Cannabis and tobacco use: where are the boundaries? A qualitative study on cannabis consumption modes among adolescents

Adolescents' Cannabis Knowledge and Risk Perception: A Systematic Review

To systematically review evidence evaluating cannabis-related knowledge and perception of risk in children and adolescents. We systematically searched Medline, PsycINFO, and EMBASE using Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. 133 studies from around the world (including ages 10-18 yrs) met inclusion criteria, with 70% meeting grade 2C quality. Increased knowledge and perception of risk of cannabis frequently correlated with lower levels of current use and intent to use. Studies examining correlations over time generally demonstrated increased adolescent cannabis use and decreased perception of risk. Included prevention-based interventions often enhanced knowledge and/or perception of risk in adolescents exposed to the intervention. Studies exploring outcomes relating to legislative changes for recreational marijuana use demonstrated considerable heterogeneity regarding knowledge and perception of risk whereas studies that focused on medicinal marijuana legislative changes overwhelmingly demonstrated a decrease in perception of risk post legalization. Increased knowledge and perception of risk of cannabis in adolescents often correlate with lower levels of current use and intention to use in the future. Further study and implementation of public health and clinically-oriented strategies that seek to increase knowledge among youth about the potential health harms of cannabis use should continue and be prioritized.

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.

Effects of cannabis smoking on the respiratory system: A state-of-the-art review

The diminished perception of the health risks associated with the consumption of cannabis (marijuana) lead to a progressive increase in its inhalational use in many countries. Cannabis can be smoked through the use of joints, spliffs and blunts, and it can be vaporised with the use of hookah or e-cigarettes. Delta-9 tetrahydrocannabinol (THC) is the main psychoactive component of cannabis smoke but contains numerous other substances. While the recreational use of cannabis smoking has been legalised in several countries, its health consequences have been underestimated and undervalued. The purpose of this review is to critically review the impact of cannabis smoke on the respiratory system. Cannabis smoke irritates the bronchial tree and is strongly associated with symptoms of chronic bronchitis, with histological signs of airway inflammation and remodelling. Altered fungicidal and antibacterial activity of alveolar macrophages, with greater susceptibility to respiratory infections, is also reported. The association with invasive pulmonary aspergillosis in immunocompromised subjects is particularly concerning. Although cannabis has been shown to produce a rapid bronchodilator effect, its chronic use is associated with poor control of asthma by numerous studies. Cannabis smoking also represents a risk factor for the development of bullous lung disease, spontaneous pneumothorax and hypersensitivity pneumonitis. On the other hand, no association with the development of chronic obstructive pulmonary disease was found. Finally, a growing number of studies report an independent association of cannabis smoking with the development of lung cancer. In conclusion, unequivocal evidence established that cannabis smoking is harmful to the respiratory system. Cannabis smoking has a wide range of negative effects on respiratory symptoms in both healthy subjects and patients with chronic lung disease. Given that the most common and cheapest way of assumption of cannabis is by smoking, healthcare providers should be prepared to provide counselling on cannabis smoking cessation and inform the public and decision-makers.

Youth and Young Adult Blunt Use Predicts Progression to Other Nicotine Product Use in the United States

BACKGROUND

Little cigars or cigarillos (LCCs) are frequently modified to smoke cannabis ("blunts") by youth and young adults. This study investigated whether young blunt users who are otherwise nicotine-naïve are more likely to initiate other tobacco products compared to never blunt users.

METHODS AND MATERIALS

Data were from four waves of the Truth Longitudinal Cohort (TLC), a national probability-based sample of youth and young adults (aged 15-24 years) in the United States (Wave 1: January-April 2017; Wave 2: February-May 2018; Wave 3: February-May 2019; Wave 4: September-December 2019). The sample was restricted to nicotine naïve respondents at Wave 1 with possible ever use of blunts (N = 5,284). Logistic regression analyses tested whether ever blunt use at Wave 1 predicted initiation of nicotine products by Wave 4, controlling for established risk factors.

RESULTS

Compared to never-blunt users, ever users of blunts at Wave 1 had significantly higher odds of ever using cigars (OR: 4.74; 95% CI: 1.80-12.47; p = 0.002), e-cigarettes (OR: 4.66; 95% CI: 2.42-8.95; p < 0.001), cigarettes (OR: 3.02; 95% CI: 1.17-7.84, p = 0.023), or hookah (OR: 3.47; 95% CI: 1.07-11.29, p = 0.039) by Wave 4. Cannabis (never blunt) use by Wave 1 predicted ever use of e-cigarettes (OR: 3.45, 95% CI: 2.38-5.02, p < 0.001), cigarettes (OR: 3.81; 95% CI: 2.26-6.43, p < 0.001), or hookah (OR: 2.13; 95% CI: 1.12-4.05, p = 0.021) by Wave 4.

DISCUSSION

Blunts are a point of nicotine initiation that places users at increased risk of progression to cigars, while the same relationship was not found for cannabis alone.

Association between cannabis use and risk of diabetes mellitus type 2: A systematic review and meta-analysis

BACKGROUND

Cannabis consumption exerts multiple effects on metabolism via various pathways, including glucose regulation and insulin secretion. Studies concerning the association between cannabis use and diabetes mellitus type 2 are discrepant.

OBJECTIVE

This study was conducted to evaluate the association between cannabis use and type 2 diabetes mellitus (T2DM).

SEARCH METHODS

We searched PubMed, Scopus, Embase, Proquest, Web of Science, and Cochrane Library with no time, language or study types restriction until July 1, 2022, using various forms of "cannabis" and "diabetes mellitus" search terms.

SELECTION CRITERIA

Randomized control trials, cohort, and case-control studies investigating the relationship between cannabis consumption and diabetes mellitus type 2 were included.

DATA COLLECTION AND ANALYSIS

The Newcastle-Ottawa scale was used to assess the quality of studies. We pooled odds ratio (OR) with 95% confidence interval (CI) using the random-effects model, generic inverse variance method, DerSimonian and Laird approach.

MAIN RESULTS

A meta-analysis of seven studies, containing 11 surveys and 4 cohorts, revealed that the odds of developing T2DM in individuals exposed to cannabis was 0.48 times (95% CI: 0.39 to 0.59) lower than in those without cannabis exposure.

CONCLUSIONS

A protective effect of cannabis consumption on the odds of diabetes mellitus type 2 development has been suggested. Yet given the considerable interstudy heterogeneity, the upward trend of cannabis consumption and cannabis legalization is recommended to conduct studies with higher levels of evidence.

Qualitative Research on Cannabis Use Among Youth: A Methodological Review

Recreational cannabis legalization has encouraged research regarding cannabis use among youth, especially the use of qualitative approaches. In fact, alcohol and drug use journals have recently encouraged qualitative submissions and provided criteria to ensure “high-quality” research. This study provides an objective account of the qualitative approaches used by researchers in this field and discusses implications for future research. A methodological review was conducted for studies published between January 2010 and November 2019. Targeted keyword searches in four research databases returned 1956 unique records. Pairs of reviewers independently screened records against eligibility criteria and charted data for study philosophical positioning, methodology, study aims, sampling, sample, data collection, and data analysis. 23 studies met the inclusion criteria. Several gaps in study quality criteria are observed: less than half of the studies specified the overarching methodology and just two stated philosophical positioning, with some methods unjustified. Implications for future research are discussed.

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.

Who mixes tobacco with cannabis and does mixing relate to nicotine dependence?

BACKGROUND

Cannabis users who mix tobacco with cannabis are exposed to nicotine in the tobacco. We identified characteristics of young adult cannabis users who mix and investigated whether mixing frequency is associated with nicotine dependence (ND).

METHODS

Data were collected in self-report questionnaires in 2017-20 from 788 young adults (44% male; mean (SD) age 30.6 (1.0) years) participating in a longitudinal investigation of the natural course of ND. Using multivariable logistic regression, we assessed whether any of 16 sociodemographic, lifestyle, psychosocial or other characteristics were associated with mixing among 313 past-year cannabis users. We also assessed whether mixing frequency was associated with ND among 289 past-year cannabis users who had ever smoked cigarettes controlling for age, sex, and other sources of nicotine (i.e., number of cigarettes smoked, other tobacco products, second-hand smoke exposure).

RESULTS

Of 788 participants, 40 % (n = 313) reported past-year cannabis use. Of these, 150 (48 %) reported mixing. Younger age, lower education and income, past-year cigarette use, use of other tobacco products and illicit drugs, poor coping skills and gambling were associated with mixing. Number of ICD-10 ND criteria endorsed was associated with mixing < weekly (b(95 % CI) = 0.3(0.02,0.7)) and weekly/daily (0.5(0.1,0.9)) after controlling for other sources of nicotine.

CONCLUSION

Mixing is associated with ND and therefore may threaten tobacco control efforts by rendering quitting cigarette smoking more difficult among smokers who mix tobacco with cannabis. Mixing tobacco with cannabis should be considered as an additional source of nicotine exposure in studies of ND in young people.

Effects of regular cannabis and nicotine use on acute stress responses: chronic nicotine, but not cannabis use, is associated with blunted adrenocortical and cardiovascular responses to stress

RATIONALE

Cannabis is one of the most prevalent substances used by tobacco smokers and, in light of the growing list of states and territories legalizing cannabis, it is expected that co-use of cannabis and nicotine will escalate significantly and will lead to continuing challenges with tobacco use.

OBJECTIVES

This study was conducted to examine the interactive effects of chronic cannabis and nicotine use on adrenocortical, cardiovascular, and psychological responses to stress and to explore sex differences in these effects.

METHODS

Participants (N = 231) included cannabis-only users, nicotine-only users, co-users of both substances, and a non/light-user comparison group. After attending a medical screening session, participants completed a laboratory stress session during which they completed measures of subjective states, cardiovascular responses, and salivary cortisol during baseline (rest) and after exposure to acute stress challenges.

RESULTS

Nicotine use, but not cannabis use, was associated with blunted cortisol and cardiovascular responses to stress across both men and women. Men exhibited larger cortisol responses to stress than women. Co-users had significantly larger stress-related increases in cannabis craving than cannabis-only users. Cannabis users reported smaller increases in anxiety during stress than cannabis non/light-users, and both male nicotine-only users and male cannabis-only users experienced significantly smaller increases in stress than their non/light-user control counterparts.

CONCLUSIONS

This study replicates and extends earlier research on the impacts of sex and nicotine use on stress responses, and it provides novel findings suggesting that when co-used with nicotine, cannabis use may not confer additional alterations to physiological nor subjective responses to stress. Co-use, however, was associated with enhanced stress-related craving for cannabis.

Associations of cannabis product source and subsequent cannabis use among adolescents

BACKGROUND

Cannabis is obtained from a variety retail and illicit sources, with unknown implications for youth cannabis use. This study assessed whether source of obtaining cannabis was associated with future cannabis use among adolescents.

METHODS

High-schoolers (N = 835) completed 3 semiannual surveys, reporting use of 7 cannabis sources (i.e., free, bought from someone, from an online dispensary, with a [valid/invalid] medical card, self-grown, or other; separate dichotomous exposure variables) at wave 1 (n = 621; M[SD] age=17.14[.40]) or wave 2 (n = 622; M[SD] age=17.51[.39]). Past-6-month (yes/no) and number of past-30-day (0-30) non-medical use of any cannabis product, combustible, edible, and vaporized cannabis, blunts, and concentrates (i.e., dabs) were reported at waves 2-3. Random-effect time-lagged repeated-measures regression was used to test longitudinal associations of youth's cannabis source (waves 1-2; time-varying exposure) with cannabis use outcomes 6 months later (waves 2-3).

RESULTS

Most youth (72.1%) received cannabis for free; 50.9% bought cannabis from someone, 15.9% used a valid medical card at a brick-and-mortar dispensary, and 3.9% grew cannabis. Buying cannabis from someone (OR=1.46, 95% CI: 1.07-1.99, p = .02) or using a valid medical card (OR=1.99, 95% CI: 1.20-3.31, p = .008) conferred greater odds of any cannabis product use 6 months later. Buying from someone predicted subsequent past-30-day use frequency (RR=1.25, 95% CI:1.05-1.48, p = .01). Some associations between particular cannabis sources and products were observed.

CONCLUSIONS

Adolescents may access cannabis from several sources. Those who purchase cannabis illicitly from someone or from a brick-and-mortar dispensary using a valid medical card may be at increased risk for more persistent and frequent patterns of non-medical cannabis use.

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

BACKGROUND AND AIMS

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

DESIGN

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

SETTING

Great Britain.

PARTICIPANTS

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

FINDINGS

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

CONCLUSION

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

Co-use and Mixing Tobacco With Cannabis Among Ontario Adults

INTRODUCTION

The legalization of nonmedical cannabis in 2018 may have important implications for tobacco use in Canada. There is a risk of renormalizing tobacco use with co-use of tobacco and cannabis introducing nontobacco users to tobacco. Co-use is the use of both substances by the same individual at the same time or on different occasions, as well as mixed together. This study assessed the prevalence of co-use and mixing of tobacco and cannabis among Ontario adults and the characteristics of the users.

AIMS AND METHODS

Data from the 1996 to 2017 cycles of the Centre for Addiction and Mental Health Monitor (n = 4481) were used to examine trends in prevalence and the proportion of Ontario adults co-using and mixing tobacco and cannabis. Logistic regression was used to study associations between user characteristics and co-use and mixing.

RESULTS

Co-use of cigarettes and cannabis among cannabis users declined from 59.8% in 1996 to 41.7% in 2017. Past-year e-cigarette use was the only predictor of co-use. From 2015 to 2017, 31.1% (95% confidence interval 27.0, 35.9) of Ontario adults who used cannabis reported mixing it with tobacco in the past year. Being white, past-year e-cigarette use, having moderate or high nicotine dependence, and having moderate or high risk for cannabis problems were significant predictors of mixing among cannabis users.

CONCLUSION

Given the well-established negative health effects associated with tobacco use, alongside a growing evidence base for negative health effects of cannabis smoking, co-use and mixing could pose a considerable public health concern in the context of legalization.

IMPLICATIONS

Considerable effort has been expended to reduce tobacco smoking. However, current efforts to reduce tobacco smoking may be diminished since this study found the prevalence of mixing tobacco and cannabis among cannabis users in Ontario to be higher than expected. Mixing tobacco and cannabis may introduce nontobacco smokers to tobacco, exposing them to health risks associated with both cannabis and tobacco smoke. Therefore, there is a need to monitor changes in tobacco use and understanding implications for tobacco control and cessation programs within the changing environment of cannabis legalization in Canada and other jurisdictions.

Adolescent Marijuana Dependence: The Role of Social Bonds and Social Learning Theory

Using the 2017 National Survey of Drug Use and Health (NSDUH) data, this research examines the extent to which social bonds and social learning theory predict adolescent marijuana dependence. Full information maximum likelihood (FIML) for logistic regression analyses were conducted in four models to test the competing theories. The results revealed partial support for both theories, such that adolescents with stronger parental bonds and negative definitions of substance use were less likely to be dependent on marijuana, while adolescents who associated with substance using peers were more likely to be dependent on marijuana. The multi-theoretical model suggested that only the social learning theory concepts of differential association and negative definitions were significant theoretical predictors of adolescent marijuana dependence. Additional analyses revealed that first using marijuana at 14 or 15 years old was also significantly related to adolescent marijuana dependence. Implications for future research and risk prevention programs are discussed.

Tobacco/nicotine and marijuana co-use motives in young adults: Associations with substance use behaviors one year later

Co-administration of tobacco/nicotine and marijuana (e.g., using both products on the same occasion by mixing them in the same delivery device) is a risky, yet common, form of co-use among young adults. Understanding motivations for co-administration co-use, and how these are associated with subsequent use and related problems, is needed to inform policy, prevention, and intervention efforts. We conducted a latent class analysis on 342 young adults with past-year co-administration of tobacco/nicotine and marijuana to determine how emergent classes of 16 co-use motives were associated with use and co-administration co-use of tobacco/nicotine and marijuana one year later. Four classes emerged: (1) a high all class that reported high endorsement of all motives, (2) a high coping class that reported high endorsement of co-use due to coping with stress and bad moods, (3) a high social/physiological reinforcement class that reported low endorsement of coping but high probability of social and relaxation motives and motives to even out effects of each substance, and (4) a low all class that reported low endorsement of all motives. The high all and high coping classes reported greater frequency and quantity of single substance use and co-administration. The high coping class reported more marijuana consequences than the low all class. The high all and high coping classes reported younger age of initiation of each individual substance and co-administration. Considering co-use motives may be useful in identifying those at highest risk for future use and consequences and tailoring interventions to the distinct needs of co-use subgroups. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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.

Interventions to prevent periodontal disease in tobacco-, alcohol-, and drug-dependent individuals

Substance abuse affects more than one sixth of the world's population. More importantly, the nature of the abuse and the type of addictive substances available to individuals is increasing exponentially. All substances with abusive potential impact both the human immuno-inflammatory system and oral microbial communities, and therefore play a critical role in the etiopathogenesis of periodontal diseases. Evidence strongly supports the efficacy of professionally delivered cessation counseling. Dentists, dental therapists, and hygienists are ideally placed to deliver this therapy, and to spearhead efforts to provide behavioral and pharmacologic support for cessation. The purpose of this review is to examine the biologic mechanisms underlying their role in disease causation, to understand the pharmacologic and behavioral basis for their habituation, and to investigate the efficacy of population-based and personalized interventions in prevention of periodontal disease.

Characteristics defining perceived popularity among same-sex and opposite-sex peers

OBJECTIVES

The objective of this study was to compare the characteristics of adolescents and young adults (AYA) who perceive themselves as popular with AYAs who perceive themselves as unpopular vis-á-vis peers from same-sex, opposite-sex, or both.

METHODS

Among a representative sample of in-school 15-24 year-olds students (n=5,179) who completed a self-administrated questionnaire, we measured self-perception of popularity, socio-demographic data, ease to make same/opposite-sex friends, emotional well-being, school variables, substance use, sensation seeking, self-perception of pubertal timing, and aggressive/violent behavior.

RESULTS

Overall, our findings put forth that popularity was associated to easiness of making same/opposite-sex friends, emotional well-being, socio-economical background, sensation seeking behaviors, and alcohol misuse. Differences appeared between males or females.

CONCLUSION

Findings indicate that popularity remains a very important issue among this age group and should be a red flag in clinical assessment. Future research should explore whether feeling of unpopularity can be used as a marker of adolescent well-being and hence help identify those youths who might need help.

Targeting the Endocannabinoid CB1 Receptor to Treat Body Weight Disorders: A Preclinical and Clinical Review of the Therapeutic Potential of Past and Present CB1 Drugs

Obesity rates are increasing worldwide and there is a need for novel therapeutic treatment options. The endocannabinoid system has been linked to homeostatic processes, including metabolism, food intake, and the regulation of body weight. Rimonabant, an inverse agonist for the cannabinoid CB1 receptor, was effective at producing weight loss in obese subjects. However, due to adverse psychiatric side effects, rimonabant was removed from the market. More recently, we reported an inverse relationship between cannabis use and BMI, which has now been duplicated by several groups. As those results may appear contradictory, we review here preclinical and clinical studies that have studied the impact on body weight of various cannabinoid CB1 drugs. Notably, we will review the impact of CB1 inverse agonists, agonists, partial agonists, and neutral antagonists. Those findings clearly point out the cannabinoid CB1 as a potential effective target for the treatment of obesity. Recent preclinical studies suggest that ligands targeting the CB1 may retain the therapeutic potential of rimonabant without the negative side effect profile. Such approaches should be tested in clinical trials for validation.

The Intersection between Spliff Usage, Tobacco Smoking, and Having the First Joint after Waking

Cannabis users who are also tobacco smokers are more likely to exhibit cannabis dependence and psychosocial problems. However, there has been minimal research around various cannabis and tobacco mixing (spliff usage) behaviours and likeliness to smoke the first joint within an hour of waking, known colloquially as wake and bake. The time of first joint and spliff usage may be related as they are associated with the intersection of tobacco and cannabis use. Compared to non-morning cannabis users, morning users reported significantly more cannabis-related problems. Through a survey of US cannabis users, we test the association between various cannabis and spliff use behaviours and likeliness to smoke the first joint within an hour of waking. Compared to those who smoked tobacco and used spliffs, the following spliff use behaviour groups were less likely to have their first joint within 60 minutes after waking: those who smoked tobacco and used spliffs (95%CI: 0.605-0.988); those who never smoked tobacco and did not use spliffs (95%CI: 0.489-0.892); those who never smoked tobacco and used spliffs (95%CI:0.022-0.915). We provided possible explanations for our results and suggested further research to better understand findings, important given expanding US cannabis markets.

Chemical characterization of marijuana blunt smoke by non-targeted chemical analysis

Background: Marijuana blunts, which are tobacco cigar wrappers filled with marijuana, are commonly smoked in the US as a means of cannabis use. The use of marijuana blunts presents toxicity concerns because the smoke contains both marijuana-related and tobacco-related chemicals. Thus, it is important to understand the chemical composition of mainstream smoke (MSS) from marijuana blunts. This study demonstrates the ability to detect and identify chemical constituents exclusively associated with blunt MSS in contrast to tobacco cigar MSS (designated as 'new exposures') through non-targeted chemical analysis.Methods: Samples collected separately from blunt MSS and tobacco cigar MSS were analyzed using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS).Results and Discussion: Two new exposures, which likely represent only a subset of all new exposures, were identified by evaluating the data from thousands of detected signals and then confirming selected compound identities in analyses using authentic chemical standards. The two confirmed new exposures, mellein and 2-phenyl-2-oxazoline, are not cannabinoids and, to the best of our knowledge, have not been previously reported in association with cannabis, tobacco, or smoke of any kind. In addition, we detected and quantified three phenols (2-, 3-, and 4-ethylphenol) in blunt MSS. Given the toxicity of phenols, quantifying the levels of other phenols could be pursued in future research on blunt MSS.Conclusion: This study shows the power and utility of GC × GC-TOFMS as a methodology for non-targeted chemical analysis to identify new chemical exposures in blunt MSS and to provide data to guide further investigations of blunt MSS.

"Hey, I Got to Smoke Some Weed": Favorable Perceptions of Marijuana Use Among Non-College-Educated Young Adult Cigarette Smokers

Introduction: As marijuana legalization progresses in the U.S., this study investigated the perceptions of marijuana use among non-college-educated young adult smokers. Methods: Twelve focus groups were conducted to explore themes related to marijuana and marijuana use among a racially and ethnically diverse sample of 75 young adult smokers (ages 18-29 years) with <4-year college education and <$90,000 annual household income living in the Washington, D.C. metropolitan area. Thematic content analysis was employed to analyze the transcripts. Data collection and analysis took place in 2017 and 2018, respectively. Results: Many participants reported smoking cigarettes to boost and maintain the psychoactive effect ("high") of smoking marijuana; some smoked marijuana to substitute frequent cigarette smoking. Participants generally stated that they believed marijuana smoking was healthier and less addictive than cigarette smoking; many preferred smoking marijuana over cigarettes. Participants also mentioned that cigarette smoking was stigmatized and not socially acceptable but marijuana smoking was "trendy" and "cool." Some reported that they smoked marijuana to cut down on cigarettes, although most were unsuccessful. Racial and ethnic differences in marijuana use were also identified. Discussion: Non-college-educated young adult smokers expressed largely favorable views towards smoking marijuana. Such positive views may lead to prolonged and escalated use of cigarettes and marijuana, resulting in exacerbated adverse health consequence of smoking both products as well as worsened outcomes of cigarette smoking cessation. Evidence-based messages are greatly needed to communicate the harm and risks of marijuana use and marijuana and tobacco co-use among this group.

Technology-Based Contingency Management in the Treatment of Substance-Use Disorders

Contingency management is one of the most efficacious interventions to promote drug abstinence. Contingency management has traditionally been delivered in person so that clinicians could confirm drug abstinence and provide access to additional therapeutic services. Now, new technologies not only permit remote confirmation of abstinence, but also remote delivery of incentives. We discuss several technology-based tools to assess substance use, and new ways to deliver contingency management to promote tobacco, alcohol, and cannabis abstinence. These new tools have the potential to dramatically increase access while maintaining high levels of treatment fidelity. Technology-based methods also allow arranging group contingencies that harness online communities, and they permit targeting multiple health-risk behaviors with a combination of sensor-based technologies. Overall, there are unprecedented opportunities to link technology with contingency management to promote drug abstinence.

Does Starting to Smoke Cigars Trigger Onset of Cannabis Blunt Smoking?

Introduction

Among United States teens during the 1990s, increasing cigar use coincided with increasing use of tobacco cigar shells filled with cannabis, called "blunts." Cigar smokers are more likely to use cannabis, and we hypothesized that starting to smoke cigars might be a probabilistic "trigger" of blunt smoking. We turned to the case-crossover approach to evaluate this hypothesis.

Methods

Within US National Surveys on Drug Use and Health, 2009-2013, we identified a nationally representative sample of newly incident blunt smokers aged 12- to 21-years-old (n = 4868) and compared month-of-onsets for smoking of cigars and blunts. Using the subjects-as-their-own-controls case-crossover design, we specified the first month prior to blunt use as a "hazard interval" and the second month prior to blunt use as a "control interval." We used Mantel-Haenszel (MH) estimators to estimate the matched-pairs odds ratio (OR).

Results

The MH OR estimate was 1.7 (95% CI = 1.3, 2.3), with excess odds of cigar onsets during the hazard interval relative to the control interval. Two alternative control interval specifications yielded congruent estimates (OR = 2.7 and 2.9, respectively).

Conclusions

A short interval right after starting to smoke cigars may be one of increased risk of starting to smoke blunts. We discuss cigar, cigarillo, and "blunt wraps" control approaches that might reduce both tobacco and cannabis-related harms.

Implications

If this evidence is correct, increased market-targeting to promote youthful cigar and cigarillo smoking might be followed by increased rates of blunt smoking in a vulnerable population. As noted by others, enhanced risk of smoking-attributable harms might be a consequence of mixed tobacco-cannabis formulations.

To smoke or not to smoke? A qualitative study among young adults

Smoking is the major preventable cause of disease and premature death in many countries, including France, where approximately 30% of adults are daily smokers. About 60% of them want to quit, however, long-term smoking cessation rates are low, particularly among individuals with low socio-economic position. The aim of this study is to examine whether motivations for smoking cessation among young adults differ across socio-economic groups.

3 focus groups of smokers and former smokers aged 22–40 years were constituted and conducted in November 2014 in Paris. Data from the focus groups were analyzed thematically and in a cross-cutting manner. Our study shows the existence of social “communities” of smokers, in occupational and festive contexts. In addition, new forms of resistance to public health messages are observed (“neutralization”), particularly among smokers with low socioeconomic position. Finally, stress is often cited as a source of unsuccessful smoking cessation or smoking relapse. Tobacco smoking is a social behavior and is associated with symbolic as well as relational benefits, particularly among smokers who have low socioeconomic position. To be effective, interventions aiming to decrease smoking levels in the population should aim to create group dynamics encouraging smokers to quit and address the physical as well as the psychological consequences of smoking withdrawal.

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Young adults who smoke congregate in social “communities”, at work or at parties.

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Persons with low socioeconomic status “neutralize” the risks related to smoking.

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Smoking is a social behavior, associated with symbolic and relational benefits.

Alcohol, tobacco, and marijuana consumption is associated with increased odds of same-day substance co- and tri-use

BACKGROUND

Little is known about event-level patterns of marijuana co- or tri-use with alcohol and tobacco. Thus, the study goal was to examine patterns of same-day alcohol, cigarette, and marijuana co- and tri-use at the individual level in non-treatment-seeking alcohol users.

METHODS

Participants (N = 551) completed an in-person interview for alcohol, cigarette, and marijuana use over the previous 30 days, and the event-level substance use patterns of n = 179 participants who reported using each of these substances at least once per month were analyzed.

RESULTS

The use of alcohol, marijuana, or cigarettes independently increased the probability of subsequent, simultaneous co-use of one of the two remaining substances. The co-use of alcohol with cigarettes and marijuana with cigarettes produced generally additive effects on the odds of same day tri-use of marijuana and alcohol, respectively. Conversely, the co-use of alcohol and marijuana produced sub-additive effects on likelihood of cigarette use. Sex moderated several of the observed patterns of co- and tri-use: the relationship between alcohol or cigarette use predicting marijuana co-use was stronger in men, whereas the observed additive relationships between drug co-use leading to tri-use was stronger in women.

CONCLUSIONS

The presented results may aid in the understanding of how simultaneous co-use of marijuana with alcohol and/or tobacco relates to the etiology, maintenance, and treatment of comorbid and trimorbid substance use disorder. Replication and extension of the results in treatment seeking populations using more fine-grained analysis approaches, e.g. ecological momentary assessment, is needed.

Evidence From Qualitative Studies of Youth About the Impacts of Tobacco Control Policy on Young People in Europe: A Systematic Review

INTRODUCTION

A range of tobacco control policies endeavor to prevent smoking uptake in young people, yet relatively little is known about how such interventions impact young people's engagement with smoking. We reviewed existing qualitative evidence on young people and smoking in Europe to assess whether, in what ways and why young people comply with, adapt to, resist, or circumvent tobacco control policies in their respective countries.

METHODS

We undertook a systematic review of academic literature presenting qualitative research from Europe on smoking and young people (11-18 years), published from 2000 to 2015. Bibliographic searches (PubMed, PsycInfo, SSCI) produced 1357 records, from which 43 relevant articles were assessed for quality and 39 included in the review.

RESULTS

Most studies were from the United Kingdom (27), with a small number (one or two each) from other European countries (Denmark, Sweden, Switzerland, Belgium, Cyprus, Greece, Hungary, Ireland, and Spain). Only 16 articles (11 from United Kingdom) provided any evidence about the impacts of tobacco control policies on young people's smoking. These focused on smoke-free legislation (four), age of sale laws (four), plain packaging (three), and black market tobacco (one).

CONCLUSIONS

There is very little qualitative evidence exploring the impacts of tobacco control on youth smoking in Europe. To develop more effective smoking prevention policies that take account of local political, social, and cultural contexts, more qualitative research from a wider range of European countries is needed to understand how tobacco control impacts on young people's social worlds and smoking behaviors.

IMPLICATIONS

Smoking is the leading cause of premature mortality in Europe. However, there is little qualitative evidence exploring the impact of tobacco control policies on young people in Europe. Most comes from the United Kingdom and focuses on a narrow range of policies. Thus, we have a limited understanding of how and in what ways tobacco control policies reach young people, their engagement with these, and how local context affects their impact. More qualitative research is needed, from a wider range of countries and on a broader range of tobacco control policies, to strengthen the evidence-base for reducing youth smoking.

Cannabis use among a nationally representative cross-sectional sample of smokers and non-smokers in the Netherlands: results from the 2015 ITC Netherlands Gold Magic Survey

OBJECTIVES

Existing evidence shows that co-occurring use of tobacco and cannabis is widespread. Patterns of co-use of tobacco and cannabis may change as more jurisdictions legalise medicinal and/or recreational cannabis sales. This analysis examined predictors of current cannabis use and characterised methods of consumption among smokers and non-smokers in a context where cannabis use is legal.

SETTING

The 2015 International Tobacco Control Netherlands-Gold Magic Survey conducted between July and August 2015.

PARTICIPANTS

Participants (n=1599; 1003 current smokers, 283 former smokers and 390 non-smokers) were asked to report their current (past 30-day) use of cigarettes and cannabis. Cigarette smokers reported whether they primarily used factory made of roll-your-own cigarettes. Those who reported any cannabis use in the last 30 days were asked about forms of cannabis used. X2and logistic regression analyses were used to assess relationships among combustible tobacco and cannabis use.

RESULTS

Past 30-day cannabis use was somewhat higher among current tobacco (or cigarette) smokers (n=57/987=5.8%) than among former or never smokers (n=10/288=3.5% and n=6/316=1.9%, respectively). Joints were the most commonly used form of cannabis use for both current cigarette smokers (96.9%) and non-smokers (76.5%). Among those who smoked cannabis joints, 95% current smokers and 67% of non-smokers reported that they 'always' roll cannabis with tobacco.

CONCLUSIONS

In this Netherlands-based sample, most cannabis was reported to be consumed via smoking joints, most often mixed with tobacco. This behaviour may present unique health concerns for non-cigarette smoking cannabis users, since tobacco use could lead to nicotine dependence. Moreover, many non-cigarette smoking cannabis users appear to be misclassified as to their actual tobacco/nicotine exposure.

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.

Patterns and Correlates of Tobacco and Cannabis co-use by Tobacco Product Type: Findings from the Virginia Youth Survey

BACKGROUND

Cannabis use is more common among tobacco users than nonusers, and co-use (i.e., use of both substances individually) may be increasing. Better understanding of patterns and correlates of co-use is needed. The current study aimed to compare rates and correlates of tobacco and cannabis co-use by tobacco product among youth.

METHODS

High school students who completed the 2013 Virginia Youth Survey and reported past 30-day tobacco use (cigarette, smokeless tobacco, cigar) were included (n = 1390). Prevalence of past 30-day tobacco-only and cannabis co-use was calculated. Demographic, tobacco, and other substance use characteristics were compared by co-use status. Multivariate logistic regression models examined correlates of co-use overall and by tobacco product.

RESULTS

Over half of tobacco users were co-users. Poly-tobacco use, particularly combusted tobacco, was more prevalent among co-users. Past 30-day alcohol use and lifetime other illegal drug use/prescription drug misuse were common correlates of co-use. Black Non-Hispanic (NH) race/ethnicity was associated with co-use when restricted to cigarette users. "Other" race/ethnicity was associated with co-use in the overall model and when restricted to cigar users. Past 30-day cigarette smoking was associated with co-use in all models except among cigar smoking co-users. Conclusions/Importance: Rates and correlates of tobacco and cannabis co-use were not uniform and differed by tobacco product type. Tobacco and cannabis co-users may be at greater risk for negative health effects associated with inhaled tobacco and other risky substance use. The efficacy of prevention efforts may be improved if risk factors associated with product-specific co-use are considered.

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.

Adolescents and young adults' perceptions of electronic cigarettes as a gateway to smoking: a qualitative study in Switzerland

Electronic cigarettes (ECs) acting as a gateway to smoking traditional cigarettes (TCs) is a growing public health concern of EC use among youths. To gather the opinions and perceptions of adolescents and young adults (AYAs) on whether and how EC can act as a gateway to smoking TC among youths. A qualitative method included 42 AYAs. Participants identified a significant risk of EC acting as a gateway to TC use, several factors contributing to this phenomenon such as a facilitated transition to smoking or its perception as a harmless toy. Participants considered an even greater gateway threat regarding very young adolescents. A minority did not identify the gateway risk and some believed that it was nicotine-dependent. This potential gateway effect brought forth several recommendations: health professionals should screen adolescents (even very young ones) for EC use and inform consumers of the potential gateway effect; this possible effect should be acknowledged to end the harmless perception many might have; there is an urge for better preventive and regulatory policies directed at protecting adolescents and children who never smoked and support those who have quit.

Emotional and Psychosocial Factors Associated With Drunkenness and the Use of Tobacco and Cannabis in Adolescence: Independent or Interactive Effects?

BACKGROUND

Although previous research has examined emotional and psychosocial factors associated with substance use, there is a paucity of studies examining both at the same time, and insufficient attention has been paid to how these factors may interact.

OBJECTIVES

The aim of this study was to simultaneously examine the contributions from emotional (emotional control and depression) and psychosocial (peers' conventional behavior, peers' substance use and parent-child relationships) factors to drunkenness and the use of tobacco and cannabis in adolescence.

METHODS

Sample consisted of 1,752 adolescents aged 15 to 16 years who had participated in the 2014 edition of the WHO Health Behaviour in School-aged Children survey in Spain. Data were collected by means of anonymous online questionnaires, and hierarchical multiple regression models (with sex and age as controls and including interactions among the examined predictors) were used for statistical analysis.

RESULTS

Emotional and psychosocial factors showed significant interactive effects on substance use. Emotional control, which tended to buffer the effects of potential risk factors, and peers' substance use were consistent predictors of substance use. In contrast, the role of other factors depended on the substance under study, with depression and peers' conventional behavior being part of interactive terms for tobacco use and cannabis use only, and the quality of parent-child relationships being absent from the final model on cannabis use. Conclusions/Importance: Exploring interactions and potential substance-specific effects is fundamental to reach a better understanding of how emotional and psychosocial factors work in concert relative to substance use in adolescence.

Marijuana and tobacco co-administration in blunts, spliffs, and mulled cigarettes: A systematic literature review

BACKGROUND

Blunts and spliffs/mulled cigarettes combine marijuana and tobacco for co-administration (use at the same time, in the same product). Co-administration of marijuana and tobacco presents significant potential for nicotine exposure, and may lead to exclusive tobacco use patterns, nicotine addiction, and compounded health effects. No review articles have summarized the number and nature of studies published on these co-administered products.

METHODS

Keywords "(blunt* OR spliff OR mull* OR joint) AND (tobacco OR smok* OR cigarette) AND (cannabis OR marijuana OR hashish)" were searched in the published literature. A total of 220 articles were considered for inclusion, 49 were reviewed by two independent qualitative coders, and 45 were included in this review.

RESULTS

Of the 45 articles, most (n=27) of studies were observational or descriptive; ten were qualitative, five employed causal designs, and three were mixed methods. A majority of the studies assessed blunts; only 11 studies assessed spliffs/mulled cigarettes. Many studies focused on sub-populations of youth, males, and African Americans. Use of co-administered marijuana and tobacco products was associated with several indicators of problematic use patterns, including perceptions of less risk, dependence on nicotine and marijuana, and greater subjective effects related to marijuana.

CONCLUSIONS

Literature on marijuana and tobacco co-administration comes largely from qualitative and observational/descriptive studies. In addition to continued surveillance, experimental research that directly assesses the smoking patterns of co-administered marijuana and tobacco products as compared with to those of marijuana and tobacco only products is needed to determine the potential long-term health consequences of using blunts, spliffs, or other co-administered products.

The association between cannabis use and motivation and intentions to quit tobacco within a sample of Australian socioeconomically disadvantaged smokers

This study aimed to (i) describe concurrent and simultaneous tobacco and cannabis use and (ii) investigate the association between cannabis use and motivation and intentions to quit tobacco in a sample of socioeconomically disadvantaged smokers. A cross-sectional survey was conducted in 2013 and 2014 with current tobacco smokers receiving aid from two community service organizations in New South Wales, Australia. At least weekly cannabis use for the month prior to survey, motivation to quit tobacco and intentions to quit tobacco were measured in 369 participants (77% consent rate). Regressions were carried out to investigate associations between weekly cannabis use and motivation and intentions to quit tobacco.Concurrent tobacco and cannabis use was reported by 19% (n = 71) of the sample and of these users, 100% reported simultaneous use. Although regular cannabis use was significantly associated with lower motivation to quit tobacco, it was not significantly associated with intentions to quit tobacco in the next 30 days. Concurrent cannabis use is common in disadvantaged smokers and may play a role in decreased motivation to quit tobacco; however, it does not appear to be associated with intentions to quit in a sample of disadvantaged smokers.

Substance Use among a Sample of Healthcare Workers in Kenya: A Cross-Sectional Study

This study describes reported substance use among Kenyan healthcare workers (HCWs), as it has implications for HCWs' health, productivity, and their ability and likelihood to intervene on substance use. The Alcohol Smoking and Substance Involvement Screening Test (ASSIST) was administered to a convenience sample of HCWs (n = 206) in 15 health facilities. Reported lifetime use was 35.8% for alcohol, 23.5% for tobacco, 9.3% for cannabis, 9.3% for sedatives, 8.8% for cocaine, 6.4% for amphetamine-like stimulants, 5.4% for hallucinogens, 3.4% for inhalants, and 3.9% for opioids. Tobacco and alcohol were also the two most commonly used substances in the previous three months. Male gender and other substance use were key predictors of both lifetime and previous three months' use rates. HCWs' substance use rates appear generally higher than those seen in the general population in Kenya, though lower than those reported among many HCWs globally. This pattern of use has implications for both HCWs and their clients.

Comorbid Cannabis and Tobacco Use in Adolescents and Adults

The prevalence of comorbid cannabis and tobacco use has been increasing among adolescents and adults and has been shown to be associated with a range of changes or deficits in physical, psychological and behavioral outcomes. Moreover, comorbid use has been shown to have a differential effect on the structure and function of the brain, especially as it relates to the reward circuitry and learning and memory. This interaction might be mediated by the involvement of the endocannabinoid system and alterations in dopamine signaling in regions associated with reward and cognitive functioning. While current findings demonstrate a differential effect of comorbid use on neurobiological and behavioral correlates compared with single substance use, additional studies are needed controlling for potential psychiatric comorbidities, age of onset of use and use of other substances. Understanding the neurobiological mechanisms associated with comorbid cannabis and tobacco use will be important in developing successful treatment outcomes in the future.

Trends in the co-occurrence of tobacco and cannabis use in 15-year-olds from 2002 to 2010 in 28 countries of Europe and North America

BACKGROUND

Cannabis and tobacco use frequently co-occur. Adolescents who consume both substances experience more respiratory distress and psychosocial problems and are less likely to stop compared with those who use either tobacco or cannabis alone. This study examined time trends in tobacco and cannabis use among 15-year-olds in Europe and North America between 2002 and 2010.

METHODS

Twenty-eight countries were included and merged into six regions based on their welfare systems. Adolescents (n = 142 796) were divided in four 'user groups': 'no-users', 'tobacco and cannabis users', 'tobacco-only users' and 'cannabis-only users'. Prevalence rates are reported by study-wave and region. Logistic regressions with study wave as independent variable were used to study trends in the user groups and regions. Interaction effects between time and gender were considered.

RESULTS

Overall, tobacco use, and concurrent tobacco and cannabis use decreased by 3 and 3.7%, respectively, but prevalence rates varied by region. Only in North America, an interaction effect between time and gender was found in tobacco and cannabis users.

CONCLUSIONS

Although this study demonstrates a decrease in tobacco and cannabis use in most regions, it also shows that the use of both substances is related. Therefore, studying the co-occurring use of tobacco and cannabis is necessary.

Assessing the overlap between tobacco and marijuana: Trends in patterns of co-use of tobacco and marijuana in adults from 2003-2012

BACKGROUND

As marijuana legalization and acceptability increase in the U.S., it is important to understand the potential impact on tobacco use. Accordingly, we assessed prevalence, correlates, and ten-year trends in co-use of marijuana and tobacco among U.S. adults.

METHODS

Data came from 378,459 adults participating in the 2003-2012 National Survey on Drug Use and Health, an annual, cross-sectional, household survey. Data from 2011-2012 were used to compute the most recent prevalence of past 30-day marijuana and tobacco use (co-use). Data from 2003-2012 were used to compute demographic correlates of co-use, overall trends in co-use, and trends by age, race, and sex. We also assessed trends in tobacco use among marijuana users and marijuana use among tobacco users.

RESULTS

From 2011 to 2012, 5.2% of participants were past month co-marijuana and tobacco users, 24.0% were tobacco-only users, and 2.3% were marijuana-only users. From 2003 to 2012, prevalence of co-use increased overall (p<.0001), and among males and females (p<.001, p<.05), those ages 26-34 (p<.001) and 50+years (p<.0001), and Whites (p<.01), Blacks (p<.05), and Hispanics (p<.01); there were no changes among adults 18-25 years. Tobacco use among marijuana users decreased between 2003 and 2012 (from 74.3% to 69.6%, p<.0001), while marijuana use increased among tobacco users (from 14.2% to 17.8, p<.0001).

CONCLUSIONS

Co-use of tobacco and marijuana increased from 2003-2012, with marijuana use increasing among past-month tobacco users and tobacco use declining among past-month marijuana users. Improved surveillance of co-use is needed as marijuana legalization policies expand and become more integrated in communities.

Reasons to use e-cigarettes and associations with other substances among adolescents in Switzerland

BACKGROUND

The objectives of this research were to describe the main reason(s) why adolescents use electronic cigarettes, to assess how e-cigarette experimenters and users differ based on personal characteristics, and to determine whether its use is associated with the use of other substances among a representative sample of youths in Switzerland.

METHODS

A representative sample of 621 youths (308 females) was divided into never users (n=353), experimenters (Only once, n=120) and users (Several times, n=148) of e-cigarettes. Groups were compared on socio-demographic data and current smoking, alcohol misuse and cannabis use. Reasons for e-cigarette use were compared between experimenters and users. A multinomial regression was performed using never users as the reference category.

RESULTS

Forty-three percent had ever tried e-cigarettes, and the main reason was curiosity. Compared to never users, experimenters were more likely to be out of school (Relative Risk Ratio [RRR]: 2.68) and to misuse alcohol (RRR: 2.08), while users were more likely to be male (RRR: 2.75), to be vocational students (RRR: 2.30) or out of school (RRR: 3.48) and to use any of the studied substances (tobacco, RRR: 5.26; alcohol misuse, RRR: 2.71; cannabis use, RRR: 30.2).

CONCLUSIONS

Although often still part of adolescent experimentation, e-cigarettes are becoming increasingly popular among adolescents and they should become part of health providers' standard substance use screening. As health providers (and especially paediatricians) do not seem to have high levels of knowledge and, consequently, little comfort in discussing e-cigarettes, training in this domain should be available to them.

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.

Effectiveness of different Web-based interventions to prepare co-smokers of cigarettes and cannabis for double cessation: a three-arm randomized controlled trial

BACKGROUND

The relationship between tobacco and cannabis use is strong. When co-smokers try to quit only one substance, this relationship often leads to a substitution effect, that is, the increased use of the remaining substance. Stopping the use of both substances simultaneously is therefore a reasonable strategy, but co-smokers rarely report feeling ready for simultaneous cessation. Thus, the question of how co-smokers can be motivated to attempt a simultaneous cessation has arisen. To reach as many co-smokers as possible, we developed brief Web-based interventions aimed at enhancing the readiness to simultaneously quit tobacco and cannabis use.

OBJECTIVE

Our aim was to analyze the efficacy of three different Web-based interventions designed to enhance co-smokers' readiness to stop tobacco and cannabis use simultaneously.

METHODS

Within a randomized trial, three brief Web-based and fully automated interventions were compared. The first intervention combined the assessment of cigarette dependence and problematic cannabis use with personalized, normative feedback. The second intervention was based on principles of motivational interviewing. As an active psychoeducational control group, the third intervention merely provided information on tobacco, cannabis, and the co-use of the two substances. The readiness to quit tobacco and cannabis simultaneously was measured before and after the intervention (both online) and 8 weeks later (online or over the phone). Secondary outcomes included the frequency of cigarette and cannabis use, as measured at baseline and after 8 weeks.

RESULTS

A total of 2467 website users were assessed for eligibility based on their self-reported tobacco and cannabis co-use, and 325 participants were ultimately randomized and analyzed. For the post-intervention assessment, generalized estimating equations revealed a significant increase in the readiness to quit tobacco and cannabis in the total sample (B=.33, 95% CI 0.10-0.56, P=.006). However, this effect was not significant for the comparison between baseline and the 8-week follow-up assessment (P=.69). Furthermore, no differential effects between the interventions were found, nor were any significant intervention or time effects found on the frequency of tobacco or cannabis use.

CONCLUSIONS

In the new field of dual interventions for co-smokers of tobacco and cannabis, Web-based interventions can increase the short-term readiness to quit tobacco and cannabis simultaneously. The studied personalized techniques were no more effective than was psychoeducation. The analyzed brief interventions did not change the secondary outcomes, that is the frequency of tobacco and cannabis use.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number (ISRCTN): 56326375; http://www.isrctn.com/ISRCTN56326375 (Archived by WebCite at http://www.webcitation.org/6UUWBh8u0).

Frequent marijuana use is associated with greater nicotine addiction in adolescent smokers

BACKGROUND

Marijuana and tobacco are the substances used most commonly by adolescents and co-occurring use is common. Use of one substance may potentiate the addictive properties of the other. The current study examined the severity of nicotine addiction among teen smokers as a function of co-occurring marijuana use.

METHODS

Participants were 165 adolescents (13-17 years old) who reported smoking at least 1 cigarette per day (CPD) in the past 30 days. General linear models examined the association of marijuana use with multiple measures of nicotine addiction including the Modified Fagerström Tolerance Questionnaire (mFTQ), Hooked on Nicotine Checklist (HONC), ICD-10, and the Nicotine Dependence Syndrome Scale (NDSS).

RESULTS

The adolescent sample (mean age=16.1 years, SD=0.95) averaged 3.0 CPD (SD=3.0) for 1.98 years (SD=1.5). Most (79.5%) also smoked marijuana in the past 30 days. In models controlling for age, daily smoking status, and years of tobacco smoking, frequency of marijuana use accounted for 25-44% of the variance for all four measures of adolescent nicotine dependence.

CONCLUSIONS

Marijuana use was associated with greater reported nicotine addiction among adolescent smokers. The findings suggest a role of marijuana in potentiating nicotine addiction and underscore the need for treatments that address both smoked substances.

The Influences of Health Beliefs and Identity on Adolescent Marijuana and Tobacco Co-Use

Among youth, the co-use of marijuana and tobacco is highly prevalent, yet a considerable gap remains in the drug-prevention literature pertaining to such co-use. In particular, the prevention field lacks research exploring how adolescents understand the health implications of smoking these two substances in combination. In this article, we draw on qualitative interviews with adolescents from three communities in British Columbia, Canada, and describe the health beliefs and social identities that they associated with smoking marijuana and tobacco. We argue that smoking prevention and cessation initiatives targeting adolescents must address both marijuana and tobacco. Such initiatives must also be designed to identify and address how adolescents frame the potential health harms associated with smoking these substances.

The co-use of tobacco and cannabis among adolescents over a 30-year period

BACKGROUND

This study explores the patterns of use and co-use of tobacco and cannabis among Ontario adolescents over 3 decades and if characteristics of co-users and single substance users have changed.

METHODS

Co-use trends for 1981-2011 were analyzed using the Centre for Addiction and Mental Health Ontario Student Drug Use and Health Survey, which includes 38,331 students in grades 7, 9, and 11. A co-user was defined as someone reporting daily tobacco and/or cannabis use in the past month. Trends over time (by gender and academic performance) were analyzed with logistic regression.

RESULTS

The prevalence of tobacco-only use, cannabis-only use, and co-use fluctuated considerably. During 1981-1993, there were more tobacco-only users than co-users and cannabis-only users; since 1993 the prevalence of tobacco use has decreased dramatically. Co-use prevalence peaked at 12% (95% confidence interval: 9, 15) in 1999, when prevalence of overall use of both substances was highest. In 2011, 92% of tobacco users also used cannabis, up from 16% in 1991.

CONCLUSIONS

In 2011 nearly all students who smoke tobacco daily also use cannabis. Non-regular use of either substance is highest now compared with the past 3 decades. Contemporary tobacco and cannabis co-users are significantly different than past users. Youth prevention programs should understand the changing context of cannabis and tobacco among youth.

Smoking mull: a grounded theory model on the dynamics of combined tobacco and cannabis use among adult men

ISSUE ADDRESSED

Australians' use of cannabis has been increasing. Over a third of Australians (35.4%) have used cannabis at some time in their lives and 10.3% are recent users. Almost two-thirds of cannabis users combine cannabis with tobacco. The aim of this study was to understand the process of mulling - smoking tobacco and cannabis together - using a grounded theory approach.

METHODS

Twenty-one in-depth semistructured interviews were conducted with men aged 25-34 and living on the North Coast of New South Wales. Interviews explored participants' smoking practices, histories and cessation attempts.

RESULTS

A model describing mulling behaviour and the dynamics of smoking cannabis and tobacco was developed. It provides an explanatory framework that demonstrates the flexibility in smoking practices, including substance substitution - participants changed the type of cannabis they smoked, the amount of tobacco they mixed with it and the devices they used to smoke according to the situations they were in and the effects sought.

CONCLUSION

Understanding these dynamic smoking practices and the importance of situations and effects, as well as the specific role of tobacco in mulling, may allow health workers to design more relevant and appropriate interventions. SO WHAT? Combining tobacco with cannabis is the most common way of smoking cannabis in Australia. However, tobacco cessation programmes rarely address cannabis use. Further research to develop evidence-based approaches for mull use would improve cessation outcomes.

Psychiatric, psychosocial, and physical health correlates of co-occurring cannabis use disorders and nicotine dependence

BACKGROUND

Several gaps in the literature on individuals with co-occurring cannabis and tobacco use exist, including the extent of psychiatric, psychosocial, and physical health problems. We examine these gaps in an epidemiological study, the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), of a large, nationally representative sample.

METHODS

The sample was drawn from Wave 2 NESARC respondents (N=34,653). Adults with current cannabis use disorders and nicotine dependence (CUD+ND) (n=74), CUD only (n=100), and ND only (n=3424) were compared on psychiatric disorders, psychosocial correlates (e.g., binge drinking; partner violence), and physical health correlates (e.g., medical conditions).

RESULTS

Relative to those with CUD only, respondents with CUD+ND were significantly more likely to meet criteria for bipolar disorder, Clusters A and B personality disorders, and narcissistic personality disorder, and reported engaging in a significantly higher number of antisocial behaviors. Relative to those with ND only, respondents with CUD+ND were significantly more likely to meet criteria for bipolar disorder, anxiety disorders, and paranoid, schizotypal, narcissistic, and borderline personality disorders; were significantly more likely to report driving under the influence of alcohol and being involved in partner violence; and reported engaging in a significantly higher number of antisocial behaviors. CUD+ND was not associated with physical health correlates.

CONCLUSIONS

Poor treatment outcomes for adults with co-occurring cannabis use disorders and nicotine dependence may be explained in part by differences in psychiatric and psychosocial problems.