Cannabis Use Is Associated With Increased Risk of Cigarette Smoking Initiation, Persistence, and Relapse Among Adults in the United States

Does cannabis and electronic nicotine delivery system (ENDS) use interfere with cigarette smoking cessation in young adulthood?

AIMS

Reducing combustible cigarette smoking is a major public health concern. Research identifies both electronic nicotine delivery systems (ENDS) and cannabis use as factors that are related to combustible cigarette cessation. The current study examined whether using substances in similar ways (e.g., inhaling them) triggers the urge to smoke, thereby undermining attempts to quit.

DESIGN

Analyses examined how using ENDS and smoking or vaping cannabis, both separately and together, were associated with reductions in daily combustible cigarette smoking among young adult smokers.

PARTICIPANTS

Three waves of data from the Community Youth Development Study, including 909 participants who reported daily cigarette smoking at age 23, 26, and/or 28, were included in analyses.

SETTING

Participants were dispersed throughout 48 US states.

MEASUREMENTS

Latent growth modeling was used to model daily cigarette smoking over time. Models using past-month ENDS use, past-month smoking/vaping cannabis, and past-month co-use of ENDS and cannabis (using ENDS and smoking/vaping cannabis within the past month) as time-varying covariates were tested.

FINDINGS

Over time, there was a tendency towards cessation of daily combustible cigarette use among this smoking sample. Smoking/vaping cannabis was associated with a decreased rate of daily combustible cigarette cessation among the sample, whereas ENDS use was associated with an increased rate of daily smoking cessation. The predicted additive effect of using ENDS and smoking/vaping cannabis was not significant.

CONCLUSIONS

Among young adult daily cigarette smokers, smoking cannabis, on its own, poses a risk to quitting combustible cigarettes, while using ENDS may promote cigarette cessation, possibly through substitution.

Associations between cannabis use and same-day health and substance use behaviors

OBJECTIVE

Cannabis use has increased in the United States as states have legalized/decriminalized recreational and/or medicinal use. The primary aim of this study was to examine daily associations between cannabis use and health (physical activity [PA]) and substance use (alcohol consumption, cigarette use) behaviors.

METHOD

Data from a 28-day nationwide study that prompted daily ecological momentary assessments (EMAs) were used to assess daily cannabis use, moderate-to-vigorous PA (MVPA), alcohol containing drinks consumed, and cigarettes smoked. Only participants who reported cannabis use on at least one day during the study period were included in the analysis (N = 98). Generalized linear mixed models were used to examine associations between cannabis use and same-day health and substance use behaviors while adjusting for race, biological sex, and age.

RESULTS

Daily cannabis use was positively associated with daily PA (p = 0.04, 3.31-minute higher PA duration on use vs. non-use days), number of alcohol containing drinks consumed (p = 0.01, 0.45 more drinks on use vs. non-use days), and number of cigarettes smoked (p = 0.01, 0.63 more cigarettes on use vs. non-use days).

CONCLUSIONS

This study was among the first to use EMAs to examine associations between daily cannabis use and same-day PA, alcohol consumption, and cigarette use. Overall, findings indicated that daily cannabis use is associated with higher engagement in these daily health and substance use behaviors. Further research is needed to understand mechanisms linking cannabis use with these and other behaviors.

Cannabis Use and Subsequent Cigarette Discontinuation Among U.S. Adults in the Population Assessment of Tobacco and Health Study, Waves 1-5

INTRODUCTION

This study examined the association between the current co-use of cannabis and cigarettes in the past 30 days and subsequent cigarette discontinuation (past 30-day point-prevalence abstinence) among U.S. adults with established cigarette use in the Population Assessment of Tobacco and Health (PATH) Study. Additionally, we investigated the impact of co-use on the subsequent discontinuation of all combustible tobacco products.

AIMS AND METHODS

A total of 26 381 observations contributed by 8218 adults with established cigarette use (ie, smoked ≥100 cigarettes in their lifetime, and currently smoking cigarettes every day or some days) from waves 1-5 of the PATH Study were included in the analysis. Weighted generalized estimating equations (GEE) models were used to evaluate the association between current co-use at baseline (waves 1-4) with the outcomes assessed at the subsequent wave (cigarette and combustible tobacco discontinuation at waves 2-5). Final models included: Demographic characteristics (age, sex, race and ethnicity, and educational attainment), behavior characteristics (intention to quit, internalizing symptoms, externalizing symptoms, and substance use problems), and wave-pair.

RESULTS

Over one-third (35.91%) of the adults currently smoking cigarettes self-reported co-use during the study period. Cannabis use among adults with established cigarette use increased over time. Co-use was associated with decreased odds of cigarette smoking discontinuation at follow-up, after adjusting for covariates (aOR: 0.81; 95% CI: 0.72, 0.93; p = .0018). Similar effect sizes were observed for the discontinuation of all combustible tobacco products (aOR: 0.75; 95% CI: 0.65, 0.86; p < .0001).

CONCLUSIONS

Cannabis use among adults with established cigarette use was inversely related to subsequent cigarette discontinuation, suggesting that co-use may reduce the likelihood of successful tobacco cessation.

IMPLICATIONS

Findings demonstrate that cannabis use may lead to lower odds of discontinuation among adults with established cigarette use; therefore, individuals who co-use cigarettes and cannabis may need additional tobacco cessation support. Notably, this study observed an increase in the co-use of cigarettes and cannabis, emphasizing the need for researchers and public health programs to shift their focus toward understanding and addressing concurrent substance use among adults who smoke cigarettes.

Frequent recreational cannabis use and its association with caries and severe tooth loss: Findings from the National Health and Nutrition Examination Survey, 2015-2018

BACKGROUND

The aim of this study was to examine the association of frequent recreational cannabis (FRC) use with untreated coronal caries, untreated root surface caries, and severe tooth loss.

METHODS

This cross-sectional study analyzed data obtained from 5,656 people, aged 18 through 59 years, who participated in the National Health and Nutrition Examination Survey from 2015 through 2018. FRC use was defined as self-reported use of marijuana or hashish at least once per month for the past 12 months. Log-binomial and logistic regression analyses were conducted before and after controlling for sociodemographic and behavioral factors to examine the association between FRC use and untreated coronal caries, root surface caries, and severe tooth loss.

RESULTS

Compared with non-FRC users, people reporting FRC use had 17% higher probabilities of having untreated coronal caries (95% CI, 1.02 to 1.35), 55% higher odds of having untreated root surface caries (95% CI, 1.21 to 1.99), and 41% higher odds of having severe tooth loss (95% CI, 1.00 to 1.99) after controlling for age, sex, race or ethnicity, nativity, education, family income to poverty ratio, and alcohol consumption.

CONCLUSIONS

This study suggests that FRC use is associated with increased coronal caries, root surface caries, and severe tooth loss in the US adult population. Further longitudinal studies are warranted to assess the impact of varying frequencies, quantities, and forms of cannabis use.

PRACTICAL IMPLICATIONS

Dental care professionals should be aware that FRC use may be associated with caries and tooth loss.

Cannabis use and associated longitudinal transitions in electronic nicotine delivery systems use among young adults in the United States

OBJECTIVE

Cannabis is increasingly the first substance used by young people and research indicates that cannabis use may precede the onset of tobacco use. Little is known, however, about the role of cannabis use in stages of electronic nicotine delivery systems (ENDS) uptake and progression across young adulthood. This study examined the associations between past 30-day (P30D) cannabis use frequency and transitions in ENDS use among young adults.

METHODS

5,018 18-29-year-olds (64.2% female) were recruited from 24 Texas colleges to participate in a multi-wave study across a 4.5-year period from 2014 to 2019. A continuous time, multi-state Markov model was used to assess associations between P30D cannabis use frequency and three ENDS use transitions, spanning at least six months 1) never to P30D use (initiation); 2) P30D to non-P30D use (desistance); and 3) non-P30D to P30D use (re-uptake). The model also included socio-demographic and time-varying intrapersonal (other tobacco use, alcohol use, sensation seeking, depressive symptoms) and interpersonal (peer ENDS use) confounding factors.

RESULTS

Past 30-day cannabis use frequency was associated with an increased probability of ENDS initiation and decreased probability of desistance in the model adjusted for socio-demographic and confounding factors. Past 30-day cannabis use frequency was not associated with an increased probability of ENDS re-uptake in the adjusted model.

CONCLUSIONS

Cannabis use is associated with the uptake and continuation of ENDS use. Findings are concerning given that the most popular ENDS devices used by young adults contain high concentrations of nicotine that increase the risk for nicotine dependence and lifelong 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.

A Bivariate Twin Study of Lifetime cannabis Initiation and Lifetime Regular Tobacco Smoking Across Three Different Countries

Regular cigarette smoking and cannabis consumption are strongly positively related to each other, yet few studies explore their underlying variation and covariation. We evaluated the genetic and environmental decomposition of variance and covariance of these two traits in twin data from three countries with different social norms and legislation. Data from the Netherlands Twin Register, FinnTwin12/16, and the Minnesota Center for Twin Family Research (total N = 21,617) were analyzed in bivariate threshold models of lifetime regular smoking initiation (RSI) and lifetime cannabis initiation (CI). We ran unstratified models and models stratified by sex and country. Prevalence of RSI was lowest in the Netherlands and prevalence of CI was highest in Minnesota. In the unstratified model, genetic (A) and common environmental factors (C) contributed substantially to the liabilities of RSI (A = 0.47, C = 0.34) and CI (A = 0.28, C = 0.51). The two liabilities were significantly phenotypically (rP = 0.56), genetically (rA = 0.74), and environmentally correlated in the unstratified model (rC = 0.47and rE = 0.48, representing correlations between common and unique environmental factors). The magnitude of phenotypic correlation between liabilities varied by country but not sex (Minnesota rP ~ 0.70, Netherlands rP ~ 0.59, Finland rP ~ 0.45). Comparisons of decomposed correlations could not be reliably tested in the stratified models. The prevalence and association of RSI and CI vary by sex and country. These two behaviors are correlated because there is genetic and environmental overlap between their underlying latent liabilities. There is heterogeneity in the genetic architecture of these traits across country.

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

Background

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

Methods

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

Results

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

Conclusion

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Latent Trajectories of Persistence of Cannabis Use Across Four Decades in 329 Men From the San Diego Prospective Study

OBJECTIVE

These analyses use data from a 40-year prospective study to extend information into the sixth and seventh decades of life regarding latent trajectory classes of cannabis use and predictors of those classes.

METHOD

Data from the San Diego Prospective Study were analyzed for 329 men of European and Hispanic ethnicity who had used cannabis at about age 23 at study entry (Time 1) and who were interviewed about every 5 years through about age 60 to 70. Latent classes of cannabis use trajectories were evaluated using latent class growth analyses, baseline predictors of class membership were determined, and significant predictors of each class were established using logistic regression analyses.

RESULTS

Four latent classes were identified ranging from 12.5% with cannabis use at every follow-up to 25.8% with no use after Time 1. Eight of 14 Time 1 predictors differed significantly across the trajectory classes, including five (age, marital status, religious identity, intensity of cannabis use, and sensation seeking) that significantly contributed to regression analyses when all significant predictors were considered together.

DISCUSSION

Forty-two percent of participants continued using cannabis long-term, including one in eight who used it at every follow-up. Predictors of continued use and identification of those most likely to stop required gathering information on a range of demographic, prior substance use, and personality characteristics.

CONCLUSIONS

Considering the potential enhanced dangers of cannabis use in later life, the high rate of continued use over four decades implies that clinicians should ask all older patients about recent cannabis use, especially if they had used it in their 20s.

Examining the association between prenatal and perinatal adversity and the psychotic experiences in childhood

BACKGROUND

Prenatal and perinatal complications are established risk factors for psychotic disorder, but far less is known about these measures and psychotic experiences (PEs). We investigated the longitudinal effect of prenatal risk factors (maternal behavior, medication complications) and perinatal risk factors (birth weight, medical complications) on frequency of PEs. We also examined the cumulative risk of prenatal/perinatal risk factors, and differences between transient PE, persistent PE, and controls.

METHODS

The Adolescent Brain Cognitive Development study is a large child cohort (age 9-10 at baseline; n = 11 872 with PE data). PEs were measured longitudinally using the Prodromal Questionnaire-Brief, Child version, and included only if reported as distressing. Mixed-effects models were used for analysis, controlling for random effects, and a substantial number of fixed-effects covariates.

RESULTS

Urinary tract infection (β = 0.11, 95% confidence interval [CI] 0.03-0.19) and severe anemia (β = 0.18, 95% CI 0.07-0.29) increased frequency of distressing PEs in childhood. Number of prenatal complications increased frequency of PEs (β = 0.03, 95% CI 0.01-0.06) and risk of persistent PEs (odds ratio [OR] = 1.08, 95% CI 1.01-1.15). Maternal smoking was associated with an increased frequency of PEs (β = 0.11, 95% CI 0.04-0.18) and persistent PEs (OR = 1.31, 95% CI 1.04-1.66). Maternal substance use was a risk factor for a 48% increased risk of persistent PEs (OR = 1.48, 95% CI 1.08-2.01). Perinatal complications showed no effect on PEs.

CONCLUSIONS

This study provides evidence that certain prenatal medical complications (severe nausea, severe anemia), cumulative number of prenatal medical complications, and maternal behaviors (smoking during pregnancy), increased frequency of distressing PEs in childhood. Maternal smoking and substance use, as well as cumulative number of prenatal complications increased risk of persistent PEs.

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.

Direct Effects of Cannabis Intoxication on Motivations for Softer and Harder Drug Use: An Experimental Approach to the Gateway Hypothesis

Aims: This study experimentally tested whether there is a gateway-type effect of cannabis administration on tobacco and cocaine motivation and whether motivational responses predicted use 6 months later. Methods: A 2 (condition: active cannabis vs. placebo joint)×3 (substance stimulus type: tobacco, cannabis, and cocaine) factor within-subjects design for both implicit and explicit motivation. Both experimental sessions were conducted in a cannabis dispensary ("coffeeshop") in Amsterdam and were separated by ∼1 week, followed by a 6-month online follow-up. Eighty-five participants between 18 and 27 years of age (57% male), who used cannabis, tobacco, and cocaine <15 times per month, participated in session 1 (session 2: N=79 and follow-up: N=81). Counterbalanced over sessions, participants smoked an active and a placebo joint following a paced puffing procedure. Before and after smoking, craving and avoidance (explicit motivation) were assessed using visual analog scales, and after smoking, the stimulus response compatibility test was completed to assess approach biases (implicit motivation). Self-reported intoxication and similarity to their usual smoking experience were assessed at the end of both sessions. Self-reported frequency/quantity and dependence symptoms for tobacco, cannabis, and cocaine were assessed at all time points. A linear mixed model approach was used to assess the effects of condition, substance stimulus type, and their interactions on explicit and implicit motivation. Results: In the active condition, participants reported higher levels of intoxication and an experience more similar to their usual smoking experience than in the placebo condition. There was no significant effect of condition, substance type, or their interaction on approach bias. Participants exhibited increased cannabis craving during the placebo condition only and increased explicit cannabis avoidance during the active condition only. Explicit tobacco avoidance decreased during both conditions. Baseline measures did not predict use at 6-month follow-up. Conclusions: In light users, cannabis intoxication did not affect implicit and explicit tobacco or cocaine motivations. Tobacco avoidance decreased regardless of condition, indicating that the cannabis cue-rich setting-rather than tetrahydrocannabinol itself-may momentarily increase the likelihood to smoke tobacco. However, motivation at baseline did not predict use 6 months later, deeming any gateway-like function unlikely.

Examining the correlates of cigarette smoking, e-cigarette use and dual use among Canadian post-secondary students

Many Canadians use nicotine products such as cigarettes and e-cigarettes. A particular subpopulation of concern is post-secondary students given they have a higher prevalence of use. Many correlates of cigarette smoking and e-cigarette use have been identified. However, less focus has been on examining the correlates of cigarette smoking, e-cigarette use and dual use. This study explores the correlates of different nicotine modality use in post-secondary students. Using data from the Canadian Campus Wellbeing Survey (CCWS; n = 27,164), a multi-level nominal regression assessed the correlates of nicotine modality use. In comparison to individuals who were <20, individuals 20-24 (OR = .448, 95% CI .321, .625), 25-29 (OR = .140, 95% CI .093, .212), 30-34 (OR = .076, 95% CI .046, .125) and over 35 (OR = .041, 95% CI .024, .071) had lower odds of e-cigarette use compared to cigarette smoking. Identifying as a woman (OR = 1.553, 95% CI 1.202, 2.006), non-heterosexual (OR = .642, 95% CI = .485,0.851), current cannabis user (OR = 1.651, 95% CI 1.296, 2.104), and being an international student (OR = .350, 95% CI .251, .487) also impacted the odds of e-cigarette use vs only cigarette smoking. When considering dual use vs cigarette smoking, individuals aged 20-24 (OR = .491, 95% CI .337, .717), 25-29 (OR = .221, 95% CI .137, .357), 30-34 (OR = .163, 95% CI .091, .292) and over 35 (OR = .122, 95% CI .065, .230) had lower odds than individuals <20. Current cannabis use (OR = 1.680, 95% CI = 1.209, 2.138), binge drinking (OR = 1.885, 95% CI 1.384, 2.568), and international student status (OR = .689, 95% CI .476, .996) also impacted cigarette smoking vs dual-use. Overall, a minority of young adults (11.5%) at post-secondary institutions in our sample use nicotine products, and the higher prevalence of e-cigarette use warrants continued monitoring. Health promotion campaigns addressing e-cigarette use are required. Additionally, tailored intervention efforts could prioritize the treatment needs of international students studying in Canada.

Cross-Substance Associations With Transitions in Cannabis and Nicotine Use in a Statewide Sample of Young Adults in Washington State

OBJECTIVE

Understanding transitions in nicotine and cannabis use has implications for prevention and efforts to reduce harmful use. Focusing on cross-substance associations, we examined how use of one substance was associated with year-to-year transitions in frequency of use of the other among young adults in the context of legalized nonmedical cannabis.

METHOD

A statewide sample from Washington (N = 4,039; ages 18-25 at baseline) provided up to 3 years of annual data on past-month cannabis use and nicotine use (tobacco cigarettes and e-cigarettes/vaping). Manifest Markov models examined how use of each substance was associated with transitions in the other across categories of past-month no use, occasional use (1-19 days), and frequent use (≥20 days).

RESULTS

Occasional and frequent nicotine use (vs. no use) predicted higher probability of transitioning from no cannabis use to occasional or frequent cannabis use and from occasional use to frequent use, whereas associations with cessation and de-escalation were inconsistent in direction, small in magnitude, and not statistically significant. Cannabis use positively predicted onset of nicotine use, and associations of cannabis use with escalation from occasional to frequent nicotine use, de-escalation in use, and cessation in use were small and inconsistent in direction.

CONCLUSIONS

The findings corroborate prior research on cannabis and nicotine use as risk factors to address in prevention efforts. The findings do not provide strong support for prioritization of dual abstinence in efforts to encourage reductions in or cessation of cannabis or nicotine use among young adults.

A Comparison of Mental Health Symptoms among Adults Who Vape Nicotine, Cannabis, or Both

OBJECTIVES

Dual use of combustible cannabis and nicotine is related to worse mental health symptoms (MHS); however, little is known about MHS among those who vape cannabis and nicotine. The current study aimed to determine if dual use of cannabis and nicotine vapes is associated with worse MHS compared to single use and to identify correlates of MHS for dual users.

METHODS

We used Amazon Mechanical Turk to survey adults (N = 492) who used nicotine or cannabis vapes in the past 30 days on stress, anxiety, depression, vape use behaviors and sociodemographic information. We conducted hierarchical linear regressions to compare MHS between dual vs. single substance vape use and to identify correlates of MHS, including sociodemographic variables and vape use characteristics.

RESULTS

The final sample was 37.6% female, 87.6% White, and 11% Hispanic/Latinx with a mean age of 34.15 years. After controlling for sociodemographic characteristics and combustible product use, dual users had significantly higher mean MHS severity than single users. For dual users, younger age and being married were associated with higher symptoms of depression and stress. Holding a medical cannabis card was associated with higher anxiety symptoms.

CONCLUSION

The findings suggest that dual use of cannabis and nicotine vapes is associated with worse MHS severity compared to single substance use.

Biobehavioral and affective stress responses during nicotine withdrawal: Influence of regular cannabis co-use

BACKGROUND

Co-use of cannabis is increasing in nicotine users and presents additional challenges in addressing nicotine dependence. This study examined the links between regular co-use of cannabis and nicotine with biobehavioral and affective changes in response to stress during nicotine withdrawal and ad libitum use.

METHODS

Participants (N = 79) who regularly used nicotine-only, cannabis-only, both substances, or neither substance were invited to attend two laboratory stress assessment sessions. For nicotine users, one session occurred during ad libitum nicotine use and one occurred after abstinence from nicotine. During the stress sessions, participants provided saliva samples for cortisol assay and completed measures of subjective states. Cardiovascular measures were collected during resting baseline, exposure to acute stressors, and a recovery rest period.

RESULTS

Nicotine-only users had higher average cortisol levels in the second lab session (nicotine withdrawal) relative to the first lab session (ad libitum nicotine use). Compared to nicotine non-users, nicotine users reported less positive affect and exhibited attenuated cortisol and systolic blood pressure (BP) stress responses. Cannabis users exhibited exaggerated diastolic BP responses to stress compared to cannabis non-users, and co-users of nicotine and cannabis had higher levels of cannabis craving than cannabis-only users (p < .01).

CONCLUSIONS

This study partially replicated earlier findings on the effects of chronic nicotine use and provided novel results regarding the influence of cannabis co-use on physiological and affective responses to stress in nicotine users during nicotine withdrawal.

"Cigarettes play the equalizer": discrimination experiences and readiness to quit cigarette smoking among African Americans experiencing homelessness: a qualitative analysis

BACKGROUND

Approximately 70-80% of people experiencing homelessness in the United States use tobacco. Smoking cessation programs specifically for this population have been found to be less effective for African American participants. The purpose of this study was to explore discrimination experiences and their impact on smoking habits and readiness to quit cigarette smoking while experiencing homelessness.

METHODS

In the qualitative phase of this mixed methods study, five focus groups were conducted for African Americans residing in a homeless shelter in Skid Row, Los Angeles, CA. Using a semi-structured interview guide, we asked participants about discrimination experiences, how smoking habits were impacted by these experiences, and tools needed to successfully abstain from cigarette smoking. Qualitative descriptive content analysis was used to explore discrimination experiences and its association with readiness to quit cigarette smoking.

RESULTS

Of the 17 participants, 14 (82.4%) were male, and the average age was 46.8 years. Using a qualitative In Vivo coding method, three themes were revealed: "Experiencing Discrimination while Black", "The Psychosocial Fabric-Why Quitting Cigarette Smoking is a Challenge", and "The Lesser of Two Evils-Choosing to Smoke over More Harmful Options." Participants discussed working in the blue-collar workforce while Black, identifying as a double minority, smoking to cope with stress, early exposure to cigarettes, smoking being a central part of one's belonging to a group, and the legality of cigarette smoking.

DISCUSSION

Our findings show that African Americans experiencing homelessness (1) may experience discrimination in multiple settings, regardless of housing status, (2) could have grown up around cigarette smoking and remain surrounded by it while experiencing homelessness, and (3) may experience a calming effect with smoking, which slows some from reacting negatively to adverse situations.

CONCLUSION

Barriers to successfully abstaining from smoking are multifactorial among African Americans experiencing homelessness and should be addressed individually. Future research should explore the cultural tailoring of interventions that support cessation efforts unique to minoritized populations to improve smoking cessation programs offered to this population.

Support Provided by Stop-Smoking Practitioners to Co-users of Tobacco and Cannabis: A Qualitative Study

INTRODUCTION

Co-use of tobacco and cannabis is highly prevalent among cannabis users and is associated with poorer tobacco cessation outcomes. This study explored the barriers and enablers influencing stop-smoking practitioners' ability to provide optimal support to co-users.

AIMS AND METHODS

Online semi-structured interviews were audio recorded. Interviewees (n = 20) were UK-based certified stop-smoking practitioners. An interview schedule informed by the "capability", "opportunity", "motivation" (COM-B) model was designed to explore participants' perceived barriers and enablers in better supporting co-users to achieve abstinence of both substances or tobacco harm reduction. The transcripts were analyzed using framework analysis.

RESULTS

Capability: Practitioners' lack of knowledge and skills undermines their delivery of smoking cessation interventions to co-users. Interestingly, when cannabis is used for medicinal reasons, practitioners feel unable to provide adequate support. Opportunity: Service recording systems play an important role in screening for co-use and supporting co-users. When responding to clients' specific needs and practitioners' uncertainties, a positive therapeutic relationship and a support network of peers and other healthcare professionals are needed. Motivation: supporting co-users is generally perceived as part of practitioners' roles but there are concerns that co-users are less likely to successfully stop smoking.

CONCLUSIONS

Practitioners are willing to support co-users, but their lack of knowledge and access to an appropriate recording system are barriers to doing so. Having a supportive team and a positive therapeutic relationship is perceived as important. Identified barriers can be mostly addressed with further training to improve tobacco cessation outcomes for co-users.

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).

Experimenter administered Δ9-THC decreases nicotine self-administration in a rat model

BACKGROUND

The co-use of nicotine and cannabis has been steadily rising in the United States. Rodent studies suggest that delta-9-tetrahydrocannabinol (THC) could increase addictive qualities of nicotine, but whether repeated THC exposure alters self-administration of nicotine has not been tested. We hypothesized that THC would increase the reinforcing effects of nicotine and alter nicotine intake.

METHODS

Adult male and female Sprague-Dawley rats were treated with THC (0, 3, 30 mg/kg) daily for 14 days prior to and during training for intravenous self-administration of nicotine. Rats were allowed to self-administer nicotine for several weeks, then tested for sensitivity to nicotine dose through multiple determinations of a nicotine dose-effect curve with or without THC pretreatment. A separate set of rats were trained on fixed ratio responding for sucrose and assessed for THC effects on behavior.

RESULTS

Post-session THC decreased nicotine self-administration in male and female rats throughout acquisition and maintenance and increased the latency to stable rates of nicotine intake during acquisition. Post-session THC shifted nicotine dose-effect curves downward, and pre-session THC suppressed responding at higher nicotine doses. Unlike nicotine, responding for sucrose was not affected by post-session THC. Pre-session THC decreased responding for sucrose, particularly for THC-naïve rats.

CONCLUSIONS

Repeated post-session THC decreased nicotine-taking behaviors but did not alter sucrose responding. Thus, post-session THC may alter sensitivity to nicotine. Pre-session THC treatment decreased lever pressing in both sucrose and nicotine studies, indicating this effect was nonspecific. These studies show that THC modulates patterns of nicotine intake in rat models.

Cannabis use in repeated representative cross-sectional studies on Italian adults after the COVID-19 pandemic

Lockdown measures in response to the COVID-19 pandemic in 2020 yielded dramatic changes in drug consumption. A cross-sectional study was conducted on a representative sample of 6003 Italian adults (18-74 years) in April-May 2020 - reporting information before lockdown and at the time of interview - and two years later (i.e., in February-March 2022). Italian adults using cannabis decreased from 7.0% in pre-pandemic to 5.9% during lockdown (percent change -15.7%) and to 6.7% in 2022 (-4.3%). The reduction was particularly evident among adults aged 55-74 years, whereas cannabis use strongly increased among those aged 18-34 years. In the last period considered (2022), cannabis use was significantly more frequent in men (adjusted odds ratio, OR = 1.43), adults aged 18-34 years (p-trend <0.001), individuals with a low or high level of education (OR = 1.42 and 1.46, respectively), those from Central or Southern Italy/islands (OR = 1.50 and 1.38, respectively), and those with an economic status above the average (OR = 3.07). In 2022, cannabis use was also more frequently reported in current smokers (OR = 3.52), current e-cigarette and heated tobacco product users (OR = 6.09 and 2.94, respectively), individuals with a risky alcohol consumption (OR = 4.60), gamblers (OR = 3.76), those with anxiety and depression (OR = 2.50 and 2.80, respectively), those using psychotropic drugs (OR = 8.96), those with a low quality of life (OR = 1.91), and those sleeping less (OR = 1.42). After the COVID-19 pandemic, cannabis use was more frequent in individuals with other addictive behaviours, and with anxiety and depressive symptoms.

Co-use of cigarettes and cannabis among people with HIV: Results from a randomized controlled smoking cessation trial

Significance

People with HIV (PWH) who smoke cigarettes have lower cessation rates than the general population. This study investigated whether changes in cannabis use frequency impedes cigarette cessation among PWH who are motivated to quit.

Methods

Between 2016-2020, PWH who smoked cigarettes were enrolled in a randomized controlled trial for cigarette cessation. Analyses were limited to PWH who reported on their past 30-day (P30D) cannabis use during four study visits (baseline, 1-month, 3-month, and 6-month) (N=374). Descriptive statistics and multivariable logistic regression were used to evaluate changes in cannabis use frequency from baseline to 6 months and associations with cigarette abstinence at 6 months among PWH who reported no use during all four visits (n=176), as well as those who reported use during at least one visit and who increased (n=39), decreased (n=78), or had no change (n=81) in use frequency.

Results

Among those who reported cannabis use during at least one visit (n=198), at baseline, 18.2% reported no use. At 6 months, 34.3% reported no use. Controlling for covariates, increased cannabis use frequency from baseline was associated with reduced odds of cigarette abstinence at 6 months versus decreased use frequency (aOR=0.22, 95% CI=0.03, 0.90) or no use at either time-point (aOR=0.25, 95% CI=0.04, 0.93).

Conclusions

Increased cannabis use over 6 months was associated with reduced odds of cigarette smoking abstinence among PWH who were motivated to quit. Additional factors that influence cannabis use and cigarette cessation simultaneously are in need of further study.

Effects of dual use of e-cigarette and cannabis during adolescence on cigarette use in young adulthood

INTRODUCTION

E-cigarette and cannabis use by adolescents are risk factors for smoking initiation. We hypothesised that increasingly common dual use of e-cigarette and cannabis in adolescence leads to more frequent cigarette smoking in young adulthood.

METHODS

Data are from a prospective cohort study in Southern California, where 1164 participants who ever used nicotine products in their lifetime completed surveys in 12th grade (T1:2016), and at 24-month (T2) and 42-month (T3) follow-ups. Past 30-day use (number of days: range=0-30) of cigarettes, e-cigarettes and cannabis, and nicotine dependence, were assessed in each survey. Nicotine dependence for cigarettes and e-cigarettes was assessed using original and modified (for e-cigarette) Hooked on Nicotine Checklists (number of dependent products: range=0-2). Path analysis examined the mediation process via nicotine dependence linking baseline e-cigarette and cannabis use to subsequent increased cigarette use.

RESULTS

Baseline exclusive use of e-cigarettes (baseline prevalence, 2.5%) was associated with 2.61-fold increase in frequency of smoking days at T3 (95% CI 1.04 to 13.1), exclusive cannabis use (26.0%) with 2.58-fold increase (95% CI 1.43 to 4.98), and dual use (7.4%) with 5.84-fold increase (95% CI 3.16 to 12.81), compared with baseline non-users. Nicotine dependence at T2 mediated 10.5% (95% CI 6.3 to 14.7) and 23.2% (95% CI 9.6 to 36.3) of the association of cannabis and dual use, respectively, with increased smoking at T3.

DISCUSSION

Adolescent e-cigarette and cannabis use was associated with more frequent smoking during young adulthood, with larger effects of dual use. Associations were partially mediated through nicotine dependence. Dual use of cannabis and e-cigarettes may contribute to the development of nicotine dependence and increased use of combustible cigarettes.

Prevalence of depressive symptoms and cannabis use among adult cigarette smokers in Canada: cross-sectional findings from the 2020 International Tobacco Control Policy Evaluation Project Canada Smoking and Vaping Survey

BACKGROUND

Tobacco smoking and cannabis use are independently associated with depression, and evidence suggests that people who use both tobacco and cannabis (co-consumers) are more likely to report mental health problems, greater nicotine dependence and alcohol misuse than those who use either product exclusively. We examined prevalence of cannabis use and depressive symptoms among Canadian adults who smoke cigarettes and tested whether co-consumers of cannabis and tobacco were more likely to report depressive symptoms than cigarette-only smokers; we also tested whether cigarette-only smokers and co-consumers differed on cigarette dependence measures, motivation to quit smoking and risky alcohol use by the presence or absence of depressive symptoms.

METHODS

We analyzed cross-sectional data from adult (age ≥ 18 yr) current (≥ monthly) cigarette smokers from the Canadian arm of the 2020 International Tobacco Control Policy Evaluation Project Four Country Smoking and Vaping Survey. Canadian respondents were recruited from Leger's online probability panel across all 10 provinces. We estimated weighted percentages for depressive symptoms and cannabis use among all respondents and tested whether co-consumers (≥ monthly use of cannabis and cigarettes) were more likely to report depressive symptoms than cigarette-only smokers. Weighted multivariable regression models were used to identify differences between co-consumers and cigarette-only smokers with and without depressive symptoms.

RESULTS

A total of 2843 current smokers were included in the study. The prevalence of past-year, past-30-day and daily cannabis use was 44.0%, 33.2% and 16.1%, respectively (30.4% reported using cannabis at least monthly). Among all respondents, 30.0% screened positive for depressive symptoms, with co-consumers being more likely to report depressive symptoms (36.5%) than those who did not report current cannabis use (27.4%, p < 0.001). Depressive symptoms were associated with planning to quit smoking (p = 0.01), having made multiple attempts to quit smoking (p < 0.001), the perception of being very addicted to cigarettes (p < 0.001) and strong urges to smoke (p = 0.001), whereas cannabis use was not (all p ≥ 0.05). Cannabis use was associated with high-risk alcohol consumption (p < 0.001), whereas depressive symptoms were not (p = 0.1).

INTERPRETATION

Co-consumers were more likely to report depressive symptoms and high-risk alcohol consumption; however, only depression, and not cannabis use, was associated with greater motivation to quit smoking and greater perceived dependence on cigarettes. A deeper understanding of how cannabis, alcohol use and depression interact among people who smoke cigarettes is needed, as well as how these factors affect cessation activity over time.

Youth tobacco use before and after flavoured tobacco sales restrictions in Oakland, California and San Francisco, California

The tobacco industry has used recent findings from the Youth Risk Behavior Surveillance System Survey (YRBSS) to claim that a sales restriction on flavoured tobacco products might increase youth combustible cigarette use. In this special communication, we examined YRBSS data and reached the opposite conclusion. We observed the patterns in youth cigarette smoking in Oakland, California following its 2017 convenience store flavoured tobacco sales restriction. We also found that 2019 YRBSS data from San Francisco, California cannot be used to evaluate the effect of the sales restriction on all flavoured tobacco products in San Francisco as the YRBSS data for this city were collected prior to enforcement of the sales restriction. For future studies, we suggest triangulating with corroborating sales, behavioural and qualitative data over time to assess the effects of tobacco control policies on youth tobacco use. We recommend that policy enactment and enforcement dates, as well as the exact data collection periods for population health surveys, be published to facilitate more rigorous policy evaluation.

Early-onset smoking and vaping of cannabis: Prevalence, correlates and trends in New Zealand 14-15-year-olds

INTRODUCTION

Initiating cannabis use at an early age elevates risk of harm. Cannabis vaping is an emerging issue, and it is unknown whether the patterning and correlates of early-onset cannabis vaping differ from those of cannabis smoking.

METHODS

We used repeat cross-sectional data from a nationally representative biennial survey (2012-2018) of students aged 14-15 years in New Zealand (N = 11,405), response rate 65% (2012), 64% (2014-2016) and 59% (2018).

RESULTS

Between 2012 and 2018 lifetime cannabis use decreased, but regular use (past month, weekly, daily) was stable. Prevalence of past month, weekly and daily use in 2016-2018 (pooled) was 8.6%, 3.4% and 1.5%, respectively. Cannabis vaping was reported by 24% of past month cannabis users. The demographic profile of early-onset cannabis smokers and vapers was similar, with elevated use of both modes among Māori (Indigenous), same- or both-sex attracted students and those in low decile (high-deprivation) schools. Correlates were similar for both modes. Cannabis use was strongly associated with tobacco and alcohol use. The next strongest associations (after adjustment) were exposure to second-hand smoke at home, student income >$50/week and low parental monitoring of whereabouts. Past week social media use, psychological distress and low parental monitoring of spending were also associated with both modes.

DISCUSSION AND CONCLUSIONS

Early-onset cannabis use is much higher in structurally disadvantaged groups, and among those who use tobacco and alcohol. Comprehensive multisubstance approaches to prevention are indicated in this age group. Efforts to reduce socio-economic inequity and exposure to other risk factors may reduce cannabis-related harm.

Nicotine Dependence among Current Cigarette Smokers Who Use E-Cigarettes and Cannabis

BACKGROUND

Co-use of tobacco and cannabis and dual use of cigarettes and e-cigarettes are very common among young adults. However, it is unclear whether co-use of cigarettes, e-cigarettes, and/or cannabis is associated with higher levels of nicotine dependence than cigarette-only use. We investigated the relationship between cigarette/nicotine dependence and co-use of tobacco and cannabis among 4 groups of cigarette smokers aged 18-35: cigarette-only smokers, cigarette-e-cigarette (CIG-ECIG) co-users, cigarette-cannabis (CIG-CAN) co-users, and cigarette-e-cigarette-cannabis (CIG-ECIG-CAN) co-users.

METHODS

Data were from a 2018 cross-sectional survey based on a national convenience sample of smokers aged 18-35 (n = 315). Cigarette/nicotine dependence was measured by the Fagerstrom Test of Nicotine Dependence (FTND) and e-cigarette dependence was measured by the Penn State E-cigarette Dependence Index. Bivariate analyses examined sociodemographic and tobacco/other substance use characteristics by co-use status and multivariable linear regression assessed the relationship between co-use and nicotine dependence.

RESULTS

In the sample, 27.6% were cigarette-only smokers, 24.8% were CIG-ECIG, 27.6% were CIG-CAN, and 20.0% were CIG-ECIG-CAN co-users. Significant differences were observed in sociodemographic and tobacco/other substance use characteristics by co-use status. E-cigarette co-users had low e-cigarette dependence, but moderate FTND scores. In adjusted analyses, only CIG-ECIG co-use was associated with higher FTND scores compared to cigarette-only smoking. However, CIG-ECIG and CIG-ECIG-CAN co-use were associated with higher FTND scores compared to CIG-CAN co-use.

CONCLUSIONS

Co-use of cigarettes and e-cigarettes was associated with greater nicotine dependence among smokers aged 18-35. Additional research is needed to understand the underlying mechanisms of these relationships and inform prevention efforts.

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.

Behavioral economic relationship between cannabis and cigarettes: Evidence from hypothetical purchase tasks

BACKGROUND

In the United States (U.S), cannabis policies have been increasingly liberalized whereas tobacco policies have been increasingly stringent. Given the high prevalence of cannabis and tobacco dual use, there are concerns that a policy regulating one substance may unintendedly influence the other. This study examined the responsiveness of the demand for cannabis joints and cigarettes when price varied.

METHODS

The study included 338 adult participants (21+) who used both cannabis and tobacco and lived in one of the U.S. states with recreational cannabis legalized by the time of interview in 2019. They completed hypothetical purchase tasks to indicate the quantity desired of cannabis joints and cigarette packs 1) when only one substance was available with escalating prices and 2) when both substances were concurrently available with escalating prices of cannabis joints and a fixed price of cigarette packs. We estimated 1) the own-price elasticity of demand for each substance using nonlinear exponential demand model, and 2) the cross-price elasticity of demand at aggregate level using nonlinear exponential demand model and at individual level using log-linear demand model.

RESULTS

The estimates for the rate of change of own-price elasticity (α) were 0.0011 (SE = 0.000039, p < 0.001) for cannabis joints and 0.00095 (SE = 0.000037, p < 0.001) for cigarette packs. The aggregate-level estimates of cross-price elasticity (I = 13.032, SE = 0.34, p < 0.001; β = 0.0029, SE = 0.0021, p > 0.05) suggest an independent relationship between the two substances. At individual level, 78.70% of the participants treated the two substances as independent, 17.46% as complements, and 3.85% as substitutes.

CONCLUSIONS

For most adults who used both cannabis and tobacco in the U.S., cannabis joints and cigarettes had an independent relationship. Policies regulating the price of cannabis may not have large unintended consequences on cigarette use.

Prevalence, perceptions, and patterns of cannabis use among cardiac inpatients at a tertiary care hospital: A cross-sectional survey

Background

Cannabis use may adversely affect cardiovascular health. Patterns of use by cardiac patients are unknown. We evaluated the prevalence, perceptions, and patterns of cannabis use among cardiac inpatients.

Methods

A consecutive cross-section of cardiac inpatients, hospitalized between November 2019 and May 2020, were surveyed in-person or via telephone. Descriptive statistics and logistic regression were used to examine the characteristics of cannabis use.

Results

The prevalence of past-12-month cannabis use was 13.8% (95% confidence interval [CI]: 11.8%-16.0%). Characteristics independently associated with cannabis use were as follows: age < 64 years (< 44 years, odds ratio [OR] = 3.96 [95% CI: 1.65-9.53]; age 45-64 years, OR = 2.72 [95% CI: 1.65-4.47]); tobacco use in the previous 6 months (OR = 1.91 [95% CI: 1.18-3.07]); having a cannabis smoker in one's primary social group (OR = 4.17 [95% CI: 2.73-6.38]); and a history of a mental health diagnosis (OR = 1.82 [95% CI: 1.19-2.79]). Among those using cannabis, 70.5% reported smoking or vaping it; 47.2% reported daily use. Most did not know the tetrahydrocannabinol (THC; 71.6%) or cannabidiol (CBD; 83.3%) content of their cannabis, or the dose of cannabis in their edibles (66.7%). As defined by Canada's Lower Risk Cannabis Use Guidelines, 96.7% of cannabis users reported ≥ 1 higher-risk use behaviour (mean = 2.3, standard deviation = 1.2). Over 60% of patients expressed no intention to quit or reduce cannabis use in the next 6 months.

Conclusions

Cannabis use appears prevalent among cardiac patients. Most users demonstrated higher-risk use behaviours and low intentions to quit. Further work is needed to understand the impacts of cannabis use on the cardiovascular system and to develop guidelines and educational tools relating to lower-risk use, for cardiac patients and providers.

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.

Impact of cannabis legalization in the United States on trends in cannabis use and daily cannabis use among individuals who smoke cigarettes

BACKGROUND

Cannabis legalization and increases in cannabis use are occurring rapidly in the United States (US). Cannabis and tobacco are often used together, but it is unclear whether cannabis legalization will differentially affect cannabis use among those using cigarettes. This study estimated changes from 2004 to 2017 in the prevalence of cannabis use and daily cannabis use by cigarette use status and examined whether state-level cannabis policy modified these trends.

METHODS

Public and restricted-use data from the 2004-2017 National Survey on Drug Use and Health were analyzed. Weighted logistic regressions were used to examine time trends in past-30-day cannabis use and daily caunabis use by cigarette use and cannabis law status from 2004 to 2017.

RESULTS

Cannabis use and daily use increased significantly among those with and without cigarette smoking. Cannabis use and daily cannabis use were consistently 2-10x more common throughout this time among those with, versus without, cigarette smoking. In 2017, cannabis use and daily cannabis use were substantially more common among individuals who use cigarettes, and even greater among those who live in states where cannabis was legal for medical or recreational (i.e., non-medical) use.

CONCLUSIONS

Cannabis use and daily cannabis use are increasing among US individuals who both smoke and do not smoke cigarettes. Cannabis and daily cannabis use are more common among those who smoke cigarettes and elevated even further among those residing in states that have legalized cannabis for recreational (i.e., non-medical) use. Tobacco control efforts should be adjusted to address increases in cannabis use among Americans who smoke cigarettes.

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.

Co-administering cannabis with tobacco and persistent tobacco smoking after 4½ years in young adults who use stimulants: A prospective population-based study

Tobacco smoking remains highly prevalent in high-risk groups, including young adults who use cannabis and a variety of other drugs. We examine whether co-administering cannabis with tobacco is associated with heavier and more persistent tobacco smoking compared to separate use of these substances among young adults who use drugs recreationally. Data are from a prospective population-based study of young adults residing in Queensland, Australia, who recurrently used ecstasy or methamphetamine. The mean age was 20.8 years at baseline, and 47% were female. An ordinal regression model was developed (n = 277) with levels of tobacco smoking at 4½ years as the outcome. At baseline, just under half the sample (44.6%) had not co-administered cannabis with tobacco in the last month, 9.5% rarely co-administered, 7.7% sometimes co-administered, and 38.2% always co-administered. Always co-administering cannabis with tobacco was associated with more frequent and persistent tobacco smoking at 4½ years (Odds Ratio (OR): 1.98, 95% Confidence Interval (CI): 1.02, 3.83), independently of factors including baseline frequency of cannabis and tobacco use. Young adults who use cannabis should be advised not to co-administrate cannabis with tobacco, and comprise an important target group for tobacco smoking cessation interventions.

Cohort Study of Cannabis Use History and Perinatal Cigarette Use Among Overweight and Obese Women

OBJECTIVES

In non-pregnant populations, cannabis use and cannabis use disorder (CUD) have been linked to tobacco use and less successful quit attempts. We compared perinatal cigarette use in women across 3 groups: never used cannabis (No CU group); used cannabis but did not meet CUD criteria (CU group); history of CUD (CUD group).

METHODS

Interviews with 257 pregnant women with overweight/obesity (M age = 28 years; 52% white) were conducted for a study of eating behavior in Western Pennsylvania from 2012-2016. Tobacco use was assessed early in pregnancy (< 20 weeks gestation), late in pregnancy (34-38 weeks gestation) and 6 months postpartum. CUD was measured with the Structured Clinical Interview for DSM-IV (SCID). Data relevant to the proposed analyses were available for 252 women. Generalized mixed effect models were used to predict perinatal cigarette use based on cannabis use group, time and their interaction, adjusting for age, race, education, income, parity, and mood/anxiety disorder.

RESULTS

Forty-eight percent of participants reported prior cannabis use and 15% were diagnosed with lifetime CUD. History of cannabis use predicted cigarette smoking in early pregnancy (OR 11.12, CI 3.27-37.85), late pregnancy (OR 6.55, CI 1.70-25.27), and 6 months postpartum (OR 7.57, CI 2.72-21.07), regardless of CUD.

CONCLUSIONS

A history of CUD did not appear to confer additional risk for perinatal cigarette use. Given increasing rates of cannabis use among pregnant women, these results highlight the importance of addressing history of cannabis use in conjunction with tobacco use to improve smoking cessation efforts.

Indicadores hospitalarios y comportamiento de pacientes internados en hospital psiquiátrico que adoptó la prohibición de fumar

Resumen Objetivo: comparar indicadores de internación, alta, costo con medicamentos y comportamientos de los pacientes antes y después de la prohibición del tabaquismo en un hospital psiquiátrico. Método: estudio ecológico, longitudinal y retrospectivo realizado en un hospital psiquiátrico. Fueron obtenidos datos secundarios, a partir de consulta a las fichas médicas, referentes a 2.142 internaciones. Fue aplicado el test de medianas para comparación de las variables antes y después de la prohibición. Resultados: con la implementación de la prohibición el porcentaje de ocupación de las camas fue reducido en las unidades masculinas de trastornos mentales (88,8% para 48,4%) y de dependencia química (94,4% para 42,8%). La media de días de internación fue reducida en la unidad masculina de dependencia química (13,5 para 12,6) en comparación con la unidad femenina (14,7 para 19,5). Los costos con psicofármacos y expectorantes, las agresiones verbales/físicas y las contenciones físicas/químicas fueron reducidas. Conclusión: la prohibición de fumar alteró los indicadores hospitalarios, redujo costos y mejoró el comportamiento de los pacientes, contrariando el mito de que esta resulta en hostilidad. Se espera que este estudio contribuya para que los enfermeros revisen sus creencias relacionadas con la prohibición del tabaquismo, considerando los resultados positivos para las relaciones interpersonales y para la administración de los servicios de salud mental, que fueron obtenidos.

Hospital indicators and inpatient behavior in a psychiatric hospital that implemented the smoking ban

Abstract Objective: to compare hospitalization and discharge indicators, medication costs and patient behavior before and after the implementation of the smoking ban in a psychiatric hospital. Method: ecological, longitudinal and retrospective study carried out in a psychiatric hospital. Secondary data referring to 2142 hospitalizations were collected from medical records. The median test was used to compare the variables before and after the ban. Results: after the implementation of the ban, there was a reduction in bed occupancy rate in male units for mental disorders (from 88.8% to 48.4%) and substance dependence (from 94.4% to 42.8%). There was a reduction in the mean length of hospital stay in the male chemical dependency unit (from 13.5 to 12.6) compared to the female unit (from 14.7 to 19.5). There was a reduction in costs of psychotropic drugs and expectorants, episodes of verbal/physical aggressions and physical/chemical restraints. Conclusion: the smoking ban changed hospital indicators, reduced costs and improved patient behavior, contradicting the myth that it results in hostility. It is hoped that this study will help nurses to review their beliefs related to smoking cessation, as there were positive results for interpersonal relationships and for the management of mental health services.

Cannabis Legalization and Adolescent Use of Electronic Vapor Products, Cannabis, and Cigarettes

OBJECTIVES

Cannabis legalization may have unintended consequences, such as effects on prevalence of adolescent use of other substances. We hypothesize that in states that have legalized recreational cannabis (RCL states), electronic vapor product use ("vaping"), cannabis, and cigarette use among adolescents is more prevalent than in states that have only legalized medical cannabis (MCL states) and states that have neither legalized recreational nor medical cannabis (NL states).

METHODS

Data are from the Center for Disease Control's 2017 Youth Risk Behavior Surveillance Survey (n = 107,665), a nationally representative survey of US high school students. We categorized student responses by cannabis legalization status of the state in which they lived at time of survey, then tested associations between cannabis legalization status and adolescent vaping, cannabis, and cigarette use, using logistic regressions.

RESULTS

Students in RCL states were significantly more likely to report current vaping behaviors compared to NL students [odds ratios (OR's) 2.07-2.21]. Students in cannabis-legal states were significantly more likely to report ever or currently using cannabis compared to NL students (OR's 1.27-1.40). MCL students were significantly less likely to report current cigarette smoking (OR = 0.86) compared to NL students.

CONCLUSIONS

Adolescents in cannabis-legal states were more likely to report vaping and cannabis use compared to adolescents in NL states. Public health officials, policymakers, and clinicians should consider the associations between cannabis legalization and adolescent vaping, cigarette, and cannabis use patterns.

Hospital indicators and inpatient behavior in a psychiatric hospital that implemented the smoking ban

OBJECTIVE

to compare hospitalization and discharge indicators, medication costs and patient behavior before and after the implementation of the smoking ban in a psychiatric hospital.

METHOD

ecological, longitudinal and retrospective study carried out in a psychiatric hospital. Secondary data referring to 2142 hospitalizations were collected from medical records. The median test was used to compare the variables before and after the ban.

RESULTS

after the implementation of the ban, there was a reduction in bed occupancy rate in male units for mental disorders (from 88.8% to 48.4%) and substance dependence (from 94.4% to 42.8%). There was a reduction in the mean length of hospital stay in the male chemical dependency unit (from 13.5 to 12.6) compared to the female unit (from 14.7 to 19.5). There was a reduction in costs of psychotropic drugs and expectorants, episodes of verbal/physical aggressions and physical/chemical restraints.

CONCLUSION

the smoking ban changed hospital indicators, reduced costs and improved patient behavior, contradicting the myth that it results in hostility. It is hoped that this study will help nurses to review their beliefs related to smoking cessation, as there were positive results for interpersonal relationships and for the management of mental health services.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Emerging Indoor Air Laws for Onsite Cannabis Consumption Businesses in the U.S

INTRODUCTION

Secondhand cannabis smoke, like secondhand tobacco smoke, creates unhealthy indoor air quality. Ventilation and engineering techniques cannot reduce this pollution to healthy levels, and complete smoke-free policies are the only way to provide healthy indoor environments. Even so, multiple state and local governments have begun to allow indoor smoking of cannabis in businesses.

METHODS

A systematic search of Lexis Advance, NewsBank, and government websites for U.S. state and local laws passed between November 6, 2012 and June 10, 2020 that permit and regulate onsite cannabis consumption businesses was conducted in February-July 2020.

RESULTS

In total, 6 of 11 states and the District of Columbia that legalized adult-use cannabis as of June 10, 2020 allowed onsite consumption and ≥56 localities within these 6 states allowed onsite cannabis consumption. Only 9% (5/56) of localities ban indoor smoking in these businesses; 23% (13/56) require indoor smoking to occur in physically isolated rooms. Other common local legal requirements address onsite odor control, ventilation/filtration, and building location.

CONCLUSIONS

The majority of the localities that allow onsite cannabis consumption do not explicitly prohibit smoking or vaping inside. Policymakers should be made aware that ventilation and other engineering interventions cannot fully protect workers and patrons. Health authorities and local leaders should educate policymakers on the science of secondhand smoke remediation and advocate for the same standards for secondhand cannabis smoking and vaping that apply to tobacco, particularly because other modes of cannabis administration do not pollute the air.

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.

Association between Smoking Cannabis and Quitting Cigarettes in a Large American Cancer Society Cohort

BACKGROUND

Cannabis use is increasing, including among smokers, an at-risk population for cancer. Research is equivocal on whether using cannabis inhibits quitting cigarettes. The current longitudinal study investigated associations between smoking cannabis and subsequently quitting cigarettes.

METHODS

Participants were 4,535 adult cigarette smokers from a cohort enrolled in the American Cancer Society's Cancer Prevention Study-3 in 2009-2013. Cigarette quitting was assessed on a follow-up survey in 2015-2017, an average of 3.1 years later. Rates of quitting cigarettes at follow-up were examined by retrospectively assessed baseline cannabis smoking status (never, former, recent), and by frequency of cannabis smoking among recent cannabis smokers (low: ≤3 days/month; medium: 4-19 days/month; high: ≥20 days/month). Logistic regression models adjusted for sociodemographic factors, smoking- and health-related behaviors, and time between baseline and follow-up.

RESULTS

Adjusted cigarette quitting rates at follow-up did not differ significantly by baseline cannabis smoking status [never 36.2%, 95% confidence interval (CI), 34.5-37.8; former 34.1%, CI, 31.4-37.0; recent 33.6%, CI, 30.1-37.3], nor by frequency of cannabis smoking (low 31.4%, CI, 25.6-37.3; moderate 36.7%, CI, 30.7-42.3; high 34.4%, CI, 28.3-40.2) among recent baseline cannabis smokers. In cross-sectional analyses conducted at follow-up, the proportion of cigarette smokers intending to quit smoking cigarettes in the next 30 days did not differ by cannabis smoking status (P = 0.83).

CONCLUSIONS

Results do not support the hypothesis that cannabis smoking inhibits quitting cigarette smoking among adults.

IMPACT

Future longitudinal research should include follow-ups of >1 year, and assess effects of intensity/frequency of cannabis use and motivation to quit on smoking cessation.

Tobacco and marijuana co-use in a cohort of young adults: Patterns, correlates and reasons for co-use

BACKGROUND

As marijuana is legalized in more states, modes of administration that facilitate co-use with tobacco are growing in popularity among young adults. This study examines the prevalence, patterns, correlates, and reasons for co-use so that targeted interventions can be developed to prevent negative consequences associated with tobacco use and co-use.

METHODS

In Fall 2019, 1887 young adults, originally recruited in 2010 from 11 colleges in North Carolina and Virginia to participate in a cohort study, completed an online survey. Co-use was defined as self-reported use of marijuana and tobacco in the past month. Tobacco-only, marijuana-only and co-users were compared using regression modeling.

RESULTS

Overall, 9.3% of the sample were co-users, 7.1% tobacco-only, and 15.8% marijuana-only users. Tobacco use was associated with an increased likelihood of marijuana use and vice-versa. Co-users were more likely to use e-cigarettes and blunts to administer marijuana and less likely to use smokeless tobacco products. They were more likely to use cocaine, have less anxiety, and be heavier marijuana users than marijuana-only users. Co-users of e-cigarettes and marijuana were less likely to be daily e-cigarette users and make quit attempts than e-cigarette users that did not use marijuana. Experimentation was the primary reason for co-use of tobacco and marijuana.

CONCLUSIONS

Co-users were more likely to use modes of administration that facilitate use of both substances and have patterns of use that may impact cessation efforts. These findings highlight the importance of surveillance of co-use and the development of interventions targeting experimentation with these substances by young adults.

Changes in cannabis, tobacco, and alcohol use among sexually active female adolescents and young adults over a twelve-year period ending in 2019

BACKGROUND

The United States has experienced an increasing divergence in cannabis, tobacco, and alcohol use among adolescents and young adults (AYA). We assessed the changes in cannabis, tobacco and alcohol use in an inner-city population of predominantly minority AYA females attending a large adolescent-specific health center in New York City.

METHODS

This was a longitudinal study of AYA women recruited and followed over a twelve-year period between 2007 and 2019. Lifetime and past 30-day use were assessed by self-administered questionnaire every six months. In addition, we assessed associations with race, ethnicity, sexual behaviors, receipt of social services, living situation at home (e.g., with or without parents), and use of other drugs.

RESULTS

Participants included 1549 AYA females aged 13-21 at baseline, 95% of whom were youth of color. Use of cannabis increased significantly over the twelve-year period, with frequent cannabis use (≥20 times in 30-days) increasing almost 18% per year (OR = 1.18; 95%CI:1.13-1.23). In contrast, past 30-day tobacco use declined over the same period (OR = 0.86; 95%CI:0.83-0.89). Past 30-day cannabis use was more likely among African Americans (OR = 1.33; 95%CI:1.08-1.63), women who had sex with both men and women compared to with men only (OR = 1.44; 95%CI:1.18-1.75), recent users of tobacco (OR = 2.20; 95%CI:1.92-2.52) and alcohol (OR = 2.84; 95%CI:2.52-3.20), and ever users of other drugs (OR = 1.69; 95%CI:1.44-1.99), independent of age, time and living situation.

CONCLUSIONS

Increasing rates of cannabis use and the association with concurrent tobacco and alcohol use in AYA females underscore the need to screen for unhealthy cannabis use, in addition to tobacco and alcohol, especially among inner-city AYA.