Tobacco use during cannabis cessation: Use patterns and impact on abstinence in a National Drug Abuse Treatment Clinical Trials Network study

Marijuana and E-cigarette Initiation Among Adolescents: A Survival Analysis

PURPOSE

Prior literature suggests marijuana and e-cigarette initiation among adolescents is surpassing combustible cigarette uptake. Marijuana and nicotine co-use is also a concern as these products grow in popularity. Initiation trajectories for marijuana and e-cigarette products are not well understood, let alone how the use of one product may impact initiation susceptibility for the other.

METHODS

We used national longitudinal data from the Population Assessment of Tobacco and Health study from 2013 to 2018. Eighth graders in Wave 1 made up the analytic sample (N = 2,270). We employed discrete time survival analyses to determine the likelihood of initiating marijuana and e-cigarettes between Waves 2 and 5. We used survival analyses to estimate the relationships between prior cigarette and marijuana use and subsequent e-cigarette initiation, as well as prior cigarette and e-cigarette use and subsequent marijuana initiation.

RESULTS

Previous marijuana initiation was associated with later e-cigarette initiation (odds ratio = 6.88, 95% confidence interval [4.89, 9.67]). Previous e-cigarette initiation was associated with later marijuana initiation (odds ratio = 9.28, 95% confidence interval [6.86, 12.56]). By wave 5, adolescents were more than 42% likely to initiate marijuana and e-cigarettes.

DISCUSSION

Susceptibility to marijuana and e-cigarette products starts as early as eighth grade and increases over time. The use of one product is significantly related to later initiation for the other. Rather than addressing marijuana and nicotine as separate concerns, interventions may benefit by recognizing the closely related nature of these products.

Who responds to a multi-component treatment for cannabis use disorder? Using multivariable and machine learning models to classify treatment responders and non-responders

BACKGROUND AND AIMS

Treatments for cannabis use disorder (CUD) have limited efficacy and little is known about who responds to existing treatments. Accurately predicting who will respond to treatment can improve clinical decision-making by allowing clinicians to offer the most appropriate level and type of care. This study aimed to determine whether multivariable/machine learning models can be used to classify CUD treatment responders versus non-responders.

METHODS

This secondary analysis used data from a National Drug Abuse Treatment Clinical Trials Network multi-site outpatient clinical trial in the United States. Adults with CUD (n = 302) received 12 weeks of contingency management, brief cessation counseling and were randomized to receive additionally either (1) N-Acetylcysteine or (2) placebo. Multivariable/machine learning models were used to classify treatment responders (i.e. two consecutive negative urine cannabinoid tests or a 50% reduction in days of use) versus non-responders using baseline demographic, medical, psychiatric and substance use information.

RESULTS

Prediction performance for various machine learning and regression prediction models yielded area under the curves (AUCs) >0.70 for four models (0.72-0.77), with support vector machine models having the highest overall accuracy (73%; 95% CI = 68-78%) and AUC (0.77; 95% CI = 0.72, 0.83). Fourteen variables were retained in at least three of four top models, including demographic (ethnicity, education), medical (diastolic/systolic blood pressure, overall health, neurological diagnosis), psychiatric (depressive symptoms, generalized anxiety disorder, antisocial personality disorder) and substance use (tobacco smoker, baseline cannabinoid level, amphetamine use, age of experimentation with other substances, cannabis withdrawal intensity) characteristics.

CONCLUSIONS

Multivariable/machine learning models can improve on chance prediction of treatment response to outpatient cannabis use disorder treatment, although further improvements in prediction performance are likely necessary for decisions about clinical care.

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

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

Have recreational marijuana laws undermined public health progress on adult tobacco use?

Public health experts caution that legalization of recreational marijuana may normalize smoking and undermine the decades-long achievements of tobacco control policy. However, very little is known about the impact of recreational marijuana laws (RMLs) on adult tobacco use. Using newly available data from the Population Assessment of Tobacco and Health (PATH) and dynamic difference-in-differences and discrete-time hazard approaches, we find that RML adoption increases prior-month marijuana use among adults ages 18-and-older by 2-percentage-points, driven by an increase in marijuana initiation among prior non-users. However, this increase in adult marijuana use does not extend to tobacco use. Rather, we find that RML adoption is associated with a lagged reduction in electronic nicotine delivery systems (ENDS) use, consistent with the hypothesis that ENDS and marijuana are substitutes. Moreover, auxiliary analyses from the National Survey on Drug Use and Health (NSDUH) show that RML adoption is associated with a reduction in adult cigarette smoking. We conclude that RMLs may generate tobacco-related health benefits.

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

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

Construct validity and reliability of the Malay version of the Fagerström test for nicotine dependence (FTND): A confirmatory factor analysis

INTRODUCTION

The Fagerström test for nicotine dependence (FTND) was forward-backwards translated into the Malay language (FTND-M) and administered to 152 daily smokers who sought treatment for smoking cessation in government health clinics in Selangor state, Malaysia.

METHODS

Using confirmatory factor analysis (CFA), four measurement models with the best relative fit were compared, one uni-dimensional model, and three different two-domain (morning and daytime smoking) models.

RESULTS

The findings indicate that the best model of the FTND-M was a two-domain model, wherein domain one represented morning smoking (time to first cigarette of the day, smoking more in the morning, and which cigarette would you hate to give up) and domain two represented daytime smoking (cigarettes per day, difficulty refraining from smoking, and smoking when ill) which showed good model fit [χ²/df=1.932, goodness of fit (GFI) of 0.967, comparative fix index (CFI) of 0.945, incremental fit index (IFI) of 0.98, Tucker-Lewis index (TLI) of 0.95 and a real mean square end of approximation (RMSEA) of 0.079, and substantial reliability >0.70].

CONCLUSIONS

This study indicates that the FTND-M can be used to assess these two dimensions of nicotine addiction among daily smokers in a clinical setting.

N-acetyl cysteine in the treatment of cannabis use disorder: A systematic review of clinical trials

BACKGROUND AND AIM

Cannabis is the most consumed illicit drug globally, with a high risk of developing cannabis use disorder (CUD). No approved pharmacological treatment exists for CUD, but N-Acetyl Cysteine (NAC) has shown promising results in different clinical studies. This study aims to conduct a systematic review of NAC clinical trials for the treatment of CUD.

METHODS

Systematic review of randomized controlled trials (RCTs) was conducted to determine the effect of NAC for the treatment of cannabis dependence/cannabis use disorder (CUD). Articles were electronically searched across different databases using PubMed, Google Scholar, EMBASE, Cochrane Library, Medline and PsycINFO from inception to June 2021. Several study characteristics, including study duration, sample size, study population and age group, intervention, adverse effects, and outcome measure were extracted. A PICO table was used for data extraction.

RESULTS

We included 08 RCTs in the qualitative analysis. The risk of bias (RoB) was assessed according to Cochrane RoB criteria, and a 5 point grading system according to the Oxford Centre for Evidence-Based Medicine was used to rate the methodological quality (level of evidence) of the included articles. Mild and well-tolerated adverse events were reported in the placebo and NAC group.

CONCLUSIONS

The studies collectively offer mixed results, although the strength of the evidence available on which to make a recommendation is strong. NAC has shown to be effective in promoting abstinence, medication adherence and reducing cannabis use and craving among cannabis dependent users. This review also suggests recommendations for future research.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Treatment Implications Associated with Cannabis and Tobacco Co-Use

PURPOSE OF THE REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Intensive Behavioural and Pharmacological Treatment for Tobacco Dependence in Pregnant Women with Complex Psychosocial Challenges: A Case Report

Up to 95% of women who use other substances also smoke tobacco during pregnancy. Challenging psychosocial circumstances and other barriers that contribute to high levels of tobacco dependence result in few quitting successfully. This case report describes the treatment of a highly tobacco dependent 34-year-old pregnant woman with a history of recent substance use, mental illness and trauma, enrolled in the Incentives to Quit Tobacco in Pregnancy program. Heavy smoking, both during the day and overnight, was reported. An extensive history of quit attempts, as well as a strong desire to cease tobacco use during pregnancy, was also noted. Treatment utilising extensive behavioural supports, including financial incentives for carbon monoxide verified abstinence and telephone-based counselling, in combination with nicotine replacement therapy (NRT), was offered to assist cessation. Excellent uptake and adherence to all aspects of treatment saw tobacco cessation achieved and maintained for 24 weeks while on the program. NRT used at doses well above those recommended for pregnancy was required to alleviate strong withdrawal symptoms and maintain abstinence. Daily monitoring of carbon monoxide, financial incentives for continued abstinence and regular phone support were critical to maintaining motivation and preventing relapse to smoking. Post-program relapse to smoking did occur, as is common, and highlights the need for longer-term intensive support for pregnant women with complex behavioural and social problems. Given the prevalence of tobacco smoking in such populations, long-term harm reduction treatment models using extensive behavioural support in combination with NRT should be considered for inclusion in current smoking cessation guidelines.

Current cannabis use and smoking cessation among treatment seeking combustible smokers

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Depressive symptoms and cannabis use in a placebo-controlled trial of N-Acetylcysteine for adult cannabis use disorder

RATIONALE

Depression is common among individuals with cannabis use disorder (CUD), particularly individuals who present to CUD treatment. Treatments that consider this comorbidity are essential.

OBJECTIVES

The goal of this secondary analysis was to examine whether N-acetylcysteine (NAC) reduced depressive symptoms among adults (age 18-50) with CUD (N = 302) and whether the effect of NAC on cannabis cessation varied as a result of baseline levels of depression. Bidirectional associations between cannabis use amount and depression were also examined.

METHODS

Data for this secondary analysis were from a National Drug Abuse Treatment Clinical Trials Network (NIDA CTN) multi-site clinical trial for CUD. Adults with CUD (N = 302) were randomized to receive 2400 mg of NAC daily or matched placebo for 12 weeks. All participants received abstinence-based contingency management. Cannabis quantity was measured by self-report, and weekly urinary cannabinoid levels (11-nor-9-carboxy-Δ9-tetrahydrocannabinol) confirmed abstinence. Depressive symptoms were measured by the Hospital Anxiety and Depression Scale.

RESULTS

Depressive symptoms did not differ between the NAC and placebo groups during treatment. There was no significant interaction between treatment and baseline depression predicting cannabis abstinence during treatment. Higher baseline depression was associated with decreased abstinence throughout treatment and a significant gender interaction suggested that this may be particularly true for females. Cross-lagged panel models suggested that depressive symptoms preceded increased cannabis use amounts (in grams) during the subsequent month. The reverse pathway was not significant (i.e., greater cannabis use preceding depressive symptoms).

CONCLUSIONS

Results from this study suggest that depression may be a risk factor for poor CUD treatment outcome and therefore should be addressed in the context of treatment. However, results do not support the use of NAC to concurrently treat co-occurring depressive symptoms and CUD in adults.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01675661.

Culturally-tailored text-messaging intervention for smoking cessation in rural American Indian communities: Rationale, design, and methods

BACKGROUND

American Indian (AI) and Alaska Native (AN) communities experience disproportionately high rates of tobacco use when compared to the overall U.S. population, especially among rural populations.

METHODS

We implemented a single-blind, randomized clinical trial of a text messaging-based smoking cessation intervention through the tobacco quitlines of five states (Alaska, Minnesota, New Mexico, Oklahoma, and Wisconsin) with high percentages of AI residents. We partnered with state quitlines and Optum, a multi-state entity that manages quitlines. Participants who called the quitlines and identified as AI/AN were given the option to enroll in this trial. Upon consent, they were randomly assigned to either the standard quitline program (control) or a program culturally tailored for AI/ANs (intervention), which used a text messaging intervention to encourage smoking cessation. We adapted the text messages based on key informant and focus group input. Baseline data was analyzed for differences across age, sex, and the Fagerström Test for Nicotine Dependence.

RESULTS

We recruited n = 487 AIs into the trial. Participants had an average age of 41.9 years (SD = 11.7) and 66% were female. The average Fagerström Test for Nicotine Dependence score was 5.38 (SD = 2.37). The intervention and control arms did not significantly differ across any of the baseline characteristics.

CONCLUSION

Implementation of this trial illustrated important lessons in adapting, implementing, and evaluating trials in collaboration with AI communities and local and national organizations. This work will inform future efforts to implement culturally-tailored interventions with AI/ANs and advance our knowledge about adapting and implementing smoking cessation interventions.

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

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

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

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

Tobacco and cannabis co-use and interrelatedness among adults

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