Treatment Implications Associated with Cannabis and Tobacco Co-Use

Urgent need for treatment addressing co-use of tobacco and cannabis: An updated review and considerations for future interventions

BACKGROUND

There are no clinical practice guidelines addressing the treatment of tobacco-cannabis co-use and a dearth of studies to inform treatment for co-use. This narrative review aims to (1) summarize promising intervention components used in published co-use treatment studies, (2) describe key gaps and emerging issues in co-use, and (3) provide recommendations and considerations in the development and evaluation of co-use interventions.

METHODS

We conducted a literature search in June 2024 across several databases to update previous reviews on tobacco-cannabis co-use treatment. We found 9 published intervention studies that specifically addressed treatment for both substances. Data from these studies were manually extracted and summarized.

RESULTS

Most of the 9 included studies (1) focused on acceptability and/or feasibility, (2) provided both psychosocial/behavioral and pharmacotherapy intervention components, (3) were conducted in adults, and (4) were delivered in-person, with some having digital asynchronous components, for a 5-to-12-week duration. The most common psychosocial/behavioral strategies used were Cognitive Behavioral Therapy, Motivational Interviewing, and Contingency Management; while the most common pharmacotherapy was Nicotine Replacement Therapy. There was no evidence of compensatory use of tobacco or cannabis when providing simultaneous treatment for both substances.

CONCLUSIONS

The literature to date provides support for well-integrated multi-component interventions of psychosocial/behavioral and pharmacotherapy strategies for co-use treatment. This review reinforces an urgent need for treatments targeting tobacco and cannabis co-use. Future interventions should address key gaps, including co-use of vaporized products among youth and young adults, tailored interventions for priority populations, and digital applications to increase reach and advance health equity.

Trends in cannabis and tobacco co-use in the United States, 2002-2021

BACKGROUND

Co-use of cannabis and tobacco poses greater risks than use of either substance individually and may be becoming more prevalent with increasing cannabis medicalization and legalization. We aimed to assess trends in the prevalence of cannabis and tobacco co-use between 2002-2019 and identify the updated prevalence and correlates of co-use in 2021 among US adults.

METHODS

This study used data from the 2002-2021 National Survey on Drug Use and Health, a nationally-representative, cross-sectional survey in the US. We assessed prevalence trends in past 30-day cannabis and tobacco co-use, exclusive cannabis use, and exclusive tobacco use overall and by sociodemographic group using joinpoint regression. Additionally, multinomial models identified correlates of co-use in 2021.

RESULTS

In 2021, the weighted prevalence of cannabis and tobacco co-use was 6.38 %, the weighted prevalence of exclusive cannabis use was 7.28 %, and the weighted prevalence of exclusive tobacco use was 15.01 %. From 2002 to 2019, the prevalence of past 30-day co-use of cannabis and tobacco increased significantly (annual percentage change [APC]: 1.9 [1.4-2.4], P<0.05) among the overall US population. All subgroups of sex, race/ethnicity, and age also saw significant increases in co-use, other than young adults ages 18-25, for whom co-use was stagnant between 2002-2014 and then decreased significantly between 2014-2019.

CONCLUSION

This study identified increasing cannabis and tobacco co-use overall and among most sociodemographic strata in the US. As cannabis policy changes rapidly, co-use requires closer surveillance, clinical screening, and dedicated research.

Tobacco-cannabis co-use among cancer patients and survivors: findings from 2 US cancer centers

BACKGROUND

Cannabis use is prevalent among cancer patients and survivors and may provide some therapeutic benefits for this population. However, benefits may be attenuated when cannabis is co-used with tobacco, which is associated with more severe tobacco and cannabis use and adverse outcomes in noncancer populations. We compared cannabis use, primary mode of use, and therapeutic and/or nontherapeutic use among 3 groups of patients and survivors based on cigarette smoking status.

METHODS

Survey data was collected from patients and survivors with cancer (n = 1732) at 2 US National Cancer Institute-designated cancer centers in states with varying cannabis regulatory policy. Prevalence of cannabis use (prior to diagnosis, after diagnosis, before treatment, after treatment), primary mode of use, and therapeutic and/or nontherapeutic use were assessed by cigarette smoking status (current, former, never) within and across centers using weighted bivariate analyses and multivariable logistic regression, controlling for demographic and clinical variables.

RESULTS

Current cigarette use was associated with greater rates of cannabis use prior to diagnosis, after diagnosis, during treatment, and after treatment within each center (all P < .001) and in pooled analyses across centers (all P < .001). Primary mode of use, knowledge of cannabis products, and therapeutic and/or nontherapeutic use also statistically differed by tobacco status and study site.

CONCLUSIONS

Results illustrate the importance of conducting assessments for both tobacco and cannabis use among cancer patients during and after cancer treatment, regardless of the cannabis regulatory environment. Given previous data indicating harms from co-use and continued tobacco use during cancer treatment, this issue introduces new priorities for cancer care delivery and research.

Prenatal Cannabis and Tobacco Co-Exposure and Its Association with Behavioural Outcomes in Middle Childhood: Co-exposition prénatale au cannabis et au tabac et son association avec les résultats comportementaux au cours de l'enfance intermédiaire

OBJECTIVES

Cannabis legalization has triggered an increase in prenatal cannabis use. Given that tobacco is commonly co-used with cannabis, determining outcomes associated with prenatal cannabis and tobacco co-exposure is crucial. While literature exists regarding the individual effects of prenatal cannabis and tobacco exposure on childhood behaviour, there is a gap regarding their combined use, which may have interactive effects. Therefore, we investigated whether prenatal cannabis and tobacco co-exposure was associated with greater externalizing and internalizing problems in middle childhood compared to prenatal exposure to either substance alone or no exposure.

METHODS

Baseline data from the Adolescent Brain Cognitive Development (ABCD) Study (collected in children ages 9-11) were used to explore differences in externalizing and internalizing scores derived from the Childhood Behavior Checklist across four groups: children with prenatal cannabis and tobacco co-exposure (CT, n = 290), children with prenatal cannabis-only exposure (CAN, n = 225), children with prenatal tobacco-only exposure (TOB, n = 966), and unexposed children (CTL, n = 8,311). We also examined if the daily quantity of tobacco exposure modulated the effect of cannabis exposure on outcomes.

RESULTS

Adjusting for covariates, a 2 × 2 ANCOVA revealed significant main effects for prenatal cannabis (p = 0.03) and tobacco exposure (p < 0.001), and a significant interaction effect on externalizing scores (p = 0.032); no significant main effects or interactions were found for internalizing scores. However, interactions between daily quantity of cannabis and tobacco exposure significantly predicted both externalizing and internalizing scores (p < 0.01).

CONCLUSIONS

These findings indicate that co-exposure is associated with greater externalizing problems than exposure to either substance alone, which did not differ from each other. Further, greater tobacco exposure may amplify the negative effect of cannabis exposure on both externalizing and internalizing behaviours in children. These findings underscore the need for interventions that target cannabis and tobacco co-use in pregnant women to circumvent their adverse impact on middle childhood behaviour.

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.

Testing a Brief Quitline Intervention for Tobacco Cannabis Co-Users: A Randomized Controlled Pilot Study

Background: Tobacco cannabis co-use is common and becoming more prevalent. Frequent and heavy users of cannabis may struggle to quit smoking. Quitlines offer free cessation treatment in the United States and 25% of quitline callers may also be cannabis users. The present paper describes a randomized pilot study of a tailored intervention for cannabis and cigarette co-users. The intervention combines the quitline smoking cessation treatment with a motivational enhancement therapy-based cannabis intervention. Methods: The randomized pilot study was conducted within four state-funded quitlines with quitline coaches as interventionists. 102 quitline callers who were cannabis and cigarette co-users were randomized to receive treatment as usual (TAU) or the new Quitline Check-Up (QLCU) intervention. Outcomes were collected 90 days post-randomization. Primary outcomes included feasibility and acceptability of delivering the QLCU in the quitline setting. Secondary outcomes included 7-day point prevalence tobacco abstinence, past 30-day cannabis use, and Cannabis Use Disorder Identification Test scores. Results: Study participants were heavy cannabis users, averaging 25 days of use in the past 30; nearly 70% used at a level considered hazardous. Fidelity ratings indicated coaches were successful at delivering the intervention. Treatment engagement was high for both groups (TAU m = 3.4 calls; QLCU m = 3.6 calls) as was treatment satisfaction. Intent-to-treat quit rates (with survey non-responders classified as smokers) were 28.6% for the TAU control group and 24.5% for the QLCU group (P = .45). Discussion: Hazardous cannabis use rates were high in this sample of tobacco cannabis co-users calling quitlines to quit smoking. The intervention for co-users was acceptable and feasible to deliver. No improvements in tobacco cessation outcomes were observed. Pragmatic intervention development within a real-world clinical setting can streamline the intervention development process. More research is needed on tobacco cannabis co-users and who can benefit from a tailored intervention. Registered: ClinicalTrials.gov NCT04737772, February 4, 2021.

Classification of patterns of tobacco and cannabis co-use based on temporal proximity: A qualitative study among young adults

PURPOSE

Co-use of tobacco and cannabis is a common and complex behavior. The lack of harmonized measures of co-use yields confusion and inconsistencies in synthesizing evidence about the health effects of co-use. We aimed to classify co-use patterns based on temporal proximity and describe preferred products and motives for each pattern in order to improve co-use surveillance.

METHODS

We conducted semi-structured interviews in a sample of 34 young adults (Mage = 22.8 years, 32.4 % female) during 2017-2019 in California, USA. We employed a qualitative thematic analysis to identify timing, reasons, and contexts for tobacco and cannabis co-use and classify co-use patterns.

RESULTS

Four emergent patterns of co-use with increasing temporal proximity between tobacco use and cannabis use were: Same-month different-day co-use (Pattern 1); Same-day different-occasion co-use (Pattern 2); Same-occasion sequential co-use (Pattern 3); and Same-occasion simultaneous co-use (Pattern 4). Participants used various product combinations within each pattern. Similar motives for all patterns were socialization, product availability, and coping with stress/anxiety. Unique motive for temporally distant patterns (Patterns 1 and 2) was seeking substance-specific effects (e.g., stimulant effect from nicotine, relaxation effects from cannabis), while unique motives for temporally close patterns (Patterns 3 and 4) were seeking combined effects from both substances (e.g., more intense psychoactive effects, mitigating cannabis adverse effects) and behavioral trigger (e.g., cannabis use triggers tobacco use).

CONCLUSIONS

Our classification of co-use patterns can facilitate consistency for measuring co-use and assessing its health impacts. Future research should also measure product types and motives for different patterns to inform intervention efforts.

Temporal associations linking alcohol and cannabis use to cigarette smoking in young adults engaged in a tobacco cessation and relapse monitoring study

Young adulthood remains a developmental period in which cigarette smoking initiation and progression to dependence and regular use is common. Moreover, co-use of alcohol and/or cannabis with tobacco is common in this age group and may have detrimental effects on tobacco use rates and cessation outcomes. Although young adults are interested in quitting smoking, achieving abstinence remains difficult, even with evidence-based treatment strategies. Understanding proximal associations between other substance use (e.g., alcohol and cannabis) and smoking may have important treatment implications. This exploratory analysis investigated the role of alcohol and/or cannabis use in contributing to smoking events on the same day or next day among young adults engaged in a smoking cessation and relapse monitoring study. We used ecological momentary assessment (EMA) data from 43 young adults (ages 18-25; 932 observations) who smoked cigarettes daily and agreed to participate in a 5-week study that included a 2-day smoking quit attempt and provision of tobacco treatment in the form of nicotine replacement therapy, brief cessation counseling, and financial incentives for abstinence (incentives were provided only during the 2-day quit attempt). We tested multilevel time-series models of daily associations between alcohol use, cannabis use, and smoking. Consistent with hypotheses, days on which participants were more likely to drink alcohol predicted increased likelihood of smoking the next day (OR = 2.27, p =.003). This effect was significant after controlling for both the one-day lagged effect of smoking (i.e., autoregression) and the concurrent (i.e., same day) effects of drinking and cannabis use. Although there was a positive concurrent effect of cannabis use on smoking (OR = 12.86, p =.003), the one-day lagged effect of cannabis use and the concurrent effect of drinking was not significant, contrary to hypotheses. Results indicate that alcohol use presents a potential threat to successful smoking cessation that extends to the following day. This suggests a risk-window in which treatment could be supplemented with just-in-time interventions and extending the focus on co-use to include this lagged impact on cessation outcomes.

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.

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).

Disparities in cannabis use outcomes, perceived risks and social norms across sexual orientation groups of US young adult women and men

Little research has examined mechanisms driving cannabis use disparities among sexual minority (SM; versus heterosexual) young adults (YAs). Participants were US YA women (N = 1345; 24.8% bisexual, 6.1% lesbian) and men (N = 998: 8.9% bisexual, 13.8% gay). Bivariate analyses examined associations between sexual orientation (heterosexual, gay/lesbian, bisexual) and cannabis use outcomes (past 30-day [current] use, use frequency, cannabis-tobacco dual use, use intentions), perceived risks (harm, addictiveness) and social norms (social acceptability, peer use). Regressions examined sexual orientation, perceived risks and social norms as correlates of cannabis outcomes. Bisexual and lesbian (versus heterosexual) women reported lower cannabis-related perceived risks, greater social norms and higher odds of current use. Bisexual (versus heterosexual) women reported more days of use, higher odds of cannabis-tobacco dual use and greater use intentions. Gay (versus heterosexual) men reported lower perceived addictiveness, greater social norms and higher odds of current use. Lower perceived risks and greater social norms predicted greater use outcomes for women and men. Bisexual women displayed higher odds of several cannabis use outcomes, whereas lesbian women and gay men displayed higher odds of current cannabis use only. Cannabis-related perceptions and social norms may be important targets for public health messaging for SMYAs.

Cannabinoids for Substance Use Disorder Treatment: What Does the Current Evidence Say?

Background: The prevalence of Substance Use Disorder (SUD) is increasing along with the need to develop approaches to reduce the harm associated with substance use, including investigating alternatives such as cannabinoids, which show promising results, although the current evidence is limited. This scoping review focuses on the limitations and potentials of cannabinoid-based treatments for SUDs. Methods: We examined between-subject randomized controlled trials (RCTs) investigating the use of CBD and THC as pharmacological treatment for SUDs in adults, with the procedures attending the expectations of the Preferred Reporting Items for Scoping reviews and Meta-Analyses (PRISMA) for Scoping Reviews guidelines and assessed risk of bias using the Cochrane Risk of Bias Assessment Tool 2. Results: Ten RCTs were included, with six demonstrating low risk of bias, and positive results were found for treating Cannabis Use Disorder, while contradictory results were found for Opioid Use Disorder, and inconclusive results for treating Cocaine Use Disorder. Conclusions: CBD and THC demonstrate potential for treating some SUDs, but evidence is limited. Robust RCTs with larger samples and longer follow-up periods are necessary to assess carefully developed outcomes for different SUD patients. New cannabinoid-based medications and scientific-based policies may advance SUD treatment. A comprehensive approach to treatment and careful methodological choices may benefit patients with SUD.

Tobacco and Cannabis Use Have a Synergistic Association on Infection Risk Following Total Knee Arthroplasty

BACKGROUND

Studies suggest an increase in the number of combined users of tobacco and cannabis. Therefore, we specifically assessed tobacco, cannabis, and combined users who underwent primary total knee arthroplasty (TKA) to determine 90-day to 2-year: (1) odds of periprosthetic joint infection; (2) odds of revision; and (3) medical complications.

METHODS

We queried a national, all payer database of patients undergoing primary TKA between 2010 and 2020. Patients were stratified according to current use of tobacco products (n = 30,000), cannabis (n = 400), or a combination (n = 3,526). These were defined according to International Classification of Disease codes, Ninth and Tenth Editions. Patients were tracked from the 2 years before TKA through 2 years afterwards. A fourth group of TKA recipients who did not have tobacco nor cannabis use was used as a matching cohort. Periprosthetic joint infections (PJIs), revisions, and other medical/surgical complications from 90 days through 2 years were evaluated between these cohorts using bivariate analyses. Multivariate analyses assessed independent risk factors for PJI at 90 days through 2 years, adjusted for patient demographics and health metrics.

RESULTS

Combined tobacco and cannabis use were associated with the highest rates of PJI following TKA. The odds of 90-day PJI risk among cannabis, tobacco, and combined users was 1.60, 2.14, and 3.39, respectively, as compared to the matched cohort (P < .001). Co-users had the highest and significantly increased revision odds at 2 years following TKA (odds ratio = 1.52, 95% confidence interval, 1.15 to 2.00). At 1 and 2 years following TKA, cannabis, tobacco, and co-users had higher rates of myocardial infarctions, respiratory failures, surgical site infections, and manipulations under anesthesia when compared to the matched cohort (all P < .001).

CONCLUSION

Tobacco and cannabis use before primary TKA demonstrated a synergistic association on PJI risk from 90 days through 2 years. Although the harms of tobacco use are well-known, this additional knowledge about cannabis should be incorporated in the shared decision-making discussions in the pre-operative setting to best prepare for expected risks following primary TKA.

Does tobacco dependence worsen cannabis withdrawal in people with and without schizophrenia-spectrum disorders?

BACKGROUND AND OBJECTIVES

Rates of cannabis use disorder (CUD) are higher in people with schizophrenia than in the general population. Irrespective of psychiatric diagnosis, tobacco co-use is prevalent in those with CUD and leads to poor cannabis cessation outcomes. The cannabis withdrawal syndrome is well-established and increases cannabis relapse risk. We investigated whether cannabis withdrawal severity differed as a function of high versus no/low tobacco dependence and psychiatric diagnosis in individuals with CUD.

METHOD

Men with CUD (N = 55) were parsed into four groups according to schizophrenia diagnosis and tobacco dependence severity using the Fagerstrom Test for Nicotine Dependence (FTND): men with schizophrenia with high tobacco dependence (SCT+, n = 13; FTND ≥ 5) and no/low tobacco dependence (SCT-, n = 22; FTND ≤ 4), and nonpsychiatric controls with high (CCT+, n = 7; FTND ≥ 5) and no/low (CCT-, n = 13; FTND ≤ 4) tobacco dependence. Participants completed the Marijuana Withdrawal Checklist following 12-h of cannabis abstinence.

RESULTS

There was a significant main effect of tobacco dependence on cannabis withdrawal severity (p < .001). Individuals with high tobacco dependence had significantly greater cannabis withdrawal severity (M = 13.85 [6.8]) compared to individuals with no/low tobacco dependence (M = 6.49, [4.9]). Psychiatric diagnosis and the interaction effects were not significant. Lastly, cannabis withdrawal severity positively correlated with FTND (r = .41, p = .002).

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

Among individuals with CUD and high tobacco dependence, cannabis withdrawal severity was elevated twofold, irrespective of diagnosis, relative to individuals with CUD and no/low tobacco dependence. Findings from this study emphasize the importance of addressing tobacco co-use when treating CUD.

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.

Associations Between Product Type and Intensity of Tobacco and Cannabis Co-use on the Same Day Among Young Adult Smokers: Smartphone-Based Daily-Diary Study

BACKGROUND

Co-use of tobacco and cannabis is highly prevalent among young US adults. Same-day co-use of tobacco and cannabis (ie, use of both substances on the same day) may increase the extent of use and negative health consequences among young adults. However, much remains unknown about same-day co-use of tobacco and cannabis, in part due to challenges in measuring this complex behavior. Nuanced understanding of tobacco and cannabis co-use in terms of specific products and intensity (ie, quantity of tobacco and cannabis use within a day) is critical to inform prevention and intervention efforts.

OBJECTIVE

We used a daily-diary data collection method via smartphone to capture occurrence of tobacco and cannabis co-use within a day. We examined (1) whether the same route of administration would facilitate co-use of 2 substances on the same day and (2) whether participants would use more tobacco on a day when they use more cannabis.

METHODS

This smartphone-based study collected 2891 daily assessments from 147 cigarette smokers (aged 18-26 years, n=76, 51.7% female) during 30 consecutive days. Daily assessments measured type (ie, cigarette, cigarillo, or e-cigarette) and intensity (ie, number of cigarettes or cigarillos smoked or number of times vaping e-cigarettes per day) of tobacco use and type (ie, combustible, vaporized, or edible) and intensity (ie, number of times used per day) of cannabis use. We estimated multilevel models to examine day-level associations between types of cannabis use and each type of tobacco use, as well as day-level associations between intensities of using cannabis and tobacco. All models controlled for demographic covariates, day-level alcohol use, and time effects (ie, study day and weekend vs weekday).

RESULTS

Same-day co-use was reported in 989 of the total 2891 daily assessments (34.2%). Co-use of cigarettes and combustible cannabis (885 of the 2891 daily assessments; 30.6%) was most commonly reported. Participants had higher odds of using cigarettes (adjusted odds ratio [AOR] 1.92, 95% CI 1.31-2.81) and cigarillos (AOR 244.29, 95% CI 35.51-1680.62) on days when they used combustible cannabis. Notably, participants had higher odds of using e-cigarettes on days when they used vaporized cannabis (AOR 23.21, 95% CI 8.66-62.24). Participants reported a greater intensity of using cigarettes (AOR 1.35, 95% CI 1.23-1.48), cigarillos (AOR 2.04, 95% CI 1.70-2.46), and e-cigarettes (AOR 1.48, 95% CI 1.16-1.88) on days when they used more cannabis.

CONCLUSIONS

Types and intensities of tobacco and cannabis use within a day among young adult smokers were positively correlated, including co-use of vaporized products. Prevention and intervention efforts should address co-use and pay attention to all forms of use and timeframes of co-use (eg, within a day or at the same time), including co-use of e-cigarettes and vaporized cannabis, to reduce negative health outcomes.

Determining the impact of cannabis use and severity on tobacco cessation outcomes: study protocol for a prospective tobacco treatment trial

BACKGROUND

Several evidence-based tobacco cessation treatment strategies exist, though significant barriers to cessation remain which must be addressed to improve abstinence rates for sub-populations of those smoking cigarettes. Cannabis co-use among those who use tobacco is common and appears to be increasing among adults in the United States (US). The literature evaluating the impact of cannabis use on tobacco cessation has been mixed and has several important limitations, which precludes development of treatment recommendations specific to individuals who use tobacco and co-use cannabis. To date, no prospective studies have evaluated the impact of cannabis use and severity on tobacco cessation or quantified cannabis use changes during tobacco treatment to assess for concurrent reductions, abstinence, or compensatory (i.e., increased) cannabis use. This study's aims are to: (1) evaluate tobacco cessation outcomes among participants who co-use cannabis compared to participants only using tobacco, (2) using daily diaries and biochemical verification, assess changes in cannabis use during tobacco treatment, and (3) assess for a dose-dependent impact of cannabis use on tobacco cessation.

METHOD

A multi-site, prospective, quasi-experimental 12-week tobacco treatment trial enrolling treatment-seeking adults (ages 18-40; N = 208) from three sites across South Carolina (US) who use tobacco daily and oversampling (2:1) those who co-use cannabis. Participants receive tobacco cessation pharmacotherapy (varenicline) paired with behavioral support, while cannabis use is not addressed as part of treatment. The primary outcome is 7-day point prevalence tobacco abstinence at the week 12 end of treatment visit, measured via biochemical verification and self-report. Secondary outcome measures include changes in cannabis use (via biochemical verification and self-report) during tobacco cessation treatment.

DISCUSSION

Results from this trial have the potential to inform tobacco treatment among those co-using cannabis, which may require a tailored approach to address the role of cannabis in quitting tobacco.

TRIAL REGISTRATION

The trial is registered with ClinicalTrials.gov: NCT04228965. January 14th, 2020.

The role of personality traits on self-medicated cannabis in rheumatoid arthritis patients: A multivariable analysis

BACKGROUND

Rheumatoid arthritis (RA) patients commonly report medicinal cannabis use (MCU). Personality has been independently associated with both RA-related outcomes and MCU, but there is no information available on how they interact in RA patients. This study aimed to investigate a potential association between personality traits and MCU in RA outpatients, as well as to identify additional factors associated with its use.

METHODS

This cross-sectional study was performed between June 2020 and August 2021. Consecutive RA outpatients had standardized evaluations using an interview format to collect sociodemographic information, comorbidities, risk of recreational substance use, RA-related disease activity/severity, health-related quality of life, depressive and anxiety symptoms, five personality traits, and MCU in the 12 months before the interview. Multivariable logistic regression estimated adjusted odds ratios (aOR). The study was IRB-approved.

RESULTS

180 patients were included; 160 (88.9%) were women with a mean age of 53.4 ± 13 years. Fifty-three (29.4%) patients reported MCU. Among them, 52 (98.1%) used topical formulations. Neuroticism had the highest overall score ([Formula: see text] = 3.47 ± 0.34). Openness to experience trait was higher in MCU patients in the comparative analysis (p = 0.007). In the multivariable regression, higher openness trait (aOR: 2.81, 95%CI: 1.11-7.10) along with moderate risk in tobacco use (aOR: 3.36, 95%CI: 1.04-10.7) and higher RA disease activity/severity (aOR: 1.10, 95%CI: 1.01-1.19) were independently associated with MCU.

CONCLUSIONS

In the current study, personality influenced the seeking of MCU for pain relief, associating dynamically with higher disease activity/severity and tobacco use. Contrary to other available information, it did not relate to psychopathology or the recreational use of cannabis. Proactive interdisciplinary clinical evaluations around MCU in RA outpatients should include personality, besides standard clinical assessments, to understand patients' motivations for its use as they may reveal important clinical information.

Differences between adults who smoke cigarettes daily and do and do not co-use cannabis: Findings from the 2020 ITC four country smoking and vaping survey

BACKGROUND

Little is known about population-level differences between adults who exclusively smoke cigarettes and those who smoke cigarettes and also use cannabis (co-consumers). Thus, this study describes differences on sociodemographic, cigarette-dependence, health and behavioral variables, and risk perceptions associated with smoking cannabis.

METHODS

This cross-sectional study included 6941 respondents from the 2020 ITC Four Country Smoking and Vaping Survey (US, Canada, Australia, England). Adult daily cigarette smokers were included and categorized as: cigarette-only smokers (never used cannabis/previously used cannabis, but not in the past 12 months, n = 4857); occasional co-consumers (cannabis use in the past 12 months, but < weekly use, n = 739); or regular co-consumers (use cannabis ≥ weekly, n = 1345). All outcomes were self-reported. Regression models were conducted on weighted data.

RESULTS

Overall, 19.9 % of respondents reported regular cannabis co-use and 10.1 % reported occasional co-use. Regular co-use was highest in Canada (27.2 %), followed by the US (24.4 %), England (12.7 %) and Australia (12.3 %). Compared to cigarette-only smokers, regular co-consumers were more likely to be male and report chest/breathing problems (p < 0.001). All co-consumers were more likely to be younger, have lower income, be experiencing financial stress, reside in Canada, have depressive symptoms, use alcohol more frequently and binge drink, use other tobacco/nicotine products, and perceive smoking cannabis as low health risk and less harmful than smoking cigarettes (all p < 0.001). Cigarette dependence measures were similar between co-consumers and cigarette-only smokers (all p ≥ 0.05).

CONCLUSIONS

Although there were no differences on cigarette dependence measures between daily cigarette smokers who do and do not use cannabis, there are several other risk factors that may affect tobacco use and abstinence among co-consumers (e.g., greater depression, high-risk alcohol consumption). Thus, tobacco cessation treatment may require multi-pronged strategies to address other health behaviors. Continued surveillance is needed to determine the nature and health implications of co-use considering changing policies, markets, and products.

Daily Cannabis Use Is a Barrier to Tobacco Cessation Among Tobacco Quitline Callers at 7-Month Follow-up

INTRODUCTION

Cannabis use is increasing among cigarette smokers in the United States. Prior studies suggest that cannabis use may be a barrier to smoking cessation. Yet, the extent to which this is the case among adults seeking to quit tobacco use remains unclear. Tobacco quitlines are the most common provider of no-cost treatment for adults who use smoke in the United States. This study investigated the association between cannabis use and smoking cessation outcomes among quitline callers.

AIMS AND METHODS

Participants included callers to the New York State Smokers' Quitline, who were seeking to quit smoking cigarettes and were contacted for outcome assessment 7 months after intake. Thirty-day point prevalence abstinence rates were calculated and compared among cannabis use groups, based on frequency of past-30-day cannabis use at baseline (none: 0 days, occasional: 1-9 days, regular: 10-19 days, and daily: 20-30 days).

RESULTS

Approximately 8.3% (n = 283) of participants (n = 3396) reported past-30-day cannabis use at baseline. Callers with daily cannabis use (20-30 days per month) had significantly lower odds of 30-day abstinence, relative to those who did not use cannabis (odds ratio = 0.5; 95% confidence interval [0.3, 0.9]).

CONCLUSIONS

Daily cannabis use appears to be associated with poorer smoking cessation treatment outcomes among adults seeking to quit smoking cigarettes via a quitline. Because quitlines are among the most accessible, affordable, and frequently utilized community-based treatments available in the United States, and the prevalence of cannabis use is increasing among cigarette smokers, detailed inquiry into cannabis use might enhance cigarette smoking cessation outcomes.

IMPLICATIONS

Quitlines are free of cost and accessible to millions of smokers in the United States. The current study found an inverse relationship between daily cannabis use at baseline and 30-day abstinence from cigarette smoking at 7-month follow-up among New York State Smokers' Quitline callers. Findings suggest that daily cannabis use may be a barrier to smoking cessation and sustained abstinence among those seeking help to stop smoking cigarettes.

Age-period-cohort analysis of trends in tobacco smoking, cannabis use, and their co-use in the Australian population

BACKGROUND AND AIM

The prevalence of tobacco smoking has declined in most high-income countries, while cannabis use has been rising. Moreover, cannabis use has been found to have increased among cigarette smokers in recent years in jurisdictions where it has been either decriminalized or legalized. This study measured trends in cannabis, tobacco and the co-use of cannabis and tobacco in Australia.

DESIGN

Age-period-cohort analysis.

SETTING AND PARTICIPANTS

Participants were n = 143 344 individuals aged 18-80 years who participated in Australia's National Drug Strategy Household Surveys (NDSHS) between 2001 and 2019.

MEASUREMENTS

Regular (weekly/more frequently): (1) tobacco smoking only, (2) cannabis use only and (3) the co-use of cannabis and tobacco.

FINDINGS

Prevalence of only smoking tobacco decreased in all age groups (P < 0.001) and birth cohorts between 2001 and 2019, but the co-use of cannabis and tobacco did not. Younger cohorts were much less likely to co-use tobacco and cannabis (P = 0.02). Period trends showed that both cannabis use only and the co-use of cannabis and tobacco have increased since 2013.

CONCLUSION

There has been a consistent decrease in exclusive tobacco smoking across age, period and birth cohorts between 2001 and 2019 in Australia, although there is a recent increasing period trend in cannabis use with or without tobacco. The non-decreasing trend of co-use may reflect the strong tobacco control policies introduced over the period and changing attitudes towards cannabis use in Australia.

Longitudinal Associations Between Use of Tobacco and Cannabis Among People Who Smoke Cigarettes in Real-world Smoking Cessation Treatment

OBJECTIVES

Cannabis use is common among people who use tobacco. However, little is known about the relationship between change in use of tobacco and cannabis over time. We examined the longitudinal associations between use of the two substances in a realworld smoking cessation context.

METHODS

This study analyzed data from a 3-month smoking cessation program delivered via Facebook in the San Francisco Bay Area, USA during 2016-2020. The sample included 487 participants who smoked cigarettes ( Mage = 25.4 years old, 39.6% Male, 40.3% White). The regressors (ie, frequency or number of days during the past 30 days using cigarettes, e-cigarettes, and cigars) and the outcome (ie, frequency of cannabis use) were measured at both baseline and 3-month follow-up. Random-effects modeling examined the longitudinal associations between the regressors and the outcome controlling for alcohol use and baseline demographics.

RESULTS

Participants who increased (or decreased) their frequency of use of cigarettes (β = 0.17, 95% confidence interval [CI] = 0.10, 0.24), e-cigarettes (β = 0.11, 95% CI = 0.05, 0.17), or cigars (β = 0.19, 95% CI = 0.06, 0.32) also increased (or decreased) their frequency of cannabis use after 3 months. Sexual minority participants (vs heterosexuals) (β = 2.12, 95% CI = 0.01, 4.24) and those whose education attainment being high school or less (vs higher education) (β = 3.89, 95% CI = 1.25, 6.53) were more likely to increase their frequency of cannabis use over time.

CONCLUSIONS

The findings indicated positive associations between change in use of tobacco and cannabis use. Promoting cessation among people who use tobacco may help to reduce their cannabis use.

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.

Towards quantifying the reciprocal associations between frequency of cannabis use and alcohol consumption: a cross-lagged analysis from the CONSTANCES cohort

OBJECTIVE

Disentangle the temporal relationships between frequency of cannabis use and alcohol consumption.

METHODS

A cross-lagged model providing standardised coefficients (SCs)±their standard errors in 13 255 men and 13 696 women enrolled in 2015 or 2016 in the French population-based 'CONSulTANts des Centres d'Examens de Santé' (CONSTANCES) cohort. Cannabis use was categorised as follows: 'No use during the past 12 months', 'Use during the past 12 months but not in the past month' and 'Use in the past month' for cannabis use at baseline, and No use during the past 12 months, 'Use less than once per month' and 'Use once per month or more' for cannabis use at 1 year of follow-up. Alcohol consumption was measured at baseline and at 1 year of follow-up and three categories were determined: low risk (<28 drinks per week in men; <14 drinks per week in women), moderate risk (≥28 and<42 in men; ≥14 and<28 in women) and high risk (≥42 in men; ≥28 in women). Analyses were adjusted for age, sex, education, income, tobacco consumption, self-rated health status and depressive symptoms.

RESULTS

Both associations from alcohol to cannabis and from cannabis to alcohol were significant (SC=0.02±0.01 with p=0.003 and SC=0.06±0.01 with p<0.001, respectively). However, the SC of the association from cannabis to alcohol was three times higher than the opposite association (p<0.001). After stratification for sex, SCs of the association from cannabis to alcohol were more than two times higher than for the opposite association in men, and more than four times higher in women (both p<0.001).

CONCLUSIONS

The association between frequency of cannabis use and subsequent alcohol consumption was stronger than the opposite association. This finding encourages considering the risk of increased alcohol consumption among cannabis users.

Ongoing tobacco use in women who experience homelessness and unstable housing: A prospective study to inform tobacco cessation interventions and policies

BACKGROUND

Tobacco use is common in people who experience homelessness. However, despite biological differences in use by sex and lower quit rates in women, research in homeless and unstably housed (HUH) women is sparse. We identified correlates of use specific to this population, with the goal of informing tobacco cessation programs tailored for HUH women.

METHODS

We conducted a prospective study among HUH women recruited from San Francisco homeless shelters, street encampments, free meal programs and low-income hotels. Between June 2016 and January 2019, study participants completed six monthly interviews to examine factors associated with tobacco use, defined as urinary cotinine >10 pg/mL or self-reported prior 30-day use.

RESULTS

Among 245 participants, 40% were Black, the median age was 53, 75% currently used tobacco and 89% had ≥one 24-hour quit attempt in the prior year. Tobacco use was more common in women with PTSD (66% vs. 48%) and depression (54% vs. 35%) compared to women without these conditions. Adjusted odds of tobacco use decreased significantly with increasing age (OR_{/5 yrs}: 0.81; 95% CI:0.68, 0.96) and increased with an increasing number of additional substances used (OR: 2.52; 95% CI: 1.88, 3.39).

CONCLUSION

Outside of a treatment setting and within a community-recruited sample population composed of HUH women, the number of additional substances used is a primary correlate of ongoing tobacco use. Tailored cessation interventions that prioritize the issue of multiple substance use, and public health policies that allocate funding to address it, may increase tobacco cessation in this population.

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.

Psychosocial and pharmacological treatments for cannabis use disorder and mental health comorbidities: a narrative review

Cannabis is the most widely used illicit drug worldwide, and it is estimated that up to 30% of people who use cannabis will develop a cannabis use disorder (CUD). Demand for treatment of CUD is increasing in almost every region of the world and cannabis use is highly comorbid with mental disorders, where sustained use can reduce treatment compliance and increase risk of relapse. In this narrative review, we outline evidence for psychosocial and pharmacological treatment strategies for CUD, both alone and when comorbid with psychosis, anxiety or depression. Psychosocial treatments such as cognitive behavioural therapy, motivational enhancement therapy and contingency management are currently the most effective strategy for treating CUD but are of limited benefit when comorbid with psychosis. Pharmacological treatments targeting the endocannabinoid system have the potential to reduce cannabis withdrawal and cannabis use in CUD. Mental health comorbidities including anxiety, depression and psychosis hinder effective treatment and should be addressed in treatment provision and clinical decision making to reduce the global burden of CUDs. Antipsychotic medication may decrease cannabis use and cannabis craving as well as psychotic symptoms in patients with CUD and psychosis. Targeted treatments for anxiety and depression when comorbid with CUD are feasible.