2021 to August 2022. Dual-vaping was defined as vaping both nicotine and cannabis (THC and/or CBD) in the past 30-days. We analyzed the prevalence of sole-nicotine, sole-cannabis, and dual-vaping of nicotine and cannabis and used multinomial logistic regression to examine associations between sociodemographic factors and sole- and dual-vaping of nicotine and cannabis.

RESULTS

The analytic sample included 2013 observations from 1858 participants (mean age 15.1 years, 46.2% female, 74.1% White, 82.2% heterosexual). Among these observations, 5.6% reported past 30-day sole-nicotine vaping, 5.5% reported sole-cannabis vaping, and 7.3% had dual-vaped. Correlates for higher odds of past 30-day dual-vaping included total social media sites used and household tobacco use, in contrast with sole-cannabis vaping, which included older age and self-reported depression (all p's <0.05).

DISCUSSION

Adolescent past 30-day dual-vaping of nicotine and cannabis was more prevalent than past 30-day sole-vaping of either nicotine or cannabis alone. Future studies should continue to collect detailed data on the type of substances, besides nicotine, that adolescents are vaping.

What Substances Are Adolescents Vaping? Estimating Nicotine-Specific and Cannabis-Specific Vaping from US National Youth Surveys

BACKGROUND

Youth use of electronic cigarettes ("e-cigarettes") is an ongoing concern. Vaping is usually assumed to be of nicotine, but survey responses may also include vaping of non-nicotine substances (particularly cannabis), which can impose different risks. The current study quantifies the proportions of nicotine-specific and cannabis-specific vaping among adolescents.

METHODS

Data from the Monitoring the Future (MTF) 2021 survey were analyzed with respect to the substance vaped: nicotine, cannabis, or flavoring only. Past-30-day (P30D) nicotine-specific vaping (exclusively, or also having vaped other substances) and cannabis-specific vaping were calculated. Results were also broken down by grade level, cigarette smoking history (current, former, or never), and frequency of e-cigarette use (<20 vs. 20+ days in P30D).

RESULTS

Among 4706 P30D e-cigarette users, 84.2% vaped nicotine; the remaining 15.8% reported not vaping any nicotine in P30D. Cannabis vaping was reported by 48.4% of P30D vapers. Vaping both nicotine and cannabis in P30D was more common in current and former smokers than in never-smokers, and in frequent vapers (of any substance). Conversely, never-smokers were more commonly vaping cannabis but not nicotine, compared to current and former smokers. Supplementary NYTS 2022 analyses were consistent with these findings.

CONCLUSIONS

A notable proportion of self-reported P30D vapers reported not vaping nicotine; nearly half vaped cannabis. Capturing the variety of substances used in vaping devices is imperative for accurate public health surveillance of both nicotine and cannabis vaping among US adolescents, considering their different respective harms and regulatory frameworks.

Assessing use of inhalable nicotine products within complex markets: the dilemma of heated tobacco products

The introduction of electronic inhalable products, such as nicotine vaping products (NVPs) and heated tobacco products (HTPs), has further diversified the nicotine market landscape. This poses unique challenges in measuring self-reported nicotine use behaviours, which have been the hallmark of tobacco surveillance systems. This paper raises concerns of potential measurement error for electronic inhalable product use in surveys due to similarities in product design between NVPs and HTPs, as well as changing trends in cannabis administration. We identify several strategies for addressing this issue (eg, including descriptive preambles in surveys that differentiate product classes from one another; incorporating survey questions that probe beyond an initial question regarding product use). In the absence of comprehensive validation studies, caution is warranted when interpreting survey results that rely on self-reported HTP use.

Correlates of adolescent sole-, dual- and poly-use of cannabis, vaped nicotine, and combusted tobacco

BACKGROUND

Compared to single substance use, adolescents' use of multiple substances is associated with more severe dependence, cessation outcomes, and health risks. This study examined correlates of use and co-use of e-cigarettes, combusted tobacco, and cannabis among high school-aged (9th-12th grade, approximately aged 14-18) adolescents.

METHODS

We analyzed the 2019 Massachusetts Youth Health Survey (MYHS) data to calculate the weighted means of any past 30-day sole-use of e-cigarettes, sole-use of combusted tobacco, sole-use of cannabis, dual-use of two of the above substances, and poly-use of all three substances. We then used weighted multinomial logistic regression to examine the associations between demographic, social and behavioral factors and sole-, dual-, and poly-use (vs. no use) of these substances.

RESULTS

Among N = 1614 respondents, any past 30-day dual-use of e-cigarettes and cannabis was the most prevalent (17.2%, SE: 1.3%). Sole-use of combusted tobacco was less than 1%, whereas 4.5% (SE: 0.7%) of respondents reported poly-use of e-cigarettes, cannabis, and combusted tobacco. Lower academic grades and self-reported depression (1 item on persistent feelings of sadness or hopelessness) were associated with increased odds of dual-use of e-cigarettes and cannabis and poly-use (vs. sole-use of any substance). Adolescents who self-reported having "any long-term emotional problems or learning disabilities" had greater odds of poly-use.

CONCLUSION

Different sets of correlates were associated with sole-, dual-, and poly-use, suggesting that certain adolescents may be more vulnerable than others to multiple substance use. Future research should examine potentially modifiable upstream influences, such as the home environment and socioeconomic factors that may affect the relationship between adolescent mental health, school performance, and multiple addictive substance use.

Electronic Nicotine Delivery Systems and E-Liquid Modifications to Vape Cannabis Depicted in Online Videos

Importance

Electronic nicotine delivery systems (ENDS) were created to vape nicotine e-liquids; however, social media demonstrates increased ENDS modifications to vape cannabis. Analysis of social media content helps with understanding ENDS modifications for cannabis use, overlapping markets for ENDS and cannabis, and the need for additional regulation.

Objective

To analyze online videos for use, modification, and marketing of ENDS to vape cannabis.

Design, Setting, and Participants

In this qualitative study, 10 searches were performed on YouTube on July 14, 2022, using different combinations of relevant search terms to identify videos depicting modifications to ENDS and e-liquids to vape cannabis. The first 40 videos from each search (400 videos total, 152 without duplicates) were extracted, of which 59 included depiction or discussion of cannabis vaping content. Content analysis of videos included iterative development of codes, consensus building across team members, and reliability checks.

Main Outcomes and Measures

Metadata (ie, video length, number of likes, comments, and views) were extracted for included videos. Coding was performed for uploader type, modifications to ENDS and e-liquids, devices used, cannabis products vaped, age restriction, purchasing links, health claims, and discussion of warning messages and cannabis regulations.

Results

Of the 59 videos analyzed, 34 (58%) included tetrahydrocannabinol; 33 (56%), cannabidiol; and 8 (14%), both. A total of 21 videos (36%) were age-restricted, while 25 (42%) included purchasing links for cannabis products, 20 (34%) for ENDS, and 7 (12%) for nicotine e-liquids. Twenty-six videos (44%) made claims about health benefits of vaping cannabis. Forty-one videos (69%) demonstrated vaping manufacturer-made cannabis products (eg, cannabis concentrates) with no modifications needed. Eighteen videos (31%) depicted modifications to e-liquids or ENDS for cannabis use. The most frequent modification was mixing e-liquids with cannabis products to be compatible with ENDS. The most frequently reported reason for modifications was to vape cannabis in public by using the same devices used for nicotine.

Conclusions and Relevance

This qualitative study of online videos found high frequencies of statements about health benefits from vaping cannabis, frequent purchasing links, and inadequate age restrictions. Exposure to such content on social media platforms may increase risk of cannabis vaping among youth. Use of the same devices for multiple substances may also enable dual use and complicate the US Food and Drug Administration's regulation of ENDS.

Associations of daily alcohol, cannabis, combustible tobacco, and e-cigarette use with same-day co-use and poly-use of the other substances

BACKGROUND

Young adults frequently use alcohol, cannabis, and tobacco together. Given the increased prevalence of e-cigarette use and recreational cannabis use, we investigated daily patterns of alcohol, cannabis, and tobacco use and distinguished combustible tobacco from e-cigarettes.

METHODS

Young adult college students (N=341) reporting past-month alcohol and cannabis use "at the same time so that their effects overlapped" completed two 28-day bursts of repeated daily surveys. Exposures were day- and person-level use of each substance. Outcomes were (1) same-day co-use of each remaining substance or (2) poly-use of the other substances.

RESULTS

Daily use of alcohol, cannabis, combustible cigarettes, and e-cigarettes increased the odds of same-day co-use of the other substances (except combustible tobacco with e-cigarettes) and each poly-use outcome. The influence of person-level substance use on daily substance use was less consistent. Only e-cigarette use increased the odds of daily alcohol use. Use of either tobacco product but not alcohol increased the odds of daily cannabis use. Person-level alcohol and cannabis use increased the odds of daily use of either tobacco product but use of one tobacco product was not associated with daily use of the other product.

CONCLUSIONS

These findings increase our understanding of emerging daily patterns of alcohol, cannabis, and tobacco co-use, and the impact of different tobacco products. Future work is needed to extend this research into non-college samples and people who use tobacco but do not use alcohol and cannabis simultaneously, and examine daily chronologies of multiple substances that could serve as dynamic markers of risk.

Community and Opinion Leadership Effects on Vaping Discourse: A Network Analysis of Online Reddit Threads

Reddit is a popular hub for discussing vaping. A deeper understanding of the factors that influence this online discourse could inform public health messaging efforts targeting this platform. Using a network analysis framework, we sought to investigate the role of opinion leaders and online communities in facilitating vaping discussions on Reddit. We collected Reddit submissions about vaping posted in May 2021 and used these submissions to generate subreddit-level (N=261) and thread-level (N=8,377) data sets. We coded subreddits into four community categories: 1) Vaping, 2) Substance use, 3) Cessation, and 4) Non-specific. We used sociometric in-degree centrality statistics to identify subreddit opinion leaders. We computed non-parametric ANOVAs and negative binomial regressions to test associations between opinion leadership and subreddit community category variables on subreddit network composition (comprised of subreddit-level network nodes and edges) and the number of commenters on Reddit threads about vaping (thread-level). Subreddit network composition was largely dependent on opinion leaders in Non-specific communities, and less so in Vaping and Substance use communities. At the thread-level, the rate of commenters was higher among threads initiated by opinion leaders than non-opinion leaders (adjusted rate ratio [aRR]=4.84). Furthermore, threads posted in Vaping (aRR=1.64), Substance use (aRR=1.92), and Cessation (aRR=1.21) communities had higher commenter rates than those posted in Non-specific communities. Communities and opinion leaders play a key role in the composition and reach of vaping discussions on Reddit. These findings provide a foundation for public health campaigns and interventions targeting Reddit and perhaps other social media platforms.

E-cigarettes may serve as a gateway to conventional cigarettes and other addictive drugs

Electronic cigarettes (e-cigarettes) are devices that allow the user to inhale nicotine in a vapor, and are primarily marketed as a means of quitting smoking and a less harmful replacement for traditional cigarette smoking. However, further research is needed to determine if vaping nicotine via e-cigarettes can be effective. Conversely, nicotine has been considered a gateway drug to alcohol and other addictive drugs and e-cigarettes containing nicotine may have the same effects. Previous reports have shown that e-cigarette use may open the gate for the use of other drugs including conventional cigarettes, cannabis, opioids, etc. The increasing prevalence of e-cigarettes, particularly among youth and adolescents in the last decade have led to an increase in the dual use of e-cigarettes with alcohol, cannabis, and other illicit drug use like heroin and 3-4-methylenedioxymethamphetamine (MDMA). The advent of e-cigarettes as a device to self-administer addictive agents such as cocaine and synthetic cathinones may bring about additional adverse health effects associated with their concurrent use. This review aims to briefly describe e-cigarettes and their different generations, and their co-use with other addictive drugs as well as the use of the device as a tool to self-administer addictive drugs, such as cocaine, etc.

Exploring Differences in Daily Vaping of Nicotine and Cannabis among People Who Use Drugs in New Zealand

Background: Little is known about daily vaping of different substances, particularly cannabis. Aim: To explore daily vaping of cannabis and nicotine products in a sample of people who use drugs in New Zealand. Method: The online New Zealand Drug Trends convenience survey (N = 23,500) was promoted to those aged 16+ via a targeted Facebook™ campaign, with 9,042 reporting vaping in the past six months. Multivariate logistic regression models were fitted to identify predictors of daily vaping of: (i) nicotine e-liquids, (ii) no-nicotine e-liquids, (iii) cannabis e-liquids/oils, (iv)cannabis herb. Results: Forty-two percent of past 6-month vapers used a vaporizing device "daily or near daily" (n = 3,508). Nicotine was most common substance used by daily vapers (96%), followed by dry herb cannabis (12%), no-nicotine e-liquids (10%) and cannabis e-liquid (6%). Daily vaping of no-nicotine e-liquids was associated with abstinence from tobacco use. Frequency of cannabis use was negatively correlated with daily vaping of nicotine liquids and positively correlated with daily vaping of no-nicotine and herbal cannabis. Younger age strongly predicted daily vaping of nicotine and no-nicotine liquids, but the reverse association was observed for daily vaping of herbal cannabis. Māori were less likely to daily vape cannabis herb than NZ Europeans. Daily vaping of both cannabis e-liquid and cannabis herb was associated with medicinal cannabis use. Conclusion: Daily vapers of nicotine and cannabis differed by several characteristics. Younger age group is at risk of daily vaping nicotine and non-nicotine, while herbal cannabis vaping is associated with older and medicinal use, suggesting a need for a nuanced vape policy response.

Longitudinal trajectories of marijuana use in tobacco products among young adult Texas college students from 2015 to 2019

AIMS

To measure longitudinal trajectories of marijuana use in four tobacco/nicotine products (hand-rolled cigarettes/spliffs, cigars/blunts, hookah, and e-cigarettes) among young adult Texas college students from 2015 to 2019.

DESIGN

This study used six consecutive waves of data from the marketing and promotions across colleges in Texas project (Project M-PACT), a longitudinal study of the tobacco behaviors of young adult college students. The first four waves were collected every 6 months (fall 2015-spring 2017), and the final two waves were conducted yearly (spring 2018 and 2019). Growth curve models measured trajectories of marijuana use in tobacco products across the 3.5-year period.

SETTING AND PARTICIPANTS

A total of 4857 young adults from 24 colleges in the largest metropolitan areas of Texas, United States (Austin, Dallas, Houston, and San Antonio): mean age = 21.0, SD = 2.3; 64.2% assigned female; 36.1% non-Hispanic white, 31.0% Hispanic, and 33.0% other or combination race/ethnicity.

MEASUREMENTS

Participants completed online surveys assessing their past 6-month use of marijuana in four tobacco products of interest (spliffs, blunts, hookah, and e-cigarettes) and socio-demographic variables (sex, race/ethnicity, age, 2-year/4-year college attendance, and sexual and gender minority identity).

FINDINGS

Observed vaping marijuana in e-cigarettes approximately doubled between the spring of 2015 and the spring of 2019, from 11.8% to 23.9% following a quadratic time trend (linear OR = 0.84, 95% CI = 0.73-0.97, quadratic OR = 1.18, CI = 1.13-1.22). This same time period saw a quadratic decline in using marijuana in hookah (P < 0.001) and no changes in using hand-rolled cigarettes/spliffs or cigars/blunts for marijuana delivery.

CONCLUSIONS

The popularity of nicotine e-cigarettes appears to be expanding the avenues for marijuana delivery among young adults in Texas, United States.

Differential Associations between Weight Status (Obesity, Overweight, and Underweight) and Substance Use in Young Adulthood

BACKGROUND

Past evidence suggests obesity co-occurs with tobacco/nicotine, cannabis, and alcohol use in young adulthood, but whether this relationship extends to nicotine or cannabis vaping is unclear. Furthermore, differential relationships between substance use and specific weight status categories (obesity, overweight, and underweight) have not been assessed. This study assessed prevalence of tobacco/nicotine, cannabis, and alcohol use by weight status categories in young adulthood.

METHODS

Of the 1322 young adults (18-29 years; 20.5 ± 2.3 years; 63% female; 42% Hispanic/Latino/a/x, 30% Asian-American/Asian, 18% Caucasian/White, 7% Multiracial, and 2% African-American/Black) from a public, urban university were surveyed on their health-risk behaviors in the spring and fall of 2021.

RESULTS

Multinomial logistic regression models assessed six-month follow-up substance use prevalence (never, lifetime but no past 30-d use, and past 30-d use) by baseline weight status (obese, overweight, underweight; reference: healthy weight). Obesity predicted lower odds of past 30-d nicotine vaping (aOR [95% CI] = 0.27 [0.08-0.92]). Overweight predicted higher odds of lifetime combustible cannabis (aOR [95% CI] = 1.58 [1.08-2.30]) and past 30-d binge drinking (aOR [95% CI] = 1.79 [1.12-2.85]). Underweight was associated with lower odds of lifetime cannabis vaping (aOR [95% CI] = 0.35 [0.12-0.99]) and combustible cannabis (aOR [95% CI] = 0.38 [0.16-0.87]).

CONCLUSIONS

Differential relationships between obesity and overweight on tobacco/nicotine, cannabis, and alcohol use suggest greater specificity is needed when evaluating relationships between higher weight status and substance use. It appears that overweight young adults may be at higher risk of substance use than obese young adults. Greater efforts to consider multiple weight status groups, not just obese, may have significant implications for tobacco/nicotine prevention and intervention efforts targeting vulnerable populations.

Use Patterns, Flavors, Brands, and Ingredients of Nonnicotine e-Cigarettes Among Adolescents, Young Adults, and Adults in the United States

IMPORTANCE

Nonnicotine e-cigarettes contain chemicals, flavorants, and solvents that have known health harms and/or have not been proven safe for inhalation.

OBJECTIVE

To evaluate nonnicotine e-cigarette use patterns, including common flavors, brands, and ingredients.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included a convenience sample of US residents aged 13 to 40 years who completed an online survey in November and December 2021. Quota sampling was used for an equal proportion of participants aged 13 to 17 years, 18 to 20 years, and 21 to 40 years, balanced for sex, race, and ethnicity per the latest US Census.

MAIN OUTCOMES AND MEASURES

Nonnicotine e-cigarette use (ever, past 30- and past 7-day, number of times used, time taken to finish); co-use with nicotine e-cigarettes; age at first try; and flavors, brands, and ingredients used.

RESULTS

Overall, 6131 participants (mean [SD] age, 21.9 [6.8] years; range, 13-40 years; 3454 [56.3%] identifying as female) completed the survey (55.1% completion rate). Among all participants, 1590 (25.9%) had ever used a nonnicotine e-cigarette, 1021 (16.7%) used one in the past 30 days, and 760 (12.4%) used one in the past 7 days. By age group, 227 of 1630 participants aged 13 to 17 years (13.9%), 497 of 2033 participants aged 18 to 20 years (24.4%), 399 of 1041 participants aged 21 to 24 years (38.3%), and 467 of 1427 participants aged 25 to 40 years (32.7%) had ever used nonnicotine e-cigarettes. Among 1590 participants who had ever used a nonnicotine e-cigarette, 549 (34.5%) had used one more than 10 times; 1017 (63.9%) finished 1 nonnicotine e-cigarette in less than 1 week. Co-use of nonnicotine with nicotine e-cigarettes was reported by 1155 participants (18.8%), 1363 (22.2%) exclusively used nicotine e-cigarettes, and 431 (7.0%) exclusively used nonnicotine e-cigarettes. Most-used flavors were sweet, dessert, or candy (578 [36.3%]); fruit (532 [33.4%]); and mint or menthol (321 [20.2%]); similar flavor patterns were observed for the top 2 flavors among those who used nonnicotine e-cigarettes in the past 30 days, followed by combinations of coffee, alcohol, flower, plant, and mint or menthol flavors by age group. Participants most reported using tetrahydrocannabinol (587 [36.9%]), cannabidiol (537 [33.7%]), melatonin (438 [27.5%]), caffeine (428 [26.9%]), and essential oils (364 [22.9%]) in their nonnicotine e-cigarettes.

CONCLUSIONS AND RELEVANCE

In this study of adolescents, young adults, and adults, a sizeable proportion reported having used nonnicotine e-cigarettes and co-using them with nicotine e-cigarettes. Surveillance studies should further assess nonnicotine e-cigarette use patterns and regulations, and prevention should be developed to address youth appeal, unsubstantiated health claims, and possible health harms.

Effects of combined THC and heroin vapor inhalation in rats

RATIONALE

Opioids are effective medications, but they have several key limitations including the development of tolerance, establishment of dependence, diversion for non-medical use, and the development of addiction. Therefore, any drugs which act in an additive or synergistic fashion with opioids to address medical applications have the potential to reduce opioid-related harms.

OBJECTIVES

To determine if heroin and Δ9-tetrahydrocannabinol (THC) interact in an additive or independent manner to alter nociception, body temperature, and spontaneous locomotor activity when inhaled or injected.

METHODS

Groups of female and male rats, implanted with radiotelemetry transmitters, were exposed to vapor generated from heroin (50 mg/mL in propylene glycol vehicle; PG), THC (50 mg/mL), or the combination for assessment of effects on temperature and activity. Thermal nociception was assessed with a warm water tail-withdrawal assay.

RESULTS

Heroin inhalation increased temperature and activity whereas THC inhalation decreased temperature and activity in both female and male Sprague-Dawley rats. Effects of combined inhalation were in opposition, and additional experiments found the same outcome for the injection of heroin (0.5 mg/kg, s.c.) and THC (10 mg/kg, i.p.) alone and in combination. In contrast, the co-administration of heroin and THC by either inhalation or injection produced additive effects on thermal nociception in both male and female Sprague-Dawley and Wistar rats.

CONCLUSIONS

This study shows that additive effects of THC with an opioid on a medical endpoint such as analgesia may not generalize to other behavioral or physiological effects, which may be a positive outcome for unwanted side effects.

Sociodemographic differences in patterns of nicotine and cannabis vaping among US adults

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About half (54.2%) of adults who used electronic vapor products (EVPs) vaped nicotine only.

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Only 7.4% of adults who used EVPs vaped cannabis only, while one-fourth (23.8%) vaped nicotine and cannabis.

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Patterns of nicotine and cannabis vaping differed by age, race/ethnicity, education, and sexual orientation.

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Vaping nicotine and cannabis and cannabis only was more common among young adults.

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Vaping cannabis only was more common among Hispanic and non-Hispanic Black adults.

Nicotine and cannabis vaping has increased over the past several years. While patterns of cigarette and cannabis co-use are well-documented, less is known about the intersection between nicotine and cannabis vaping, especially among adults. Thus, we categorized nicotine and cannabis vaping among adults (18+) who currently (past 30-day) used electronic vapor products (EVPs) from Wave 4 of the Population Assessment of Tobacco and Health Study (n = 3795) as: 1) nicotine only, 2) cannabis only, 3) nicotine and cannabis, and 4) non-nicotine/non-cannabis e-liquid. We calculated vaping pattern proportions overall and by sociodemographic characteristics. Adjusted multinomial logistic regression models assessed associations between sociodemographic characteristics and vaping categories relative to nicotine-only vaping. Approximately half (54.2%) of adults who currently used EVPs vaped nicotine only, 7.4% vaped cannabis only, 23.8% vaped nicotine and cannabis, and 14.6% vaped non-nicotine/non-cannabis e-liquid. Young adults (aged 18–24) (vs. adults aged 35+) had at least three-fold greater odds of vaping cannabis only, nicotine and cannabis, and non-nicotine/non-cannabis e-liquid, compared to nicotine only. Hispanic and non-Hispanic Black (vs. non-Hispanic White) adults had 2.5–3 times greater odds of vaping cannabis only and non-nicotine/non-cannabis e-liquid, compared to nicotine only. Sexual minority adults (vs. heterosexual adults) had 1.5 times greater odds of vaping nicotine and cannabis, compared to nicotine only. Nearly half of adults who vaped EVPs consumed something other than nicotine only, and nicotine/cannabis vaping patterns differed by sociodemographic groups. Vaping and nicotine reduction efforts must recognize that adults who currently vape may be vaping cannabis, or neither nicotine nor cannabis.

Prevalence of Cannabis Use and Cannabis Route of Administration among Massachusetts Adults in Buprenorphine Treatment for Opioid Use Disorder

BACKGROUND

Recent prevalence estimates of cannabis use among individuals receiving medication treatment for OUD (MOUD) are lacking, and no study has characterized cannabis route of administration (cROA) in this population. These knowledge gaps are relevant because cannabis' effects and health outcomes vary by cROA and the availability and perceptions of cROA (e.g., vaping devices) are changing.

METHODS

The Vaping In Buprenorphine-treated patients Evaluation (VIBE) cross-sectional survey assessed the prevalence and correlates of cannabis use and cROA among adults receiving buprenorphine MOUD from 02/20 to 07/20 at five community health centers in Massachusetts, a state with legal recreational and medical cannabis use.

RESULTS

Among the 92/222 (41%) respondents reporting past 30-day cannabis use, smoking was the most common cROA (75%), followed by vaping (38%), and eating (26%). Smoking was more often used as a single cROA vs. in combination others (p = 0.01), whereas vaping, eating, and dabbing were more often used in combination with another cROA (all p < 0.05). Of the 39% of participants reporting multiple cROA, smoking and vaping (61%), and smoking and eating (50%), were the most prevalent combinations. Nonwhite race (vs. white) and current cigarette smoking (vs. no nicotine use) were associated with past 30-day cannabis use in multiple logistic regression.

CONCLUSIONS

Prevalence of past 30-day cannabis use among individuals receiving buprenorphine MOUD in Massachusetts in 2020 was nearly double the prevalence of cannabis use in Massachusetts' adult general population in 2019 (21%). Our data are consistent with state and national data showing smoking as the most common cROA.

Patterns of Cannabis Use among Canadian Youth over Time; Examining Changes in Mode and Frequency Using Latent Transition Analysis

Background: Historically substance use literature has focused on smoking as the main mode of cannabis consumption, so there are knowledge gaps surrounding current understanding of edibles and vaping. These alternative modes of cannabis use are already common among Canadian youth; however, little is known about how these cannabis use patterns change over time. Methods: This study examined the mode (smoking, eating/drinking, vaping) and frequency of cannabis use among a large sample of Canadian youth who participated in 2017-2018 and 2018-2019 data collection waves of the COMPASS study. Using latent transition analysis, this sample consisting of 18,824 youth in grades 9-12 were categorized into cannabis use classes stratified by sex, and their transition between these classes over the one-year period was examined. Results: Three cannabis use classes were identified (occasional multimode, regular multimode, and smoking) alongside one nonuse class. Among youth who reported cannabis use at baseline, transitioning to a multimode group, and/or increasing frequency of multimode use was likely over the one-year period. Conclusions: These findings may highlight a key leverage point for harm-reduction strategies which aim to prevent cannabis related harms associated with high frequency use.

Unknown population-level harms of cannabis and tobacco co-use: if you don't measure it, you can't manage it

BACKGROUND

Nationally representative data of cannabis-tobacco co-use have shown that these substances are closely entwined and have significant adverse health consequences, although population-level harms of co-use are largely unknown. Current epidemiological research does not assess co-use in a manner that has yielded the necessary data to draw conclusions regarding health effects. This has given rise to a hidden population of co-users who go under-served. Therefore, this paper has two aims: (1) to review new challenges in the collection of co-use data due to rapidly changing regulations of cannabis and nicotine products and (2) to provide recommendations for the terminology and assessment of co-use.

ARGUMENT

We argue that: (1) the prevalence of co-use is not being assessed accurately at a population level and (2) changes in legalization have created novel challenges, but without proper monitoring the impact on co-use will go undetected. We propose a three-level tiered set of recommendations for co-use assessments, which includes assessments of cannabis, tobacco and co-use metrics ranging from least burdensome (self-report of co-administered products) to most burdensome (assays, event-level data).

CONCLUSIONS

We propose that clinical studies begin to incorporate cannabis-tobacco co-use assessments to justify better their inclusion in clinical trials and national surveillance surveys. Integration of co-use assessments will aid in understanding the true impact on co-use of the changing cannabis and tobacco/nicotine regulatory environments. Co-use is prevalent and problematic, and the ability to make conclusions about its health outcomes is hindered by lack of nuance in data collection. If you do not measure it, you cannot manage it.

Lessons from the public health responses to the US outbreak of vaping-related lung injury

AIM

To describe an outbreak of lung injuries in 2019 among people who vaped in the United States (type of injuries, people afflicted, substances vaped and cause of the injuries) and to analyse critically the regulatory responses of public health authorities and the media reporting of the outbreak.

METHODS

Case studies of the reporting of the e-cigarette or vaping product use associated lung injury (EVALI) outbreak. We examined data on the number of cases of lung injury provided by the US Centers for Disease Control (CDC), public advice on the causes of the outbreak provided by the CDC and the Food and Drug Administration (FDA), major media reports of the outbreak and proposed regulatory responses by governments in the United States, Australia and the United Kingdom.

RESULTS

The CDC initially suggested that the cause of the outbreak was nicotine vaping because the outbreak followed a large increase in nicotine vaping among US adolescents. Case-control studies revealed that the majority of cases had vaped illicit cannabis oils that were contaminated by vitamin E acetate. The CDC's public advice and the media were slow to report the evidence on the role of cannabis vaping. Popular government regulatory proposals-bans on sales of nicotine flavours and vaporizers-were based on the assumption that nicotine vaping was the cause of the outbreak.

CONCLUSIONS

Media reporting in the United States, Australia and the United Kingdom of the US Centers for Disease Control's analysis of the causes of the e-cigarette or vaping product use associated lung injury outbreak contributed to regulatory over-reactions to nicotine vaping by the public health community.

Concurrent E-cigarette and marijuana use and health-risk behaviors among U.S. high school students

The use of electronic cigarettes (e-cigarettes) and marijuana remain prevalent problems among adolescents nationwide. We assessed current (past 30-day) exclusive e-cigarette use, exclusive marijuana use, and concurrent use with unintentional injury and violent behaviors, alcohol and other drug use behaviors, and sexual behaviors among U.S. high school students. We analyzed 2017 Youth Risk Behavior Survey data including 12,578 high school students nationwide. Multivariable logistic regression models were performed to compare these health-risk behaviors among exclusive e-cigarette users, exclusive marijuana users, and concurrent users with non-users among the overall sample, and then to compare exclusive e-cigarette users and exclusive marijuana users with concurrent users among current users only. All models adjusted for adolescent sex, grade, and race/ethnicity, and other tobacco product use. Approximately 77% of students were non-users, 5.2% were exclusive e-cigarette users, 9.9% were exclusive marijuana users, and 7.8% were concurrent users. Compared to non-users, exclusive e-cigarette users and exclusive marijuana users were more likely to engage in most negative health-risk behaviors associated with unintentional injuries and violence, alcohol and other drug use, and sexual behaviors. Among current users only, exclusive e-cigarette users and exclusive marijuana users were at reduced odds of engaging in most of these health-risk behaviors when compared to concurrent users of both substances. The relationship between exclusive and concurrent e-cigarette and marijuana use and health-risk behaviors highlights the importance of comprehensive educational efforts during high school. Findings suggest need for more studies on influence of e-cigarette and marijuana use on injury and violence risk among youth.