Trends in cannabis use disorder by cigarette smoking status in the United States, 2002-2016

A robust brain network for sustained attention from adolescence to adulthood that predicts later substance use

Substance use, including cigarettes and cannabis, is associated with poorer sustained attention in late adolescence and early adulthood. Previous studies were predominantly cross-sectional or under-powered and could not indicate if impairment in sustained attention was a predictor of substance use or a marker of the inclination to engage in such behavior. This study explored the relationship between sustained attention and substance use across a longitudinal span from ages 14 to 23 in over 1000 participants. Behaviors and brain connectivity associated with diminished sustained attention at age 14 predicted subsequent increases in cannabis and cigarette smoking, establishing sustained attention as a robust biomarker for vulnerability to substance use. Individual differences in network strength relevant to sustained attention were preserved across developmental stages and sustained attention networks generalized to participants in an external dataset. In summary, brain networks of sustained attention are robust, consistent, and able to predict aspects of later substance use.

The relationship between cannabis and nicotine use: A systematic review and meta-analysis

BACKGROUND AND AIMS

Cannabis and nicotine (tobacco or e-cigarettes) use commonly co-occurs and understanding their relationship can help to inform public health strategies to prevent their harms. We conducted a systematic review and meta-analysis to estimate the association of cannabis use given prior nicotine use and vice versa.

METHODS

PubMed, Embase, PsycINFO, Google Scholar and a hand-search were conducted in 2023 for longitudinal studies of the general population with no restrictions in settings (locations). Random-effects meta-analysis was conducted to estimate odds ratios between cannabis and nicotine use in both directions. The impact of unmeasured confounding was assessed using E-values.

RESULTS

From 5387 identified records, we included 20 studies. Among cannabis-naïve youths, baseline use of any nicotine products was positively associated with initiation of any cannabis use at follow-up [odds ratio (OR) = 5.39, 95% confidence interval (CI) = 3.19, 9.11; adjusted OR (aOR) = 2.59, 95% CI = 2.01, 3.32]. In nicotine-naïve participants (youths + adults), baseline cannabis use was positively associated with the initiation of any nicotine use at follow-up (OR = 4.08, 95% CI = 2.05, 8.11; aOR = 2.94, 95% CI =1.54, 5.61). There were no significant associations between baseline cannabis use and subsequent initiation of any nicotine (aOR = 3.29, 95% CI = 0.85, 12.76) or daily nicotine use (aOR = 2.63, 95% CI = 0.41, 16.95) among youths. The median E-values were 5.5 for nicotine exposure and cannabis use initiation and 4.1 for cannabis exposure and nicotine use initiation, indicating that substantial unmeasured confounding would need to have a strong association with both outcomes to fully explain away the cannabis and nicotine relationship.

CONCLUSION

Although the evidence for associations between cannabis use and tobacco use is mixed, a majority of studies to date have found that cannabis use is associated with prior nicotine use and vice versa.

Trends in marijuana and heavy alcohol use by cigarette smoking status among US adults: An analysis of the 2002-2019 NSDUH

BACKGROUND

Polysubstance use is associated with adverse health outcomes, yet little research has measured changes in polysubstance use. We aimed to 1) estimate trends in marijuana and heavy alcohol use by cigarette smoking and demographic subgroups, and 2) examine patient factors associated with concurrent use among adults who were smoking.

METHODS

We conducted a repeated cross-sectional analysis of 687,225 non-institutionalized US adults ≥18 years from the 2002-2019 National Survey on Drug Use and Health. Participants were stratified into current, former, and never smoking groups. Main outcomes were prevalence of heavy alcohol use, marijuana use, and concurrent use of both substances.

RESULTS

From 2002-2019, heavy alcohol use declined from 7.8 % to 6.4 %, marijuana use rose from 6.0 % to 11.8 %, and concurrent use of alcohol and marijuana remained stable. Among adults who were smoking from 2005 to 2019, higher education was associated with higher odds of heavy alcohol use, while older ages, female gender, non-White race/ethnicity, and government-provided health insurance were associated with lower odds. The odds of marijuana use decreased in females, older ages, and higher incomes while increasing in people with poorer health status, higher education, government-provided or no health insurance, and serious mental illness. Compared to White adults who were smoking, Black counterparts had higher odds of marijuana use (OR=1.23; 95 %CI: 1.15-1.29), while Hispanic (OR=0.68; 95 %CI: 0.63-0.72) and other racial/ethnic identities (OR=0.83; 95 %CI: 0.77-0.90) had lower odds.

CONCLUSIONS

Our study suggests marijuana use might not be sensitive to changes in the use of tobacco and alcohol.

A robust brain network for sustained attention from adolescence to adulthood that predicts later substance use

Substance use, including cigarettes and cannabis, is associated with poorer sustained attention in late adolescence and early adulthood. Previous studies were predominantly cross-sectional or under-powered and could not indicate if impairment in sustained attention was a predictor of substance-use or a marker of the inclination to engage in such behaviour. This study explored the relationship between sustained attention and substance use across a longitudinal span from ages 14 to 23 in over 1,000 participants. Behaviours and brain connectivity associated with diminished sustained attention at age 14 predicted subsequent increases in cannabis and cigarette smoking, establishing sustained attention as a robust biomarker for vulnerability to substance use. Individual differences in network strength relevant to sustained attention were preserved across developmental stages and sustained attention networks generalized to participants in an external dataset. In summary, brain networks of sustained attention are robust, consistent, and able to predict aspects of later substance use.

Combustible cigarette smokers versus e-cigarette dual users among Latinx individuals: Differences in alcohol and drug use severity

The Latinx population in the United States (U.S.) experiences significant tobacco and other substance use-related health disparities. Yet, little is known about the couse of combustible cigarettes and e-cigarettes (dual use) in relation to substance use behavior among Latinx smokers. The present investigation compared English-speaking Latinx adults living in the United States who exclusively smoke combustible cigarettes versus dual users in terms of alcohol use and other drug use problem severity. Participants were 297 Hispanic/Latinx daily cigarette smokers (36.4% female, Mage = 35.9 years, SD = 8.87) recruited nationally across the United States using Qualtrics Panels to complete self-report measures of behavioral health outcomes. Five analysis of covariance models were conducted to evaluate differences in overall alcohol consumption, dependence, related problems, hazardous drinking, and drug use problem severity between exclusive combustible cigarette smokers (N = 205) and dual users (N = 92). Results indicated that dual users evinced greater levels of alcohol consumption, dependence, alcohol-related problems, and hazardous drinking compared to exclusive combustible cigarette smokers (ps < .001). Dual users also reported greater levels of drug use problems relative to exclusive combustible cigarette smokers (p < .001). The current findings are among the first to document that dual cigarette and e-cigarette use status (compared to exclusive combustible cigarette smoking) may serve as a clinically relevant risk indicator for a range of deleterious substance use problems among Latinx individuals. Future research is needed to corroborate these findings and examine dual-use status as a longitudinal predictor of alcohol and other substance-related problems. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The Combined Effects of Nicotine and Cannabis on Cortical Thickness Estimates in Adolescents and Emerging Adults

Early life substance use, including cannabis and nicotine, may result in deleterious effects on the maturation of brain tissue and gray matter cortical development. The current study employed linear regression models to investigate the main and interactive effects of past-year nicotine and cannabis use on gray matter cortical thickness estimates in 11 bilateral independent frontal cortical regions in 223 16-22-year-olds. As the frontal cortex develops throughout late adolescence and young adulthood, this period becomes crucial for studying the impact of substance use on brain structure. The distinct effects of nicotine and cannabis use status on cortical thickness were found bilaterally, as cannabis and nicotine users both had thinner cortices than non-users. Interactions between nicotine and cannabis were also observed, in which cannabis use was associated with thicker cortices for those with a history of nicotine and tobacco product (NTP) use in three left frontal regions. This study sheds light on the intricate relationship between substance use and brain structure, suggesting a potential modulation of cannabis' impact on cortical thickness by nicotine exposure, and emphasizing the need for further longitudinal research to characterize these interactions and their implications for brain health and development.

Cannabis Use Among Adults in Cigarette Smoking Cessation Treatment in Ontario, Canada: Prevalence and Association With Tobacco Cessation Outcome, 2015-2021

Objectives. To examine cannabis use prevalence and its association with tobacco cessation among adults enrolled in cigarette smoking cessation treatment before and after Canada legalized recreational cannabis in October 2018. Methods. The sample comprised 83 206 adults enrolled in primary care-based cigarette smoking cessation treatment between 2015 and 2021 in Ontario, Canada. Past-30-day cannabis use was self-reported at enrollment and cigarette smoking abstinence at 6-month follow-up. Results. Past-30-day prevalence of cannabis use increased from 20.2% in 2015 to 37.7% in 2021. The prevalence increased linearly both before and after legalization. Cannabis and tobacco co-use was associated with lower odds of self-reported cigarette smoking abstinence at 6-month follow-up than tobacco use only (24.4% vs 29.3%; odds ratio [OR] = 0.78; 95% confidence interval [CI] = 0.75, 0.81). This association was attenuated after adjustment for covariates (OR = 0.93; 95% CI = 0.89, 0.97) and weakened slightly over time. Conclusions. Cannabis use prevalence almost doubled from 2015 to 2021 among primary care patients in Ontario seeking treatment to quit cigarettes and was associated with poorer quit outcomes. Further research into the impact of cannabis policy on cannabis and tobacco co-use is warranted to mitigate harm. (Am J Public Health. 2024;114(1):98-107. https://doi.org/10.2105/AJPH.2023.307445).

People with HIV who smoke cigarettes non-daily

Cigarette smoking is a leading cause of mortality in people with HIV (PWH) in the United States (US). A rising proportion of US tobacco users smoke non-daily, a phenomenon that is common among PWH. PWH who smoke non-daily may be attractive targets for cessation efforts, and, thus, a fuller understanding of non-daily smoking in PWH is important. We merged datasets from two randomized controlled tobacco treatment trials for PWH conducted in three cities from 2014-2020. The final dataset included 872 PWH. We analyzed sociodemographic characteristics and behavioral measures, such as nicotine dependence, motivation to quit, anxiety, and other substance use for associations with non-daily smoking, and we assessed non-daily smoking as a predictor of cessation. 13.4% of the sample smoked non-daily. In multivariable analyses, non-White race, higher anxiety, and higher motivation to quit were associated with non-daily smoking. PWH who smoked non-daily had 2.14 times the odds of those who smoked daily of quitting at six-months (95% C.I.:1.30-3.51, P=0.002). PWH who smoke non-daily differ in some demographic and behavioral characteristics from those who smoke daily. PWH reporting non-daily smoking were more likely to quit in our trials and targeting them should be a priority of future cessation efforts.

Cumulative vulnerabilities and smoking abstinence: A test from a randomized clinical trial

Smoking cessation is often associated with socioeconomic and intrapersonal vulnerabilities such as psychopathology. Yet, most research that focuses on predicting smoking cessation outcomes tends focus on a small number of possible vulnerabilities. In a secondary data analysis, we developed and empirically evaluated a comprehensive, cumulative vulnerability risk composite reflecting psychologically based transdiagnostic processes, social determinants of health, and psychopathology. Participants were adult smokers who responded to study advertisements (e.g., flyers, newspaper ads, radio announcements) for an in-person delivered 4-session smoking cessation trial (N = 267; 47% female; Mage = 39.4, SD = 13.8). Results indicated that the decline in point prevalence abstinence (PPA) from quit week to 6-month post-quit was statistically significant (p < .001). There were statistically significant effects of cumulative risk score on the intercept (p < .001) and slope (p = .01). These findings were evident in unadjusted and adjusted (controlling for sex, treatment condition, and nicotine dependence) models. The present results indicate smokers with greater cumulative vulnerability demonstrated poorer smoking cessation outcomes. There may be clinical advantages to better understanding cumulative vulnerability among treatment-seeking smokers and other smoking populations to enhance the impact of public health efforts to reduce smoking.

Anxiety sensitivity and cigarette use on cannabis use problems, perceived barriers for cannabis cessation, and self-efficacy for quitting among adults with cannabis use disorder

Many individuals diagnosed with cannabis use disorder (CUD) report a desire to quit using cannabis due to problems associated with use. Yet, successful abstinence is difficult for a large subset of this population. Thus, the present study sought to elucidate potential risk factors for cannabis use problems, perceived barriers for quitting, and diminished self-efficacy for remaining abstinent. Specifically, this investigation examined cigarette user status, anxiety sensitivity, and the interplay between these individual difference factors in terms of cannabis-related problems, perceived barriers for cannabis cessation, and self-efficacy for quitting cannabis use. The sample consisted of 132 adult cannabis users who met criteria for CUD and were interested in quitting (38 % female; 63.6 % Black; Mage = 37.22; SDage = 28.79; 54.6 % current tobacco users). Findings revealed a significant interaction, such that anxiety sensitivity was related to cannabis use problems and perceived barriers for cannabis cessation among current cigarette users, but not among cigarette non-users. There was no significant interaction for self-efficacy for remaining abstinent. The current findings suggest that cigarette users constitute a subgroup that may be especially vulnerable to the effects of anxiety sensitivity in terms of cannabis use problems and perceived barriers for quitting cannabis use.

The Heart and Cannabis (THC) Cohort: Differences in Baseline Health and Behaviors by Cannabis Use

BACKGROUND

Evidence on the cardiovascular health effects of cannabis use is limited. We designed a prospective cohort study of older Veterans (66 to 68 years) with coronary artery disease (CAD) to understand the cardiovascular consequences of cannabis use. We describe the cohort construction, baseline characteristics, and health behaviors that were associated with smoking cannabis.

OBJECTIVE

To understand the cardiovascular consequences of cannabis use.

DESIGN

We designed a prospective cohort study of older Veterans (66 to 68 years) with CAD.

PARTICIPANTS

A total of 1,015 current cannabis smokers and 3,270 non-cannabis smokers with CAD.

MAIN MEASURES

Using logistic regression, we examined the association of baseline variables with smoking cannabis in the past 30 days.

RESULTS

The current cannabis smokers and non-current smokers were predominantly male (97.2% vs 97.1%, p=0.96). Characteristics associated with recent cannabis use in multivariable analyses included lack of a high school education (odds ratio [OR] 2.15, 95% confidence interval [CI]: 1.10 to 4.19), financial difficulty (OR 1.47, 95% CI: 1.02 to 2.11), tobacco use (OR 3.02, 95% CI: 1.66 to 5.48), current drug use (OR 2.82, 95% CI: 1.06 to 7.46), and prior drug use (OR 2.84, 95% CI: 2.11 to 3.82). In contrast, compared to individuals with 0 to 1 comorbid conditions, those with 5 chronic conditions or more (OR 0.43, 95% CI: 0.27 to 0.70) were less likely to smoke cannabis.

CONCLUSIONS

In this older high-risk cohort, smoking cannabis was associated with higher social and behavioral risk, but with fewer chronic health conditions.

Prevalence of cannabis use among tobacco smokers: a systematic review protocol

INTRODUCTION

Understanding the prevalence of cannabis use among tobacco smokers has important implications for research in terms of intervention effectiveness and measurement in smoking cessation trials. The co-use of these substances also has important implications for health service planning, specifically ensuring appropriate and adequate clinical treatment. To date, there have been no synthesis of the literature on the prevalence of tobacco and cannabis co-use in adult clinical populations. Improved understanding of the current prevalence, route of administration and specific subpopulations with the highest rates of tobacco and cannabis co-use will support future intervention development. We aim to provide a pooled estimate of the percentage of smokers who report using cannabis and to examine the prevalence of co-use by sociodemographic characteristics.

METHODS AND ANALYSIS

We will conduct a systematic review using six scientific databases with published articles from 2000 to 2022 inclusive (CENTRAL, CINAHL, EMBASE, Medline, PsycINFO, Psychology and Behavioural Sciences Collection, Scopus). Peer-reviewed journal articles published in English that report on tobacco and cannabis use will be included. Rates of co-use (simultaneous or sequentially) and routes of administration will be assessed. Use in populations groups will be described. Quality assessments will be conducted for all included studies. Data will be synthesised using a narrative approach. This study will be conducted from June 2022 to the end of August 2022.

ETHICS AND DISSEMINATION

This review is based on previously published data and, therefore, ethical approval or written informed consent will not be required. It is the intention of the research team to disseminate the results of the systematic review as a peer-reviewed publication and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42020194051.

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.

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.

Cigarette dependence is more prevalent and increasing among US adolescents and adults who use cannabis, 2002-2019

SIGNIFICANCE

Cannabis use is increasing among cigarette smokers. If cannabis use is associated with cigarette dependence, a barrier to smoking cessation, this could have public health implications for tobacco control. The current study estimated the prevalence of cigarette dependence among US individuals who smoke cigarettes by cannabis use status, and investigated trends in cigarette dependence from 2002 to 2019 among cigarette smokers by cannabis use status and cigarette consumption (ie, cigarettes per day, CPD).

METHODS

Data were drawn from the 2002-2019 annual National Survey on Drug Use and Health and included US individuals aged 12+ years who used cigarettes at least once in the past month (n=231 572). Logistic regression was used to estimate the prevalence of cigarette dependence, measured as time to first cigarette <30 min, by past-month cannabis use (no use, non-daily use, daily use), and to estimate trends in cigarette dependence from 2002 to 2019 overall and stratified by cannabis use and smoking level (light, 1-5 CPD; moderate, 6-15 CPD; heavy, 16+ CPD).

RESULTS

Across all levels of cigarette use, cigarette dependence was significantly more common among individuals with daily cannabis use compared with those with non-daily or no cannabis use. From 2002 to 2019, cigarette dependence increased among cigarette smokers with non-daily cannabis use, and among light and moderate cigarette smokers with no cannabis use.

CONCLUSIONS

US individuals who use both cigarettes and cannabis report a higher prevalence of cigarette dependence relative to individuals who use cigarettes and do not use cannabis at virtually all levels of cigarette consumption. Further, cigarette dependence is increasing in the USA both among those who use and do not use cannabis. Given the increase in cannabis use among those using cigarettes, efforts to elucidate the nature of the association between cannabis and cigarette dependence are needed.

Cannabis Abuse and Perioperative Complications After Treatment of Intracranial Aneurysms: A Nationwide Analysis

OBJECTIVE

In the present retrospective cohort analysis, we examined the differences in baseline characteristics and peri- and postoperative outcomes stratified by 3 groups: cannabis abuse or dependence versus none, surgical versus endovascular treatment, and unruptured and ruptured intracranial aneurysms.

METHODS

A study population of 26,868 patients was defined using the 2009-2016 National Inpatient Sample database. The baseline characteristics were compared between the cannabis and no-cannabis groups, and the traits that differed significantly were factored into the multivariate analysis using 1:1 propensity score matching. The matched groups were analyzed to compare the cannabis and no-cannabis cohorts for the following endpoints: mortality, length of stay, discharge disposition, total hospital charges, and several peri- and postoperative outcomes.

RESULTS

In the surgically and endovascularly treated groups for unruptured intracranial aneurysms, those in the cannabis group were more likely to be male and younger and to smoke tobacco than were those in the no-cannabis group. After matching, no significant endpoint differences were noted. Similarly, in the surgically and endovascularly treated ruptured aneurysm groups, those in the cannabis group were more likely to be male and younger and to smoke tobacco. After matching, the cannabis group within the endovascular treatment group had had a longer length of stay and were more likely to have developed any hydrocephalus, obstructive hydrocephalus, sepsis, and acute kidney injury. Those in the cannabis group who had undergone surgery were more likely to have developed any hydrocephalus, specifically, communicating hydrocephalus.

CONCLUSIONS

The cannabis group with ruptured intracranial aneurysms was more likely to experience certain adverse outcomes after surgical or endovascular treatment compared with the no-cannabis group. However, such was not the case for cannabis abusers treated for unruptured aneurysms.

Cannabis use and co-use in tobacco smokers and non-smokers: prevalence and associations with mental health in a cross-sectional, nationally representative sample of adults in Great Britain, 2020

BACKGROUND AND AIMS

In Great Britain, cannabis and tobacco are commonly used substances, both independently and together. Use of either substance is associated with mental health problems, but prevalence of co-use within these populations is unknown. We aimed to (1) estimate prevalence of cannabis use, frequency of use and routes of administration (ROA) among tobacco smokers and non-smokers and (2) investigate mental health problems among non-users, tobacco-only, cannabis-only and co-users of both substances.

DESIGN

Cross-sectional national on-line survey (Action on Smoking and Health) fielded in February-March 2020.

SETTING

Great Britain.

PARTICIPANTS

Adults in Great Britain aged ≥ 18 years (n = 12 809) MEASUREMENTS: Tobacco use status [smoker (daily or non-daily) or non-smoker (never or ex-smoker)], cannabis use frequency (never to daily), detailed ROAs of cannabis, self-reported treatment for mental health disorders (depression, anxiety and any). Statistically weighted prevalence estimates were computed to ensure representativeness. Correlates were assessed using χ² tests and logistic regression.

FINDINGS

In Great Britain in 2020, 7.1% of the sample had used cannabis in the past year. Tobacco smokers had greater odds of using cannabis in the past year (21.9%) and using cannabis daily (8.7%) than non-smokers [past-year: 4.7%; adjusted odds ratio (aOR) = 10.07, 95% confidence interval (CI) = 8.4-12.0; daily: 0.7%; aOR = 24.6, 95% CI = 18.0-33.6)]. Co-administration with tobacco was common (46.2% of non-smokers, 80.8% of tobacco smokers). Co-users reported the highest prevalence of any treatment for mental health problems (54.2%) in comparison to cannabis-only (45.8%), tobacco-only (33.2%) and non-users (22.7%; all P ≤ 0.05).

CONCLUSION

Approximately one in 13 adults in Great Britain reports having used cannabis in the past year, approximately four times as many among cigarette smokers as non-smokers. Co-administration of cannabis and tobacco, via smoking, appears to be common, including among self-identified non-smokers. Mental health problems appear to be particularly common among dual users.

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.

Cigarette Use and Cannabis Use Disorder Onset, Persistence, and Relapse: Longitudinal Data From a Representative Sample of US Adults

Objective: The current study prospectively investigated the relationship between cigarette use and the onset of, persistence of, and relapse to cannabis use disorder (CUD) 3 years later among adults in the United States. Methods: Analyses included respondents who completed Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (2001-2002 and 2004-2005, respectively) and responded to questions about cigarette use, cannabis use, and CUD (n = 34,653). CUDs were defined by DSM-IV criteria using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-Diagnostic Version IV. Multivariable logistic regression models were used to calculate the odds of CUD onset, persistence, and relapse at Wave 2 by Wave 1 cigarette use status. Analyses were adjusted for sociodemographics, psychiatric disorders, nicotine dependence, and alcohol and other substance use disorders. Results: Cigarette use at Wave 1 was associated with onset of CUD at Wave 2 among those without Wave 1 cannabis use (adjusted odds ratio [AOR] = 1.62; 95% CI, 1.35-1.94) but not among those with Wave 1 cannabis use (AOR = 1.00; 95% CI, 0.83-1.19). Cigarette use at Wave 1 was also associated with persistence of CUD at Wave 2 among those with CUD at Wave 1 (AOR = 1.63; 95% CI, 1.30-2.00) and relapse to CUD at Wave 2 among those with remitted CUD at Wave 1 (AOR = 1.23; 95% CI, 1.09-1.45). Conclusions: Among adults, cigarette use is associated with increased onset and persistence of and relapse to CUD 3 years later. Additional attention to cigarette use in community prevention and clinical treatment efforts aimed at reducing CUD may be warranted.

Cannabis Use and the Onset of Cigarette and E-cigarette Use: A Prospective, Longitudinal Study Among Youth in the United States

INTRODUCTION

Cigarette use is declining among youth in the United States, whereas cannabis use and e-cigarette use are increasing. Cannabis use has been linked with increased uptake and persistence of cigarette smoking among adults. The goal of this study was to examine whether cannabis use is associated with the prevalence and incidence of cigarette, e-cigarette, and dual product use among U.S. youth.

METHODS

Data included U.S. youth ages 12-17 from two waves of the Population Assessment of Tobacco and Health (PATH) Study (Wave 1 youth, n = 13 651; Wave 1 tobacco-naive youth, n = 10 081). Weighted logistic regression models were used to examine the association between Wave 1 cannabis use and (1) Wave 1 prevalence of cigarette/e-cigarette use among Wave 1 youth and (2) Wave 2 incidence of cigarette/e-cigarette use among Wave 1 tobacco-naive youth. Analyses were run unadjusted and adjusted for demographics and internalizing/externalizing problem symptoms.

RESULTS

Wave 1 cigarette and e-cigarette use were significantly more common among youth who used versus did not use cannabis. Among Wave 1 tobacco-naive youth, Wave 1 cannabis use was associated with significantly increased incidence of cigarette and e-cigarette use by Wave 2.

CONCLUSIONS

Youth who use cannabis are more likely to report cigarette and e-cigarette use, and cannabis use is associated with increased risk of initiation of cigarette and e-cigarette use over 1 year. Continued success in tobacco control-specifically toward reducing smoking among adolescents-may require focusing on cannabis, e-cigarette, and cigarette use in public health education, outreach, and intervention efforts.

IMPLICATIONS

These data extend our knowledge of cigarette and e-cigarette use among youth by showing that cannabis use is associated with increased prevalence and incidence of cigarette and e-cigarette use among youth, relative to youth who do not use cannabis. The increasing popularity of cannabis use among youth and diminished perceptions of risk, coupled with the strong link between cannabis use and tobacco use, may have unintended consequences for cigarette control efforts among youth.

Cannabis use assessment and its impact on pain in rheumatologic diseases: a systematic review and meta-analysis

OBJECTIVES

Despite classic analgesic or effective treatments in rheumatic diseases, such as synthetic DMARDs in RA, patients remain in pain and often turn to non-prescribed pharmacological alternatives, such as cannabis self-therapeutic use. However, this medical use of cannabis has not been thoroughly studied.

METHODS

We performed a systematic literature review up to June 2020. The incidence of cannabis consumption was calculated by metaproportion. Differences between cannabis users and non-users were expressed as standardized mean differences using the inverse-variance method. We also assessed the effects of cannabis on pain.

RESULTS

A total of 2900 patients reported cannabis consumption in a sample of 10 873 patients [incidence 40.4% (95% confidence interval (CI): 0.28, 0.54)], and 15.3% (95% CI: 0.07, 0.27) specified that they were currently taking cannabis. Cannabis use was higher in the four fibromyalgia studies [68.2% (95% CI: 0.41, 0.90), n = 611] compared with seven articles concerning RA or lupus [26.0% (95% CI: 0.14, 0.41), n = 8168]. Cannabis consumption was associated with a decrease in pain intensity [VAS pain at baseline 8.2 (2.9) vs 5.6 (3.5) mm over time; pooled effect size -1.75 (95% CI: -2.75, -0.76)]. Cannabis users were younger [58.4 (11.4) vs 63.6 (12.1) years; P <0.001], more often smokers [OR 2.91 (95% CI: 1.84, 4.60)] or unemployed [OR 2.40 (95% CI: 1.31, 4.40)], and had higher pain intensity [5.0 (2.4) vs 4.1(2.6) mm; P <0.001] than non-users.

CONCLUSION

Nearly 20% of patients suffering from rheumatologic diseases actively consume cannabis, with an improvement in pain. The issue of cannabis use in the management of these patients should be addressed during medical consultation, essentially with cannabis-based standardized pharmaceutical products.

Multi-directional pathways of tobacco and marijuana use, including comorbid use, among a population-based cohort of adolescents in Texas: A six-wave cross-lagged model

PURPOSE

Past 30-day tobacco and marijuana use commonly occur among adolescents. It is unclear whether use of one product precedes the other, especially given the new climate surrounding marijuana legalization and the increasing popularity of e-cigarettes.

METHODS

Six-panel cross-lagged regression models, with six months between each panel/Wave (2014-17), were used to model stability paths, bi-directional paths, and comorbid paths (i.e., correlations) between past 30-day use of marijuana and tobacco products. Data were derived from three cohorts of adolescents (n = 3907; weighted N = 461,069) in 6th, 8th, and 10th grades at baseline.

RESULTS

Few bidirectional relationships between past 30-day tobacco and marijuana use were observed in early adolescence (6th grade). During the middle adolescence developmental period (8th grade), past 30-day marijuana use was prospectively associated with greater risk of past 30-day tobacco use. In late adolescence (10th grade), increased odds of past 30-day marijuana use given prior past 30-day e-cigarette use, and vice versa, were observed. For all cohorts, stability paths were common, especially for past 30-day marijuana use. Comorbid use was common in middle adolescence (8th grade) but small in magnitude.

CONCLUSIONS

This is the first study to longitudinally situate comorbid, past 30-day use of tobacco and marijuana and simultaneously examine bi-directional past 30-day use of these products for adolescents. Marijuana use more often and more strongly predicted subsequent tobacco use than the reverse, especially during middle adolescence (13-15 years old). Marijuana use should be considered when creating interventions that address adolescent e-cigarette use in the U.S.

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.

Opioid Use Disorder Trends from 2002 to 2017 by Cigarette Smoking Status in the United States

Introduction

There have been significant increases in opioid use and opioid-related overdose deaths in the United States (US). While cigarette smoking remains disproportionately high among individuals with opioid use disorder (OUD), it is unknown whether trends in OUD differ by cigarette use. This study examined differences in OUD by smoking status and trends in OUD by smoking status over time.

Methods

Data were harnessed from US National Surveys on Drug Use and Health, annual cross-sectional, nationally representative samples of individuals aged 12 and older. Past-year OUD prevalences were estimated each year from 2002 to 2017 among persons with current daily, current nondaily, former, and never cigarette smoking (n = 891 548). Linear time trends of OUD were examined using logistic regression models.

Results

In 2017, OUD was significantly more common among persons with daily (2.6%) and nondaily (1.5%) smoking compared with those with former (0.5%) or never (0.2%) smoking. Overall, the prevalence of OUD increased between 2002 and 2017, although trends differed by smoking status. Adjusting for background characteristics, the prevalence of OUD increased significantly among individuals with daily (adjusted odds ratio [AOR] = 1.06; 95% confidence interval [CI]: 1.04, 1.07), nondaily (AOR = 1.03; 95% CI: 1.01, 1.05), and former smoking (AOR = 1.05; 95% CI: 1.02, 1.09), but decreased among those who never smoked (AOR = 0.98; 95% CI: 0.97, 0.99).

Conclusions

In the United States, the prevalence of OUD was higher among individuals with current cigarette smoking relative to those with former and never smoking. OUD increased among persons with current and former smoking from 2002 to 2017, in contrast to a decrease in OUD among those who never smoked.

Implications

OUDs are increasing in the United States and are associated with difficulty quitting cigarettes. Our data from representative national samples of US individuals showed that although OUD increased among those with both current and former smoking over time, OUD remained significantly higher among persons with current (daily and nondaily) smoking versus persons who formerly smoked cigarettes. In addition, youth with cigarette smoking had particularly high prevalences of OUDs. Cigarette smoking may be important to address alongside OUD to reduce the harmful consequences of OUD and cigarette use especially among younger individuals.

International differences in patterns of cannabis use among adult cigarette smokers: Findings from the 2018 ITC Four Country Smoking and Vaping Survey

BACKGROUND

Although evidence shows that co-use of cigarettes and cannabis is common, there is little research examining if co-use patterns vary depending on the regulatory environment for cannabis. This study examined patterns of co-use and perceptions of relative harm among cigarette smokers in four countries with different histories, and at different stages of cannabis legalization.

METHODS

Data are from the 2018 International Tobacco Control 4CV Survey and included 10035 adult cigarette smokers from Canada, United States (US), Australia, and England. At the time of the survey, Canada and the US had relatively more permissive cannabis regulations compared to Australia and England.

RESULTS

Among this sample of 10035 cigarette smokers, Canada had the highest rate of cannabis co-use in the last 12 months (36.3%), followed by the US (29.1%), England (21.6%), and Australia (21.4%). Among past 12 month co-users (n = 3134), the US (40.2%) and Canada (35.2%) had the highest rates of daily cannabis use, followed by smokers in England (26.3%) and Australia (21.7%); Australian co-users had the highest rate of infrequent (

CONCLUSION

Patterns of tobacco and cannabis co-use differed between countries. Smokers in Canada and the US had higher rates of co-use, daily cannabis use, dual-daily use of both cannabis and cigarettes, and were more likely to perceive smoked cannabis as less harmful than cigarettes compared to England and Australia. Further attention as to how varying cannabis regulations may impact co-use patterns is warranted.

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Key Words

• Cannabis
• Co-use
• Harm Perceptions
• Policy
• Regulation
• Tobacco cigarettes

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MESH Headings Collapse

Grants

• P01 CA200512 NCI NIH HHS

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Affiliation(s)

Shannon Gravely Department of Psychology, University of Waterloo, Waterloo, Canada.
Pete Driezen Department of Psychology, University of Waterloo, Waterloo, Canada; School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada
Danielle M Smith Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
Ron Borland School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia; Cancer Council Victoria, Melbourne, VIC, Australia
Eric N Lindblom O'Neill Institute for National & Global Health Law, Georgetown University Law Center, Washington, DC United States
David Hammond School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada
Ann McNeill King's College London, Addictions Department, Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom; UK Centre for Tobacco & Alcohol Studies, Nottingham, United Kingdom
Andrew Hyland Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
K Michael Cummings Department of Psychiatry & Behavioral Sciences, Medical University of South Carolina, Charleston, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, United States
Gary Chan Centre for Youth Substance Abuse Research, The University of Queensland, Brisbane, QLD, Australia
Mary E Thompson Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada
Christian Boudreau Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada
Nadia Martin Department of Psychology, University of Waterloo, Waterloo, Canada
Janine Ouimet Department of Psychology, University of Waterloo, Waterloo, Canada
Ruth Loewen Department of Psychology, University of Waterloo, Waterloo, Canada
Anne C K Quah Department of Psychology, University of Waterloo, Waterloo, Canada
Maciej L Goniewicz Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
James F Thrasher Department of Health Promotion, Education & Behavior, Arnold School of Public Health, University of South Carolina, Columbia, United States; Tobacco Research Department, Center for Population Health Research, National Institute of Public Health, Cuernavaca, Mexico
Geoffrey T Fong Department of Psychology, University of Waterloo, Waterloo, Canada; School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada; Ontario Institute for Cancer Research, Toronto, Canada

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Current cannabis use and smoking cessation among treatment seeking combustible smokers

INTRODUCTION

Combustible tobacco smoking and cannabis use frequently occur together, and the use of both substances is associated with overall greater severity of tobacco and cannabis related problems. Observational work has found that cannabis use is associated with tobacco cessation failure, but research directly testing the longitudinal associations of cannabis use on tobacco cessation during smoking cessation treatment is lacking. The current study examined the impact of current cannabis use on combustible tobacco cessation outcomes.

METHODS

207 daily combustible tobacco smokers (M_age = 38.24 years, SD = 14.84, 48.1 % male) were enrolled in a randomized controlled smoking cessation trial. Survival analyses and multi-level modeling were used to assess lapse and relapse behavior through 12-week follow up. The current study is a secondary data analysis.

RESULTS

Results of the current study suggest that cannabis use is associated with faster time to lapse (OR = 0.644, se = .188, p =  .019), but not relapse (OR = -0.218, se = .403, p =  .525), compared to combustible tobacco-only smokers. Additionally, cannabis use was associated with lower likelihood of achieving any 7-day point prevalence abstinence during the 12 week follow up (b = 0.93, se = 0 0.24, p =  0.0001).

CONCLUSIONS

The current study provides novel evidence that cannabis use may be related to combustible tobacco use in terms of faster time to lapse and lower likelihood of any 7-day point prevalence abstinence following smoking cessation treatment. Developing integrated cannabis-tobacco cessation treatments is an important next step in research focused on tobacco-cannabis use.

Is cannabis use associated with tobacco cessation outcome? An observational cohort study in primary care

BACKGROUND

Some studies suggest cannabis use negatively affects tobacco cessation outcomes, but findings have been mixed. We examined whether cannabis use was associated with tobacco cessation outcomes in a real-world primary care setting.

METHODS

The analytic dataset consisted of 35,246 patients who enrolled between 2014 and 2016 in a primary care-based smoking cessation program in Ontario, Canada. Past 30-day cannabis use, for recreational or medical purposes, was self-reported at enrollment. Thirty-day point prevalence tobacco smoking abstinence was self-reported via online or telephone survey at 6 months post-enrollment.

RESULTS

Thirty days prior to enrollment, 79.9 % of patients had not used cannabis, 16.3 % used cannabis for recreational purposes only, and 3.8 % used cannabis for medical purposes. Unadjusted and adjusted odds of tobacco cessation at 6 months were reduced for patients using cannabis compared to non-users (ORs = 0.76-0.86, ps<0.05). When cannabis use was categorized by purpose, both unadjusted and adjusted odds of cessation were significantly lower for recreational users (ORs = 0.77-0.84, ps<0.05). Medical users had decreased odds of cessation in unadjusted analysis (OR = 0.74, 95 % CI = 0.61-0.89, p = 0.001), but not after adjustment for potential confounders. However, post-estimation contrasts did not indicate a significant difference between the effect of recreational and medical cannabis use.

CONCLUSIONS

In a large real-world sample of patients seeking smoking cessation treatment, concurrent cannabis use was associated with decreased success with quitting smoking. Recreational cannabis use was consistently related to poorer cessation outcomes, but medical use was not. Additional research is needed to inform treatment strategies for this growing sub-population of smokers.

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.

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.

Is policy 'liberalization' associated with higher odds of adolescent cannabis use? A re-analysis of data from 38 countries

BACKGROUND

Policy makers worldwide face the choice of whether to reform cannabis policy from the 'full prohibition' model. A paper by Shi et al. (2015) suggested that such 'liberalization' is significantly associated with higher odds of adolescent cannabis use.

AIM

To test the validity and reliability of Shi et al's conclusion that the HBSC data show an association between policy 'liberalization' and increased likelihood of adolescent cannabis use.

METHODS

Replication and re-analysis of the same pooled data from three waves of the Health Behaviour in School-aged Children (HBSC) survey (2001/2, 2005/6 and 2009/10). This replicates - as far as possible - the coding and analytical strategy of the Shi et al article. The re-analysis makes some improvements by: excluding a variable ('number of siblings') for which many cases have missing data; including available data from the theoretically relevant case of Sweden for the latter two waves of the HBSC survey, which Shi et al omit; and including random slopes for gender between countries as well as random intercepts for countries in the mixed effects model, as the predictive effect of gender on cannabis use varies across countries.

RESULTS

Shi et al's verbal summary of their findings is not supported by detailed interpretation of their own numerical results. Without making the suggested amendments, it is possible to find a statistically significant association between policy 'liberalization' and higher odds of some measures of adolescent cannabis use. But when these improvements are made, this association becomes statistically non-significant.

CONCLUSION

Using a larger and more theoretically relevant sample of the HBSC respondents and an improved statistical model shows that the HBSC data do not reveal a statistically significant association between policy 'liberalization' and higher odds of adolescent cannabis use.