Co-use of cannabis, tobacco, and alcohol during adolescence: policy and regulatory implications

Blunt smoking during emerging adulthood: Characterizing transitions in cannabis and cigar co-use among a diverse cohort in Texas

OBJECTIVE

To characterize and compare transitions in blunt smoking behaviors among a diverse cohort of youth and young adults observed between Spring 2019 and Fall 2021.

METHODS

We analyzed n = 14,152 observations (i.e., completed surveys) provided by n = 2,610 youth and young adults over six (6) waves from Spring 2019 to Fall 2021 via the Texas Adolescent Tobacco and Marketing Surveillance (TATAMS) system. Participants were recruited in age-cohorts, reflecting 16.5 years (0.5), 18.5 years (0.6), and 20.1 years (0.8) of age at baseline. We applied a three-state Markov model to estimate blunt initiation (never → ever), onset (never → current), continuation (ever → current), and discontinuation (current → ever). First, we compared transitions in blunt smoking by race/ethnicity, with non-Hispanic (NH) Whites as the referent. Second, we stratified the Markov models by race/ethnicity to identify common and unique predictors of blunt transitions, including sex, age, alcohol use, depression, anxiety, and tobacco cigar smoking.

RESULTS

At baseline, 73% of participants had never smoked blunts, 15.3% had ever smoked blunts s, and 11.7% currently smoked blunts. NHB (HR: 2.15; 95% CI: 1.21-3.84) and Hispanic (HR: 1.72; 95% CI: 1.08-2.72) participants had significantly greater risk of blunt smoking initiation, relative to NHWs. Similarly, NHBs had great risk for continuation (HR: 1.65; 95% CI: 1.16-2.34) and lower risk of discontinuation (HR: 0.57; 95% CI: 0.42-0.77), relative to NHWs. Alcohol use predicted greater risk for onset among NHW (HR: 5.22; 95% CI: 1.40-19.45), NHB (HR: 3.14; 95% CI: 1.32-7.46), and Hispanic (HR: 2.99; 95% CI: 1.80-4.97) participants.

CONCLUSIONS

Blunt smoking initiation was most common among NHB and Hispanic youth and young adults while risk for sustained blunt smoking was higher in NHB youth and young adults. Research and interventions should investigate the link between alcohol use and elevated blunt smoking among young people.

Longitudinal examination of alcohol demand and alcohol-related reinforcement as predictors of heavy drinking and adverse alcohol consequences in emerging adults

BACKGROUND AND AIMS

Behavioral economic theory predicts that high alcohol demand and high proportionate alcohol-related reinforcement are important determinants of risky alcohol use in emerging adults, but the majority of research to date has been cross-sectional in nature. The present study investigated prospective and dynamic relationships between alcohol demand and proportionate alcohol-related reinforcement in relation to heavy drinking days and alcohol problems.

DESIGN

Longitudinal cohort with assessments every 4 months for 20 months.

SETTING

Ontario, Canada.

PARTICIPANTS

Emerging adults reporting regular heavy episodic drinking (n = 636, Mage = 21.44; 55.8% female).

MEASUREMENTS

Heavy drinking days (HDD; Daily Drinking Questionnaire), alcohol problems (Brief Young Adult Alcohol Consequences Questionnaire), alcohol demand (Alcohol Purchase Task) and proportionate alcohol-related reinforcement (Activity Level Questionnaire).

FINDINGS

Linear mixed effects models revealed that behavioral economic indicators and alcohol-related outcomes significantly decreased over the study, consistent with 'aging out' of risky alcohol use. Random intercept cross-lagged panel models revealed significant between-person relationships, such that higher alcohol demand and alcohol-related reinforcement were positively associated with HDD and alcohol problems (random intercepts = 0.187-0.534, Ps < 0.01). Moreover, alcohol demand indicators (particularly the rate of change in elasticity of the demand curve, as measured by α, and the maximum expenditure, Omax) and proportionate alcohol-related reinforcement significantly forecasted changes in HDD at all time points (|βs| = 0.063-0.103, Ps < 0.05) in cross-lagged relationships, with bidirectional associations noted for the rate of change in elasticity (βs = -0.085 to -0.104, Ps < 0.01). Proportionate alcohol-related reinforcement also significantly forecasted changes in alcohol problems at all time points (βs = 0.072-0.112, Ps < 0.01).

CONCLUSIONS

Multiple behavioral economic indicators (demand elasticity, maximum expenditure and reinforcement ratio) forecast changes in heavy episodic drinking and alcohol problems over the course of emerging adulthood. These results further implicate alcohol demand and proportionate alcohol-related reinforcement as etiologically and developmentally important mechanisms in alcohol use trajectories.

Perspectives regarding cannabis use: Results from a qualitative study of individuals engaged in substance use treatment in Georgia and Connecticut

Objective

Cannabis use is increasingly pervasive throughout the U.S. People in treatment for substance use disorders (SUD) may be especially at-risk of harm due to this changing context of cannabis in the U.S. This study's objective was to qualitatively describe experiences and beliefs around cannabis among people who had entered treatment for any SUD in the past 12-months.

Methods

From May to November of 2022, we conducted 27 semi-structured interviews (n=16 in Georgia, n=11 in Connecticut) with individuals in treatment for SUD in Georgia and Connecticut. Interviews were recorded, transcribed, and thematically analyzed using an emergent approach.

Results

All participants had used cannabis in the past. Four themes emerged from the interviews. Participants: (1) perceived cannabis as an important contributor to non-cannabis substance use initiation in adolescence; (2) viewed cannabis as a substance with the potential to improve health with fewer side effects than prescription medications; (3) expressed conflicting opinions regarding cannabis as a trigger or tool to manage cravings for other non-cannabis substances currently; and 4) described concerns related to negative legal, social service, and treatment-related consequences as well as negative peer perception relating to the use of cannabis.

Conclusion

Although participants described cannabis's important role as an initiatory drug in adolescence and young adulthood, many felt that cannabis was a medicinal substance for a range of health challenges. These findings suggest SUD treatment clinicians should address medicinal beliefs related to cannabis among their clients and emphasizes the need for research on cannabis use and SUD treatment outcomes.

Emotion Recognition and Self-Reported Emotion Processing in Alcohol and Cannabis Co-Using Young Adults

Alcohol and cannabis use are each associated with impairments in emotion recognition accuracy, which may promote interpersonal problems. It is unclear if emotion recognition or self-reported emotion processing differs between young adult alcohol and cannabis co-users (ACCs) and healthy controls (HCs). This study examined whether ACCs and HCs differed in their emotion recognition across two different behavioral tasks with static or dynamic faces and determined if there were differences in self-reported socio-emotional processing and alexithymia. 22 ACCs (mean age = 21.27 ± 1.75) and 25 HCs (mean age = 21.48 ± 2.68), matched on age, sex, and IQ, completed the Metrisquare Emotion Recognition Task and CANTAB Emotion Recognition Task. The ACCs and HCs were compared on task accuracy and self-reported measures, including the Social Emotional Questionnaire (SEQ) and the Perth Alexithymia Questionnaire (PAQ). No significant main effects of the Group variable or the Emotion-Group interaction variable were present for either task. The ACCs had lower SEQ (p = 0.014) and higher PAQ (p = 0.024) scores relative to the HCs, indicating greater difficulties in socio-emotional processing and identifying one's own emotions, respectively. Understanding the behavioral correlates of the self-reported difficulties in emotion processing reported by ACCs is needed to develop interventions to reduce these symptoms and promote healthy socio-emotional functioning in this population.

VC, Niez RA, Delos Santos FE, Magramo MM, Yap-Tan AR, Sy FAR, Kasimieh O. Predictors and Prevalence of Alcohol and Cannabis Co-use Among Filipino Adolescents: Evidence From a School-based Student Health Survey

OBJECTIVES

This study explored the prevalence and predictors of alcohol and cannabis co-use among 9263 Filipino adolescents, using data from the 2019 Global School-based Student Health Survey (GSHS).

METHODS

We conducted a cross-sectional secondary analysis of the GSHS, targeting adolescents aged 13-17 years and excluding cases with incomplete data on alcohol and cannabis use. Our analysis employed the bivariate chi-square test of independence and multivariable logistic regression using Stata version 18 to identify significant predictors of co-use, with a p-value threshold set at 0.05.

RESULTS

The weighted prevalence of co-users was 4.2% (95% confidence interval [CI], 3.4 to 5.3). Significant predictors included male sex (adjusted odds ratio [aOR], 4.50; 95% CI, 3.31 to 6.10; p<0.001) and being in a lower academic year, specifically grade 7 (aOR, 4.08; 95% CI, 2.39 to 6.99; p<0.001) and grade 8 (aOR, 2.20; 95% CI, 1.30 to 3.72; p=0.003). Poor sleep quality was also a significant predictor (aOR, 1.77; 95% CI, 1.29 to 2.44; p<0.001), as was a history of attempted suicide (aOR, 5.31; 95% CI, 4.00 to 7.06; p<0.001). Physical inactivity was associated with lower odds of co-use (aOR, 0.45; 95% CI, 0.33 to 0.62; p<0.001). Additionally, non-attendance of physical education classes (aOR, 1.48; 95% CI, 1.06 to 2.05; p=0.021), infrequent unapproved parental checks (aOR, 1.37; 95% CI, 1.04 to 1.80; p=0.024), and lower parental awareness of free-time activities (aOR, 0.63; 95% CI, 0.45 to 0.87; p=0.005) were associated with higher odds of co-use. Factors not significantly linked to co-use included age group, being in grade 9, always feeling lonely, having no close friends, being bullied outside school, and whether a parent or guardian understood the adolescent's worries.

CONCLUSIONS

The findings highlight the critical need for comprehensive interventions in the Philippines, addressing not only physical inactivity and parental monitoring but also focusing on sex, academic grade, participation in physical education classes, sleep quality, and suicide attempt history, to effectively reduce alcohol and cannabis co-use among adolescents.

Emerging adult perceptions of higher-risk cannabis consumption behaviours

BACKGROUND

Emerging adults have the highest cannabis consumption rates in Canada and are among the most vulnerable to cannabis-related harms. Since certain cannabis consumption behaviours carry greater risks of harm, the Lower-Risk Cannabis Use Guidelines (LRCUG) provide harm reduction strategies. To address a critical gap in the literature, the current study examined emerging adults' awareness of the guidelines and perceptions of higher-risk cannabis consumption behaviours identified within the LRCUG.

METHODS

Emerging adults (N = 653) between the ages of 18-25 years were recruited from across Canada. Participants were presented with five vignettes depicting a character's cannabis consumption behaviours. Each vignette focused on a unique aspect of the character's consumption (frequency, polysubstance use, family history of mental illness, method of consumption, and potency). Participants were randomly assigned to one of three conditions within each of the five vignettes that were altered to capture varying levels of risk (e.g. weekly, almost daily, or daily consumption). Following each vignette, participants were asked to respond to four items relating to overall risk of harm, cognitive health, physical health, and mental health.

RESULTS

Participants perceived: (1) frequent consumption to be associated with greater risks than less frequent consumption; (2) simultaneous consumption of cannabis and tobacco as being associated with higher risk of harm, yet no difference between simultaneous consumption of cannabis and alcohol or cannabis consumption alone; (3) consuming cannabis with a family history of psychosis or substance use disorder as being associated with greater overall risk than consumption with no family history; (4) smoking and vaping cannabis as associated with more risk than ingesting edibles; and (5) higher-potency THC-dominant strains as being associated with more risk than lower-potency CBD-dominant strains, yet no difference between the two higher-potency THC-dominant strains.

CONCLUSIONS

While emerging adults seemed to appreciate the risks associated with some cannabis consumption behaviours, they had difficulty identifying appropriate levels of harm of other higher-risk behaviours. Through an improved understanding of emerging adult perceptions, effective education campaigns should be designed to improve the awareness of cannabis risks and encourage the uptake of harm reduction awareness and strategies.

Alcohol, cannabis, and nicotine use have distinct associations with COVID-19 pandemic-related experiences: An exploratory Bayesian network analysis across two timepoints

BACKGROUND

Substance use trends during the COVID-19 pandemic have been extensively documented. However, relatively less is known about the associations between pandemic-related experiences and substance use.

METHOD

In July 2020 and January 2021, a broad U.S. community sample (N = 1123) completed online assessments of past month alcohol, cannabis, and nicotine use and the 92-item Epidemic-Pandemic Impacts Inventory, a multidimensional measure of pandemic-related experiences. We examined links between substance use frequency, and pandemic impact on emotional, physical, economic, and other key domains, using Bayesian Gaussian graphical networks in which edges represent significant associations between variables (referred to as nodes). Bayesian network comparison approaches were used to assess the evidence of stability (or change) in associations between the two timepoints.

RESULTS

After controlling for all other nodes in the network, multiple significant edges connecting substance use nodes and pandemic-experience nodes were observed across both time points, including positive- (r range 0.07-0.23) and negative-associations (r range -0.25 to -0.11). Alcohol was positively associated with social and emotional pandemic impacts and negatively associated with economic impacts. Nicotine was positively associated with economic impact and negatively associated with social impact. Cannabis was positively associated with emotional impact. Network comparison suggested these associations were stable across the two timepoints.

CONCLUSION

Alcohol, nicotine, and cannabis use had unique associations to a few specific domains among a broad range of pandemic-related experiences. Given the cross-sectional nature of these analyses with observational data, further investigation is needed to identify potential causal links.

The Role of Cigarillo Flavor in the Co-Use of Cigarillos and Cannabis among Young Adults

Background: Research suggests flavor facilitates cigarillo use, but it is unknown if flavor impacts patterns of co-use of cigarillos and cannabis ("co-use"), which is common among young adult smokers. This study's aim was to determine the role of the cigarillo flavor in co-use among young adults. Methods: Data were collected (2020-2021) in a cross-sectional online survey administered to young adults who smoked ≥2 cigarillos/week (N = 361), recruited from 15 urban areas in the United States. A structural equation model was used to assess the relationship between flavored cigarillo use and past 30-day cannabis use (flavored cigarillo perceived appeal and harm as parallel mediators), including several social-contextual covariates (e.g., flavor and cannabis policies). Results: Most participants reported usually using flavored cigarillos (81.8%) and cannabis use in the past 30 days ("co-use") (64.1%). Flavored cigarillo use was not directly associated with co-use (p = 0.90). Perceived cigarillo harm (β = 0.18, 95% CI = 0.06, 0.29), number of tobacco users in the household (β = 0.22, 95% CI = 0.10, 0.33), and past 30-day use of other tobacco products (β = 0.23, 95% CI = 0.15, 0.32) were significantly positively associated with co-use. Living in an area with a ban on flavored cigarillos was significantly negatively associated with co-use (β = -0.12, 95% CI = -0.21, -0.02). Conclusions: Use of flavored cigarillos was not associated with co-use; however, exposure to a flavored cigarillo ban was negatively associated with co-use. Cigar product flavor bans may reduce co-use among young adults or have a neutral impact. Further research is needed to explore the interaction between tobacco and cannabis policy and use of these products.

Associations between Alcohol-Free Sources of Reinforcement and the Frequency of Alcohol and Cannabis Co-Use among College Freshmen

Co-use of alcohol and cannabis is common among young adults in the United States. A behavioral economics framework indicates that greater engagement in substance-free sources of reinforcement may be protective against co-use frequency. The current study tested the association between proportionate alcohol-free reinforcement and the frequency of co-use among college freshmen. Participants (N = 86) were freshmen who enrolled in a freshman orientation course and completed surveys at the beginning of the semester. Past month alcohol use, cannabis use, and reinforcement from alcohol-free and alcohol-involved activities were assessed. A zero-inflated Poisson regression was used to test the association between proportionate alcohol-free reinforcement and days of co-use. The results indicated that proportionate alcohol-free reinforcement was negatively associated with co-use days in the count model when controlling for alcohol use days and gender as covariates (β: -3.28, p = 0.016). Proportionate alcohol-free reinforcement did not significantly differentiate individuals who did not engage in co-use in the zero-inflated model (β: -1.68, p = 0.497). The study suggested that greater proportionate alcohol-free reinforcement may be associated with lower engagement in the co-use of alcohol and cannabis among young adults. Increasing engagement in alcohol-free sources of reinforcement may be considered a target for co-use prevention or harm reduction efforts.

Old Dog, New Tricks: A Review of Identifying and Addressing Youth Cannabis Vaping in the Pediatric Clinical Setting

Cannabis vaping has emerged as a predominant mode of cannabis use among United States (US) adolescents and young adults (AYA) primarily due to the popularity of modifiable designs of vaping devices coupled with changes in cannabis policies and increased availability of cannabinoid products. New methods for cannabis vaping by e-liquid/oil vaping, dry plant vaping, and cannabis concentrate vaping (ie, dabbing) have had high uptake among American youth with unclear long-term health implications. Issues with contamination, mislabeling, and expansion of the vaped cannabis market to include not only delta-9-tetrahydrocannabinol (delta-9-THC) and cannabidiol (CBD) but also delta-9-THC analogs (eg, delta-8 and delta-10) sold as hemp-derived "legal highs" further complicated this healthcare space. Recent research suggests that cannabis/THC vaping carries distinct and overlapping risks when compared to cannabis smoking and may be associated with greater risk for acute lung injuries, seizures, and acute psychiatric symptoms. Primary care clinicians providing care for AYA are in an ideal position to identify cannabis misuse and intervene early to address cannabis vaping. To improve public health outcomes, a need exists for pediatric clinicians to be educated about different ways/methods that youth are vaping cannabinoid products and associated risks related to cannabinoid vaping. Further, pediatric clinicians need to be trained how to effectively screen for and discuss cannabis vaping with their youth patients. In the current article, we present a clinically focused review of cannabis vaping among young people with 3 main aims to: (1) identify and describe the cannabis vaping products commonly used by American youth; (2) review the health correlates of youth cannabis vaping; and (3) discuss clinical considerations related to identifying and treating youth who vape cannabis.

Prevalence and sociodemographic factors associated with polysubstance use: analysis of a population-based survey in Jamaica

BACKGROUND

In Latin America and the Caribbean, there is a dearth of research exploring polysubstance use. This study aims to determine the prevalence, varying combinations and associated sociodemographic characteristics of polysubstance use in Jamaica.

METHODS

This study involved a secondary data analysis of the Jamaica National Drug Prevalence Survey 2016 dataset where 4,623 participants between the age of 12 and 65 years from each household were randomly selected as respondents. Statistical analysis was performed to determine the prevalence and the sociodemographic correlates of polysubstance use among Jamaicans.

RESULTS

19.6% of respondents used two or more drugs in their lifetime. Of this amount 68.7% reported past year use and 61.9% reported past month use. Bivariate analyses reported polysubstance use was statistically significantly higher amongst males (U = 54,579, p = 0.000), those living in rural areas (U = 91,892, p = 0.003), non-Christian (U = 89,514, p = 0.014), and married persons (U = 74,672, p = 0.000). Past month polysubstance use was statistically significantly higher among employed persons than unemployed persons were (U = 81,342, p = 0.001). Surprisingly, there was a lack of significant differences between education level, household income and past month concurrent polysubstance use (p = 0.609; p = 0.115 respectively). Logistic regression model indicated males were 3.076 times more likely than females to report past month polysubstance use than females. Also, when compared to those 55-65 years old, participants 35-54 years were 2.922 times more likely and those 18-34 years were 4.914 times more likely to report past month polysubstance use. Additionally, those living in rural areas were 1.508 times more likely than participants living in urban areas to report past month polysubstance use. As it relates to occupational status, when compared to armed forces, skilled workers were 4.328 times more likely and unskilled workers were 7.146 times more likely to report past month polysubstance use.

CONCLUSIONS

One in five Jamaicans identified as polysubstance users, predominated by marijuana as the most common factor amongst the polysubstance combinations examined, signalling the need for early marijuana interventions.

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

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

Societal Costs and Outcomes of Medical and Recreational Marijuana Policies in the United States: A Systematic Review

Significant support exists in the United States for legalization of marijuana/cannabis. As of 2021, 36 states and four territories approved the legalization of medical cannabis via medical marijuana laws (MMLs), and 15 states and District of Columbia (DC) have adopted recreational marijuana laws (RMLs). We performed structured and systematic searches of articles published from 2010 through September 2021. We assess the literature pertaining to adolescent marijuana use; opioid use and opioid-related outcomes; alcohol use; tobacco use; illicit and other drug use; marijuana growing and cultivation; employment, earnings, and other workplace outcomes; academic achievement and performance; criminal activity; perceived harmfulness; traffic and road safety; and suicide and sexual activity. Overall, 113 articles satisfied our inclusion criteria. Except for opioids, studies on use of other substances (illicit drugs, tobacco, and alcohol) were inconclusive. MMLs and RMLs do not generate negative outcomes in the labor market, lead to greater criminal activity, or reduce traffic and road safety.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Changes in alcohol use by cannabis use status among adolescents and young adults in the United States: Emerging evidence for both substitution and complementarity

BACKGROUND

The majority of adolescents and young adults (AYA) who use cannabis also use alcohol. Although cannabis use is increasing in the United States (US), it is not known whether the increase contributes to either increased co-use of alcohol and cannabis (e.g., complementarity) or replacement of alcohol with cannabis (e.g., substitution). The current study estimated the prevalence of alcohol use by cannabis use status among US AYA ages 12 to 25 in 2018 and trends in alcohol use by cannabis use status from 2002 to 2018.

METHODS

Data were drawn from the 2002 to 2018 National Survey on Drug Use and Health public use data files. The analytic sample included AYA ages 12 to 25 (2018 sample, n = 26,924; total combined sample 2002 to 2018, n = 576,053). Linear and logistic regression models were used to estimate past-month alcohol use, daily alcohol use, and average quantity of alcohol consumed among AYA with and without past-month cannabis use from 2002 to 2018.

RESULTS

In 2018, any alcohol use and daily alcohol use were significantly more common among AYA who used cannabis use than those who did not use cannabis. Overall, any alcohol use, daily alcohol use, and average drinks per day declined from 2002 to 2018 among AYA irrespective of recent cannabis use. However, the decline in any alcohol use, daily alcohol use, and average alcohol drinks per day was more rapid among AYA who used cannabis (daily and nondaily) than those who did not use cannabis. The rate of decline in average alcohol drinks per day was also higher among AYA with daily compared to nondaily cannabis use.

CONCLUSIONS

Even with declines in alcohol use over time, drinking is much more common among AYA who report cannabis than those without recent cannabis use, which is consistent with complementarity. Yet, because the decline in alcohol use has been more rapid among AYA who use cannabis, there is also evidence of substitution. Thus, the current data on alcohol and cannabis use are consistent with both complementarity and substitution. However, these relationships may change as cannabis legalization expands over time.

The Relationship between Cannabis and Tobacco Co-administration and Long-Term Patterns of Cannabis Use in Young Adults Who Use Stimulants: A Prospective Population-Based Study

BACKGROUND

Co-administering cannabis with tobacco (i.e. co-administration of the substances mixed together) is a common practice among cannabis users, but the consequences of this practice are not well understood. This study examines the relationship between co-administering cannabis with tobacco and the long-term frequency of cannabis use in a young adult population group with high rates of cannabis and tobacco use.

METHODS

The data are from an Australian prospective population-based study of young adults who recurrently used amphetamine-type stimulants (ATS). The mean age of participants was 20.8 years at baseline, sample size (n = 277), and 47% were female. We examined the frequency and quantity of cannabis consumption over 4 ½ years. Negative binomial regression analysis was conducted to examine the frequency of cannabis use at 12-month follow-up and at 4 ½ years, with co-administering practices as the predictor.

RESULTS

At every time interval, participants who always co-administered their cannabis with tobacco used cannabis on more days in the last month than those who only sometimes co-administered, rarely co-administered, or never co-administered these substances (p < 0.001). Sometimes co-administering cannabis with tobacco at baseline predicted more frequent cannabis use at 12-month follow-up (adjusted IRR: 2.25, 95% CI: 1.05, 4.78), independently of the baseline frequency of cannabis use. However, levels of co-administering cannabis with tobacco at 12-month follow-up (rarely, sometimes, and always) did not predict high levels of cannabis use at 4 ½ years follow-up after adjusting for cannabis use at 12-month follow-up.

CONCLUSIONS

Among people who use ATS and cannabis, frequent cannabis use may be a marker of the practice of co-administering cannabis with tobacco, and can be used to target tobacco cessation interventions in these populations.

Alcohol and Cannabis Use Disorder Symptom Severity, Conduct Disorder, and Callous-Unemotional Traits and Impairment in Expression Recognition

Background: Alcohol and cannabis are commonly used by adolescents in the United States. Both alcohol use disorder (AUD) and cannabis use disorder (CUD) have been associated with reduced emotion expression recognition ability. However, this work has primarily occurred in adults and has not considered neuro-cognitive risk factors associated with conduct problems that commonly co-occur with, and precede, substance use. Yet, conduct problems are also associated with reduced emotion expression recognition ability. The current study investigated the extent of negative association between AUD and CUD symptom severity and expression recognition ability over and above any association of expression recognition ability with conduct problems [conduct disorder (CD) diagnostic status]. Methods: In this study, 152 youths aged 12.5-18 years (56 female; 60 diagnosed with CD) completed a rapid presentation morphed intensity facial expression task to investigate the association between relative severity of AUD/CUD and expression recognition ability. Results: Cannabis use disorder identification test (CUDIT) scores were negatively associated with recognition accuracy for higher intensity (particularly sad and fearful) expressions while CD diagnostic status was independently negatively associated with recognition of sad expressions. Alcohol use disorder identification test (AUDIT) scores were not significantly associated with expression recognition ability. Conclusions: These data indicate that relative severity of CUD and CD diagnostic status are statistically independently associated with reduced expression recognition ability. On the basis of these data, we speculate that increased cannabis use during adolescence may exacerbate a neuro-cognitive risk factor for the emergence of aggression and antisocial behavior.

Qualitative examination of simultaneous alcohol and cannabis use reasons, evaluations, and patterns among heavy drinking young adults

Use of alcohol and cannabis together so their effects overlap (simultaneous use) is common among college students and associated with numerous negative consequences. The aim of this study was to gain insight into college students' recent simultaneous use events in order to inform future studies (i.e., generate hypotheses, inform measures/assessments of simultaneous use, and identify factors influencing simultaneous use). Qualitative interviews of simultaneous use experiences among heavy drinking college students (n = 38) were conducted to better understand reasons for simultaneous use, evaluations of simultaneous use events, and patterns of substance use during simultaneous use events. Findings indicated that students' reasons for simultaneous use included traditional four-factor motive types (i.e., social, conformity, enhancement, and coping), cross-fading motives, harm reduction motives (e.g., to drink less), and reactive/situational reasons (e.g., because it was offered/available). There was variability in participants' subjective evaluations of how positive versus negative simultaneous use events were and how this compared to single-substance events. Evaluation of simultaneous use events depended on patterns of use, external and internal context, and consequences experienced. Additionally, patterns of simultaneous use including order of substances, timing of using each substance, and quantities of substances used were highly variable across participants. Notably, participants endorsed patterns of use they perceived to reduce negative consequences during simultaneous use events. Further research on reasons for simultaneous use and patterns of use may help identify simultaneous use occasions that result in greater risk; identification of high-risk simultaneous use occasions and evaluation of these occasions can then help inform targeted interventions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Early and Late Adolescent Factors that Predict Co-use of Cannabis with Alcohol and Tobacco in Young Adulthood

The changing legal landscape of cannabis in the USA has coincided with changes in how cannabis is used, including its co-use with other substances. This study analyzed 10 years of data from a diverse cohort of youth (N = 2429; 54% Hispanic, 16% Asian, 16% white, 3% black, 10% multiracial) to examine predictors in early and late adolescence of co-use of alcohol with cannabis (AC) and tobacco with cannabis (TC) at age 21. Two forms of co-use were examined: concurrent (use of both substances in past month) and sequential (use of one substance right after the other). Analyses focused on four predictor domains: individual (e.g., resistance self-efficacy), peer (e.g., time spent around peers who use), family (e.g., sibling use), and neighborhood (i.e., perceived alcohol and drug problems in neighborhood). For each co-use combination (AC or TC), we estimated parallel process piecewise latent growth models in a structural equation modeling framework using Mplus v8. The final AC and TC co-use models included all predictor variables from the four domains. Increases in positive expectancies and time spent around peers who use AC, as well as steeper decreases in resistance self-efficacy, were all related to a greater likelihood of AC co-use in young adulthood. Increases in sibling TC use and time spent around peers who use TC, as well as steeper decreases in resistance self-efficacy, were all related to a greater likelihood of TC co-use in young adulthood. Overall, findings highlight the importance of addressing peer influence in prevention programming during both early and late adolescence.

Perceived reward from using cigarettes with alcohol or cannabis and concurrent use: A smartphone-based daily diary study

INTRODUCTION

Smoking cigarettes under the influence of alcohol or cannabis is associated with perceived pleasure. However, it is unclear whether these changes in perceived reward impact the extent of concurrent use of cigarettes with alcohol or cannabis. The current study investigated if self-reported changes in perceived reward from concurrent use of cigarettes with alcohol or cannabis are related to the extent of concurrent use in real-world contexts using a smartphone-based Ecological Momentary Assessment (EMA) study.

METHODS

The sample included 126 diverse young adult smokers in the San Francisco Bay Area who reported current alcohol or cannabis use at baseline (M = 22.8 years, 50.8% male, 40.5% sexual minority, 39.7% Non-Hispanic White). Participants completed an online baseline survey and 30 days of smartphone-based daily EMA surveys of cigarette, alcohol, and cannabis use. The baseline assessed self-reported changes in perceived pleasure of smoking cigarettes while using alcohol or cannabis separately. EMA surveys included detailed questions about concurrent use (i.e., the extent of smoking while using another substance) covering the previous day. A total of 2,600 daily assessments were analyzed using mixed models.

RESULTS

Higher perceived pleasure from smoking cigarettes while drinking alcohol or using cannabis at baseline were both associated with a greater extent of concurrent use of cigarettes with alcohol (b = 0.140; SE = 0.066; t = 2.1; p = .035) and cannabis (b = 0.136; SE = 0.058; t = 2.4; p = .019) on a given day.

CONCLUSIONS

Results suggest that perceived reward from concurrently using cigarettes with alcohol or cannabis is associated with the extent of concurrent use. Findings can inform tailored smoking cessation interventions.

Impact of state-level cannabis legalization on poly use of alcohol and cannabis in the United States, 2004-2017

BACKGROUND

Cannabis policy has shifted toward legalization in many parts of the United States (US). While attention has been focused on whether legalization will lead to changes in cannabis use, it is conceivable that legalization will also affect use of substances that individuals frequently use with cannabis. This study assessed whether cannabis legalization impacted the prevalence of poly use of cannabis and alcohol from 2004 to 2017 and estimated the prevalence of cannabis and alcohol poly use in 2017.

METHODS

Public and restricted-use data from the US 2004-2017 National Survey on Drug Use and Health were analyzed. Data on past-month cannabis and alcohol use were assessed each year. Cannabis legalization was determined by the presence or absence of medical marijuana laws (MML) and recreational marijuana laws (RML) in each state. Difference-in-difference approach was used to estimate the association of MML and RML on cannabis and alcohol use overall and by sociodemographic subgroups (e.g., age, income, education).

RESULTS

Between 2004 and 2017, poly use of cannabis and alcohol increased while alcohol-only use decreased. MML were associated with increases in poly use only among adults over age 50 and among those with higher annual incomes and higher education, while RML were associated with increases in poly use broadly among adults across sociodemographic groups.

CONCLUSIONS

Legalization of cannabis was associated with increases in cannabis-alcohol poly use in the US. RML were associated with increases across demographics, while the impact of MML was more limited to certain sociodemographic groups.

Does cannabis complement or substitute alcohol consumption? A systematic review of human and animal studies

BACKGROUND

Whether alcohol and cannabis complement or substitute each other has been studied for over two decades. In the changing cannabis policy landscape, debates are moving rapidly and spill-over effects on other substances are of interest.

AIMS

update and extend a previous systematic review, by: (a) identifying new human behavioural studies reporting on substitution and/or complementarity of alcohol and cannabis, and (b) additionally including animal studies.

METHODS

We replicated the search strategy of an earlier systematic review, supplemented with a new search for animal studies. Search results were crossed checked against the earlier review and reference lists were hand searched. Findings were synthesised using a narrative synthesis.

RESULTS

Sixty-five articles were included (64 in humans, one in animals). We synthesised findings into categories: patterns of use, substitution practices, economic relationship, substance use disorders, policy evaluation, others and animal studies. Overall, 30 studies found evidence for substitution, 17 for complementarity, 14 did not find evidence for either, and four found evidence for both.

CONCLUSIONS

Overall, the evidence regarding complementarity and substitution of cannabis and alcohol is mixed. We identified stronger support for substitution than complementarity, though evidence indicates different effects in different populations and to some extent across different study designs. The quality of studies varied and few were designed specifically to address this question. Dedicated high-quality research is warranted.

Co-occurring Use of Cannabis and Tobacco and the Presence of Acute Respiratory Symptoms among Young Adult Light and Intermittent Smokers

BACKGROUND

Cannabis use and intermittent smoking are becoming increasingly prevalent among young adults. Thus, identifying health consequences of co-occurring use of these substances represents an emerging research priority. Purpose/Objectives: This study evaluated the relationship between tobacco/cannabis co-use and acute symptoms of respiratory illness among young adult intermittent smokers. We hypothesized that tobacco/cannabis co-use would be more strongly associated with respiratory symptoms relative to use of neither or one product. Methods: A secondary analysis of a three-year observational study was conducted. Non-daily smokers (n = 563) aged 18-24 were recruited via social media and completed electronic surveys at baseline and annually for two years, producing three total assessments. Past-two-week use of tobacco and cannabis was measured at each assessment, as was severity of six acute respiratory symptoms. The respiratory measure was dichotomized to indicate the presence or absence of symptoms. Results: Tobacco/cannabis co-use decreased from 54.8% at baseline to 43.4% at year two (p < .001). Mean respiratory symptoms also declined significantly over time (ps < .05). At each timepoint, co-use was more strongly associated with presence of respiratory symptoms than the use of neither product (aORs = 2.73-4.39, ps ≤ .013). Co-users were also 38%-183% more likely to endorse the presence of respiratory symptoms than single product users at each timepoint (aORs = 1.38-2.83, ps = .023-.212). Conclusions/Importance: Although co-occurring use of tobacco and cannabis by young adults may represent experimental use of multiple substances, it may also promote or exacerbate acute symptoms of respiratory illness. Further exploration with more granular patterns of co-use and across different routes of administration is warranted.

Alcohol Use Disorder Increases Risk of Traumatic Brain Injury-Related Hospitalization: Insights From 3.8 Million Children and Adolescent Inpatients

Objectives

We conducted a cross-sectional study to identify the demographic predictors of traumatic brain injury (TBI), and the risk of association of psychiatric comorbidities including alcohol use disorder (AUD) and TBI-related hospitalizations in the children and adolescent population.

Methods

We included 3,825,523 children and adolescent inpatients (age 8-18 years) using the nationwide inpatient sample (NIS) database (2010-2014), and 61,948 inpatients had a primary diagnosis of TBI. These inpatients were grouped by comorbid AUD (N = 2,644). Multivariable logistic regression model adjusted for demographics, and psychiatric comorbidities including other substance use disorders (SUDs) was used to evaluate the odds ratio (OR) of AUD as a risk factor for TBI-related hospitalization.

Results

The majority of the TBI inpatients were adolescents (12-18 years, 82.2%), males (71.2%), and whites (59.2%). Males had three times higher odds (95% CI 3.14-3.26) for TBI-related hospitalization compared to females. Among psychiatric comorbidities, mood (4.1%) and anxiety (2.2%) disorders were prevalent in TBI inpatients, and were not associated with increased odds for TBI-related hospitalization. Among SUD, alcohol and tobacco use (4.4% each), and cannabis use (3.5%) were prevalent, and among all substances, AUD was associated with higher odds (OR 3.5, 95% CI 3.35-3.67) of TBI-related hospitalization. These patients with TBI and comorbid AUD also had higher odds for abusing stimulants (OR 5.11, 95% CI 3.85-6.77), cannabis (OR 4.69, 95% CI 4.12-5.34), and tobacco (OR 3.77, 95% CI 3.34-4.27).

Conclusion

AUD is an independent risk factor for TBI-related hospitalization with an increased risk of 50% in the children and adolescent population compared to non-alcohol users. TBI inpatients with AUD are prevalent in white, and male adolescents. These at-risk populations are also at higher risk of comorbid mood disorders and increased substance use including stimulants, cannabis, and tobacco.

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.

Quantitative biochemical screening for marijuana use and concordance with tobacco use in urban adolescents

BACKGROUND

Assessing the prevalence and level of exposure (dose) of tobacco and marijuana use is important in studies of harm from use of these substances. We used biochemical analysis of urine to quantitatively assess exposure to nicotine and delta 9-tetrahydrocannabinol (THC) in adolescents receiving medical care in a public hospital METHODS: Participants were 686 adolescents between 12 and 21 years old seen at Zuckerberg San Francisco General Hospital between 2012 and 2014. Urine samples were assayed using high sensitivity liquid chromatographic assays for cotinine, a major metabolite of nicotine, and 11-nor-9-carboxy-delta 9-THC (THC-COOH), a major metabolite of THC. A commonly used immunoassay screen for THC-COOH was also performed.

RESULTS

The THC-COOH immunoassay substantially underestimated THC exposure, as measured with the high sensitivity assay. THC use was detected in 25% of participants, with higher prevalence with increasing age and in non-Hispanic blacks. Active tobacco smokers had an 80% prevalence of THC use (odds ratio for cigarette smoking predicting THC use 13.2). Urine cotinine and THC-COOH were significantly correlated (r = 0.60).

CONCLUSIONS

The use of a high sensitivity chromatographic urine assay provides a much more complete picture of adolescent tobacco use compared to a commonly used immunoassay. The immunoassay provides high specificity but moderate sensitivity. We confirm high concordance of tobacco and marijuana use and the high predictive value of cigarette smoking in predicting marijuana use, and provide novel data on the quantitative correlation between level of exposure to nicotine and THC. Quantitative screening of nicotine and THC exposure may enhance our understanding of addiction and harm from single and dual product use.

Trends of poly-substance use among Canadian youth

INTRODUCTION

Poly-substance use, increasingly understood as a behaviour with uniquely adverse consequences, is on the rise among Canadian youth. High levels of e-cigarette vaping and the recent legalization of recreational cannabis use may result in an acceleration of this trend. The aim of this work was to characterise changes in youth poly-substance use over time, generate baseline data for future investigations, and highlight areas of interest for policy action.

METHODS

Descriptive statistics and regression models explored patterns and trends in concurrent use of multiple substances (alcohol, cigarettes, cannabis, and e-cigarettes) among Canadian high school students taking part in the COMPASS prospective cohort study during Y2 (2013/2014; n = 45,298), Y3 (2014/2015, n = 42,355), Y4 (2015/2016; n = 40,436), Y5 (2016/2017; n = 37,060), and Y6 (2017/2018; n = 34,879).

RESULTS

Poly-substance use increased significantly over time, with over 50% of students who used substance reporting past-year use of multiple substances by 2017/2018. Male and Indigenous students were significantly more likely to report poly-substance use than female and white students respectively. E-cigarette vaping doubled from Y5 to Y6 and was included in all increasingly prevalent substance use combinations.

CONCLUSIONS

Youth poly-substance use, rising since 2012/2013, saw a particularly steep increase after 2016/2017. Differential effects were observed for distinct demographic subpopulations, indicating tailored interventions may be required. E-cigarette vaping surged in parallel with the observed increase, suggesting a key role for this behaviour in shaping youth poly-substance use.

Substance Use in Adolescents: Latest Trends

Adolescent substance use is an ever-changing topic that can be difficult to stay on top of its many components. Recent data show encouraging declines in the use of some substances such as cigarettes, alcohol, and opioids, although they are still prevalent in the adolescent population. Newer issues such as vaping and the legalization of marijuana bring up new challenges in discussing substance use with young patients. Perceptions of risk and evolving campaigns aimed at young people make these two topics particularly important to address with adolescents. This article reviews the statistics regarding the most commonly used substances in the United States, and some important ways that we can reach out to the adolescent population that is so vulnerable to the harms of substance use. [Pediatr Ann. 2019;48(11):e418-e422.].

Cannabis-induced altered states of consciousness are associated with specific dynamic brain connectivity states

BACKGROUND

Cannabis, and specifically one of its active compounds delta-9-tetrahydrocannabinol in recreational doses, has a variety of effects on cognitive processes. Most studies employ resting state functional magnetic resonance imaging techniques to assess the stationary effects of cannabis and to-date one report addressed the impact of delta-9-tetrahydrocannabinol on the dynamics of whole-brain functional connectivity.

METHODS

Using a repeated-measures, within-subjects design, 19 healthy occasional cannabis users (smoking cannabis ⩽2 per week) underwent resting state functional magnetic resonance imaging scans. Each subject underwent two scans: in the intoxicated condition, shortly after smoking a cannabis cigarette, and in the non-intoxicated condition, with the subject being free from cannabinoids for at least one week before. All sessions were randomized and performed in a four-week interval. Data were analysed employing a standard independent component analysis approach with subsequent tracking of the functional connectivity dynamics, which allowed six connectivity clusters (states) to be individuated.

RESULTS

Using standard independent component analysis in resting state functional connectivity, a group effect was found in the precuneus connectivity. With a dynamic independent component analysis approach, we identified one transient connectivity state, characterized by high connectivity within and between auditory and somato-motor cortices and anti-correlation with subcortical structures and the cerebellum that was only found during the intoxicated condition. Behavioural measures of the subjective experiences of changed perceptions and tetrahydrocannabinol plasma levels during intoxication were associated with this state.

CONCLUSIONS

With the help of the dynamic connectivity approach we could elucidate neural correlates of the transitory perceptual changes induced by delta-9-tetrahydrocannabinol in cannabis users, and possibly identify a biomarker of cannabis intoxication.

Types of cannabis and tobacco/nicotine co-use and associated outcomes in young adulthood

Cannabis and tobacco/nicotine use are highly comorbid. Given expanding access to cannabis through legalization for recreational use, it is important to understand how patterns of cannabis and tobacco/nicotine co-use are associated with young adult outcomes. A predominantly California-based sample of 2,429 young adults (mean age = 20.7) completed an online survey. Based on past-year reports of cannabis and tobacco/nicotine use, we defined 5 mutually exclusive groups: (a) single-product use; (b) concurrent use only (using both products, but only on separate occasions); (c) sequential use only (using both products on the same occasion, one right after the other, but not mixing them together); (d) coadministration only (using both products on the same occasion by mixing them in the same delivery device); and (e) both sequential use and coadministration. We examined group differences in use patterns, dependence, consequences of use, and psychosocial functioning. Fifty percent of respondents reported cannabis use, 43% tobacco/nicotine use, and 37% co-use of both substances. The most prevalent method of co-use involved smoking combustible products. Overall, individuals who co-used both substances on the same occasion in some way reported heavier use and greater problematic behaviors than those who did not. Sequential use (especially among those that also engaged in coadministration) was typically associated with worse physical and mental functioning overall compared to using each substance separately. Findings illuminate both prevalence and risks associated with co-use of cannabis and tobacco/nicotine products and can inform policies for states considering regulation of cannabis and tobacco/nicotine products. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Prevalence and Correlates of Simultaneous and Separate 30-Day Use of Tobacco and Cannabis: Results from the California Adult Tobacco Survey

Background: There is limited information on separate use and simultaneous use of tobacco and cannabis products, particularly for new electronic nicotine delivery systems (ENDS). This study presents detailed information about the prevalence and correlates of individual use, separate use, and simultaneous use of tobacco and cannabis in California, the first state to allow medical marijuana in the US. It specifically distinguishes between simultaneous use (both substances used in the same occasion) and separate use (both products used, but not simultaneously). Objectives: Participants in the 2016 California Adult Tobacco Survey (N = 3,058; age range 18-64 years) completed online surveys between February and March 2016 that assessed tobacco and cannabis use in the past 30 days. Results: Participants' use of tobacco (15% cigarettes) was higher than use of ENDS (6%) or cannabis (10%); the overall rate of separate use was 6% and the overall rate of simultaneous use was 3%. Correlates of tobacco use included lower levels of education and income. Correlates of simultaneous tobacco and cannabis use included being unemployed or having a disability. Conclusions/Importance: This survey of California residents suggests how use patterns change in states that legalize medical marijuana prior to recreational cannabis, although it may underestimate prevalence due to reliance on self-reported use. Persons who were unemployed and persons with disabilities were at higher risk for simultaneous use of tobacco and cannabis. These findings suggest that prevention and cessation interventions intended to target simultaneous use should address these populations, as well as adolescents and young adults.