Differences in Tobacco Product Use Among Past Month Adult Marijuana Users and Nonusers: Findings From the 2003-2012 National Survey on Drug Use and Health

Cannabis policy liberalization is only associated with increased blunt use if states lack strong tobacco control

INTRODUCTION

Co-use of tobacco and cannabis has long been an issue for prevention and intervention efforts targeting these substances. Blunt use-cannabis inside a cigar wrapper-has been a consistent mode of cannabis consumption since the 1990s. Since then, both tobacco control and cannabis policies have changed considerably. This paper examines the influence of tobacco taxes and smoke-free policies as well as medical and recreational cannabis policies on blunt use among young people.

METHODS

Combining state-level tobacco control and cannabis policy data with the restricted-access youth cohort of the Population Assessment of Tobacco and Health (PATH) study, we use multilevel logistic regression models to examine the impact of these policies on past-year blunt use.

RESULTS

While we found a main effect whereby both legal medical and recreational cannabis policies are associated with higher odds of blunt use among youth, interaction effects demonstrate that this association only emerges in states lacking a comprehensive tobacco smoke-free policy. In states with smoke-free policies, we found no significant associations between cannabis policy and odds of blunt use.

CONCLUSIONS

Denormalization through smoke-free policies may mitigate the effects of recreational and medical cannabis policies on blunt use. Smoke-free policies represent a possible cost-effective mechanism to curb the co-use of tobacco and cannabis in the form of blunts. States with medical and recreational cannabis policies may benefit from greater prevention efforts for young people specifically focused on blunt use, especially in states that do not have strong tobacco control.

Patterns of blunt and cigar use in the United States, 2015-2019

INTRODUCTION

The use of cigars for blunts (i.e., cannabis rolled in cigar paper) is well-documented; prevalence of cigar and blunt use and associated characteristics are less studied.

METHODS

Pooled data from the 2015-2019 National Survey on Drug Use and Health (NSDUH) were analyzed in 2023. Respondents aged 12+ who reported past 30-day cigar use were categorized into three mutually exclusive use categories: (1) exclusively cigars, (2) exclusively blunts, and (3) both cigars and blunts. We examined associations between cigar-blunt use categories and sociodemographic characteristics.

RESULTS

Among respondents aged 12+ who reported past 30-day cigar use, 48.6% (95% CI=47.6-49.6) reported exclusive cigar use; 44.3% (95% CI=43.3-45.3) reported exclusive blunt use; and 7.2% (95% CI=6.8-7.6) reported cigars and blunts. The prevalence differed by age, with exclusive blunt use most prevalent among youth (72.5% [95% CI=70.7-74.3]) and young adults (62.4% [95% CI=61.4-63.5]), and exclusive cigar use most prevalent among adults 26+ (61.2% [95% CI=59.8-62.5]). Exclusive blunt users smoked more days in the past month (17.5; 95% CI=16.8-18.2), compared to 13.8 days (95% CI=13.2-14.4) for cigar and blunt users, and 7.7 days (95% CI=7.5-8.0) for exclusive cigar users. There were significant differences in sociodemographic characteristics, with female (41.6%; 95% CI=40.3-42.9) and Hispanic (18.2%; 95% CI=17.3-19.2) participants more likely to report exclusive blunt use.

CONCLUSIONS

Exclusive blunt use was the most prevalent pattern of past-30-day cigar use among youth and young adults. Those who use cigars as blunts smoked more cigars per month, suggesting this may be an important group for education and policy efforts.

IMPLICATIONS

Studies that aggregate cigars and blunts into one group may limit potentially meaningful subgroup risk profiles. Additionally, when assessing cigar use, particularly among youth and young adults, it is important to consider blunt use to avoid missing youth who exclusively use cigars for blunts and may not consider blunts as cigar products. Accurate measurement may better inform tobacco and cannabis regulatory actions. Finally, given the high prevalence of blunt use among youth and young adults identified in the present study, additional education efforts may be warranted for this population to reduce long-term risks.

Secondhand cannabis smoke exposure and respiratory symptoms among adults living in a state with legalized medical cannabis with limited smoke-free protections

Background

Little is known about the demographic and health correlates of secondhand cannabis smoke (SHCS) exposure, despite increased availability and use of cannabis across the U.S. This study examined the prevalence and correlates of SHCS exposure in a sample of N=5,410 adults living in Oklahoma and the association of SHCS exposure with self-reported respiratory problems.

Methods

Data were from a repeated cross-sectional online survey of adults ages 18 and older who completed measurements of past 30-day SHCS exposure in the respondent's home, in a vehicle, and/or in an indoor setting; harm perceptions of SHCS exposure; frequency of current respiratory symptoms; past 30-day use of cannabis, alcohol, and cigarettes.

Results

Almost half (42 %) reported past 30-day SHCS exposure. In bivariate tests, those exposed were male, younger, non-Hispanic (NH) black or Hispanic, reported lower educational and financial attainment, had lower harm perceptions of SHCS exposure, endorsed more respiratory symptoms, and reported past 30-day cannabis and cigarette use (all p's < 0.01). In an adjusted regression model, young adulthood (ages 18-24), NH black race (vs NH White), and past 30-day cigarette smoking and cannabis use emerged as the strongest correlates of SHCS exposure. In interaction models, respiratory symptoms were highest among those reporting past 30-day SHCS exposure and past 30-day cannabis use.

Conclusion

SHCS exposure is common and associated with more frequent respiratory symptoms, particularly among cannabis users. Those exposed were more socially and economically vulnerable.

Tobacco Quitline Callers Who Use Cannabis and Their Likelihood of Quitting Cigarette Smoking

INTRODUCTION

Cigarette smoking continues to decline in the U.S., but cannabis use is increasing. Many people who smoke cigarettes also use cannabis. This study examines the characteristics of persons who co-use and those who do not co-use and the likelihood of quitting cigarettes for callers to Kick It California, a large state tobacco quitline.

METHODS

Data were examined from Kick It California callers from January 2020 through December 2023 (N=45,151), including those from a subgroup randomly sampled and reached for evaluation at 7 months after quitline enrollment (n=3,545). The rate of cigarette smoking cessation at 7 months after enrollment for people who co-use cannabis was compared with that for people who do not. Analyses started in 2023 and concluded in January 2024.

RESULTS

More than a quarter (27.2%) of Kick It California callers co-used cannabis. They were more likely to be male, to be younger, and to have a mental health condition than those who did not. Those who co-use cannabis and those who do not have similar rates of receiving quitline counseling or using Food and Drug Administration-approved cessation aids. Controlled for effects of personal characteristics and use of smoking-cessation services, people who co-use cannabis were less likely to quit cigarette smoking 7 months after enrollment (23.2% vs 28.9%; p<0.001). Among those who co-use, 42.9% intended to quit using cannabis in the next 30 days.

CONCLUSIONS

A substantial percentage of tobacco quitline callers use cannabis. Those who do co-use quit cigarette smoking at a lower rate than those who do not. Over 40% of people who co-use reported intention to quit cannabis, making tobacco quitlines a rich environment to learn about people who co-use and develop strategies for intervention.

Predicting Time to Return to Cannabis Use After a Cessation Attempt: Impact of Cumulated Exposure to Nicotine-Containing Products

Objective: Cannabis is frequently co-used with tobacco/nicotine products, especially among young adults. Little is known about the effects of this co-use on cannabis cessation outcomes. Within a sample of young adults using cannabis frequently (current use of ≥5 days/week in the past 3 months), this study aimed to (a) document sources of exposure to tobacco/nicotine products, whether used simultaneously with cannabis or on different occasions, (b) examine if the level of cumulated exposure to tobacco/nicotine (self-reported or from biochemical testing) could predict time to cannabis lapse during a cannabis abstinence period, and (c) explore the relationship between nicotine/tobacco exposure and time to cannabis lapse according to tobacco cigarette smoking status. Method: Urine cotinine measures and self-reported data on use of different tobacco/nicotine products, collected from 32 participants (aged 19 to 23), were analyzed to predict time to lapse during a 2-week period of attempted abstinence from cannabis, controlling for cannabis dependence and sex. Results: Half of participants (56.3%) used at least one tobacco/nicotine product. Higher urine cotinine, representing higher cumulated tobacco/nicotine exposure, was related to a higher risk of lapsing (Hazard Ratio [HR] = 1.64; 95%CI [1.04, 2.58]). The risk of lapsing was even higher ([HR] = 3.46; 95%CI [1.17, 10.25]) among heavily tobacco/nicotine exposed (>600 ng/mL, urine cotinine) participants than among unexposed (<50 ng/mL) or lightly/moderately exposed (50-600 ng/mL) participants. Among those smoking cigarettes (solely or in combination with other products), there was no relation between cotinine level and time to lapse, likely due to a reduced variability in abstinence probability and a high likelihood of lapse observed for higher cotinine levels, mainly achieved by cigarette use. Conclusions: With a rapidly changing landscape of tobacco/nicotine use, our results underscore the need to consider all sources of tobacco/nicotine exposure to fully understand the specific and cumulative contributions of tobacco/nicotine to cannabis cessation outcomes.

Patterns of blunt and cigar use in the United States, 2015-2019

Background

The use of cigars for blunts (i.e., cannabis rolled in cigar paper) is well-documented; proportions of cigar and blunt use and associated characteristics are less studied.

Methods

Pooled data from the 2015-2019 National Survey on Drug Use and Health (NSDUH) were analyzed in 2023. Respondents aged 12+ who reported past 30-day cigar use were categorized into three mutually exclusive use categories: (1) exclusively cigars, (2) exclusively blunts, and (3) both cigars and blunts. We examined associations between cigar-blunt use category and sociodemographic characteristics.

Results

Among people 12 and older who reported past 30-day cigar use, 48.6% (95% CI=47.6-49.6) reported exclusive cigar use; 44.3% (95% CI=43.3-45.3) reported exclusive blunt use; and 7.2% (95% CI=6.8-7.6) reported cigars and blunts. The prevalence differed by age, with exclusively blunts most prevalent among youth (72.5% [95% CI=70.7-74.3]) and young adults (62.4% [95% CI=61.4-63.5]), and exclusively cigars most prevalent among adults 26+ (61.2% [95% CI=59.8-62.5]). Exclusive blunt users smoked more days in the past month (17.5; 95% CI=16.8-18.2), compared to 13.8 days (95% CI=13.2-14.4) for cigar and blunt users, and 7.7 days (95% CI=7.5-8.0) for exclusive cigar users. There were significant differences in characteristics, with exclusive blunt use more prevalent among female (41.6%; 95% CI=40.3-42.9) and Hispanic (18.2%; 95% CI=17.3-19.2) participants.

Conclusions

Exclusive blunt use was the most prevalent pattern of past-30-day cigar use among youth and young adults. Those who use cigars as blunts smoke more cigars per month, suggesting this may be an important group for additional education and policy efforts.

Cannabis use disorder and adverse cardiovascular outcomes: A population-based retrospective cohort analysis of adults from Alberta, Canada

AIM

To measure the association between cannabis use disorder (CUD) and adverse cardiovascular disease (CVD) outcomes.

DESIGN AND SETTING

We conducted a matched, population-based retrospective cohort study involving five linked administrative health databases from Alberta, Canada.

PARTICIPANTS

We identified participants with CUD diagnosis codes and matched them to participants without CUD codes by gender, year of birth and time of presentation to the health system. We included 29 764 pairs (n = 59 528 individuals in total).

MEASUREMENTS

CVD events were defined by at least one incident diagnostic code within the study period (1 January 2012-31 December 2019). Covariates included comorbidity, socio-economic status, prescription medication use and health service use. Using mortality-censored Poisson regression models, we computed survival analyses for time to incident CVD stratified by CUD status. In addition, we calculated crude and stratified risk ratios (RRs) across various covariates using the Mantel-Haenszel technique.

FINDINGS

The overall prevalence of documented CUD was 0.8%. Approximately 2.4% and 1.5% of participants in the CUD and unexposed groups experienced an incident adverse CVD event (RR = 1.57; 95% confidence interval = 1.40-1.77). CUD was significantly associated with reduced time to incident CVD event. Individuals who appeared to have greater RRs for incident CVD were those without mental health comorbidity, who had not used health-care services in the previous 6 months, who were not on prescription medications and who did not have comorbid conditions.

CONCLUSIONS

Canadian adults with cannabis use disorder appear to have an approximately 60% higher risk of experiencing incident adverse cardiovascular disease events than those without cannabis use disorder.

Anxiety sensitivity reduction-smoking cessation intervention among individuals who engage in dual cigarette and cannabis use: A secondary analysis

INTRODUCTION

Cannabis use among individuals who smoke is prevalent in the general population and related to adverse health effects, including higher levels of interoceptive perturbation (i.e., a disturbance in internal experiences). An important aspect of smoking cessation among individuals who co-use cannabis is to address behavioral associations between physiological sensations and habitual behaviors via integrated treatments focused on reducing reactivity to internal perturbations such as anxiety sensitivity (i.e., the belief that such symptoms produce personal harm).

METHODS

The current study involved a secondary analysis of a randomized clinical trial (RCT) of an integrated anxiety sensitivity-smoking cessation intervention compared to standard smoking cessation. The current study sought to extend findings from the initial trial to examine if the integrated intervention produced better smoking cessation outcomes than standard care among individuals who engage in dual cigarette and cannabis use. Participants were 149 adults who engage in dual cigarette and cannabis use (41.6 % female; Mage = 30.89, SD = 13.1).

RESULTS

Results indicated that the anxiety sensitivity intervention produced statistically significant differences in distal (long-term) smoking abstinence at 3-, 6-, and 12-month follow-up assessments but not proximal (short-term; quit-week to 2-weeks) smoking abstinence.

CONCLUSIONS

Overall, the potential of an integrated anxiety sensitivity smoking cessation intervention to yield better long-term smoking abstinence rates than standard cessation treatment among individuals who engage in dual cigarette and cannabis use is clinically significant.

Analysis of Complications in Patients With a History of Cannabis Use and Tobacco Use Undergoing Implant-Based Breast Reconstruction

BACKGROUND

There is limited information regarding the perioperative effects of marijuana in breast reconstructive surgeries.

OBJECTIVES

The objective of this study was to explore the association between a history of cannabis use and postoperative complications in the setting of implant-based breast reconstruction.

METHODS

Two databases, TriNetX and PearlDiver, were queried for patients undergoing implant-based breast reconstruction. Patients were divided into 4 groups based on active ICD-10 diagnostic codes: (1) cannabis use only, (2) tobacco use only, (3) cannabis and tobacco use, and (4) neither cannabis nor tobacco use. Associations with postoperative complications were analyzed with a logistic regression test.

RESULTS

TriNetX search revealed that 327 patients had an active diagnosis of cannabis use only and 1118 had an active diagnosis of tobacco use only. Patients in the cannabis only cohort had a significantly increased risk of developing surgical site infection. Patients in the tobacco only cohort had significantly increased risk of developing wound dehiscence, need for debridement, and surgical site infection. The PearlDiver search included 472 patients who had an active diagnosis of both cannabis and tobacco use and 17,361 patients with a diagnosis of tobacco use only. Patients with a diagnosis of cannabis and tobacco use had a significantly increased risk of developing postoperative complications including surgical site infection, wound dehiscence, need for incision and drainage, and debridement.

CONCLUSIONS

Patients undergoing implant-based breast reconstruction with an active diagnosis of cannabis with or without tobacco use were at increased risk of developing postoperative complications, and the risk was even higher in patients using both tobacco and cannabis.

LEVEL OF EVIDENCE: 3

The effect of marijuana use on short-term outcomes with bariatric surgery

BACKGROUND

Despite increasing marijuana use nationwide, there are limited data on implications of marijuana use on bariatric surgery outcomes.

OBJECTIVE

We investigated associations between marijuana use and bariatric surgery outcomes.

SETTING

Multicenter statewide study utilizing data from the Michigan Bariatric Surgery Collaborative, a payor-funded consortium including over 40 hospitals and 80 surgeons performing bariatric surgery statewide.

METHODS

We analyzed data from the Michigan Bariatric Surgery Collaborative clinical registry on patients who underwent a laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass between June 2019 and June 2020. Patients were surveyed at baseline and annually on medication use, depression symptoms, and substance use. Regression analysis was performed to compare 30-day and 1-year outcomes between marijuana users and nonusers.

RESULTS

Of 6879 patients, 574 reported baseline marijuana use and 139 reported use at baseline and 1 year. Marijuana users were more likely to be current smokers (14% versus 8%, P < .0001), screen positive for alcohol use disorder (20.0% versus 8.4%, P < .0001), and score higher on the Patient Health Questionnaire-8 (6.1 versus 3.0, P < .0001). There were no statistically significant differences in 30-day outcomes or co-morbidity remission at 1 year. Marijuana users had higher adjusted total mean weight loss (47.6 versus 38.1 kg, P < .0001) and body mass index reduction (17 versus 14 kg/m2, P < .0001).

CONCLUSIONS

Marijuana use is not associated with worse 30-day outcomes or 1-year weight loss outcomes and should not be a barrier to bariatric surgery. However, marijuana use is associated with higher rates of smoking, substance use, and depression. These patients may benefit from additional mental health and substance abuse counseling.

Cannabis use among cancer survivors in 22 states: Results from the Behavioral Risk Factor Surveillance System, 2020

BACKGROUND

This study identified factors associated with recent cannabis use and cannabis use for medical purposes among cancer survivors relative to individuals without a history of cancer.

METHODS

Data from the Behavioral Risk Factor Surveillance System were analyzed for the 22 states completing the optional cannabis module in 2020. Weighted multiple logistic regression was performed to explore variables associated with past 30-day cannabis use and cannabis use for medical purposes, stratified by history of cancer. Covariates included state-level cannabis policy, sociodemographic characteristics, health status indicators, and substance use.

RESULTS

Cannabis use was lower among cancer survivors compared to individuals with no history of cancer (7.57% vs. 10.83%). However, a higher proportion of cancer survivors reported use for medical purposes (82.23% vs. 62.58%). After adjusting for state-level policy, biological sex, age, educational attainment, self-reported race/ethnicity, home ownership, mental health status and physical health status, current smoking (odds ratio [OR], 5.14 vs. 3.74) and binge drinking (OR, 2.71 vs. 2.69) were associated with cannabis use in both groups. Characteristics associated with medical cannabis use varied for the two groups; however, daily use (20-30 days; OR, 1.72 vs. 2.43) was associated with cannabis use for medical purposes in both groups after adjusting for other variables in the model.

CONCLUSIONS

A high proportion of individuals report cannabis use for medical purposes with higher rates among cancer survivors. Findings support the urgent need for ongoing cannabis research to better understand and inform its use for medical purposes, as well as the development of high-quality standardized education materials and clinical practice guidelines.

Cannabis and nicotine co-use among primary care patients in a state with legal cannabis access

The aim of this exploratory analysis was to evaluate cannabis exposure, reasons for use and problematic cannabis use among adult primary care patients in Washington state (United States) who co-use cannabis and nicotine (tobacco cigarettes and/or nicotine vaping) compared to patients who endorse current cannabis use only. As part of a NIDA Clinical Trials Network (CTN) parent study, patients who completed a cannabis screen as part of routine primary care were randomly sampled (N = 5,000) to a receive a confidential cannabis survey. Patients were stratified and oversampled based on the frequency of past-year cannabis use and for Black, indigenous, or other persons of color. Patients who endorsed past 30-day cannabis use are included here (N = 1388). Outcomes included; prevalence of cannabis use, days of cannabis use per week and times used per day, methods of use, THC:CBD content, non-medical and/or medical use, health symptoms managed, and cannabis use disorder (CUD) symptom severity. We conducted unadjusted bivariate analyses comparing outcomes between patients with cannabis and current nicotine co-use to patients with cannabis-only use. Nicotine co-use (n = 352; 25.4 %) was associated with differences in method of cannabis use, THC:CBD content, days of use per week and times used per day, number of health symptoms managed, and CUD severity (all p < 0.001), compared to primary care patients with cannabis-only use (n = 1036). Interventions targeting cannabis and nicotine co-use in primary care are not well-established and further research is warranted given findings of more severe cannabis use patterns and the adverse health outcomes associated with co-use.

Role of Neuronal Nicotinic Acetylcholine Receptors in Cannabinoid Dependence

Cannabis is among the most widely consumed psychoactive drugs around the world and cannabis use disorder (CUD) has no current approved pharmacological treatment. Nicotine and cannabis are commonly co-used which suggests there to be overlapping neurobiological actions supported primarily by the co-distribution of both receptor systems in the brain. There appears to be strong rationale to explore the role that nicotinic receptors play in cannabinoid dependence. Preclinical studies suggest that the ɑ7 nAChR subtype may play a role in modulating the reinforcing and discriminative stimulus effects of cannabinoids, while the ɑ4β2 * nAChR subtype may be involved in modulating the motor and sedative effects of cannabinoids. Preclinical and human genetic studies point towards a potential role of the ɑ5, ɑ3, and β4 nAChR subunits in CUD, while human GWAS studies strongly implicate the ɑ2 subunit as playing a role in CUD susceptibility. Clinical studies suggest that current smoking cessation agents, such as varenicline and bupropion, may also be beneficial in treating CUD, although more controlled studies are necessary. Additional behavioral, molecular, and mechanistic studies investigating the role of nAChR in the modulation of the pharmacological effects of cannabinoids are needed.

Self-Reported Medical and Nonmedical Cannabis Use: Results from the 2018 Behavioral Risk Factor Surveillance System in 14 States

As policies legalizing adult cannabis use increase in the United States, understanding and characterizing the proportion of individuals consuming cannabis for medical and nonmedical purposes is important to inform targeted health education efforts. Data came from 7672 adults (> = 18 years) with past month cannabis use who responded to questions about reason for cannabis use on the 2018 Behavioral Risk Factor Surveillance System survey in 14 states. State and aggregated data were analyzed using weighted frequencies for descriptive analyses, and prevalence ratios were computed to identify demographic and substance use characteristics associated with medical only use or use for both medical and nonmedical reasons (vs. nonmedical use). Overall, 28.6% (95% CI: 26.7, 30.4) of adults who use cannabis reported using cannabis medically, 34.2% (95% CI: 32.3, 36.2) nonmedically, and 37.2% (95% CI: 35.2, 39.2) both medically and nonmedically. Characteristics associated with medical only use (compared with nonmedical only use) included being female; aged > 45 years; out of work, a homemaker, or unable to work; having daily or near daily cannabis use; having past month cigarette use; having no past month alcohol use; self-reporting poor health; and ever having been diagnosed with certain chronic diseases. Medical only use of cannabis is the least prevalent reason for use; use for both medical and nonmedical reasons is the most prevalent. Monitoring reasons for cannabis use can aid states in understanding differences between medical and nonmedical cannabis users, providing context to use patterns, and targeting health education messages to appropriate audiences.

Changes in Little Cigar and Cigarillo Use during the COVID-19 Pandemic: A Cross-Sectional Analysis of a Nationally Representative Sample of Young Adult Users

We examined the smoking behaviors of U.S. young adults ages 18-36 regarding little cigars and cigarillos (LCCs) during the COVID-19 pandemic. Survey data were collected from a nationally representative sample of young adults between October and November 2020. Respondents who reported using LCCs with tobacco (CAI) and/or with marijuana (CAB) within the past 6 months prior to the survey (n = 399) were included in the study. Logistic regression analyses assessed the association between their perceived risk of having COVID when smoking LCCs and pandemic-related behavioral changes in CAI and CAB use (e.g., worrying, quit attempts, smoking more, smoking less). Findings showed that users with a higher perceived risk of getting COVID-19 when smoking LCCs were more likely to endorse trying to quit CAI and CAB during the pandemic. Compared to the non-Hispanic White population, the non-Hispanic Black population were less likely to endorse smoking less CAI and trying to quit CAB during the pandemic. Dual users of CAI and CAB and females were more likely to endorse smoking more CAB compared to CAB-only users and males, respectively. Tailored cessation strategies are needed for dual users, non-Hispanic Black young adults, and young women. Raising awareness about the risks of LCC use can be an effective strategy for LCC smoking cessation.

The Reshaping of the E-Cigarette Retail Environment: Its Evolution and Public Health Concerns

E-cigarette use represents a public health controversy in the US and globally. Despite the potential of e-cigarettes to support cigarette cessation, their use increases health risks and risk for addiction, particularly in young people. Various federal, state, and local laws have impacted tobacco retail in general and e-cigarettes in particular. In the US, 2019–2020 federal laws increased in the minimum legal sales age for tobacco to 21 and banned flavored cartridge-based e-cigarettes. Many states and localities were early adopters of Tobacco 21 and implemented more comprehensive flavor restrictions than the federal ban. Meanwhile, cannabis retail is increasingly being legalized in the US—while cannabis-based product regulation has notable gaps at the federal, state, and local levels. These regulatory complexities have impacted specialized retailers selling e-cigarettes, including “vape shops” that exclusively sell e-cigarettes, “smoke shops” that sell e-cigarettes and other tobacco (and potentially CBD/THC and other un- or under-regulated products), and online retail. This commentary outlines public health concerns related to: (1) youth access; (2) consumer exposure to a broader range of tobacco products and marketing in retail settings where they may seek products to aid in cigarette cessation (i.e., such broad product exposure could hinder cessation attempts); (3) consumer exposure to un-/under-regulated products (e.g., delta-8-THC, kratom); and (4) federal, state, and local regulations being undermined by consumer access to prohibited products online and via the mail. These concerns underscore the need for ongoing surveillance of how retailers and consumers respond to regulations.

A difference-in-difference approach to examining the impact of cannabis legalization on disparities in the use of cigarettes and cannabis in the United States, 2004-17

AIMS

To estimate the impact of recreational and medical cannabis laws (RCL, MCL) on the use of cannabis and cigarettes in the United States.

DESIGN

A difference-in-difference approach was applied to data from the 2004-17 National Survey on Drug Use and Health (NSDUH).

SETTING

United States.

PARTICIPANTS

Nationally representative cross-sectional survey of Americans aged 12 years and older (combined analytical sample for 2004-17, n = 783 663).

MEASUREMENTS

Data on past-month use of (1) cigarettes and (2) cannabis were used to classify respondents into four groups: cigarette and cannabis co-use, cigarette-only use, cannabis-only use or no cigarette or cannabis use. State of residence was measured by self-report. MCL/RCL status came from state government websites.

FINDINGS

Difference-in-difference analyses suggest that MCL was associated with an increase in cigarette-cannabis co-use overall [adjusted odds ratio (aOR) = 1.09; 95% confidence interval (CI) = 1.02-1.16], with the greatest increases among those aged 50 years and above (aOR = 1.60; CI = 1.39-1.84), married (aOR = 1.19; CI = 1.07-1.31), non-Hispanic (NH) black (aOR = 1.14; CI = 1.02-1.07) and with a college degree or above (aOR = 1.15; CI = 1.06-1.24). MCL was associated with increases in cigarette-only use among those aged 50 years and above (aOR = 1.07; CI = 1.01-1.14) and NH black (aOR = 1.16; CI = 1.06-1.27) and increases in cannabis-only use among those aged 50 years and above (aOR = 1.24; CI = 1.07-1.44) and widowed/divorced/separated (aOR = 1.18; CI = 1.01-1.37). RCL was associated with an increase in cannabis-only use overall (aOR = 1.21; 95% CI = 1.09-1.34), a decline in cigarette-only use overall (aOR = 0.89; 95% CI = 0.81-0.97) and increases in co-use among those who were married (aOR = 1.24; CI = 1.02-1.50) and aged 50 years and above (aOR = 1.37; CI = 1.03-1.84).

CONCLUSIONS

Recreational and medical cannabis legalization have had a varying impact on the use, and co-use, of cannabis and cigarettes in the United States.

Cigarillo Flavor and Motivation to Quit among Co-Users of Cigarillos and Cannabis: A Structural Equation Modeling Approach

Flavored cigar restrictions have the potential to benefit public health. Flavor availability facilitates cigarillo use, but it is unknown if flavor impacts patterns of co-use of cigarillos and cannabis, an increasingly prevalent behavior among young adults. Data were collected (2020-2021) in a cross-sectional online survey administered to a convenience sample of young adults who smoked cigarillos from 15 areas with high cigar use prevalence. We assessed the relationship between flavored cigarillo use and motivation to quit cannabis and cigarillo use among past 30-day co-users (N = 218), as well as several covariates (e.g., cigarillo price and flavor/cannabis policy). Flavored cigarillo perceived appeal and harm were hypothesized parallel mediators. Most co-users reported usually using flavored cigarillos (79.5%), which was not significantly associated with motivation to quit cigarillos or cannabis. Perceived cigarillo harm (β = 0.17, 95% CI = 0.00, 0.33), advertising exposure (β = 0.12, 95% CI = 0.00, 0.24), and income (among racial/ethnic minorities; β = -0.13, 95% CI = -0.25, -0.02) were significant predictors of motivation to quit cigarillos. There were no significant predictors of motivation to quit cannabis. Cigarillo flavor was not associated with motivation to quit, so findings could suggest that banning flavors in cigars may have a neutral impact on co-use with cannabis among young adults.

Age groups differences in the prevalence and popularity of individual tobacco product use in young adult and adult marijuana and tobacco co-users and tobacco-only users: Findings from Wave 4 of the population assessment of tobacco and health study

BACKGROUND

Tobacco use is high among marijuana and tobacco users, compared to tobacco-only users. This study examined the relative ranking (based on prevalence) of past 30-day tobacco product use separately across young adult and older adult past 30-day marijuana and tobacco co-users and tobacco-only users.

METHOD

Prevalence and relative ranking of past 30-day use of eight different tobacco products and blunts were examined in young adult (ages 18-24) and adults (ages 25 +) tobacco users who did and did not report past 30-day marijuana use (unweighted n = 33,644) from Wave 4 of the Population Assessment of Tobacco and Health study. Multiple logistic regressions examined increased odds of using each product in the past 30-days by marijuana and tobacco co-use.

RESULTS

Nearly half (47.9%) of past 30-day young adult tobacco users reported past 30-day marijuana use (e.g., co-use); 27.7% of adult tobacco users reported past 30-day co-use. Cigarettes were the most popular product used in the past 30-days across tobacco-only and co-users of both age groups. Rankings of all other tobacco products differed between the age groups. Among young adult co-users, blunts were ranked the second most popular product used in the past 30-days, followed by e-cigarettes, and then cigarillos/filtered cigars. Among adult co-users, blunts were ranked the fourth most popular product used in the past 30-days. Adult co-users reported significantly higher prevalence of past 30-day use of all combustible products compared to tobacco only users.

CONCLUSIONS

Co-users may be at increased risk of health consequences given high rates of combustible tobacco use.

Age of initiation of cigarillo use among young adults: Findings from the Population Assessment of Tobacco and Health (PATH) study, 2013-2017

SIGNIFICANCE

Young adults, especially those who identify as racial/ethnic minorities, are legal targets of the tobacco industry. Cigarillo initiation is a risk among these vulnerable groups. Estimating the age of initiation of cigarillo use among young adults may inform the timing of prevention interventions.

METHODS

Weighted interval-censored survival analyses of the Population Assessment of Tobacco and Health (PATH) young adult (ages 18-24 at their first wave of adult participation) annual datasets were conducted (2013-2017). Young adult never cigarillo users (n = 7,101; represents N = 24,023,488) at their first wave of adult participation (2013-2016) were followed-up through 2014-2017 to estimate the age of initiation of ever, past 30-day and fairly regular cigarillo use outcomes. Differences by sex and by race/ethnicity, accounting for previous use of other tobacco products and marijuana and blunt use, were assessed using weighted interval-censored Cox proportional hazards models.

RESULTS

Among PATH young adults, by age 21, 5.8% initiated ever cigarillo use, 4.1% initiated past 30-day cigarillo use, and 1.4% initiated fairly regular cigarillo use. By age 26, 15% initiated ever cigarillo use, and 10.4% initiated past 30-day cigarillo use. Males had higher risk of initiating ever (AHR: 1.63, 95% CI: 1.37-1.95) and past 30-day cigarillo use (AHR: 1.65, 95% CI: 1.32-2.06) at earlier ages than females. Non-Hispanic Blacks had higher risk of initiating ever (AHR: 2.81, 95% CI: 2.26-3.50), past 30-day (AHR: 4.88, 95% CI: 2.95-5.09) and fairly regular cigarillo use (AHR: 4.62, 95% CI: 2.70-7.93) at earlier ages than non-Hispanic Whites. Hispanics had higher risk of initiating past 30-day cigarillo use at earlier ages than non-Hispanic Whites (AHR: 1.51, 95% CI: 1.12-2.03). Non-Hispanic Other race (i.e., Asian, multiracial, etc.) had lower risk of initiating ever (AHR: 0.43, 95% CI: 0.28-0.65) and past 30-day cigarillo use (AHR: 0.40, 95% CI: 0.26-0.63) at earlier ages than Non-Hispanic Whites.

CONCLUSION

Along with those aged 21 and younger, interventions should target young adults over the age of 21, specifically males, non-Hispanic Black and Hispanic young adults, to stall initiation and progression of cigarillo use behaviors.

A procedure to detect and identify specific chemicals of potential inhalation toxicity concern in aerosols

OBJECTIVE

Understanding the potential inhalation toxicity of poorly characterized aerosols is challenging both because aerosols may contain numerous chemicals and because it is difficult to predict which chemicals may present significant inhalation toxicity concerns at the observed levels. We have developed a novel systematic procedure to address these challenges through non-targeted chemical analysis by two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) and assessment of the results using publicly available toxicity data to prioritize the tentatively identified detected chemicals according to potential inhalation toxicity.

MATERIALS AND METHODS

The procedure involves non-targeted chemical analysis of aerosol samples utilizing GC × GC-TOFMS, which is selected because it is an effective technique for detecting chemicals in complex samples and assigning tentative identities according to the mass spectra. For data evaluation, existing toxicity data (e.g. from the U.S. Environmental Protection Agency CompTox Chemicals Dashboard) are used to calculate multiple toxicity metrics that can be compared among the tentatively identified chemicals. These metrics include hazard quotient, incremental lifetime cancer risk, and metrics analogous to hazard quotient that we designated as exposure-(toxicology endpoint) ratios.

RESULTS AND DISCUSSION

We demonstrated the utility of our procedure by detecting, identifying, and prioritizing specific chemicals of potential inhalation toxicity concern in the mainstream smoke generated from the machine-smoking of marijuana blunts.

CONCLUSION

By designing a systematic approach for detecting and identifying numerous chemicals in complex aerosol samples and prioritizing the chemicals in relation to different inhalation toxicology endpoints, we have developed an effective approach to elucidate the potential inhalation toxicity of aerosols.

The Relations between Youth Cannabis Use, School Cannabis Use-Related Disciplinary Approaches and Student Perceptions of School Support

Background: In the school year immediately following cannabis legalization in Canada, this paper investigated youth perceptions of school support for the prevention and cessation of substance use. Scant research has examined student perceptions in relation to school disciplinary approaches. This study was the first to classify school discipline approach styles using school-level measures.Objective: The objective of this study was to examine whether different school cannabis use-related disciplinary approaches are associated with student cannabis use and perceptions of school supportiveness for the prevention and cessation of substance use.Results: School- and student-level survey data from Year 7 (the 2018/2019 school year) of the COMPASS study were used, including 68,037 grade 9-12 (Secondary I-V in Quebec) students attending 131 Canadian secondary schools. Schools were classified as using different cannabis use-related disciplinary styles based on school-administrator reported approaches to student first-offense violations of school cannabis policies. We identified that although none of the cannabis use-related disciplinary approach styles examined were associated with cannabis use, they were associated with student perceptions. Students attending schools classified as using a Permissive/Supportive approach had a higher likelihood of perceiving their school as supportive for substance use prevention/cessation than their peers at Authoritarian schools. Students who perceived their school as supportive for substance use prevention/cessation were less likely to report current cannabis use than their peers who perceived their school as unsupportive.Conclusions: Unlike previous studies using school classification styles that are based on student perceptions, results do not support direct associations between school cannabis use-related disciplinary styles and student cannabis use. Future prospective research should examine whether supportive disciplinary approaches (e.g., counseling referrals, educational programs) promote student perceptions of school supportiveness, and in turn, deter student substance use.

Cigar Use Progression Among New Cigar Initiators: A Two-Part Growth Curve Analysis Among a Youth and Young Adult Cohort

INTRODUCTION

Youth and young adults (YYAs) are at high risk of cigar use. This study's objective was to examine progression and sociodemographic differences in current cigar use and frequency among new cigar initiators.

AIMS AND METHODS

We conducted a two-part latent growth model among a nationally representative cohort of cigar initiators (aged 15-25) to examine 24-month trajectories of current cigar use and frequency (n = 1483). The cohort was recruited via address-based sampling with online data collection from 2014 to 2019 and surveyed approximately every 6 months.

RESULTS

The unconditional odds of current cigar use (ie, past 30-day use) within 6 months of initiation was 0.72 (95% confidence interval: 0.63, 0.82), corresponding to a probability of 42%. The odds of current use among recent cigar initiates declined 6 months after initiation and was followed by a stabilization in use over time. Among continued users, frequency (# days used in past 30 days) increased linearly over time but remained low (3.47 days/months at 24 months). Younger individuals, non-Hispanic African Americans, those with lower subjective financial status, and current users of cigarettes, other tobacco products and/or marijuana were at highest risk within 6 months of initiation. Males, younger users, and current cigarette smokers had the highest risk for cigar progression over time.

CONCLUSIONS

This study is the first to examine longitudinal cigar use patterns among YYA cigar initiators. Findings emphasize the need for research across the cigar use spectrum and the importance of interventions targeted by age, stage of use, cigarette, other tobacco, and marijuana use and key sociodemographics to interrupt use pathways.

IMPLICATIONS

This study is the first to examine progression of cigar use among YYAs who have newly initiated cigars. Results show a high probability of current cigar use within 6 months of initiation followed by a rapid decline and stabilization over time. Frequency increases among those who continue using cigars. Males, younger users, and current cigarette smokers had the highest risk for cigar progression over time. Findings emphasize the need for targeting interventions by age, stage of use, cigarette, other tobacco, and marijuana use and key sociodemographics to interrupt use pathways.

Nonmedical Cannabis Use: Patterns and Correlates of Use, Exposure, and Harm, and Cancer Risk

Cannabis has certain health benefits, but some people may experience harms from use. Co-use of tobacco and cannabis is common. Smoke from cannabis contains many of the same carcinogens and toxicants as the smoke from tobacco, raising concerns that cannabis smoking may be a risk factor for cancer. With growing access to and acceptance of medical and nonmedical cannabis, there is an urgent need to understand the risks and benefits of the current modes of cannabis use and how cannabis may be associated with cancer risk. This monograph summarizes a session from a National Cancer Institute Symposium on nonmedical cannabis use and cancer risk. We had 3 objectives: describe the relation between nonmedical cannabis use and cancer risk, delineate patterns and correlates of cannabis co-use with tobacco, and document potentially harmful inhalational exposure resulting from smoked and vaped cannabis. Methodological limitations in the literature and future research recommendations are provided.

Impact of California's tobacco and cannabis policies on the retail availability of little cigars/cigarillos and blunt wraps

BACKGROUND

Recent changes in California's tobacco and cannabis policies could impact the retail availability of little cigars/cigarillos (LCCs) and blunt wraps that are used for blunt smoking. This study was intended to test whether tobacco flavor bans and minimum pack sizes of LCCs have reduced tobacco availability in California jurisdictions, whereas, permissive policies on sales and marketing of cannabis increased availability.

METHODS

Measures of retail availability of LCCs and blunt wraps were obtained from the 2016-2019 longitudinal sample of licensed tobacco retailers (LTRs, n = 4062) from California's Healthy Stores for Healthy Communities campaign. Additional data sources included the California Cannabis Local Laws database and geographic location of 1063 cannabis retailers used for constructing a spatial index of accessibility to the LTRs. Two-level generalized structural equation models were developed to assess effects of store- and jurisdiction-level predictors of change in tobacco availability (+, -, no change).

RESULTS

Neither permissive cannabis policies nor accessibility to cannabis retailers were associated with an increase in retail availability of the tobacco products. Enactment of a tobacco flavor ban, however, was associated with reduced availability of LCCs and blunt wraps, which was more pronounced in jurisdictions that had permissive cannabis policies (i.e. policy interaction).

CONCLUSIONS

A tobacco flavor ban may be an effective strategy to reduce retail availability of LCCs, blunt wraps and possibly other tobacco in California jurisdictions. This finding is of particular relevance as the tobacco industry has successfully petitioned for a referendum vote on California's statewide flavor ban in the 2022 election.

Cannabis Use and Oral Health in a National Cohort of Adults

BACKGROUND

Cannabis use is common and increasing among adults. Evidence connects cannabis use to poor periodontal health, but few prospective studies exist of adults in the United States.

METHODS

This investigation examined associations between cannabis use and self-reported adverse oral health conditions among participants (N = 18,872) in the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative cohort. Survey-weighted regression modeling estimated associations between cannabis use and seven self-reported measures of oral health status, adjusted for tobacco use and other disease risk factors.

RESULTS

Reporting past-30-days cannabis use in any of PATH Waves 1-3 was positively and statistically significantly associated at Wave 4 with multiple periodontal disease sequalae and with self-rated fair or poor overall oral health (adjusted odds ratio versus never-users: 1.75; 95% confidence interval: 1.52, 2.01).

CONCLUSIONS

These findings provide further evidence that cannabis use is an independent risk factor for poor oral health, although study limitations (self-reported outcomes, limited information on cannabis use frequency and modality) must be considered.

PRACTICAL IMPLICATIONS

Dental professionals should engage patients in clear, nonjudgmental dialogue about cannabis use to address oral health risks and avoid potential patient safety issues in care delivery. General recommendations for addressing cannabis use in dental practice are presented.

Initiation of Moderately Frequent Cannabis use in Adolescence and Young Adulthood is Associated with Declines in Verbal Learning and Memory: A Longitudinal Comparison of Pre- versus Post-Initiation Cognitive Performance

OBJECTIVE

Cannabis use is associated with relative cognitive weaknesses as observed by cross-sectional as well as longitudinal research. Longitudinal studies, controlling for relevant confounds, are necessary to differentiate premorbid from post-initiation contributions to these effects.

METHODS

We followed a sample of adolescents and young adults across ten years. Participants provided neurocognitive data and substance use information at two-year intervals. Participants who initiated cannabis and/or alcohol use were identified (n = 86) and split into alcohol-only initiators (n = 39) and infrequent (n = 29) and moderately frequent (n = 18) cannabis initiators. Participants completed the Rey Auditory Verbal Learning Task (RAVLT) and the Iowa Gambling Task (IGT). Group differences before and after substance use initiation and the extent to which alcohol, nicotine, and cannabis use frequencies contributed to cognitive functions over time were examined.

RESULTS

After controlling for parental education, RAVLT new learning was worse in moderately frequent cannabis users prior to use initiation. RAVLT total learning and delayed recall showed significant declines from pre- to post-initiation in moderately frequent cannabis users. Regression analyses confirmed that frequencies of cannabis, but not alcohol, use contributed to post-initiation variations. Nicotine use showed an independent negative association with delayed memory. Findings for the IGT were not significant.

CONCLUSIONS

Verbal learning and memory may be disrupted following the initiation of moderately frequent cannabis use while decreased new learning may represent a premorbid liability. Our use of a control group of alcohol-only users adds interpretive clarity to the findings and suggests that future studies should carefully control for comorbid substance 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.

Prenatal exposure to tobacco and cannabis, early cannabis initiation, and daily dual use of combustible cigarettes and cannabis during young adulthood

INTRODUCTION

Daily combustible cigarette use is common among cannabis users, and dual use of cigarettes and cannabis is associated with detrimental outcomes. This study addresses gaps in the literature by examining data from the prenatal and adolescent phases of a prospective, longitudinal study to predict adult daily dual use.

METHODS

Young adult offspring (M age = 22.8 years, 53% female) from a prenatal cohort reported on combustible cigarette and cannabis use (N = 500, 58% Black, 42% White). Pathways to daily dual use were modeled using variables from the gestational and adolescent phases of the study including prenatal tobacco, alcohol, and cannabis exposures; ages at initiation of cigarettes and cannabis; and adolescent learning/memory, impulsivity, and behavior problems.

RESULTS

Prenatal cannabis and tobacco use were not directly linked to adult daily dual use of cannabis and tobacco. However, structural equation modeling revealed three significant indirect pathways from prenatal cigarette and cannabis exposures to adult daily dual use of cigarettes and cannabis via early cigarette initiation, early cannabis initiation, and adolescent behavior problems.

CONCLUSIONS

This study identified pathways from prenatal cannabis and tobacco exposure to adult daily dual use, in addition to clarifying adolescent outcomes that may be part of the pathways. In a climate of growing acceptance of cannabis use and increasing legalization of recreational use, these findings serve as a warning that early exposure to cannabis may have an important role in shaping long-term dual use of tobacco and cannabis.

Exploring the Point-of-Sale Among Vape Shops Across the United States: Audits Integrating a Mystery Shopper Approach

INTRODUCTION

Vape shops represent prominent, unique retailers, subject to Food and Drug Administration (FDA) regulation in the United States.

AIMS AND METHODS

This study assessed compliance of US vape shop retail marketing strategies with new regulations (eg, required age verification, prohibited free samples) and pre-implementation conditions for other regulations (eg, health warning labels on all nicotine products, required disclosures of e-liquid contents).

RESULTS

95.0% of shops displayed minimum-age signage; however, mystery shoppers were asked for age verification at 35.6% upon entry and at 23.4% upon purchase. Although 85.5% of shops had some evidence of implementing FDA health warnings, 29.1% had signage indicating prohibited health claims, 16.3% offered free e-liquid samples, 27.4% had signage with cartoon imagery, and 33.3% were within two blocks of schools. All shops sold open-system devices, 64.8% sold closed-system devices, 68.2% sold their own brand of e-liquids, 42.5% sold e-liquids containing cannabidiol, 83.2% offered price promotions of some kind, and 89.9% had signage for product and price promotions.

CONCLUSIONS

Results indicated that most shops complied with some implementation of FDA health warnings and with free sampling bans and minimum-age signage. Other findings indicated concerns related to underage access, health claims, promotional strategies, and cannabidiol product offerings, which call for further FDA and state regulatory/enforcement efforts.

The Influence of Cannabis and Nicotine Co-use on Neuromaturation: A Systematic Review of Adolescent and Young Adult Studies

Accumulating evidence suggests that the use of cannabis and nicotine and tobacco-related products (NTPs) during the adolescent years has harmful effects on the developing brain. Yet, few studies have focused on the developing brain as it relates to the co-administration of cannabis and NTPs, despite the high prevalence rates of co-use in adolescence. This review aims to synthesize the existing literature on neurocognitive, structural neuroimaging, and functional neuroimaging outcomes associated with cannabis and NTP co-use. A systematic search of peer-reviewed articles resulted in a pool of 1107 articles. Inclusion criteria were 1) data-based study; 2) age range of 13 to 35 years or, for preclinical studies, nonadult subjects; 3) cannabis and NTP group jointly considered; and 4) neurocognitive, structural neuroimaging, or functional neuroimaging as an outcome measure. Twelve studies met inclusion criteria. Consistent with the literature, cannabis and nicotine were found to have independent effects on cognition. The available research on the co-use of cannabis and NTPs demonstrates a potential nicotine-related masking effect on cognitive deficits associated with cannabis use, yet there is little research on co-use and associations with neuroimaging indices. In neuroimaging studies, there is preliminary evidence for hippocampal volume differences in co-users and a lack of evidence for co-use differences related to nucleus accumbens activity during reward processing. Notably, no structural neuroimaging studies were found to examine the combined effects of nicotine and cannabis in adolescent-only populations. Further research, including longitudinal studies, is warranted to investigate the influence of cannabis and NTP co-use on maturation.

Treatment Implications Associated with Cannabis and Tobacco Co-Use

PURPOSE OF THE REVIEW

The goal of this article is to summarize the treatment-focused literature on cannabis and tobacco co-use and the treatment implications of co-use. This review will focus on: 1) the impact of co-use on cessation outcomes, 2) compensatory use/substitution of the non-treated substance among co-users, and 3) treatment interventions to address co-use. This article will highlight the limitations to co-use captured in the literature and offer considerations and directives for co-use research and treatment moving forward.

RECENT FINDINGS

The degree to which co-use affects cessation for a single, targeted substance remains in question, as the literature is largely mixed. Cannabis treatment trials are better equipped to answer these questions given that they do not typically exclude tobacco users. While the relationship between tobacco use and poorer cannabis outcomes appears to have some evidence, the reverse relationship (cannabis use affecting tobacco outcomes) is not consistently supported.

SUMMARY

The co-use of cannabis and tobacco and its impact on single substance cessation and/or compensatory substance use during cessation is generally overlooked in treatment trials, while interventions to address both substances are rare. Capturing co-use adds burden for researchers, clinicians, and participants, but is warranted given the prevalence of co-use and a rapidly changing cannabis and tobacco regulatory environment, which may further complicate co-occurring substance use. Co-users are a heterogeneous population; trials focused on co-users, in addition to better data capture and consistent terminology, will aid in an understanding of nuanced patterns of co-use critical to inform treatment interventions.

Marijuana Use and Adherence to Smoking Cessation Treatment Among Callers to Tobacco Quitlines

Introduction

Tobacco kills over half a million adults annually in the United States. Most smokers want to quit, and over 400,000 call state-funded quitlines for help each year. Marijuana use among tobacco users is common and may impede quitting, but co-use rates among quitline callers are unknown. The purpose of our observational study was to describe marijuana use among quitline callers in states with legalized marijuana.

Methods

Participants were 1,059 smokers aged 21 or older from Oregon, Alaska, and Washington, DC, who called quitlines from September through December 2016. Data on quitline callers’ demographics, tobacco and marijuana use, and quitline use were collected. We used χ² and regression analyses to compare marijuana users with nonusers on demographic characteristics and quitline use.

Result

Among quitline callers in our study, 24% reported using marijuana in the past 30 days: 28.9% in Alaska, 16.7% in Washington, DC, and 25.0% in Oregon (P = .009). Current users, compared with non-users (n = 772), were less likely to be women (48.4% vs 62.0%, respectively, P < .001). Current marijuana users were less likely to be given nicotine replacement therapy (68.4%) than current nonusers (74.1%) (P < .001), but more likely to complete 3 or more counseling calls (P = .005). Of those who used marijuana in the past 30 days, 62.3% used marijuana on 1 to 19 days, 9.0% used on 20 to 29 days, and 28.7% on all 30 days. Among current marijuana users, the percentage who wanted to quit or reduce marijuana use (42.6%) was higher in Alaska (54.6%) and the District of Columbia (56.8%) than in Oregon (37.9%), P = .03.

Conclusion

One in 4 quitline callers reported past 30-day marijuana use. Given that nearly half (43%) wanted to reduce marijuana use, addressing co-use may be an important addition to quitline treatment. Future studies should assess co-use effects on tobacco cessation outcomes and explore combined treatment or bidirectional referrals between quitlines and marijuana treatment providers.

Correlates of lifetime blunt/spliff use among cigarette smokers in substance use disorders treatment

BACKGROUND

Co-use of tobacco and cannabis has been associated with greater dependence on and lower quit rates for both substances. Tobacco/cannabis co-use among individuals with substance use disorders (SUDs), a population with high rates of cigarette smoking, may hinder the effectiveness of smoking cessation interventions. We examined rates of lifetime (i.e., ever vs. never) cannabis use among current cigarette smokers in SUD treatment, and we identified the subgroup who had used tobacco and cannabis together in the form of blunts and/or spliffs. We then examined variables associated with lifetime use of blunts and/or spliffs.

METHODS

We surveyed 562 clients in 20 residential SUD treatment programs in California, USA, in 2019. Measures included demographics, lifetime use of any cannabis product, lifetime use of blunt/spliffs, patterns of tobacco use, and smoking cessation-related questions. We asked current cigarette smokers who also reported lifetime cannabis use whether they had ever used blunts and/or spliffs. We then assessed relationships of demographic, tobacco use, use of cannabis/tetrahydrocannabinol (THC) in e-cigarettes/vape pens, and smoking cessation-related variables with ever use versus never use of blunts/spliffs.

RESULTS

Among 340 current cigarette smokers, 93.2% (n = 317) reported lifetime use of any cannabis product. Among current cigarette smokers with lifetime cannabis use, 64.4% reported lifetime blunt/spliff use. Compared to those who had never used blunts/spliffs, lifetime blunt/spliff users were more likely to be younger (OR = 0.93, 95% CI 0.90-0.95), more likely to report lifetime use of cigars/cigarillos (OR = 2.95, CI 1.37-6.32), and to have ever used cannabis/THC in e-cigarettes/vape pens (OR = 4.26, CI 1.54-11.80). They were less often ready to quit smoking within 30 days (OR = 0.37, CI 0.23-0.60), but more likely to want help with smoking cessation (OR = 2.39, CI 1.52-3.77).

CONCLUSION

Current cigarette smokers in SUD treatment reported a high prevalence of lifetime cannabis use. Smokers with a history of blunt/spliff use were more likely to report lifetime use of e-cigarettes/vape pens for cannabis/THC delivery. They wanted help to quit smoking, but felt less prepared to quit in the next 30 days. Cannabis co-use may warrant clinicians' attention when providing smoking cessation interventions during SUD treatment.

Are School Substance Use Policy Violation Disciplinary Consequences Associated with Student Engagement in Cannabis?

Schools are increasingly concerned about student cannabis use with the recent legalization in Canada; however, little is known about how to effectively intervene when students violate school substance use policies. The purpose of this study is to assess the disciplinary approaches present in secondary schools prior to cannabis legalization and examine associations with youth cannabis use. This study used Year 6 (2017/2018) data from the COMPASS (Cannabis use, Obesity, Mental Health, Physical Activity, Alcohol use, Smoking, Sedentary behavior) study including 66,434 students in grades 9 through 12 and the 122 secondary schools they attend in British Columbia, Alberta, Ontario, and Quebec. Student questionnaires assessed youth cannabis use and school administrator surveys assessed potential use of 14 cannabis use policy violation disciplinary consequences through a ("check all that apply") question. Regression models tested the association between school disciplinary approaches and student cannabis use with student- (grade, sex, ethnicity, tobacco use, binge drinking) and school-level covariates (province, school area household median income). For first-offence violations of school cannabis policies, the vast majority of schools selected confiscating the product (93%), informing parents (93%), alerting police (80%), and suspending students from school (85%), among their disciplinary response options. Few schools indicated requiring students to help around the school (5%), issuing a fine (7%), or assigning additional class work (8%) as potential consequences. The mean number of total first-offence consequences selected by schools was 7.23 (SD = 2.14). Overall, 92% of schools reported always using a progressive disciplinary approach in which sanctions get stronger with subsequent violations. Students were less likely to report current cannabis use if they attended schools that indicated assigning additional class work (OR 0.57, 95% CI (0.38, 0.84)) or alerting the police (OR 0.81, 95% CI (0.67, 0.98)) among their potential first-offence consequences, or reported always using the progressive discipline approach (OR 0.77, 95% CI (0.62, 0.96)) for subsequent cannabis policy violations. In conclusion, results reveal the school disciplinary context in regard to cannabis policy violations in the year immediately preceding legalization. Various consequences for cannabis policy violations were being used by schools, yet negligible association resulted between the type of first-offence consequences included in a school's range of disciplinary approaches and student cannabis use.

Longitudinal associations between marijuana and cigar use in young adults

BACKGROUND

We assess the longitudinal associations between marijuana and cigar (little cigars and cigarillos [LCCs] and large cigars) use on subsequent initiation of marijuana and cigar use.

METHODS

Data are from a cohort study of 2189 young adults recruited in fall 2010 from 11 colleges in the Southeast. We used discrete-time survival analysis to examine whether ever use of marijuana at baseline (spring 2011, freshman year) predicted initiation of LCCs and large cigars and whether ever use of these cigar products predicted initiation of marijuana use across 10 waves of data collection (2011-2018).

RESULTS

The sample was 65.3 % female, 83.6 % White, 5.9 % Hispanic, and 61.8 % had college-educated mothers. At baseline, 70 % reported never using LCCs, 71 % reported never using large cigars, and 74 % reported never using marijuana. Ever use of marijuana at baseline was associated with an increased risk of LCC initiation (Incident rate ratio [IRR] = 1.6, 95 %CI = 1.0, 2.5) but not large cigar initiation. Ever use of LCCs (IRR = 1.4, 95 %CI = 1.1, 1.8) and ever use of large cigars (IRR = 1.3, 95 %CI = 1.1, 1.8) at baseline both predicted initiation of marijuana use.

CONCLUSIONS

Our findings support growing evidence that marijuana and LCCs are strongly associated and use of one substance predicts use of the other. In contrast to studies of adults, we also found that young adults who have tried large cigars may be at increased risk for subsequent marijuana use. These findings highlight the need to consider each product as a potential gateway of the other when developing interventions for young adults.

Marijuana use and subsequent cigarette use among U.S. adolescents: A longitudinal study

BACKGROUND

The extant literature on the relationship between marijuana and tobacco among youth is mixed. The present study examined the temporal association of marijuana use with subsequent cigarette use in a nationally representative sample of U.S. adolescents.

METHODS

We used data from Waves 1, 2 and 3 of the Population Assessment of Tobacco and Health. A propensity score method was used to address imbalance between marijuana ever and non-ever users. Logistic regressions were used to examine the temporal associations of marijuana ever use at Wave 1 on cigarette use at Waves 2 and 3 among youth that were classified as never cigarette users at Wave 1.

RESULTS

Among the 422 youth marijuana ever users at Wave 1, 15.5% reported subsequent past 12-month (P12M) cigarette use and 8.2% reported subsequent past 30-day (P30D) cigarette use at Wave 2. Of the 7924 youth never marijuana users at Wave 1, 3.5% reported P12M cigarette use and 1.4% reported P30D cigarette use. Youth marijuana ever users at Wave 1 were more likely to report P12M cigarette use (aOR = 5.11; 95% CI 2.91-8.95) and P30D cigarette use (aOR = 6.14; 95% CI 2.89-13.04) at Wave 2.

CONCLUSIONS

Our findings suggest that youth marijuana ever users were more likely to report subsequent P12M cigarette use and P30D cigarette use. Given the known health effects related to both products, findings suggest there is a need for continued monitoring of both marijuana and cigarette use among adolescents, especially in a rapidly changing regulatory environment.

Chemical characterization of marijuana blunt smoke by non-targeted chemical analysis

Background: Marijuana blunts, which are tobacco cigar wrappers filled with marijuana, are commonly smoked in the US as a means of cannabis use. The use of marijuana blunts presents toxicity concerns because the smoke contains both marijuana-related and tobacco-related chemicals. Thus, it is important to understand the chemical composition of mainstream smoke (MSS) from marijuana blunts. This study demonstrates the ability to detect and identify chemical constituents exclusively associated with blunt MSS in contrast to tobacco cigar MSS (designated as 'new exposures') through non-targeted chemical analysis.Methods: Samples collected separately from blunt MSS and tobacco cigar MSS were analyzed using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS).Results and Discussion: Two new exposures, which likely represent only a subset of all new exposures, were identified by evaluating the data from thousands of detected signals and then confirming selected compound identities in analyses using authentic chemical standards. The two confirmed new exposures, mellein and 2-phenyl-2-oxazoline, are not cannabinoids and, to the best of our knowledge, have not been previously reported in association with cannabis, tobacco, or smoke of any kind. In addition, we detected and quantified three phenols (2-, 3-, and 4-ethylphenol) in blunt MSS. Given the toxicity of phenols, quantifying the levels of other phenols could be pursued in future research on blunt MSS.Conclusion: This study shows the power and utility of GC × GC-TOFMS as a methodology for non-targeted chemical analysis to identify new chemical exposures in blunt MSS and to provide data to guide further investigations of blunt MSS.

Tobacco and Marijuana Use Among US College and Noncollege Young Adults, 2002-2016

OBJECTIVES

To assess trends and behavioral patterns of marijuana and cigarette and/or cigar (ie, smoked tobacco) use among 18- to 22-year-old US young adults who were in or not in college.

METHODS

Data were from the 2002-2016 National Survey on Drug Use and Health. Past-30-day and past-12-month use of marijuana and smoked tobacco were assessed by college enrollment status. χ² tests were used to examine within- and between-group differences. Trends were assessed by using logistic regression and relative percentage change (RPC).

RESULTS

Among both college and noncollege individuals during 2002 to 2016, exclusive marijuana use increased (faster increase among college students; RPC = 166.6 vs 133.7), whereas exclusive smoked tobacco use decreased (faster decrease among college students; RPC = -47.4 vs -43.2). In 2016, 51.6% of noncollege and 46.8% of college individuals reported past-12-month usage of marijuana and/or smoked tobacco products (P < .05). Exclusive marijuana use was higher among college than noncollege individuals, both for past-30-day (11.5% vs 8.6%) and past-12-month use (14.6% vs 10.8%). Exclusive smoked tobacco use was higher among noncollege than college individuals, both for past-30-day (17.7% vs 10.4%) and past-12-month (17.4% vs 12.2%) use (P < .05).

CONCLUSIONS

Exclusive marijuana use is increasing among young adults overall, whereas exclusive smoked tobacco use is decreasing: faster rates are seen among college students. Exclusive marijuana use is higher among college students, whereas exclusive smoked tobacco use is higher among noncollege individuals. Surveillance of tobacco and marijuana use among young people is important as the policy landscape for these products evolves.

Substances used in electronic vapor products among adults in the United States, 2017

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Electronic vapor products are used by adults for a variety of substances.

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Nicotine was the most commonly reported substance used in electronic vapor products.

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Many adults also use these devices for flavors and marijuana.

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Adults younger than 30 years and females were more likely to report flavor use.

Introduction

Electronic vapor products (EVPs), including e-cigarettes, can be used to aerosolize many substances. Examination of substances used in EVPs by US adults has been limited; we assessed past-year use of EVPs to deliver various substances.

Methods

Data came from the 2017 SummerStyles Survey, a web-based survey of US adults (N = 4107). Ever EVP users were asked if they had used nicotine, marijuana, flavors or “something else” in an EVP during the past year. Weighted estimates for any, exclusive, and combined EVP substance use were calculated among ever (n = 586) and current (past 30-day; n = 121) EVP users.

Results

Past-year use of nicotine, flavors, and marijuana in EVPs was 30.7%, 23.6%, and 12.5% among ever EVP users, respectively; and 72.3%, 54.6%, and 17.8% among current EVP users. Among ever EVP users, the most commonly used substances were nicotine only (29.6%), nicotine plus flavors (27.2%), flavors only (16.4%), and marijuana only (14.9%). Among current EVP users, the most common substances used were nicotine plus flavors (39.1%), nicotine only (29.6%), and flavors only (11.2%). Among ever users, males and 18–29 year olds were more likely to report use of flavors than females and respondents ≥30 years.

Conclusions

Approximately 7 in 10 current EVP users reported nicotine use, about 1 in 2 used flavors, and nearly 1 in 6 used marijuana. These findings suggest that EVPs are used to consume a variety of substances and could guide efforts to address tobacco and non-tobacco substance use.

Marijuana use among young adult non-daily cigarette smokers over time

Recent data regarding growth in concurrent use of nicotine and marijuana have raised concern that reductions in legal restrictions on marijuana use may increase risk for tobacco-related harms. Previous studies have shown cross-sectional links between use of both substances, but less is known about associations over time. The goal of the present study was to test the hypothesis that there is a bidirectional relationship between use of marijuana and use of tobacco products over time, such that increasing use of either substance would predict increasing use of the other. Participants (n = 391, 52% male) were 18-24 year-old Californians who were non-daily cigarette smokers at enrollment and had never been daily smokers. They reported nicotine/tobacco and marijuana use quarterly over 2 years. Longitudinal negative binomial and logistic regression models indicated that each additional timepoint at which participants reported recent marijuana use predicted 9-11% increases in tobacco quantity and frequency. Additionally, each additional timepoint at which cigarette or tobacco use was reported predicted 19-22% greater marijuana frequency. Data suggest that young adults who use marijuana more frequently are likely at risk for greater tobacco exposure, and vice versa. These findings suggest a need for preventive measures that focus on concurrent use of both substances rather than either individually.

Population-level patterns and mental health and substance use correlates of alcohol, marijuana, and tobacco use and co-use in US young adults and adults: Results from the population assessment for tobacco and health

BACKGROUND AND OBJECTIVES

This study identified the most common patterns of current alcohol and marijuana use with the spectrum of tobacco products (cigarettes, hookah, e-cigarettes, cigars/little cigars, and other products), among US young adults and older adults and examined associations of mental health and substance use problems with each pattern.

METHODS

Wave 1 adult dataset (2013-2014) of the Population Assessment of Tobacco and Health (PATH) Study. Weighted analyses estimated the prevalence of the top 10 patterns of current alcohol, marijuana, and tobacco use and co-use separately by young adults aged 18-24 (n = 9,112) and adults 25+ years (n = 23,208). Multivariable models examined associations of substance use and mental health problems to patterns of use, adjusting for demographics.

RESULTS

Across both age groups, alcohol-only use was the most popular use pattern (20.7% for young adults and 32.2% older adults) however poly-substance use patterns were more frequent than single use patterns. Cigarettes were the only tobacco product used exclusively; all other tobacco products were used with together, or with alcohol or marijuana. Only one young adult pattern emerged containing e-cigarettes, and this pattern included co-use with alcohol and cigarettes (1.3%). Mental health and substance use problems were most strongly correlated with dual and poly-substance use patterns, regardless of age.

SCIENTIFIC SIGNIFICANCE

Prevention and intervention campaigns should focus on multiple product use, as single substance use is uncommon. Alcohol is common in all patterns, suggesting it should also gain more focus in marijuana and tobacco prevention and intervention programs. (Am J Addict 2018;27:491-500).

Tobacco and cannabis co-use: Drug substitution, quit interest, and cessation preferences

The co-use of tobacco and cannabis is a common practice worldwide and carries with it substantial public health burden. Few interventions exist that target both substances and little is known about quit interest, treatment preferences, and drug substitution during past cessation attempts, which is critical to guide the development of treatment strategies. The goal of this study was to provide descriptive information regarding quit interest, treatment preferences, and perceived drug substitution among adult (age 18 +) cannabis-tobacco co-users. Participants (N = 282) from two independent survey samples (recruited from Amazon Mechanical Turk) from across the United States were combined. Among all participants, 57% were female, 79% were White, and average age was 33.31 (SD = 9.54) years old. Approximately 80% had tried to quit smoking cigarettes at least once, while 40% had tried to quit using cannabis at least once. Of those who tried to quit, 50% self-reported a perceived increase in their cannabis use during tobacco cessation and 62% self-reported a perceived increase in their tobacco use during cannabis cessation. Average quit interest (10-point scale) for cannabis was 2.39 (SD = 2.35) and for tobacco was 7.07 (SD = 2.90). Results of this study suggest that tobacco use should be addressed among cannabis-tobacco co-users, but interventions should consider lack of interest in cannabis cessation. Reduction-based strategies for cannabis use appear to be more acceptable to this nontreatment-seeking, co-using population. Drug substitution during quit attempts for one substance should be further explored as an important treatment consideration. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Patterns and correlates of the co-use of marijuana with any tobacco and individual tobacco products in young adults from Wave 2 of the PATH Study

BACKGROUND

Past-month marijuana use has increased significantly among US young adults (aged 18-24) and marijuana use often overlaps with tobacco use. This study investigated the relative prevalence and correlates of individual tobacco product use among young adult marijuana and tobacco users to determine if unique typologies could be identified.

METHOD

Data were from young adults (18-24) in Wave 2 of the Population Assessment of Tobacco and Health (PATH) Study. Analyses examined the prevalence of different patterns of past 30-day marijuana and tobacco use and co-use. Weighted adjusted models were used to examine correlates of different marijuana and individual tobacco co-use profiles (compared to no-use of either product).

RESULTS

Prevalence estimates showed that 30.9% of young adults report past month tobacco-only use, 21.3% report past-month co-use of marijuana and at least one tobacco product, and 4.5% report past 30-day marijuana-only use. Correlates of co-use differed by tobacco product. Using 3+ tobacco products and frequency of past 30-day alcohol use were robustly and consistently associated with each marijuana and individual tobacco co-use profile and any co-use of marijuana with tobacco.

CONCLUSIONS

Among US young adults between 2014 and 2015, co-use of marijuana and tobacco was common, and there was heterogeneity in correlates associated with use of different tobacco products among those who used marijuana. Different correlates suggest different targets for marijuana and tobacco prevention and intervention in this age group.

Cigarette smoking quit ratios among adults in the USA with cannabis use and cannabis use disorders, 2002-2016

BACKGROUND

The prevalence of cigarette smoking is nearly three times higher among persons who use cannabis and have cannabis use disorders (CUDs), relative to those who do not. The current study examined cigarette quit ratios from 2002 to 2016 among US adults with and without cannabis use and CUDs.

METHODS

The current study analysed US adults aged 18 years and older from the National Survey on Drug Use and Health, an annual cross-sectional study. Quit ratios (ie, proportion of former smokers among ever-smokers) were calculated annually from 2002 to 2016. Time trends in quit ratios by cannabis use/CUDs were tested using logistic regression.

RESULTS

In 2016, the quit ratios for people with any cannabis use (23%) and CUDs (15%) were less than half the quit ratios of those without cannabis use and CUDs (51% and 48%, respectively). After controlling for demographics and substance use disorders, the quit ratio did not change from 2002 to 2016 among persons with CUD, though it non-linearly increased among persons with cannabis use, without cannabis use and without CUDs. Quit ratios increased more rapidly among those who reported past-month cannabis use compared with those without past-month cannabis use.

CONCLUSIONS

Cigarette smoking quit ratios remain dramatically lower among people who use cannabis and have CUDs and quit ratios did not change significantly from 2002 to 2016 among those with CUDs. Public health and clinical attention are needed to increase quit ratios and reduce harmful cigarette smoking consequences for persons with cannabis use and CUDs.

Association of Marijuana, Mental Health, and Tobacco in Colorado

OBJECTIVES

Marijuana's evolving legality may change marijuana use patterns in adults. Co-use of marijuana and tobacco are strongly associated, and populations with mental health disorders are disproportionately likely to use either substance, but neither association has been assessed in the context of legal recreational marijuana. We assessed the associations of tobacco smoking with marijuana use and with mental health disorders in Colorado in 2015.

METHODS

Data came from a population-based survey of adults (n = 8023). Multiple logistic regressions were used with current tobacco smoking as the primary outcome. Past 30-day marijuana use and mental health status were the independent variables of interest. Covariates included age, sex, ethnicity, poverty level, and education.

RESULTS

Adults who used marijuana in the past 30 days had 3.4 (95% confidence interval [CI] 2.7, 4.2) greater odds of currently smoking tobacco compared to adults who had not recently used marijuana, after adjusting for sociodemographic and economic factors. A mental health disorder was independently associated with tobacco smoking (adjusted odds ratio [OR] 1.7, 95% CI 1.4, 2.1). Prevalence of co-use among adults self-reporting a mental health disorder was significantly higher compared those without a mental health disorder (11.1% vs 4.3%; P < 0.0001).

CONCLUSIONS

This study examined the associations between mental health, marijuana use, and tobacco smoking after the legalization of recreational marijuana in Colorado. Adults using marijuana and/or self-reporting a mental health disorder were more likely to smoke tobacco and should be targeted for cessation interventions.

Tobacco and cannabis co-use and interrelatedness among adults

Cannabis and tobacco co-use is prevalent, but consensus regarding the reasons for co-use among adults and the degree of interrelatedness between these substances is lacking. Reasons for co-use have been explored with younger users, but little data exists for more experienced users with entrenched patterns of co-use. The goal of this study was to examine characteristics and patterns of cannabis-tobacco co-use among adults in the Southeastern United States (US), where there is a legal landscape of generally restrictive cannabis legislation coupled with more permissive tobacco control compared to other US regions. Participants (N = 432) were regular cannabis users recruited through Amazon Mechanical Turk. Measures included demographics, patterns of cannabis and tobacco use, and reasons for co-use. Within this sample, 42% were current users of tobacco (n = 182). Cannabis-tobacco co-users were older and had more years of cannabis use than cannabis-only users. Among the co-using sub-sample, there was little consistency in the reasons for co-use, suggesting individual differences in the use of both substances. High levels of cannabis-tobacco interrelatedness (i.e., temporally concurrent use) were associated with smoking more cigarettes (tobacco) per day and greater nicotine dependence scores when compared to users with low levels of interrelatedness. Though these results are limited by a small sample size and generalizability issues, there were individual differences in cannabis-tobacco relatedness, which may be of importance when considering treatment strategies for cannabis, tobacco, or both. With additional research, personalized strategies adapted to cannabis-tobacco relatedness profiles among co-users may be warranted as a treatment strategy.

A Sequential Explanatory Mixed Methods Study of Young Adult Tobacco and Marijuana Co-Use

Background: The co-occurring use of tobacco and marijuana among young adults is an important behavioral phenomenon within the field of substance use. Studying tobacco and marijuana use together among young adults can provide important insight into patterns of initiation and continuation. Objectives: The primary goal of this study was to examine characteristics associated with co-use among young adults and to discover the ways experiences of co-users can help contextualize trends in co-use. Methods: This study employed a sequential explanatory mixed methods design. Quantitative analyses used 12 years of nationally representative National Health and Nutrition Examination Survey (NHANES) data (2005-2016) to assess the characteristics and experiences of young adult (21-30) co-users. Results from analyses of NHANES, prior literature, and theoretical constructs were used to develop a guide for 20 in-depth, semi-structured interviews with young adult co-users living in the state of Maryland. Interviews were analyzed using thematic analysis. Quantitative results and qualitative findings were integrated. The original NHANES analysis occurred during October and November 2017, interviews took place during December 2017 and January 2018, and all mixed methods integration was conducted in 2018. Results: Tobacco and marijuana co-users have unique characteristics and experiences compared to single product users; the experiences of co-users can offer unique insights on co-use. Meta-inferences emerged from integration. Conclusions/importance: Co-users conceptualize tobacco and marijuana differently and hold different risk perceptions for each substance. Co-users may be at risk for polytobacco product use. These findings highlight the profound influence these two substances have on young adult co-users' experiences and behaviors.