Predictors and consequences of simultaneous alcohol and cannabis use in adolescents

Alcohol and cannabis use for pain management: Translational findings of relative risks, benefits, and interactions

Chronic pain affects over 20% of the global population and contributes to the vast burden of psychiatric illness. While effective treatments for chronic pain remain limited, both alcohol and cannabis have been used for centuries to manage pain and closely associated negative affective symptoms. However, persistent misuse of alcohol and/or cannabis in such a negative reinforcement fashion is hypothesized to increase the risk of severity of substance use disorders (SUDs). The current review describes neurobiological evidence for the analgesic efficacy of alcohol and primary cannabis constituents and how use or co-use of these substances may influence SUD risk.

Substitution and Complementarity in the Consumption of Alcohol, Cannabis, and Opium

Understanding the behavior of populations of drug consumers has been and remains a topic of keen interest. Using a unique dataset on 25 districts from Bengal, India, from 1911 to 1925, we analyze whether populations of consumers treat alcohol, cannabis, and opium as economic substitutes or complements in a legal regime. Additionally, we examine responsiveness to prices and income. Our analysis has three main findings. First, we find evidence of substitution between alcohol and cannabis bud. Second, cannabis leaf is a complement for alcohol but a substitute for cannabis bud. Third, we find negative income elasticity for alcohol, cannabis bud, and opium consumption. These findings on the link between consumption patterns and economic factors can guide harm reduction strategies.

Psychometric properties of the Spanish simultaneous alcohol and cannabis motives measure (S-SMM) and its short form (S-SMM-SF) among young adults

Background: Simultaneous Alcohol and Cannabis (SAC) use is associated with greater negative consequences than individual use. Motives to use are robust predictors of alcohol and cannabis consumption, both separately and simultaneously. Despite the recent development of both a SAC motives measure and its short form, no Spanish adaptation is currently available.Objectives: To provide a Spanish adaptation of the full-length and short-form versions of the simultaneous alcohol and cannabis motives measure and to examine its psychometric properties in a sample of young adult SAC users.Methods: A targeted sampling procedure was used to recruit 612 young cannabis users, of whom 479 reported SAC use (18-25 years old [M = 21.01, SD = 2.14]; 36% female). Following adaptation and translation, participants completed the scale, along with measures of frequency of alcohol, cannabis, and simultaneous use, cannabis motives, and alcohol- and cannabis-related negative consequences.Results: Confirmatory factor analyses showed a four-factor structure (conformity, positive effects, calm/coping, and social). Moreover, the results indicated acceptable internal consistency (.70-.88), providing evidence of convergent, discriminant, and predictive validity for most dimensions.Conclusions: The results suggest that both versions of the scale are valuable tools for assessing motives for SAC consumption among young adults. These scales could aid in investigating motives for SAC use and informing interventions to mitigate associated harms.

The Prevalence and Correlates of Cannabis-Related Harms in a Nationally Representative Sample of Norwegian High School Students

PURPOSE

Although adolescents are at increased risk for a wide spectrum of cannabis-related harms, comprehensive harm measures are seldom employed in studies of young people who use cannabis. This study examined the type and prevalence of cannabis-related harms and their associations with various cannabis use indicators in a sample of adolescent who use cannabis.

METHODS

A nationally representative sample of Norwegian high school students (N = 3,490, age 17-19 years, 48% male) reported whether they used cannabis, and if so, age of first initiation, use frequency, simultaneous use with alcohol, and whether they experienced any of the 18 possible cannabis-related harms. Associations between these harms and cannabis use indicators were analyzed using regression models while accounting for other known sociodemographic, temperamental, and substance use risks.

RESULTS

Among respondents who reported lifetime cannabis use (20%), 65% reported having experienced at least one cannabis-related harm (M = 4.7 ± 4.8). Although "Feelings of shame" (44%) and "Adverse psychoactive effects" (42%) were most frequently reported, harmed relationships (21%), unprotected/unwanted sex (17%), and school troubles (17%) were also prevalent. Early cannabis use initiation (Incidence rate ratio = 1.564, p < .01) and simultaneous use with alcohol (Incidence rate ratio = 1.385, p < .01), but not frequency of use, were associated with greater number of experienced harms.

DISCUSSION

By examining a wide range of diverse harms, our results underscore the need for a more nuanced understanding of negative consequences of cannabis use during sensitive periods of adolescent development. Prevention efforts targeting early initiation and simultaneous use of cannabis and alcohol may prove particularly useful in preventing cannabis-related harm among adolescents.

The association between cannabis and alcohol co-use and momentary subjective effects: Risks for increasingly hazardous cannabis use

BACKGROUND

Co-use of cannabis and alcohol is associated with a higher prevalence of health-related, psychiatric, and psychosocial impairments. The aims of this study were to 1) examine the association between cannabis and alcohol co-use and subjective effects, 2) determine whether the time between cannabis and alcohol use is associated with subjective effects, and 3) examine whether subjective responses to co-use are associated with hazardous cannabis use over time.

METHODS

Young adults who co-used cannabis and alcohol (N = 155, 55.5 % women, Mean age=21 yo) completed baseline, six-month, and twelve-month assessments of hazardous cannabis use. Co-use and subjective effects were assessed across 21 days of EMA at baseline.

FINDINGS

Co-use was associated with greater momentary subjective intoxication, compared to cannabis- and alcohol-only, and stimulation and bad effects, compared to cannabis-only. Subjective intoxication was significantly higher for co-use within 0-90minutes compared to cannabis-only. Subjective intoxication was significantly higher for co-use within 0-120minutes compared to alcohol-only. Co-use within 0-30minutes was associated with significantly greater stimulation and bad effects, compared to cannabis-only use moments. The extent to which an individual becomes more intoxicated when co-using the greater the risk the individual had for increasing hazardous cannabis use six and twelve months later.

CONCLUSION

Findings indicate that co-use is associated with increased intoxication, compared to cannabis or alcohol use alone, and increased stimulation and bad effects, compared to cannabis use alone. Subjective responses to co-use in a naturalistic setting are important to consider when evaluating long-term risk of cannabis use among young adults.

Proximal antecedents and acute outcomes of simultaneous alcohol and cannabis use: Systematic review of daily- and event-level studies

Many studies have revealed that individuals who engage in simultaneous use of alcohol and cannabis report elevated substance-related consequences relative to those who use only alcohol or cannabis; however, evidence from emerging studies examining within-person differences across simultaneous use and single substance use occasions is less consistent. This systematic review aimed to synthesize findings from existing day- and event-level studies of within-person differences in the proximal antecedents and acute outcomes associated with simultaneous use versus single substance use episodes. Our search strategy revealed 30 eligible articles. Two categories of antecedents (i.e., internal [e.g., motives] and external [e.g., social context]) and three categories of outcomes (i.e., consumption behavior, general positive and negative consequences, and specific consequences) were identified. The current literature consistently suggests that greater day- or event-level social and enhancement motives, as well as being in a social context, predict greater likelihood of engaging in simultaneous use compared with alcohol- or cannabis-only use. However, there was heterogeneity in findings regarding the role of other person-level antecedents. Further, while most evidence pointed to heavier alcohol consumption on simultaneous use occasions versus alcohol-only occasions, findings for elevations in acute negative and positive substance-related consequences on simultaneous use versus single substance use occasions were mixed. Additionally, four studies found that increased consequences on simultaneous use occasions depended on the level of alcohol consumed. This review identifies several antecedents for simultaneous use events but suggests that simultaneous use occasions are not always associated with more acute harms than single substance use occasions. Given the extent to which the current literature is mixed, this review emphasizes the importance of methodological improvements and future research examining the mechanisms linking simultaneous use with substance-related consequences to help reconcile findings across within-person and between-person studies.

The Association Between Adolescent Vaping and Subsequent Use of Other Substances and Risk Factors for Polysubstance Use

Objectives

Adolescent vaping has become a public health concern. The aim of this study was to examine the associations between adolescent vaping and subsequent use of other substances and risk factors for polysubstance use.

Methods

The Well-being and Experiences Study is a longitudinal, intergenerational study conducted in Manitoba, Canada. The sample for this study consisted of adolescents and emerging adults who participated in Waves 1 (N = 1,002; 2017-18; aged 14–17 years) and 2 (n = 756; 2019; aged 15–20 years). Multinomial logistic regression analysis was performed.

Results

Adolescent vaping was associated with continued use of alcohol, cannabis, and cigarettes (adjusted relative risk ratio [aRRR] range: 12.92–19.39), new onset use of cannabis (aRRR: 6.04) and cigarettes (aRRR: 3.66), and concurrent and simultaneous polysubstance use (aRRR range: 3.14–24.25). Several risk factors were identified for concurrently using three or four substances in the past year (aRRR range: 1.76–2.86) and simultaneously using alcohol, cannabis, and nicotine (aRRR range: 1.99–3.11). Among those who reported vaping nicotine at Wave 2, 33.6% of males and 24.2% of females reported doing so as a coping mechanism.

Conclusions

Adolescent vaping is a risk factor for subsequent use of other substances and polysubstance use. Efforts are needed to prevent vaping initiation and help adolescents with cessation. Strategies should include selective interventions for those with histories of childhood adversity and mental health disorder.

Simultaneous Substance Use With Alcohol in a Community-Based Sample of Young Adults

Objective: Simultaneous substance use is associated with worse outcomes than concurrent use. Further investigations into simultaneous use are warranted because there is limited knowledge about the co-use of substances other than alcohol and cannabis. Study aims were to examine: (1) the prevalence of simultaneous use of substances with alcohol, (2) the extent to which use patterns are related to key correlates (i.e., psychological functioning, sensation seeking), and (3) differences by college status. Methods: Participants were 623 young adult drinkers who were recruited online to complete a one-time survey. Results: Cannabis (54.3%), tobacco (53.7%), and stimulants (46.5%) were most frequently used with alcohol. Moderation analyses showed the positive association between simultaneous use and psychological distress was stronger for students whereas the positive association with sensation seeking was stronger for nonstudents. Conclusions: Results highlight the need for future research and intervention efforts that consider the link between simultaneous use and psychological wellbeing while acknowledging that educational attainment may differentially influence these factors.

Examining the Impact of Simultaneous Alcohol and Cannabis Use on Alcohol Consumption and Consequences: Protocol for an Observational Ambulatory Assessment Study in Young Adults

BACKGROUND

There is significant conflicting evidence as to how using cannabis while drinking alcohol (ie, simultaneous alcohol and cannabis use) impacts alcohol volume consumed, patterns of drinking, and alcohol-related consequences. The impact of simultaneous use on drinking outcomes may be influenced by several within-person (eg, contextual) and between-person (individual) factors.

OBJECTIVE

This study was designed to examine naturalistic patterns of alcohol and cannabis use to understand how simultaneous use may impact drinking outcomes. The primary aims were to understand the following: (1) if simultaneous use is associated with increased alcohol consumption and riskier patterns of drinking, (2) if simultaneous use leads to increased alcohol consequences, and (3) how contextual circumstances moderate the impact of simultaneous use on consumption and consequences.

METHODS

Data collection involves a 28-day ambulatory assessment protocol in which a sample of non-treatment-seeking young adults who report simultaneous use of alcohol and cannabis complete ecological momentary assessments (random, event-contingent, and time-contingent surveys) of alcohol and cannabis use, contexts, motives, and consequences on their personal smartphones while continuously wearing an alcohol biosensor bracelet. Participants also complete a baseline assessment, brief internet-based check-in on day 14, and a final session on day 28. Community-based recruitment strategies (eg, social media and flyers) were used to enroll 95 participants to obtain a target sample of 80, accounting for attrition.

RESULTS

Recruitment and data collection began in May 2021 and continued through June 2024. Initial results for primary aims are expected in October 2024. As of March 2024, the project had recruited 118 eligible participants, of whom 94 (79.7%) completed the study, exceeding initial projections for the study time frame. Remaining recruitment will provide the capacity to probe cross-level interactions that were not initially statistically powered. Strengths of the project include rigorous data collection, good retention and compliance rates, faster-than-expected enrollment procedures, use of a novel alcohol biosensor, and successful adaptation of recruitment and data collection procedures during the COVID-19 pandemic.

CONCLUSIONS

This is the first investigation to assess the key momentary predictors and outcomes of simultaneous use as well as self-reported and objective (via alcohol biosensor) measures of alcohol consumption and patterns. The results of this study will inform prevention efforts and studies of individuals who use cannabis who are engaged in alcohol treatment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/58685.

Simultaneous Alcohol and Cannabis Use and High-Risk Sexual Behaviors

Background

Alcohol and cannabis use rates are highest in college-aged young adults, and both alcohol and cannabis use are independently related to high-risk sexual behaviors (HRSBs). HRSBs (e.g., sex without protection against sexually transmitted infections) are a prevalent public health problem in college students, with little research examining simultaneous alcohol and cannabis use (i.e., using both alcohol and cannabis at the same time so the effects overlap) and HRSBs.

Method

We examined simultaneous alcohol and cannabis-related HRSB frequency, gender differences in simultaneous alcohol and cannabis-related HRSBs, and differences in HRSBs between simultaneous and non-simultaneous users. Alcohol and cannabis using college students (N = 534; Average Age = 19; 66.9% reported identifying as female) were recruited through a psychology department's human subjects research pool and completed a one-time, online, self-report survey.

Results

One-third of participants engaged in simultaneous alcohol and cannabis use prior to sexual intercourse in the past 3 months. Additionally, over one-third of participants reported heavy drinking (4/5 or more drinks for women/men) simultaneously with cannabis use prior to sexual intercourse in the past 3 months. Simultaneous alcohol and cannabis use was significantly and positively related to sexual intercourse after simultaneous use and after heavy drinking simultaneously with cannabis use. Past year simultaneous alcohol and cannabis users, relative to non-simultaneous users, reported increased incidents of sex without protection against sexually transmitted infections. No gender differences in simultaneous alcohol and cannabis-related HRSBs were found.

Conclusions

Future research should continue examining simultaneous alcohol and cannabis use and HRSBs.

Explanatory factors of polydrug use in mid-late teens and the relevance of information sources: Correlational and configurational assessment in Tarragona (Spain)

Background

Substance use among adolescents is a public health problem, and the simultaneous use of multiple substances aggravates this problem. Although the facilitators of specific substance use in adolescents have been widely investigated, polydrug use is a less common topic. Likewise, the role that the origin of the information available to adolescents regarding substance use plays in relation to polydrug use is practically unexplored.

Objectives

This work analyzed the relevance of the origin of the information sources available to adolescents regarding substance use, among which we distinguished those that were monitored (or supervised) by public agencies from those that were unmonitored (or unsupervised) in the consumption of more than one substance. As control variables, we considered three individual factors and four environmental factors. The relevance of these sources was analysed from a dual perspective: on the one hand, their statistical relevance was measured, and on the other hand, how they combined with the control variables was analysed to identify risk and risk-free profiles in substance poly-drug use.

Methods

This paper utilized a sample of N = 573 adolescents aged ≥17 years. This sample was collected from a survey administered in the spring of 2023. We examined the impact of unmonitored information sources (peers, siblings, and the Internet) and supervised sources (school, parents, and media) on the combined consumption of alcohol, tobacco, and cannabis. Additionally, we took three individual factors (gender, early onset of alcohol, and tobacco use) and four environmental factors (parental control, alcohol, tobacco, and cannabis use among peers) into account as control variables. Initially, we conducted a regression analysis to adjust for the impact of these factors on polydrug use. Subsequently, we employed a fuzzy set qualitative analysis (fsQCA) to investigate how predictor factors combined with the formation of adolescent profiles associated with polydrug consumption and nonconsumption.

Results

Unmonitored information sources were associated with a greater incidence of poly consumption, with ORs of 1.703 and p values of 0.004. However, the protective effects of regulated information sources remained ambiguous. Among the variables positively linked with of polydrug use, are female sex (OR = 1.329, p = 0.0076), early alcohol consumption (OR = 4.680, p < 0.0001), and early tobacco consumption (OR = 3.242, p < 0.001) were the most important. Peer drinking (OR = 1.556, p = 0.0187) and peer cannabis use (OR = 1.351, p = 0.0226) were also significantly correlated. The use of the fsQCA made it possible to identify the profiles of adolescents associated to polysubstance use and non-use. The conditions of the configurations that explained use were characterized by an early onset of the joint consumption of tobacco and alcohol. The profile of non-consuming adolescents is that of adolescents whose peers do not use tobacco or cannabis and who have parental control and monitored sources.

The effects of simultaneous alcohol and cannabis use on subjective drug effects: A narrative review across methodologies

Over 75% of young adults who use cannabis also report drinking alcohol, leading to increased risks that include impaired cognition, substance use disorders, and more heavy and frequent substance use. Studies suggest that subjective responses to either alcohol or cannabis can serve as a valuable indicator for identifying individuals at risk of prolonged substance use and use disorder. While laboratory studies show additive effects when alcohol and cannabis are used together, the impact of co-using these substances, specifically with respect to cannabidiol, on an individual's subjective experience remains unclear. This narrative review explores the effects of simultaneous alcohol and cannabis (SAM) use on subjective drug effects, drawing from qualitative research, laboratory experiments, and naturalistic studies. Experimental findings are inconsistent regarding the combined effects of alcohol and cannabis, likely influenced by factors such as dosage, method of administration, and individual substance use histories. Similarly, findings from qualitative and naturalistic studies are mixed regarding subjective drug effects following SAM use. These discrepancies may be due to recall biases, variations in assessment methods, and the measurement in real-world contexts of patterns of SAM use and related experiences. Overall, this narrative review highlights the need for more comprehensive research to understand more fully subjective drug effects of SAM use in diverse populations and settings, emphasizing the importance of frequent and nuanced assessment of SAM use and subjective responses in naturalistic settings.

The company you keep: The neglected role of affiliating with delinquent friends in the development of the cannabis-violence link

A growing body of research suggests a potential role of cannabis use on aggressive behaviors. In literature on adolescents, the lack of consideration of important confounders, such as adolescent's affiliation with delinquent peers, limits the possibility to determine whether there might be a direct or indirect link between cannabis use and aggression. Therefore, we sought to examine the effect of delinquent peers on the association between cannabis use and violence. We re-analyzed data from 850 ninth graders who were followed from mid-adolescence to early adulthood. Generalized Estimations Equations (GEE) were conducted to examine whether affiliation with delinquent peers may mediate the relationship between cannabis use and violence. Cross-Lagged Panel Models were also conducted to estimate the directionality of these relationships over time. We additionally tested whether similar relationships may be identifiable when examining rule-breaking behaviors and/or alcohol use. GEE models revealed that both cannabis use and affiliation with delinquent peers were statistically associated with aggressive behaviors. Cannabis use, alcohol use and delinquent peers also predicted rule-breaking behaviors. More precisely, cross-lagged models showed that affiliation with delinquent peers played a partially mediating role in the cannabis-aggression link, and that similar cross-lagged estimates were observed when examining rule-breaking behaviors instead of aggression. Our results indicate that cannabis use may be associated with aggression as well as rule-breaking behaviors, suggesting a broader effect on conduct problems. More importantly, our study highlights the non-negligible role of affiliating with delinquent peers during adolescence.

The prevalence of alcohol consumption and its related factors in adolescents: Findings from Global School-based Student Health Survey

BACKGROUND

Alcohol consumption has become very common among adolescents in recent years and its prevalence varies in different countries. This study aimed to investigate the prevalence of alcohol consumption and related factors in adolescents aged 11 to 16 years.

METHODS

This descriptive cross-sectional study was performed on 288385 adolescents (girls, 53.9% of total) aged 11 to 16 years. In the present study, the GSHS data (2003-2018) available to public on the websites of the US Centers for Disease Control and Prevention (CDC) and WHO was used. To investigate the factors affecting alcohol consumption, univariate and multivariate logistics models with 95% confidence limits were used.

RESULTS

The overall prevalence of alcohol consumption in adolescents was 25.2%, which was 28.3% and 22.4% in boys and girls, respectively. Among the surveyed countries, the highest prevalence was in Seychelles (57.9%) and the lowest in Tajikistan (0.7). Multivariate analysis showed that the Age for 16 and more than 16 years old (OR = 3.08,95%CI: 2.54-3.74), truancy for more than 10 days (OR = 1.24, 95%CI: 1.08-1.43), loneliness at sometimes of the times (OR = 1.04, 95%CI: 1.01-1.07), insomnia at most of the times (OR = 1.85, 95%CI: 1.70-2.01), daily activity (OR = 1.03, 95%CI: 1.00-1.07), bullied for 1-9 Days in a month (OR = 1.24, 95%CI: 1.09-1.40), cigarette (OR = 4.01, 95%CI: 3.86-4.17), used marijuana for more than 10 days in a month (OR = 5.58, 95%CI: 4.59-7.78), had sex (OR = 2.76, 95%CI: 2.68-2.84), and suicide plan (OR = 1.48, 95%CI: 1.42-1.54) were important factors affecting drinking alcohol. (Table 4). In this study, the sensitivity, specificity, positive predictive value, and negative predictive value were 42.79%, 93.96%, 70.80%, and 82.75.

CONCLUSIONS

According to the results of the present study, the prevalence of alcohol consumption among teenagers was high. Therefore, it is suggested that demographic, family, and psychological factors should be taken into consideration in health programs for the prevention and treatment of alcohol consumption in adolescents.

Changes in co-use of alcohol and cannabis among Nordic adolescents in the 21st century: Results from the European School Survey Project on Alcohol and Other Drugs study

INTRODUCTION

In the 21st century, there has been a decline in alcohol use among adolescents in most Nordic countries, while trends of cannabis use have diverged. We explore how alcohol and cannabis use, respectively, and co-use of the two substances, have changed among Nordic adolescents. Three hypotheses are used to frame the study: (i) cannabis use has substituted alcohol use; (ii) there has been a parallel decline in both substances; and/or (iii) there has been a 'hardening' of users, implying that alcohol users increasingly use cannabis.

METHODS

Data from the European School Survey Project on Alcohol and Other Drugs, conducted among 15- to 16-year-olds in Denmark, Finland, Iceland, Norway and Sweden (N = 74,700, 49% boys), were used to explore trends of past-year alcohol and cannabis use in the period 2003-2019.

RESULTS

The proportion of adolescents reporting alcohol use decreased significantly in all Nordic countries except Denmark. The proportion of those using cannabis only was low (0.0%-0.7%) and stable in all countries. The total number of substance use occasions declined among all adolescents in all countries but Denmark. Among alcohol users, cannabis use became increasingly prevalent in all countries but Denmark.

DISCUSSION AND CONCLUSIONS

We found no support for the 'parallel decline hypothesis' in alcohol and cannabis use among Nordic adolescents. Partially in line with the 'substitution hypothesis', cannabis use accounted for an increasing proportion of all substance use occasions. Our results suggests that the co-use of alcohol and cannabis has become more common, thus also providing support to the 'hardening' hypothesis.

Associations between simultaneous use of alcohol and cannabis and cannabis-related problems in 2014-2016: evidence from the Washington panel survey

BACKGROUND

To address the research question of how simultaneous users of alcohol and cannabis differ from concurrent users in risk of cannabis use problems after the recreational marijuana legalization in Washington State.

METHODS

We used generalized estimating equations with a Poisson distribution to analyze the association between simultaneous use of alcohol and marijuana (SAM) and cannabis-related problems compared to concurrent use. The data is a longitudinal sample of drinkers and cannabis users (n = 257, 47% female) aged 18 years and older from Washington State in 2014-2016. We adjusted for survey weights to account for differential probability of selection and response rates. The primary outcome is the past-six-month CUDIT problem subscale (ranging from 0 to 28), which is the total score for seven CUDIT problem items, after excluding the three items that covered marijuana use frequency. Covariates include marijuana use frequency (daily/near daily use, regular use, or infrequent use), marijuana daily quantity, alcohol daily volume, panel survey cycle, medical marijuana recommendation, driving time to nearest marijuana outlet, age of marijuana use onset, and other demographics.

RESULTS

After adjusting for covariates, we found that compared to concurrent use, SAM was significantly positively associated with CUDIT problem subscale (IRR = 1.68, 95% CI: 1.25-2.27, p < 0.001); daily/near daily use of marijuana was strongly significantly associated with CUDIT problem subscale compared with infrequent use (IRR = 5.1, 2.71-9.57, p < 0.001) or regular use (IRR = 3.05, 1.91-4.85, p < 0.001). Secondary analyses using CUDIT total score as the outcome also showed a significant positive association with SAM compared to concurrent use (IRR = 1.17, 1.02-1.34, p < 0.05).

CONCLUSIONS

This study highlighted the importance of SAM, in addition to cannabis use frequency for predicting cannabis-related problems.

Latent Classes of Simultaneous Alcohol and Cannabis Use and Associations with Consequences using Daily Data

Objective

Simultaneous alcohol and cannabis use (i.e., marijuana, [SAM], using alcohol and cannabis so effects overlap) is associated with increased consumption and consequences compared to single-substance use. SAM use prevalence is increasing, yet there is heterogeneity in use patterns among those engaging in SAM use, which may lead to differential consequences.

Method

This study drew on daily data to characterize latent profiles of cannabis, alcohol, and SAM use patterns and to test class differences on related consequences after 3 months among college students engaging in SAM use (77.08% White, 51.67% female). Class indicators were 10 person-level substance use variables derived from repeated daily surveys.

Results

Results yielded a three-class solution: Heavy Alcohol, Cannabis, and SAM (Heavy Use, n = 105); Heavy Alcohol-Light Cannabis (n = 75); and Light Alcohol-Heavy Cannabis (n = 60). There were significant person-level differences between classes on all substance use indicators (e.g., quantity and frequency of alcohol, cannabis, and SAM) but not sex or race/ethnicity. At 3-month follow-up, the Heavy Use class endorsed more SAM consequences than the other classes. The Heavy Use class did not differ on alcohol or cannabis consequences compared to the Heavy Alcohol-Light Cannabis or Light Alcohol-Heavy Cannabis classes, respectively. The Light Alcohol-Heavy Cannabis class endorsed the fewest alcohol consequences. The Heavy Alcohol-Light Cannabis class endorsed the fewest cannabis consequences.

Conclusions

Findings highlight distinct patterns of co-use and their association with consequences at follow-up. Heavy alcohol or cannabis use was associated with consequences for that substance, but heavy use of only one substance was not indicative of SAM-specific consequences.

Simultaneous Cannabis and Alcohol Use among Medical Cannabis Patients

Background: During the past two decades of cannabis legalization, the prevalence of medical cannabis (MC) use has increased and there has also been an upward trend in alcohol consumption. As less restricted cannabis laws generate more adult cannabis users, there is concern that more individuals may be simultaneously using medical cannabis with alcohol. A few studies have examined simultaneous use of medical cannabis with alcohol, but none of those studies also assessed patients' current or previous non-medical cannabis use. This paper explores simultaneous alcohol and medical cannabis use among medical cannabis patients with a specific focus on previous history of cannabis use and current non-medical cannabis use. Methods: A retrospective cohort study of MC patients (N = 319) from four dispensaries located in New York. Bivariate chi-square tests and multivariable logistic regression are used to estimate the extent to which sociodemographic and other factors were associated with simultaneous use. Results: Approximately 29% of the sample engaged in simultaneous use and a large share of these users report previous (44%) or current (66%) use of cannabis for non-medical purposes. MC patients who either previously or currently use cannabis non-medicinally, men, and patients using MC to treat a pain-related condition, were significantly more likely to report simultaneous alcohol/MC use. Conclusions: Findings indicate that there may be differential risks related to alcohol/MC use, which should be considered by cannabis regulatory policies and prevention/treatment programs. If patients are using cannabis and/or alcohol to manage pain, clinicians should screen for both alcohol and cannabis use risk factors.

Alcohol First, Cannabis Last: Identification of an Especially Risky Use Pattern among Individuals Who Co-Use Alcohol and Cannabis

Background: Alcohol and cannabis co-use is common and confers increased risk for potential harms, such as negative consequences and substance dependence. The existing evidence suggests that factors such as dose of delta-9-tetrahydrocannabinol (THC) consumed and order of use of each substance (i.e., using alcohol or cannabis first or last when co-using) may impact co-use outcomes. Existing co-use research has focused primarily on college-samples or young adults, and few studies have explored these nuanced relations among community samples. Methods: We examined survey data from 87 community members (mean age 32.9 years, 49.4% female) recruited from legal market cannabis dispensaries. Using a combination of regression techniques (i.e., OLS, negative binomial, censor-inflated) we modeled relations among co-use ordering patterns, THC dose and cannabis outcomes as well as interactions with sex assigned at birth and age. Results: Individuals who endorsed co-use reported significantly higher CUDIT scores than those who had never co-used (p < 0.01). Using alcohol first and cannabis last (a pattern we refer to as "AFCL") was more common among females than males (p < 0.01). In the context of typical substance use weeks, more frequently engaging in the AFCL pattern was associated with significantly higher CUDIT scores (p < 0.001) and negatively predicted positive consequences (p < 0.001). Other patterns predicted higher CUDIT scores during heavy use weeks. Conclusions: Results indicate that co-use ordering patterns are related to substance use outcomes. Further research leveraging within-subjects, longitudinal designs is needed to test causal relations between these variables.

The significance of information variables in polydrug use by adolescents: insights from a cross-sectional study in Tarragona (Spain)

Substance use, especially among adolescents, is a significant public health concern, with profound implications for physical and psychological development. This study aimed to evaluate the quantity and sources of information available to adolescents regarding polydrug use. A cross-sectional survey was conducted in Tarragona involving adolescents with an average age of 16.44 years. This study assessed the number of substances used (alcohol, cigarettes, and cannabis) in the past month, along with information sources related to substance use. Monitored sources (e.g., schools, parents, and mass media) and unmonitored sources (e.g., peers, siblings, internet) were distinguished. In addition, four individual and four environmental control variables were considered. Multinomial logistic regression analysis revealed that incorporating variables related to adolescents' substance use information and its sources enhanced the explanatory model, surpassing control variables. The degree of information about substance use did not significantly explain consumption patterns, but the number of information sources, both monitored and unmonitored, did. The unmonitored sources were associated with increased polydrug use. Conversely, greater reliance on supervised sources for information was linked to reduced single-substance and polydrug use. This protective effect increased with an increase in the number of substances used. In conclusion, information obtained from monitored sources acts as a deterrent to substance consumption, consistent with findings suggesting that greater health literacy among adolescents discourages substance use. Conversely, this study suggests that information from more informal sources may encourage heavier polydrug use, aligning with reports indicating that adolescents with a more comprehensive understanding of substance use consequences tend to engage in heavier drug use.

Dual alcohol and cannabis use in male and female adolescents: Relationships with family variables

Family dynamics influence adolescents' use of alcohol and other substances, such as cannabis. The aim of this study was to understand the relationship between family variables and alcohol use, dual use of alcohol and cannabis, and non-use in adolescents according to sex. A cross-sectional study was conducted. The sample comprised 879 adolescents (56.4 % boys; M(SD)age = 14.25 (1.88) years). Multinomial regression analysis showed that for boys, the presence of family conflict increased the likelihood of being an alcohol (OR = 1.19) and dual (OR = 1.23) user rather than a non-user. For girls, communication reduced the probability of being an alcohol user (OR = 0.88), and the presence of consequences for breaking rules reduced the probability of being a dual user rather than a non-user (OR = 0.83) or an alcohol user (OR = 0.84). These findings highlight the importance of family prevention of adolescents' substance use, bearing in mind the participants' sex.

Profiles of alcohol and cannabis protective behavioral strategies use across two large, multi-site college student samples of concurrent alcohol and cannabis users

Concurrent use of alcohol and cannabis among college students is common and confers greater harms than the use of either of these substances alone. Large and growing bodies of literature have demonstrated the independent utility of behaviors used before, during, after, or instead of alcohol and cannabis use that minimize related harms (i.e., protective behavioral strategies [PBS]). However, little is known about the relationship between alcohol and cannabis PBS and their joint influence on harms among college students who concurrently use alcohol and cannabis. In the present study, we used data from two large, multi-site samples of college students, and restricted analyses to those who reported at least one episode of alcohol and cannabis use in the past 30 days (Study 1: N = 1104[Mage = 20.3, SD = 3.8; 70.0 % female; 79.5 % white]; Study 2: N = 2034[Mage = 20.2, SD = 3.2; 69.1 % female; 76.6 % white]). A latent profile analysis supported a 4-profile solution that was largely consistent across samples: Profile 1 (low alcohol/cannabis PBS; 8.8-11.9 %), Profile 2 (average alcohol/cannabis PBS; 33.1-37.7 %), Profile 3 (average alcohol PBS/low cannabis PBS; 16.3-25.2 %), and Profile 4 (high alcohol/cannabis PBS; 29.8-37.2 %). Profile 4 reported the least alcohol/cannabis use, fewest negative alcohol-/cannabis-related consequences, and lowest alcohol/cannabis use severity. In contrast, Profile 1 was the opposite for alcohol-related outcomes, and Profile 3 was the opposite for cannabis-related outcomes. These findings are preliminary but may suggest that targeting both alcohol and cannabis PBS in intervention is generally beneficial except some groups at risk for a particular substance may benefit from increased focus on that substance in intervention.

Recreational marijuana legalization and marijuana and alcohol co-use among adolescents: Differential associations among racial and ethnic groups

We examined associations of the 2016 legalization of recreational marijuana (RML) in California with marijuana and alcohol co-use among race/ethnic groups using successive cross-sections from 7th, 9th, and 11th graders (N = 3,319,329) in the 2010-11 to 2018-19 California Healthy Kids Surveys. Multilevel logistic regressions indicated a stronger positive association between RML and co-use among non-Hispanic/Latine White youth (OR = 1.21) relative to Hispanic/Latine (OR = 1.02) or Black youth (OR = 0.85). Among drinkers who had not consumed five or more drinks on any occasion in the past 30-days (non-heavy drinkers), the positive association between RML and co-use was stronger among American Indian/Alaska Native youth (OR = 2.19) compared to non-Hispanic/Latine Whites (OR = 1.56). For heavier drinkers it was stronger for Native Hawaiian/Pacific Islanders (OR = 1.47). Among marijuana users, there was a stronger inverse association between RML and co-use among Black youth (OR = 0.72) compared to non-Hispanic/Latine White youth (OR = 0.84). RML may increase the risk of co-use to a greater extent among non-Hispanic/Latine White youth than other race/ethnic groups in California, but broadly increases the risk among youth who engage in alcohol use or heavy drinking.

Associations of daily alcohol, cannabis, combustible tobacco, and e-cigarette use with same-day co-use and poly-use of the other substances

BACKGROUND

Young adults frequently use alcohol, cannabis, and tobacco together. Given the increased prevalence of e-cigarette use and recreational cannabis use, we investigated daily patterns of alcohol, cannabis, and tobacco use and distinguished combustible tobacco from e-cigarettes.

METHODS

Young adult college students (N=341) reporting past-month alcohol and cannabis use "at the same time so that their effects overlapped" completed two 28-day bursts of repeated daily surveys. Exposures were day- and person-level use of each substance. Outcomes were (1) same-day co-use of each remaining substance or (2) poly-use of the other substances.

RESULTS

Daily use of alcohol, cannabis, combustible cigarettes, and e-cigarettes increased the odds of same-day co-use of the other substances (except combustible tobacco with e-cigarettes) and each poly-use outcome. The influence of person-level substance use on daily substance use was less consistent. Only e-cigarette use increased the odds of daily alcohol use. Use of either tobacco product but not alcohol increased the odds of daily cannabis use. Person-level alcohol and cannabis use increased the odds of daily use of either tobacco product but use of one tobacco product was not associated with daily use of the other product.

CONCLUSIONS

These findings increase our understanding of emerging daily patterns of alcohol, cannabis, and tobacco co-use, and the impact of different tobacco products. Future work is needed to extend this research into non-college samples and people who use tobacco but do not use alcohol and cannabis simultaneously, and examine daily chronologies of multiple substances that could serve as dynamic markers of risk.

Neuroanatomical predictors of problematic alcohol consumption in adolescents: a systematic review of longitudinal studies

AIMS

This study aimed to systematically review the literature on neuroanatomical predictors of future problematic drinking in adolescents.

METHODS

Using PRISMA guidelines, a systematic review was conducted to evaluate neuroanatomical predictors of problematic alcohol consumption in adolescents. EMBASE, MEDLINE, and PsycINFO databases were searched from inception to 6 January 2023. Studies were included if they were original, had a prospective design, had a sample size of at least 12, had a follow-up period of at least 1 year, had at least one structural neuroimaging scan before 18 with no prior alcohol use, and had alcohol use as the primary outcome. Studies were excluded if they had animals only and were not in English. Risk of bias was conducted using the CASP tool.

RESULTS

Out of 1412 studies identified, 19 studies met the criteria, consisting of 11 gray matter (n = 4040), 5 white matter (n = 319), and 3 assessing both (n = 3608). Neuroanatomical predictors of future problematic drinking in adolescents were reported to be distributed across various brain regions such as the orbitofrontal cortex and paralimbic regions. However, the findings were largely heterogeneous.

CONCLUSIONS

This is the first systematic review to map out the existing literature on neuroanatomical predictors of problematic drinking in adolescents. Future research should focus on the aforementioned regions to determine their role in predicting future problematic drinking with more certainty.

24-month outcomes of an eHealth universal program for students and parents to prevent adolescent alcohol use: A cluster randomized controlled trial in schools

Background

Parents play a critical role in delaying adolescent initiation of alcohol and other drug use. However, the majority of prevention programs focus on adolescents only. This study tested the acceptability and effectiveness of an eHealth universal program for students and parents to prevent adolescent alcohol use.

Methods

A cluster randomized controlled trial (RCT) was conducted between 2018 and 2020 with students from one grade level (aged 12-14 years) from 12 Australian secondary schools randomly allocated to the intervention or control conditions. Students accessed a web-based program in class and parents accessed the program online at their convenience. Data were collected via online questionnaires from students (N = 572) and parents (N = 78) at baseline, and 12- and 24- months post baseline. Multilevel, mixed effects regression models were used to analyse student data.

Findings

More students in the control group reported having at least one standard alcoholic drink and engaging in heavy episodic drinking in the previous 12 months at both 12- and 24-month follow up compared to students in the intervention, however, these differences were not statistically significant. Students in the intervention group reported greater increases in alcohol-related knowledge, compared to the control students. Qualitative data from parents indicated that they found the program useful, however, the number of parents who enrolled in the research study (13.9 %) was low. Parent engagement increased following implementation of an interactive parent/adolescent homework task.

Conclusions

Small sample size, low prevalence of alcohol use and parental engagement, and relatively short follow-up period may have contributed to lack of observed intervention effect, other than on alcohol-related knowledge. Parents who engaged with the program found it useful, however, implementation strategies that encourage parent-child interaction and communication may increase parent engagement for future programs.

Effects of combined use of alcohol and delta-9-tetrahydrocannibinol on working memory in Long Evans rats

The increase in social acceptance and legalization of cannabis over the last several years is likely to increase the prevalence of its co-use with alcohol. In spite of this, the potential for effects unique to co-use of these drugs, especially in moderate doses, has been studied relatively infrequently. We addressed this in the current study using a laboratory rat model of voluntary drug intake. Periadolescent male and female Long-Evans rats were allowed to orally self-administer ethanol, Δ9-tetrahydrocannibinol (THC), both drugs, or their vehicle controls from postnatal day (P) 30 to P47. They were subsequently trained and tested on an instrumental behavior task that assesses attention, working memory and behavioral flexibility. Similar to previous work, consumption of THC reduced both ethanol and saccharin intake in both sexes. Blood samples taken 14 h following the final self-administration session revealed that females had higher levels of the THC metabolite THC-COOH. There were modest effects of THC on our delayed matching to position (DMTP) task, with females exhibiting reduced performance compared to their control group or male, drug using counterparts. However, there were no significant effects of co-use of ethanol or THC on DMTP performance, and drug effects were also not apparent in the reversal learning phase of the task when non-matching to position was required as the correct response. These findings are consistent with other published studies in rodent models showing that use of these drugs in low to moderate doses does not significantly impact memory or behavioral flexibility following a protracted abstinence period.

Developmental trajectories of alcohol and cannabis concurrent use in a nationally representative sample of United States youths

BACKGROUND

Previous studies have identified common trajectories of single type substance use over the course of adolescence; however, no study to date has examined joint trajectories of cannabis and alcohol concurrent use. Given that expansion of legal cannabis has increased availability, it is important to understand patterns of concurrent use in adolescents and factors that place male and female youth at risk for harmful trajectories of concurrent use. The current study sought to identify joint trajectories of cannabis and alcohol use - and predictors of harmful use trajectories - among male and female adolescents.

METHOD

We used 4 waves of data from 6997 early adolescent participants (age 12-14 years at Wave 1) in the Population Assessment of Tobacco and Health, a nationally representative longitudinal study in the United States. Participants reported their cannabis and alcohol use reassessed yearly for 5 years (2013-2018). We used joint trajectory growth mixture modeling to identify trajectory groups as defined by changes in alcohol and cannabis use over time.

RESULTS

Five classes of alcohol and cannabis concurrent use trajectories were identified. Both internalizing and externalizing symptoms at Wave 1 increased the odds of membership in trajectory groups characterized by more harmful use trajectories. Internalizing symptomatology was a stronger predictor of membership in escalating use trajectories among girls, whereas externalizing symptomatology stronger predictor among boys.

CONCLUSIONS

These findings underscore the utility of jointly considering alcohol and cannabis use when describing common developmental trajectories of use and identifying risk factors for trajectories characterized by harmful use.

Alcohol and cannabis co-use in a national sample of U.S. adults ages 30-80

INTRODUCTION

Growing cannabis legalization has coincided with an increased focus on use of both alcohol and cannabis (AC co-use) among younger people; however, little is known about AC co-use among adults over age 30. This study examines the prevalence of different types of AC co-use among adults, as well as compares AC co-users and alcohol-only users on individual, social network, and neighborhood characteristics.

METHODS

Data come from three annual surveys of a nationally representative sample of 1,770 U.S. adults, initially between the ages of 30-80, conducted between 2019 and 2021. The baseline sample is 52.8 years old on average, 51.8 % female, and 60.1 % non-Hispanic White.

RESULTS

Past month co-use at baseline was reported by 8.4% of adults, and mostly consisted of simultaneous use, with less than 5% of the sample initiating co-use over the two-year follow-up period. Multivariable models indicate AC co-use was cross-sectionally associated with respondents being male, younger, Hispanic (vs White), and having more alcohol use and related problems, and with their social network composition (e.g., having more drinking buddies and cannabis users in the network). However, co-use status was not associated with mental health, physical ailments, or neighborhood quality. Longitudinal analyses indicated that AC co-use at baseline predicted more alcohol use one year later and alcohol related problems two years later among men only.

CONCLUSIONS

AC co-use among adults over age 30 deserves further attention given its prevalence and associations with heavier drinking and related problems. Network-focused interventions may be a promising approach for reducing AC co-use.

Alcohol and cannabis co-use: Receptiveness to treatments and application to intervention planning

Given the prevalence of alcohol and cannabis co-use among college students, prevention for co-use is crucial. We examined hypothetical receptiveness to substance-specific interventions among students who reported co-use. Students who use alcohol and cannabis were more receptive to alcohol interventions than cannabis interventions. Campus prevention experts should consider offering evidence-based alcohol-focused interventions as a potential pathway for decreasing substance use among college students who engage in co-use.

Effects of combined use of alcohol and delta-9-tetrahydrocannibinol on working memory in Long Evans rats

The increase in social acceptance and legalization of cannabis over the last several years is likely to increase the prevalence of its co-use with alcohol. In spite of this, the potential for effects unique to co-use of these drugs, especially in moderate doses, has been studied relatively infrequently. We addressed this in the current study using a laboratory rat model of voluntary drug intake. Periadolescent male and female Long-Evans rats were allowed to orally self-administer ethanol, Î" 9 -tetrahydrocannibinol (THC), both drugs, or their vehicle controls from postnatal day (P) 30 to P47. They were subsequently trained and tested on an instrumental behavior task that assesses attention, working memory and behavioral flexibility. Similar to previous work, consumption of THC reduced both ethanol and saccharin intake in both sexes. Blood samples taken 14h following the final self-administration session revealed that females had higher levels of the THC metabolite THC-COOH. There were modest effects of THC on our delayed matching to position (DMTP) task, with females exhibiting reduced performance compared to their control group or male, drug using counterparts. However, there were no significant effects of co-use of ethanol or THC on DMTP performance, and drug effects were also not apparent in the reversal learning phase of the task when non-matching to position was required as the correct response. These findings are consistent with other published studies in rodent models showing that use of these drugs in low to moderate doses does not significantly impact memory or behavioral flexibility following a protracted abstinence period.

Marijuana Use in Middle and High School Students: Insights from the 2020 National Youth Tobacco Survey

OBJECTIVE

The use of marijuana by middle and high school students could have important consequences, including physical harm, poor decision making, increased use of tobacco products, and involvement in the legal system. Determining the level of use by students provides the initial information needed to understand the extent of the problem and possible approaches to reducing student use.

METHODS

The National Youth Tobacco Surveys provide important information about the frequency of use of nicotine and tobacco products by a representative sample of students in schools in the United States. The 2020 survey included a question about the use of marijuana by survey respondents. The results from the survey were analyzed using descriptive statistics and logistic regression to model the association between the use of marijuana and the use of electronic or conventional cigarettes.

RESULTS

The final survey from 2020 included 13,357 students, with 6537 male respondents and 6820 female respondents. Ages ranged from younger than 12 to 18 and older years; 961 students used both cigarettes and marijuana, and 1880 students used both electronic cigarettes (e-cigarettes) and marijuana. The adjusted odds ratio for the use of marijuana increased in female students, in non-Hispanic Black students, Hispanic students, and all ages from 13 through 18 and older. The perception of harm associated with either e-cigarettes or cigarettes did not change the odds ratio for using marijuana. Students who did not smoke cigarettes or did not smoke e-cigarettes had significantly lower odds ratios for using marijuana.

CONCLUSIONS

The 2020 National Youth Tobacco Survey indicates that approximately 18.4% of middle school and high school students have used marijuana. Parents, educators, public health officials, and policymakers need to understand that there is a relatively high use of marijuana among students and that education programs should focus on its use with or without other tobacco products.

Alcohol & cannabinoid co-use: Implications for impaired fetal brain development following gestational exposure

Alcohol and marijuana are two of the most consumed psychoactive substances by pregnant people, and independently, both substances have been associated with lifelong impacts on fetal neurodevelopment. Importantly, individuals of child-bearing age are increasingly engaging in simultaneous alcohol and cannabinoid (SAC) use, which amplifies each drug's pharmacodynamic effects and increases craving for both substances. However, to date, investigations of prenatal polysubstance use are notably limited in both human and non-human populations. In this review paper, we will address what is currently known about combined exposure to these substances, both directly and prenatally, and identify shared prenatal targets from single-exposure paradigms that may highlight susceptible neurobiological mechanisms for future investigation and therapeutic intervention. Finally, we conclude this manuscript by discussing factors that we feel are essential in the consideration and experimental design of future preclinical SAC studies.

Who's at greatest risk? Latent profiles of alcohol and cannabis use and related consequences among college students

BACKGROUND

There is significant heterogeneity in alcohol and cannabis use patterns among college students, with some engaging in use patterns that heighten their risk for adverse consequences. Person-centered approaches can help identify those subgroups of students with riskier use patterns. Latent Profile Analyses (LPA) were conducted to identify subgroups based on alcohol and cannabis use frequency and quantity, to explore demographic covariates and to examine mean differences across subgroups on alcohol- and cannabis-related consequences, simultaneous use, and other substance use.

METHODS

Participants were 2,423 college students (Mage = 20.1; 72  % female) recruited from seven US universities who endorsed past-month alcohol and cannabis use and completed an online survey of substance use behaviors.

RESULTS

A four-profile solution was the best fitting model. Profile 1 represented "light, infrequent alcohol and cannabis use" (73.8 %), Profile 2 represented "heavy, infrequent alcohol and moderate, frequent cannabis use" (15.9 %), Profile 3 represented "moderate, frequent alcohol and cannabis use" (5.6 %) and Profile 4 represented "very heavy, frequent alcohol and heavy, frequent cannabis use" (4.7 %). Students who identify as male, White non-Hispanic, and/or Greek-affiliated were more likely to be in the heavy alcohol use profiles. Profiles 3 and 4 represent high-risk profiles, with both having a higher likelihood of simultaneous use, Profile 3 endorsing more cannabis consequences, and Profile 4 endorsing more alcohol consequences.

CONCLUSION

Results suggest that heavy alcohol or heavy co-use heightens risk for serious adverse consequences.

A qualitative examination of the decision-making process of simultaneous alcohol and cannabis use: Intentions and willingness

BACKGROUND

Alcohol and cannabis use are common among young adults and most young adults who use both substances have used them simultaneously (i.e., using both substances so their effects overlap). Because simultaneous use is associated with a greater number and severity of consequences than single substance use, research is needed to examine the decision-making process of engaging in this high-risk behavior. We conducted a qualitative examination of intentions (i.e., plans) and willingness (i.e., one's openness to engage in the behavior if an opportunity presents itself) to engage in simultaneous use from the perspective of young adults who frequently report this substance use behavior.

METHODS

We recruited 36 young adults who reported simultaneous use and heavy drinking (4+/5+ drinks for women/men; 64% women, ages 18 to 25) to participate in semi-structured interviews. All interviews were double coded for thematic analysis and both novel and a priori themes were found.

RESULTS

Young adults distinguished between intending to engage in simultaneous use and being willing to engage in simultaneous use. They reported that intentions and willingness varied from occasion to occasion. They also reported that context and alcohol consumption influenced their willingness to engage in simultaneous use. Peer pressure or offers increased their willingness to use cannabis while drinking and having current or next-day responsibilities decreased their willingness to engage in simultaneous use. Additionally, planned simultaneous use occasions were characterized as being special events where young adults consumed more substances, but were more likely to monitor their use than unplanned occasions.

CONCLUSIONS

Intentions and willingness may be important proximal predictors of simultaneous use of alcohol and cannabis. Building off this qualitative work, quantitative research should identify which factors influence the decision-making process to engage in simultaneous use and determine when intentions and willingness are most predictive of risky simultaneous use behavior.

Indirect and direct effects of simultaneous alcohol and cannabis use on alcohol hangovers

INTRODUCTION

Simultaneous use of alcohol and cannabis (i.e., using both on same occasion) is a risk factor for heavier drinking and negative alcohol consequences; however, little research has investigated risk conferred for specific negative consequences. One theoretically relevant negative consequence may be alcohol hangovers; however, no studies have tested cross-sectional or prospective relations between simultaneous use and experiencing alcohol hangovers.

METHOD

The current study (N = 2,964) used public-access data from the National Longitudinal Study on Adolescent to Adult Health (Add Health) to test whether simultaneous alcohol and cannabis use conferred risk for hangover frequency directly or indirectly through heavier drinking. The current study also tested moderated mediation by depressive symptoms, considering simultaneous users have higher levels of depressive symptoms, and depressive symptoms largely mirror those of a hangover.

RESULTS

In a cross-sectional model, simultaneous use was associated with more frequent hangovers both directly and indirectly through heavier drinking. In a prospective model, simultaneous use indirectly predicted more frequent hangovers through heavier drinking; however, the direct path was not significant. None of the paths from simultaneous use to drinking or hangovers were moderated by depressive symptoms in either model.

CONCLUSIONS

The current study suggests that, both concurrently and prospectively, heavier drinking explained significant variance in the relation between simultaneous use and hangover frequency. The significant direct effect of simultaneous use in the cross-sectional model suggests that simultaneous users may have individual characteristics, outside of depressive symptoms, that confer risk for more frequent hangovers above and beyond heavier drinking.

The role of alcohol and cannabis co-use in drinking rate and its impact on consequences

BACKGROUND

The impact of alcohol and cannabis co-use on college student drinking and related outcomes is complex. Specific characteristics or patterns of co-use events beyond drinking quantity may be important to the experience of consequences. The present study used repeated daily surveys to examine the association between co-use (versus use of alcohol only) and drinking rate on negative consequences.

METHODS

The sample included 318 college students (M_age  = 19.8, 47% female, 76% non-Hispanic White) who were co-users of alcohol and cannabis, recruited from three U.S. college campuses. Participants completed 56 days of data collection (number of drinking days ranged from 1 to 38). Two measures of drinking rate were examined: (1) daily rate (number of drinks divided by number of hours spent drinking per day); and (2) peak hour rate (maximum number of drinks consumed in a single hour) to account for anomalous drinking days of long duration. Generalized linear mixed models examined: (1) associations of co-use with peak hour rate (model 1a) and daily rate (model 1b); (2) associations of peak hour rate (model 2a) and daily rate (model 2b) with experiencing any negative consequence; and (3) interactions of co-use with peak hour rate (model 3a) and daily rate (model 3b) on experiencing a consequence.

RESULTS

Co-use was positively associated with peak hour rate but not daily rate. Both peak hour and daily rate positively predicted likelihood of experiencing a negative consequence. The interaction of both peak hour and daily rate by co-use was significant such that the association of rate with experiencing a consequence was stronger on alcohol-only days compared to co-use days.

CONCLUSIONS

Daily drinking rate and peak hour drinking rate are unique and should be considered when discussing drinking patterns. Both predict negative consequences and may be important aspects of interventions for negative drinking-related outcomes among college students.

Nuanced relations between simultaneous alcohol and cannabis use motives and negative consequences among college students: The role of multiple product use

Simultaneous alcohol and marijuana (SAM) use is common, but it exacerbates negative consequences. Individuals use alcohol and cannabis products in different ways and have distinct reasons for use. The present study examines day-level effects of motives on consequences on SAM-use days, accounting for consumption, and tests whether using multiple alcohol (e.g., beer + liquor) and/or cannabis (e.g., concentrate + leaf) products on the same day mediates these relations. College students engaging in SAM use at least once in the past month (N = 281; Mage = 20.17) completed two bursts of 28 consecutive days of data collection. We examined within-person effects of motives (effect-enhancement, social, offered [it was offered], coping) on number of negative consequences and on experiencing hangover, nausea, or blackout; and indirect effects via two concurrent mediators: using multiple alcohol products and multiple cannabis products. Total effect models showed effect-enhancement motives were related to nausea, social motives to number of total consequences and hangover, and coping motives to blackout. Effect-enhancement, social, and offered motives evinced significant indirect effects on consequence outcomes via multiple alcohol, but not cannabis, product use. Coping motives did not exhibit significant indirect effects, and were related to multiple cannabis, but not alcohol, product use, although all other motives were related to both mediators. Findings support recent work demonstrating within-person relations between social motives and negative consequences on SAM-use days. Limiting the number of alcohol products consumed on SAM-use days may be beneficial, particularly for young adults using to enhance intoxication or for social reasons. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Simultaneous alcohol and marijuana use among college students in the United States, 2006-2019

•

US college students’ simultaneous alcohol and marijuana (SAM) use rate was rising.

•

There was an upward trend of SAM use among Black college students (2006–2019).

•

Hispanic and Asian American/Pacific Islander students’ trend remained stable.

Objective

Simultaneous alcohol and marijuana (SAM) use exposes college students to a myriad of adverse consequences. However, there is no recent nationally representative study on SAM use among college students in the United States (US). To provide an update to the literature, the present study aimed to examine the trends, prevalence, and correlates of SAM use among US college students between 2006 and 2019, using nationally representative data.

Method

We used data from the 2006–2019 National Survey on Drug Use and Health (NSDUH) and the analytic sample was limited to the 55,669 full-time college student respondents (ages 18–22). Using logistic regression analysis, we assessed trends in SAM use prevalence and examined sociodemographic and psycho-social-behavioral correlates of SAM use.

Results

The proportion of US college students who reported SAM use increased significantly from 8.13% (2006–2010) to 8.44% (2015–2019). However, examination by race/ethnicity revealed that the increasing trend was largely driven by Black college students, whose SAM use prevalence increased significantly from 5.50% (2006–2010) to 9.30% (2015–2019), reflecting a 69.09% increase. SAM use rates did not change significantly among other racial/ethnic groups.

Conclusions

This study uncovered an upward trend and prevalence of SAM use among US college students, calling for more research and public health interventions in this area. At-risk subgroups that warrant more attention include college students who are Black, female, above the legal drinking age, have a lower than $20,000 household income, and reside in small metropolitan areas.

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.

Cannabis use and subjective response to alcohol in the human laboratory

BACKGROUND

Cannabis is often used in combination with alcohol; yet, whether cannabis use impacts risk factors for alcohol use disorder (AUD) remains unknown. Subjective response (SR) to alcohol represents a biobehavioral risk factor for subsequent heavy drinking and for developing AUD. Given the high prevalence of alcohol and cannabis co-use, it is plausible to hypothesize that cannabis users differ in SR to alcohol compared to non-cannabis users. The purpose of this study is to examine the influence of past-month cannabis use on subjective response to alcohol in the human laboratory.

METHODS

This study culled data from multiple alcohol administration trials to test whether cannabis users, compared to non-cannabis users, differed in subjective response to alcohol, comprised of four domains: stimulation, sedation, negative affect, and craving. Non-treatment-seeking heavy drinkers (N = 168) completed a battery of self-report scales of mood and alcohol/cigarette/cannabis use and problems. All participants completed an intravenous alcohol administration session wherein SR domains were measured at the following breath alcohol concentrations (BrAC): baseline (i.e., 0), 20, 40, and 60 mg%.

RESULTS

Multilevel statistical analyses revealed that cannabis users had a greater reduction in negative affect during alcohol administration, compared to non-cannabis users. No significant differences were found for the other SR domains.

CONCLUSIONS

Using a large sample and advanced data analytic methods, this study extends the literature by suggesting that cannabis users are more sensitive to alcohol-induced reductions in negative affect compared to non-cannabis users. This work extends research on how cannabis use may influence risk factors for AUD, such as subjective response to alcohol.

Additive roles of tobacco and cannabis co-use in relation to delay discounting in a sample of heavy drinkers

RATIONALE

Alcohol use disorder (AUD) is associated with steeper delay discounting rates; however, it is unknown whether substance co-use, particularly cannabis use, has an additive effect on discounting rates among heavy drinkers. Furthermore, it is unclear whether substance co-use and delay discounting are independently associated with AUD severity.

OBJECTIVES

The purpose of this study was to determine whether alcohol, tobacco, and cannabis co-use impacts delay discounting rates. We also sought to determine whether substance co-use and delay discounting were associated with AUD symptom counts.

METHODS

The study sample was culled from several human laboratory studies and consisted of 483 heavy drinking individuals who completed a baseline visit (prior to experimental procedures). Participants were divided into groups based on self-reported alcohol, tobacco, and cannabis use during the past 30 days: alcohol only (n = 184), alcohol + cigarettes (n = 89), alcohol + cannabis (n = 82), and tri-use (n = 128). We examined discounting rates across the 4 groups and used multiple linear regression to test whether co-use and delay discounting were associated with AUD symptoms.

RESULTS

After adjusting for covariates, individuals in the alcohol + cannabis group and the tri-use group had steeper discounting rates relative to the alcohol-only group. In addition, tri-use and delay discounting rates were independently correlated with a greater number of AUD symptoms.

CONCLUSIONS

Delay discounting rates were significantly greater among subgroups reporting cannabis use providing partial support for an additive effect, while also highlighting the importance of co-use substance type. Both tri-use and delay discounting were associated with greater AUD severity, which may provide relevant intervention targets.

Patterns of Cannabis and Alcohol Co-Use: Substitution Versus Complementary Effects

PURPOSE

The purpose of this review is to discuss the literature regarding the concurrent use (co-use) of alcohol and cannabis and competing hypotheses as to whether cannabis acts as a substitute for (i.e., replacing the effects of alcohol, resulting in decreased use) or a complement to (i.e., used to enhance the effects of alcohol, resulting in increased use) alcohol. The impact of cannabis use on alcohol-related outcomes has received increased attention in the wake of ongoing legalization of cannabis for both medical and recreational purposes. Evidence for both hypotheses exists in the literature across a broad range of data collection methods and samples and is carefully reviewed here. In addition, various mechanisms by which cannabis may act as an alcohol substitute or complement are explored in depth with the goal of better understanding equivocal findings.

SEARCH METHODS

This review includes articles that were identified from a search for studies on alcohol and cannabis co-use, with a specific focus on studies exploring complementary versus substitution aspects of co-use. Search terms were included in Google Scholar, PsycINFO, MEDLINE, and Web of Science. Eligible studies were those that measured alcohol and cannabis co-use in human samples in laboratory, survey, or ecological momentary assessment studies, or that directly referenced substitution or complementary patterns of use.

SEARCH RESULTS

Search results returned 650 articles, with 95 meeting inclusion criteria.

DISCUSSION AND CONCLUSIONS

Results of this review reveal compelling evidence for both substitution and complementary effects, suggesting nuanced yet significant distinctions across different populations examined in these studies. Several mechanisms for the impact of cannabis use on alcohol-related outcomes are identified, including patterns and context of co-use, timing and order of use, cannabinoid formulation, pharmacokinetic interactions, and user characteristics (including diagnostic status), all of which may influence substitution versus complementary effects. This review will inform future research studies examining this topic in both clinical and community samples and aid in the development of treatment and prevention efforts targeting those populations most vulnerable to negative consequences of co-use. Finally, this review highlights the need for additional research in more diverse samples and the use of mixed-methods designs to examine both pharmacological and contextual influences on co-use.

The Effect of Momentary Affect on Substance Use among Young Adults Who Experience Homelessness

IntroductionLittle is known about the momentary patterns and predictors of substance use among young adults who experience homelessness. To enhance understanding of substance use patterns, smartphone-based ecological momentary assessment (EMA) was utilized to examine the real-time association between affect and substance use. Methods: 251 young adults (aged 18-27) with history of homelessness were recruited from supportive housing programs and drop-in facilities in Los Angeles. Exploratory factor analysis was used to examine the latent structure of positive and negative affective states and mixed-effects logistic regression models were completed separately for both the full remaining sample (n = 227) and a subsample of alcohol or cannabis users (n = 145) to evaluate whether positive or negative affect predicted lead, recent, or lagged substance use. Results: Greater positive affect within-person was associated with greater odds of alcohol or cannabis use within the past two hours, and participants who reported feeling more negative than their peers experienced greater odds of reporting use within the past 4 h and the following two hours. Conclusion: Results suggest that individuals experience a heightened positive mood compared to their own average mood, concurrently or immediately after engaging in alcohol or cannabis use. Heightened positive mood might be an anticipatory effect of drinking or cannabis use. Future research should consider a longer study period to capture multiple drinking or drug use events over a longer period and consider more environmental exposures that may influence the frequency or intensity of substance use.

Recreational Marijuana Legalization and Co-use With Alcohol Among Adolescents

INTRODUCTION

Little is known about the possible impacts of recreational marijuana legalization on alcohol and marijuana co-use among underage youth. This study examines the association between recreational marijuana legalization in California in 2016 and alcohol and marijuana co-use among adolescents. Additional analyses investigate the associations between recreational marijuana legalization and co-use among past 30-day drinkers and marijuana users and the frequency of alcohol and marijuana use among co-users.

METHODS

This study used annual cross-sectional data from 7th, 9th, and 11th graders (N=3,319,329) who participated in the California Healthy Kids Survey from 2010-2011 to 2018-2019. Measures included past 30-day alcohol and marijuana use and student demographic characteristics, survey year, pre-post recreational marijuana legalization, and urbanicity. Multilevel regression analyses were conducted in 2021.

RESULTS

Recreational marijuana legalization was associated with greater odds of past 30-day alcohol and marijuana co-use in the total sample (OR=1.06, 95% CI=1.05, 1.07). Recreational marijuana legalization was more strongly associated with co-use among adolescents who reported past 30-day alcohol use (OR=1.58, 95% CI=1.52, 1.62) and heavy drinking (OR=1.25, 95% CI=1.21, 1.29) but was inversely related to co-use among past 30-day marijuana users (OR=0.76, 95% CI=0.74, 0.78). Among past 30-day co-users, there was a positive association with the frequency of marijuana use (β=0.36, SE=0.07).

CONCLUSIONS

Recreational marijuana legalization may increase the risk of alcohol and marijuana co-use among adolescents. Greater restrictions on the numbers of alcohol and marijuana retail outlets and hours of operation and advertising and higher taxes on alcohol and marijuana products may help reduce the availability of these substances to adolescents.

Factors Associated with Simultaneous or Concurrent Use of Alcohol and Marijuana in Argentina

Background: The identification of factors promoting simultaneous alcohol and marijuana (SAM) use is important to promote early intervention efforts. The associations between impulsivity facets and SAM (or concurrent alcohol and marijuana, CAM) use have been analyzed in North American samples. These topics, however, remain unexplored in South American samples. This study assessed if internalizing symptoms, five impulsivity dimensions, and emotional regulation strategies differentiate between participants who reported last 2-month SAM use, CAM use, alcohol, or marijuana only use, or that reported no substance use. Methods: A sample of 1057 Argentinian citizens answered an online survey. A multinominal logistic regression was conducted on drug use membership. Results: Circa 25% of the sample reported SAM use. Higher sensation seeking differentiated between SAM use versus no substance use, and those with lower sensation seeking were more likely to be classified into the alcohol-only group or into the nonuse group, than into the SAM use group. Stress scores uniquely predicted membership into the alcohol-only category. Those with lower use of emotional suppression were more likely than nonusers to be classified in all drug use categories, except CAM use. Higher emotional suppression scores were associated with membership into the nonuse group or the alcohol-only group, when compared to the SAM use group. Hazardous drinking was significantly greater in SAM than in alcohol-only users. Conclusions: The study highlights the relevance of sensation seeking as a predictor of SAM use and pinpoints emotional suppression as common factor modulating hazardous drug use behaviors.

Simultaneous use of marijuana and alcohol: Potential prevention targets among young adults who use alcohol

Simultaneous alcohol and marijuana use (SAM) such that their effects overlap has emerged as a behavior that is riskier than using either substance separately. It has been associated with high-risk binge drinking and driving while intoxicated during young adulthood, and it has been demonstrated to cause greater physical and mental impairment than use of alcohol or marijuana separately. To identify intervention and prevention targets specific to SAM, we examined the relationships between alcohol- and marijuana-specific beliefs and attitudes (risk factors) and self-reported SAM compared to non-simultaneous co-use (CAM) and alcohol use only in the past 30 days in a sample of young adults (n = 1,023, mean age = 23.17; SD = 0.43). Of those who reported drinking alcohol in the past 30 days, 20.7% reported SAM, 12.6% reported CAM, and 66.6% reported using only alcohol. Results from multinomial logistic regression analyses indicated that some marijuana-specific risk factors (e.g., belief that it is not at all wrong for someone their age to use marijuana) differentiated SAM or CAM from alcohol use only, but alcohol-specific risk factors generally did not. However, the perceptions that parents approved of their using marijuana or frequently drinking heavily were associated with a greater likelihood of SAM compared to CAM (OR ranged from 2.25 to 3.53). Findings point to the salience of individuals' attitudes and beliefs around marijuana use and their perception of parental approval of heavy drinking and marijuana use as potential targets for prevention programs targeting risk reduction among young adults.

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.