Treatment models for targeting tobacco use during treatment for cannabis use disorder: case series

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cannabis Use in Physicians: A Systematic Review and Meta-Analysis

Background: Cannabis use by physicians can be detrimental for them and their patients. We conducted a systematic review and meta-analysis on the prevalence of cannabis use by medical doctors (MDs)/students. Method: PubMed, Cochrane, Embase, PsycInfo and ScienceDirect were searched for studies reporting cannabis use in MDs/students. For each frequency of use (lifetime/past year/past month/daily), we stratified a random effect meta-analysis depending on specialties, education level, continents, and periods of time, which were further compared using meta-regressions. Results: We included 54 studies with a total of 42,936 MDs/students: 20,267 MDs, 20,063 medical students, and 1976 residents. Overall, 37% had used cannabis at least once over their lifetime, 14% over the past year, 8% over the past month and 1.1 per thousand (‱) had a daily use. Medical students had a greater cannabis use than MDs over their lifetime (38% vs. 35%, p < 0.001), the past year (24% vs. 5%, p < 0.001), and the past month (10% vs. 2%, p < 0.05), without significance for daily use (0.5% vs. 0.05%, NS). Insufficient data precluded comparisons among medical specialties. MDs/students from Asian countries seemed to have the lowest cannabis use: 16% over their lifetime, 10% in the past year, 1% in the past month, and 0.4% daily. Regarding periods of time, cannabis use seems to follow a U-shape, with a high use before 1990, followed by a decrease between 1990 and 2005, and a rebound after 2005. Younger and male MDs/students had the highest cannabis use. Conclusions: If more than a third of MDs tried cannabis at least once in their lifetime, this means its daily use is low but not uncommon (1.1‱). Medical students are the biggest cannabis users. Despite being common worldwide, cannabis use is predominant in the West, with a rebound since 2005 making salient those public health interventions during the early stage of medical studies.

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

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

Internet-Delivered Tobacco Treatment for People Using Cannabis: A Randomized Trial in Two Australian Cannabis Clinics

Background

Tobacco use is disproportionately higher in people who smoke cannabis than in the general population, increasing the severity of dependence for cannabis use, decreasing the likelihood of successful quit attempts for both cannabis and tobacco, and increasing the risk of relapse for both substances. Opportunities to address tobacco use in people using cannabis are being missed.

Objective

This study aims to investigate the feasibility of engaging tobacco smokers who were accessing treatment for cannabis, with a tobacco-focused internet-based Healthy Lifestyle Program (iHeLP; 4 modules). It was hypothesized that iHeLP completion would be associated with decreases in tobacco use and improved quality of life (QoL) and psychological health. It was also hypothesized that iHeLP completion would be higher in those who additionally received telephone support. Given that iHeLP aimed to improve healthy lifestyle behaviors, it was also hypothesized that there would be reductions in cannabis use.

Methods

A total of 13 smokers seeking treatment for cannabis use were randomly allocated to iHeLP alone or iHeLP plus telephone support. Participants were engaged in iHeLP over 8 weeks and completed a 12-week follow-up assessment.

Results

Results from 10 participants who completed the follow-up indicated that the acceptability of iHeLP was high-very high in terms of general satisfaction, appropriateness of services, effectiveness, and met need. Additional telephone support increased modal module completion rates for iHeLP from 0 to 2 but did not provide any other significant advantages over iHeLP alone in terms of cannabis use, tobacco use, QoL, or psychological health. Participants in the iHeLP-alone condition (n=4) reported a mean reduction of 5.5 (SD 9.00) tobacco cigarettes per day between baseline and follow-up, with a concomitant mean reduction in expired carbon monoxide (CO) of 5.5 parts per million (ppm, SD 6.91). The iHeLP plus telephone support group (n=6) reported a mean reduction of 1.13 (SD 4.88) tobacco cigarettes per day and a mean reduction of 9.337 ppm of expired CO (SD 5.65). A urinalysis indicated that abstinence from cannabis was achieved by 2 participants in the iHeLP-alone group and three participants in the iHeLP plus telephone support group. Between baseline and follow-up assessments, iHeLP-alone participants reported a mean reduction in days of use of cannabis in the prior month of 6.17 days (SD 13.30). The average reduction in the number of days of cannabis use for the iHeLP plus telephone support group was also 6.17 days (SD 13.59).

Conclusions

Despite the small sample size, this study provides preliminary support for the use of internet-delivered, tobacco-focused interventions in tobacco smokers seeking treatment for cannabis use.

Digital health for assessment and intervention targeting tobacco and cannabis co-use

Purpose of review

This article aims to summarize current research on digital health for assessment and intervention targeting tobacco and cannabis co-use and to answer the following questions: Which digital tools have been used? Which populations have been targeted? And what are implications for future research?

Recent findings

Ecological Momentary Assessment (EMA) via text messages or interactive voice response calls has been used to capture co-use patterns within a time window or co-administration of both substances via blunts among young adults. Feasibility of multicomponent interventions targeting dual cessation of both substances among adult co-users with cannabis use disorder, delivered via smartphone apps, online, and computer modules has been demonstrated.

Summary

Digital tools, particularly those using EMAs and mobile sensors, should be expanded to assess co-use of emerging tobacco and cannabis products. Digital cessation interventions should be tailored to different groups of co-users and address specific mechanisms underlying different co-use patterns.

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.

Understanding women's feelings about safety and hazards of street drinking in London through interpretative phenomenological analysis

AIMS

Drinking alcohol in outdoor public places (e.g. streets and parks) and outside of formally organised events is perceived and reported as antisocial behaviour and may be indicative of a problematic relationship with alcohol, and other clinical needs. This paper aims to address a lack of qualitative research on street drinking in the United Kingdom and develop a textured understanding of the lived-experience of how some women engage in street drinking, in the context of one London borough.

METHOD

The authors collected semi-structured interviews as part of a larger mixed methods study on street drinking from April to August 2018. A sub-set of interviews (n = 3) with women who were accessing local drug and alcohol services and had a history of street drinking behaviour were selected as a case series for triangulating analysis with a smaller, homogenous sample. These data were analysed using Interpretative Phenomenological Analysis with a reflexive, feminist, social constructionist approach.

RESULTS

The authors developed and named a superordinate theme, Constellations of Safety and Hazards for Women Drinking in Public and Private. Within this, four themes were defined and illustrated from the data: Drinking outdoors to be away from hazards at home; Women's awareness of geo-temporal factors to moderate risk; Women identifying risks of accepting drinks from strangers; and Threats of untreated trauma within histories of heavy drinking. Definitions and illustrations from participants aid explanations of how the texts add detail or disruption to dominant discourses.

CONCLUSION

The case studies illustrating how these women have experienced alcohol misuse and behaviour change provide reflexive accounts of exercising agency in managing embodied and affective states of vulnerability. This was demonstrated by asserting choice around environmental spaces and friendships, even when still in positions deemed as 'risky'. These three women's decisions around drinking in public, outdoor spaces were shaped by complex interactions of interpersonal, intrapersonal, socio-economic, and cultural structures. Understanding behaviours is improved with data that situates people in contexts where they experience and make sense of their lives.

Is Cannabis Use Associated With Increased Risk of Cigarette Smoking Initiation, Persistence, and Relapse? Longitudinal Data From a Representative Sample of US Adults

OBJECTIVE

The current study prospectively investigated the relationship between cannabis use and cigarette smoking initiation, persistence, and relapse during a 3-year period among adults in the United States.

METHODS

Analyses included respondents who completed Waves 1 (2001-2002) and 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions and responded to questions about cannabis use and smoking status (n = 34,639). Multivariable logistic regression models were used to calculate the odds of cigarette use at Wave 2 among Wave 1 daily smokers, nondaily smokers, former smokers, and nonsmokers by Wave 1 cannabis use.

RESULTS

In unadjusted analyses, Wave 1 cannabis use was associated with increased odds of Wave 2 daily and nondaily smoking for Wave 1 nonsmokers (daily OR = 2.90; 95% CI, 2.10-4.00; nondaily OR = 4.45; 95% CI, 3.97-5.00) and Wave 2 relapse to daily and nondaily smoking for Wave 1 former smokers (daily OR = 4.18, 95% CI, 3.01-5.81; nondaily OR = 5.24; 95% CI, 3.74-7.34). Wave 1 cannabis use was associated with decreased odds of Wave 2 smoking cessation for Wave 1 daily cigarette smokers (OR = 0.57; 95% CI, 0.51-0.64). The associations remained significant for daily smoking initiation (OR = 1.43; 95% CI, 1.06-1.93), daily smoking relapse (OR = 1.47; 95% CI, 1.00-2.16), and smoking cessation (OR = 0.77; 95% CI, 0.69-0.87) after adjusting for demographics and psychiatric disorders. Associations remained significant for nondaily smoking initiation (OR = 1.85; 95% CI, 1.59-2.16) and nondaily smoking relapse (OR = 1.63; 95% CI, 1.05-2.54) after adjusting for these covariates as well as for alcohol and substance use disorders.

CONCLUSIONS

Cannabis use was associated with increased initiation of, persistence of, and relapse to cigarette smoking. Additional attention to cannabis use in tobacco control efforts and in clinical settings aimed at reducing cigarette smoking and smoking-related negative consequences may be warranted.

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.

The Relationship Between Tobacco and Cannabis Use: A Review

BACKGROUND

Based on the prevalence and health implications of tobacco and cannabis use, aiming to reduce their use, especially among youth, is a sound objective at both the individual and public health level. A proper understanding of the relationships between tobacco and cannabis use may help to achieve this goal.

OBJECTIVES

To review the relationships between tobacco and cannabis use.

METHODS

A selective review of the literature.

RESULTS

We present an overview of the motivations for tobacco and cannabis use, and their perceived harmfulness. The article then reviews the gateway theory, reverse gateway theory, route of administration theory, and common liability theory. We describe the link between co-use and dependence symptoms, and the substitution phenomenon between tobacco and cannabis use. Three forms of simultaneous use-mulling, blunt smoking, and chasing-and their impacts are explained. We summarize the impact of tobacco use on cannabis (and vice versa) treatment outcomes, and, finally, review new treatments that simultaneously target tobacco and cannabis dependence. Most of the literature reviewed here relates to substance use among adolescents and young adults.

CONCLUSIONS

The use of tobacco and cannabis-two of the most widely used substances around the world-are strongly intertwined in several respects. Both health professionals and researchers should have well-informed views on this issue to better evaluate, understand, inform, and provide care to their patients.

Sequential and simultaneous treatment approaches to cannabis use disorder and tobacco use

Tobacco smoking among those seeking treatment for cannabis use disorder (CUD) is common and is a negative predictor of cannabis outcomes. Quitting tobacco may be beneficial for those seeking to quit cannabis use. This initial proof of concept, controlled trial was designed to compare a simultaneous versus sequential tobacco intervention among those seeking treatment for CUD. Sixty-seven adults received either a simultaneous (SIM) or sequential (SEQ) approach to tobacco cessation in the context of outpatient treatment for CUD. A tobacco intervention (TI) that combined web-based counseling with nicotine replacement therapy (NRT) was provided during weeks 1-12 for SIM and was delayed until weeks 13-24 for SEQ. During weeks 1-12, no between-condition significant differences were observed on treatment participation or cannabis use outcomes. The majority of SIM participants initiated TI counseling (62%), 50% made at least one quit attempt and 41% initiated NRT. Interestingly, 39% in SEQ made tobacco quit attempts and 18% initiated NRT on their own before the TI was offered to them. However, only 30% of those in SEQ continued treatment during weeks 13-24, which compromised between-condition comparisons following the TI, but illustrated a potential clinical concern with delaying the TI. Tobacco cessation outcomes generally were poor and did not differ between conditions. This initial controlled trial suggests that addressing tobacco use during CUD treatment is acceptable and generates action towards tobacco cessation. Additional trials testing more intensive TI models may be necessary to identify more efficacious interventions for co-use of cannabis and tobacco.

A scoping review and meta-analysis of psychosocial and pharmacological treatments for cannabis and tobacco use among African Americans

The rates of co-occurring cannabis and tobacco use are higher among African Americans relative to other racial/ethnic groups. One plausible approach to treating co-use among African Americans is to examine the effectiveness of treatments for the sole use of cannabis and tobacco to identify effective approaches that might be combined to treat the dual use of these substances. The current meta-analysis sought to include studies that reported cannabis and/or tobacco use outcomes from randomized clinical trials (RCTs) with 100% African American samples. A total of 843 articles were considered for inclusion, 29 were reviewed by independent qualitative coders, and 22 were included in the review. There were no articles on cannabis use treatment with a 100% African American sample, resulting in a need to lower the threshold (60%) and conduct a scoping review of cannabis studies. Preliminary evidence from a small number of studies (k = 7) supports the use of Motivational Interviewing and Cognitive-Behavioral Therapy to treat cannabis use among African Americans, but not Contingency Management. Results from a meta-analysis of 15 tobacco studies found higher rates of smoking abstinence in the treatment condition relative to control conditions overall and across short and long-term follow-up periods. Significant differences in smoking abstinence were also found when examining the effects of pharmacological treatments relative to their control conditions. The clinical and research implications of these findings for future psychosocial and pharmacological trials for cannabis and tobacco use and co-use among African Americans are described. (PsycINFO Database Record

Mobile contingency management as an adjunctive treatment for co-morbid cannabis use disorder and cigarette smoking

INTRODUCTION

Cannabis is the most widely used illicit drug in the U.S. with 19.8 million current users. Population-based data indicate that almost all cannabis users (90%) have a lifetime history of tobacco smoking and the majority (74%) currently smoke tobacco. Among cannabis users, smoking tobacco is associated with increased frequency of cannabis use, increased morbidity, and poorer cannabis cessation outcomes. There is a lack of research, however, focused on addressing cessation of both substances simultaneously. The purpose of the current pilot study was to evaluate the feasibility and acceptability of a multi-component tobacco/cannabis abstinence treatment.

METHODS

Five participants completed Abstinence Reinforcement Therapy, an intervention that included five sessions of cognitive-behavioral telephone counseling for tobacco/cannabis, pharmacotherapy for smoking cessation, and five weeks of mobile contingency management to remain abstinent from tobacco and cannabis.

RESULTS

Feasibility of recruitment, retention and treatment completion was high. Satisfaction with the treatment was also high.

CONCLUSION

Results support the feasibility and acceptability of this approach with dual cannabis and tobacco users and suggest that further research examining the efficacy of this approach is warranted.

Prevalence, correlates, and trends in tobacco use and cessation among current, former, and never adult marijuana users with a history of tobacco use, 2005-2014

BACKGROUND

Approximately 70% of current (past 30-day) adult marijuana users are current tobacco users, which may complicate tobacco cessation. We assessed prevalence and trends in tobacco cessation among adult ever tobacco users, by marijuana use status.

METHODS

Data came from the National Survey on Drug Use and Health, a cross-sectional, nationally representative, household survey of U.S. civilians. Analyses included current, former, and never marijuana users aged≥18 reporting ever tobacco use (cigarette, cigar, chew/snuff). We computed weighted estimates (2013-2014) of current tobacco use, recent tobacco cessation (quit 30days to 12months), and sustained tobacco cessation (quit>12months) and adjusted trends in tobacco use and cessation (2005-2014) by marijuana use status. We also assessed the association between marijuana and tobacco use status.

RESULTS

In 2013-2014, among current adult marijuana users reporting ever tobacco use, 69.1% were current tobacco users (vs. 38.5% of former marijuana users, p<0.0001, and 28.2% of never marijuana users, p<0.0001); 9.1% reported recent tobacco cessation (vs. 8.4% of former marijuana users, p<0.01, and 6.3% of never marijuana users, p<0.001), and 21.8% reported sustained tobacco cessation (vs. 53.1% of former marijuana users, p<0.01, and 65.5% of never marijuana users, p<0.0001). Between 2005 and 2014, current tobacco use declined and sustained tobacco cessation increased among all marijuana use groups.

CONCLUSIONS

Current marijuana users who ever used tobacco had double the prevalence (vs. never-marijuana users) of current tobacco use, and significantly lower sustained abstinence. Interventions addressing tobacco cessation in the context of use of marijuana and other substances may be warranted.

Feasibility and Preliminary Effectiveness of Varenicline for Treating Co-Occurring Cannabis and Tobacco Use

Few studies have evaluated treatment for co-occurring cannabis and tobacco use. The objective of this pilot study was to evaluate the feasibility and preliminary effectiveness of varenicline for co-occurring cannabis and tobacco use. Participants who reported cannabis use on ≥5 days per week were recruited from an urban, outpatient opioid treatment program (OTP). Participants were randomized to either four weeks of standard OTP clinical care (SCC; medication-assisted treatment for opioid use disorder and individual behavioral counseling), followed by four weeks of SCC plus varenicline (SCC+VT), or to four weeks of SCC+VT followed by four weeks of SCC. All participants contributed feasibility and outcome data during both study phases. Of 193 persons screened, seven were enrolled. Retention at eight weeks was 100%. No adverse effects prompted varenicline discontinuation. Participants reported lower cannabis craving during the SCC+VT phase compared to baseline, and lower frequencies and quantities of cannabis use compared to both baseline and the SCC alone phase. In the SCC+VT phase, participants also reported fewer cigarettes per day. Among persons with co-occurring cannabis and tobacco use, varenicline is well-tolerated and may reduce cannabis craving, cannabis use, and tobacco use.

Cigarette Smoking Is Associated With Increased Risk of Substance Use Disorder Relapse: A Nationally Representative, Prospective Longitudinal Investigation

OBJECTIVE

Little is known about the relationship between cigarette smoking and long-term outcomes for substance use disorder (SUD). The current study examined the association between smoking and SUD relapse among adults with remitted SUDs.

METHODS

Analyses were conducted on respondents who completed Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions and met DSM-IV criteria for substance abuse and dependence prior to but not during the year before the Wave 1 interview (n = 5,515). Relationships between smoking status (Wave 2 smoking vs nonsmoking among Wave 1 smokers; Wave 2 smoking vs nonsmoking among Wave 1 nonsmokers) and Wave 2 substance use and SUD relapse were examined using logistic regression analyses. Analyses were adjusted for demographics, psychiatric and alcohol use disorders, nicotine dependence, and SUD severity.

RESULTS

In the fully adjusted models, continued smoking at Wave 2 among Wave 1 smokers was associated with significantly greater odds of substance use (OR = 1.56, 95% CI, 1.10-2.20) and SUD relapse (OR = 2.02, 95% CI, 1.65-2.47) compared to Wave 2 nonsmoking. In the fully adjusted model, smoking at Wave 2 among Wave 1 nonsmokers was associated with significantly greater odds of SUD relapse compared to Wave 2 nonsmoking (OR = 4.86, 95% CI, 3.11-7.58).

CONCLUSIONS

Continued smoking among smokers and smoking initiation among nonsmokers were associated with greater odds of SUD relapse. More research is needed to examine the timing of SUD relapse in relation to smoking behaviors. Incorporating smoking cessation and prevention efforts into substance abuse treatment may improve long-term substance use outcomes for adult smokers with SUDs.

A review of the additive health risk of cannabis and tobacco co-use

INTRODUCTION

Cannabis and tobacco are the most widely used substances, and are often used together. The present review examines the toxicant exposure associated with co-use (e.g., carbon monoxide, carcinogens), co-use via electronic nicotine delivery systems (ENDS), and problematic methodological issues present across co-use studies.

METHOD

An extensive literature search through PubMed was conducted and studies utilizing human subjects and in vitro methods were included. Keywords included tobacco, cigarette, e-cigarette, ENDS, smoking, or nicotine AND marijuana OR cannabis OR THC.

RESULTS

Co-use may pose additive risk for toxicant exposure as certain co-users (e.g., blunt users) tend to have higher breath carbon monoxide levels and cannabis smoke can have higher levels of some carcinogens than tobacco smoke. Cannabis use via ENDS is low and occurs primarily among established tobacco or cannabis users, but its incidence may be increasing and expanding to tobacco/cannabis naïve individuals. There are several methodological issues across co-use research including varying definitions of co-use, sample sizes, lack of control for important covariates (e.g., time since last cigarette), and inconsistent measurement of outcome variables.

CONCLUSIONS

There are some known additive risks for toxicant exposure as a result of co-use. Research utilizing consistent methodologies is needed to further establish the additive risk of co-use. Future research should also be aware of novel technologies (e.g., ENDS) as they likely alter some toxicant exposure when used alone and with cannabis.

Psychosocial interventions for cannabis use disorder

BACKGROUND

Cannabis use disorder is the most commonly reported illegal substance use disorder in the general population; although demand for assistance from health services is increasing internationally, only a minority of those with the disorder seek professional assistance. Treatment studies have been published, but pressure to establish public policy requires an updated systematic review of cannabis-specific treatments for adults.

OBJECTIVES

To evaluate the efficacy of psychosocial interventions for cannabis use disorder (compared with inactive control and/or alternative treatment) delivered to adults in an out-patient or community setting.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 6), MEDLINE, EMBASE, PsycINFO, the Cumulaive Index to Nursing and Allied Health Literature (CINAHL) and reference lists of articles. Searched literature included all articles published before July 2015.

SELECTION CRITERIA

All randomised controlled studies examining a psychosocial intervention for cannabis use disorder (without pharmacological intervention) in comparison with a minimal or inactive treatment control or alternative combinations of psychosocial interventions.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by The Cochrane Collaboration.

MAIN RESULTS

We included 23 randomised controlled trials involving 4045 participants. A total of 15 studies took place in the United States, two in Australia, two in Germany and one each in Switzerland, Canada, Brazil and Ireland. Investigators delivered treatments over approximately seven sessions (range, one to 14) for approximately 12 weeks (range, one to 56).Overall, risk of bias across studies was moderate, that is, no trial was at high risk of selection bias, attrition bias or reporting bias. Further, trials included a large total number of participants, and each trial ensured the fidelity of treatments provided. In contrast, because of the nature of the interventions provided, participant blinding was not possible, and reports of researcher blinding often were unclear or were not provided. Half of the reviewed studies included collateral verification or urinalysis to confirm self report data, leading to concern about performance and detection bias. Finally, concerns of other bias were based on relatively consistent lack of assessment of non-cannabis substance use or use of additional treatments before or during the trial period.A subset of studies provided sufficient detail for comparison of effects of any intervention versus inactive control on primary outcomes of interest at early follow-up (median, four months). Results showed moderate-quality evidence that approximately seven out of 10 intervention participants completed treatment as intended (effect size (ES) 0.71, 95% confidence interval (CI) 0.63 to 0.78, 11 studies, 1424 participants), and that those receiving psychosocial intervention used cannabis on fewer days compared with those given inactive control (mean difference (MD) 5.67, 95% CI 3.08 to 8.26, six studies, 1144 participants). In addition, low-quality evidence revealed that those receiving intervention were more likely to report point-prevalence abstinence (risk ratio (RR) 2.55, 95% CI 1.34 to 4.83, six studies, 1166 participants) and reported fewer symptoms of dependence (standardised mean difference (SMD) 4.15, 95% CI 1.67 to 6.63, four studies, 889 participants) and cannabis-related problems compared with those given inactive control (SMD 3.34, 95% CI 1.26 to 5.42, six studies, 2202 participants). Finally, very low-quality evidence indicated that those receiving intervention reported using fewer joints per day compared with those given inactive control (SMD 3.55, 95% CI 2.51 to 4.59, eight studies, 1600 participants). Notably, subgroup analyses found that interventions of more than four sessions delivered over longer than one month (high intensity) produced consistently improved outcomes (particularly in terms of cannabis use frequency and severity of dependence) in the short term as compared with low-intensity interventions.The most consistent evidence supports the use of cognitive-behavioural therapy (CBT), motivational enhancement therapy (MET) and particularly their combination for assisting with reduction of cannabis use frequency at early follow-up (MET: MD 4.45, 95% CI 1.90 to 7.00, four studies, 612 participants; CBT: MD 10.94, 95% CI 7.44 to 14.44, one study, 134 participants; MET + CBT: MD 7.38, 95% CI 3.18 to 11.57, three studies, 398 participants) and severity of dependence (MET: SMD 4.07, 95% CI 1.97 to 6.17, two studies, 316 participants; MET + CBT: SMD 7.89, 95% CI 0.93 to 14.85, three studies, 573 participants), although no particular intervention was consistently effective at nine-month follow-up or later. In addition, data from five out of six studies supported the utility of adding voucher-based incentives for cannabis-negative urines to enhance treatment effect on cannabis use frequency. A single study found contrasting results throughout a 12-month follow-up period, as post-treatment outcomes related to overall reduction in cannabis use frequency favoured CBT alone without the addition of abstinence-based or treatment adherence-based contingency management. In contrast, evidence of drug counselling, social support, relapse prevention and mindfulness meditation was weak because identified studies were few, information on treatment outcomes insufficient and rates of treatment adherence low. In line with treatments for other substance use, abstinence rates were relatively low overall, with approximately one-quarter of participants abstinent at final follow-up. Finally, three studies found that intervention was comparable with treatment as usual among participants in psychiatric clinics and reported no between-group differences in any of the included outcomes.

AUTHORS' CONCLUSIONS

Included studies were heterogeneous in many aspects, and important questions regarding the most effective duration, intensity and type of intervention were raised and partially resolved. Generalisability of findings was unclear, most notably because of the limited number of localities and homogeneous samples of treatment seekers. The rate of abstinence was low and unstable although comparable with treatments for other substance use. Psychosocial intervention was shown, in comparison with minimal treatment controls, to reduce frequency of use and severity of dependence in a fairly durable manner, at least in the short term. Among the included intervention types, an intensive intervention provided over more than four sessions based on the combination of MET and CBT with abstinence-based incentives was most consistently supported for treatment of cannabis use disorder.

Marijuana and tobacco use and co-use among African Americans: results from the 2013, National Survey on Drug Use and Health

BACKGROUND

Although studies have identified an increased likelihood of marijuana and tobacco co-use among African Americans as compared to other racial groups, few studies have specifically examined the prevalence and substance use characteristics of co-users among African Americans in a national survey.

METHODS

The current secondary analysis examined the prevalence rates and substance use characteristics (e.g., marijuana dependence) of 2024 African American past month marijuana and tobacco users and co-users participating in the 2013 National Survey on Drug Use and Health.

RESULTS

Findings revealed that 18.5%, 53.8% and 27.7% of African Americans smoked marijuana only, tobacco only and marijuana and tobacco in the past 30days, respectively. Relative to participants who smoked marijuana only, African Americans who smoked marijuana and tobacco were more likely to be marijuana dependent in the past year and report more days of marijuana use in the past month. Further, relative to participants who smoked tobacco only, African Americans who smoked marijuana and tobacco were less likely to be dependent on nicotine, reported fewer days of cigarette use in the past month, and began smoking cigarettes, cigars and marijuana at a younger age, but were more likely to be marijuana dependent in the past year and reported more days of cigar use in the past month.

CONCLUSIONS

Marijuana and tobacco co-use is a significant public health problem, especially among African Americans. Additional research on effective prevention and treatment interventions for African Americans who smoke marijuana and tobacco is warranted.

Outcomes from a computer-assisted intervention simultaneously targeting cannabis and tobacco use

BACKGROUND

Cannabis users frequently report concurrent tobacco use, and tobacco use is associated with poorer outcomes during treatment for cannabis use disorders (CUD). Interventions that simultaneously target both tobacco and cannabis use disorders may enhance cessation outcomes for either or both substances.

METHODS

This study evaluated an intervention integrating highly effective treatments for cannabis and tobacco use disorders. Thirty-two participants meeting diagnostic criteria for CUD and reporting daily tobacco use were enrolled in a 12-week computer-assisted behavioral treatment for CUD. Participants were encouraged to participate in a tobacco intervention that included a computer-assisted behavioral treatment tailored for tobacco and cannabis co-users, and nicotine-replacement therapy (NRT). Cannabis and tobacco outcomes were evaluated using descriptive statistics and were compared to a historical control group that received treatment for CUD but not tobacco.

RESULTS

Participants achieved 3.6±4.3 consecutive weeks of cannabis abstinence, which was comparable to the historical control group (3.1±4.4). A majority of the sample (78%) completed at least one tobacco module and 44% initiated NRT. Over half (56%) initiated tobacco quit attempts, and 28% were tobacco abstinent for at least two consecutive weeks. Participants showed greater reduction in tobacco use (cigarettes per day) than the historical control group, but differences in tobacco abstinence rates during the final month of treatment were not statistically significant (12.5% vs. 4%).

CONCLUSION

Findings suggest that providing a tobacco intervention during treatment for CUD is feasible and may positively impact tobacco use without negatively affecting cannabis use outcomes.

Cannabis problem experiences among users of the tobacco-cannabis combination known as blunts

BACKGROUND

In most of the world, cannabis smokers mix loose tobacco inside a joint, pipe, spliff, or cone. More recently, a 'blunt' formulation combines these two drugs by inserting cannabis into a hollowed-out cigar. Epidemiological research linking simultaneous use of these two drugs and the development of cannabis use disorders (CUD) remains unclear. This study estimates associations linking blunt smoking with levels and subtypes of cannabis problems.

METHODS

Cross-sectional data on 27,767 past-year cannabis users were analyzed from the US National Survey on Drug Use and Health (NSDUH) conducted from 2009 to 2012. Ten self-reported items of DSM-IV CUD features elicited a single latent trait of cannabis problem (CP) severity, which was then regressed on past-year blunt smoking and past-month blunt frequency measures within the context of a conceptual model. Differential item functioning (DIF) analysis evaluated potential bias in CP feature response by blunt smoking history.

RESULTS

Past-year blunt smoking was associated with higher CP severity compared to cannabis users who did not smoke blunts. Days of blunt smoking in the past month also predicted higher CP severity than less frequent blunt use. Those smoking blunts experienced more subjectively felt tolerance and having spent more time obtaining or using cannabis, but were less likely to experience other problems, even at the same level of CP severity.

CONCLUSIONS

These findings suggest smoking blunts might promote the development of problematic cannabis use. Responses to cannabis problems differed by history of blunt smoking, possibly implicating an influence of tobacco on measurement of cannabis use disorders.