Dual cannabis and alcohol use disorders in young adults: Problems magnified

Independent and concurrent cannabis use with alcohol, cigarettes, and other substances among college students: Rates and consequences

Objective: The purpose of this study was to examine patterns of concurrent cannabis and other substance use and their differential associations with cannabis-related problems and academic outcomes in college students. Participants: Participants were undergraduate students (N = 263; M age = 19.1 years; 61.2% female) who were eligible if they used cannabis at least 3 days in the past month (M = 10.1 days). Method: Substance use, academic-related outcomes, and measures of Cannabis Use Disorder (CUD) severity and problems were obtained in an online survey. Results: The five groups evaluated were cannabis-only users (5.3%), cannabis and alcohol (47.1%), cannabis, alcohol and cigarettes (16.7%), cannabis, alcohol and other substances (14.8%), or all-substances (16%). Cannabis-only and all-substance users reported using cannabis most frequently (ps ≤ .034), but only the latter reported greater CUD severity, problems, and poorer academic outcomes. Discussion: College student polysubstance users may be at increased risk for poorer outcomes compared to cannabis-only users and other groups.

Positive psychological interventions on alcohol use and consequences: Pilot randomized trial in a young adult cannabis-using sample

INTRODUCTION

Young adults exhibit high rates of concurrent alcohol and cannabis use, which is associated with more negative alcohol-related consequences. Positive psychological interventions have successfully been leveraged to target alcohol, cannabis, and nicotine use, as well as substance use disorders, and may be a useful harm reduction approach to reduce alcohol-related consequences. This pilot study sought to generate effect sizes for two positive psychological interventions, Savoring and Three Good Things, on frequency of alcohol use, quantity of alcohol use, and alcohol-related consequences.

METHODS

The current study used data from a pilot study testing positive psychological interventions to reduce cannabis use and cannabis-related consequences in young adults (ages 18 to 25) who used cannabis at least once per week within the prior month (N = 50, Mage = 22.72, 72 % men, 40 % White). Participants reported baseline alcohol and cannabis use and alcohol-related consequences, then the study randomized them to complete a daily Savoring intervention, Three Good Things, or a control exercise, and completed daily text message surveys for two weeks (i.e., the intervention period) and a follow-up survey.

RESULTS

Analyses revealed no significant differences across experimental conditions on alcohol use frequency, alcohol use quantity, or alcohol-related consequences at baseline or follow-up. Paired samples t-tests demonstrated that participants in the Savoring group showed large, significant decreases in alcohol-related consequences (t[16] = 2.28, p = .04, gav = 0.54); no decreases occurred in frequency or quantity of alcohol use. The Three Good Things group showed no significant decreases in alcohol-related consequences, frequency of alcohol use, or quantity of alcohol use.

CONCLUSIONS

Results suggest that a larger scale clinical trial is warranted to determine whether Savoring and Three Good Things might function as harm reduction interventions to reduce alcohol-related consequences in young adults who concurrently use alcohol and cannabis. Future research should use a larger sample, a longer intervention administration period, and a longer follow-up period to examine these positive psychological interventions more rigorously.

Effects of combined exposure to ethanol and delta-9-tetrahydrocannabinol during adolescence on synaptic plasticity in the prefrontal cortex of Long Evans rats

Significant exposure to alcohol or cannabis during adolescence can induce lasting disruptions of neuronal signaling in brain regions that are later to mature, such as the medial prefrontal cortex (mPFC). Considerably less is known about the effects of alcohol and cannabis co-use, despite its common occurrence. Here, we used male and female Long-Evans rats to investigate the effects of early-life exposure to ethanol, delta-9-tetrahydrocannabinol (THC), or their combination on high frequency stimulation (HFS)-induced plasticity in the prelimbic region of the mPFC. Animals were injected daily from postnatal days 30-45 with vehicle or THC (escalating doses, 3-20 mg/kg) and allowed to drink vehicle (0.1% saccharin) or 10% ethanol immediately after each injection. In vitro brain slice electrophysiology was then used to record population responses of layer V neurons following HFS in layer II/III after 3-4 weeks of abstinence. We found that THC exposure reduced body weight gains observed in ad libitum fed rats, and reduced intake of saccharin and ethanol. Compared to controls, there was a significant reduction in HFS-induced long-term depression (LTD) in rats exposed to either drug alone, and an absence of LTD in rats exposed to the drug combination. Bath application of indiplon or AR-A014418, which enhance GABAA receptor function or inhibit glycogen synthase kinase 3β (GSK3β), respectively, suggested the effects of ethanol, THC or their combination were due in part to lasting adaptations in GABA and GSK3β signaling. These results suggest the potential for long-lasting adaptations in mPFC output following co-exposure to alcohol and THC.

Effects of combined exposure to ethanol and delta-9-tetrahydrocannabinol during adolescence on synaptic plasticity in the prefrontal cortex of Long Evans rats

Significant exposure to alcohol or cannabis during adolescence can induce lasting disruptions of neuronal signaling in brain regions that are later to mature, such as the medial prefrontal cortex (mPFC). Considerably less is known about the effects of alcohol and cannabis co-use, despite its common occurrence. Here, we used male and female Long-Evans rats to investigate the effects of early-life exposure to ethanol, delta-9-tetrahydrocannabinol (THC), or their combination on high frequency stimulation (HFS)-induced plasticity in the prelimbic region of the mPFC. Animals were injected daily from postnatal days 30 to 45 with vehicle or THC (escalating doses, 3-20 mg/kg) and allowed to drink vehicle (0.1% saccharin) or 10% ethanol immediately after each injection. In vitro brain slice electrophysiology was then used to record population responses of layer V neurons following HFS in layer II/III after 3-4 weeks of abstinence. We found that THC exposure reduced body weight gains observed in ad libitum fed rats, and reduced intake of saccharin and ethanol. Compared to controls, there was a significant reduction in HFS-induced long-term depression (LTD) in rats exposed to either drug alone, and an absence of LTD in rats exposed to the drug combination. Bath application of indiplon or AR-A014418, which enhance GABAA receptor function or inhibit glycogen synthase kinase 3β (GSK3β), respectively, suggested the effects of ethanol, THC or their combination were due in part to lasting adaptations in GABA and GSK3β signaling. These results suggest the potential for long-lasting adaptations in mPFC output following co-exposure to alcohol and THC.

A 2-year follow-up of the effects of combined binge drinking and cannabis consumption on academic performance and adjustment in Spanish third-year university students

Introduction

The study was based on 2-year follow-up of the effects of binge drinking and cannabis co-consumption on academic performance and adjustment in Spanish Third-Year University Students and to further explore the impact of academic adjustment on this relationship.

Methods

A total of 144 students (aged 19-20 years) enrolled in the third year of university completed the study. The students were recruited during in first academic year (T1) via a survey that included items regarding the use of alcohol (AUDIT-C), cannabis and other drugs and demographic variables. Then, participants meeting the study criteria were then selected and invited by e-mail to a clinical (face-to face) structured interview. The participants completed a calendar of alcohol consumption during the 6 months prior to the interview (Alcohol Timeline Follow back), and recorded cannabis consumption in 3 months prior to the interview. To examine the effects of alcohol and cannabis co-consumption on the outcome variables, we categorized participants into three consumption groups (i.e., control, BD, and BDCA) based on the number of BD days and cannabis unit scores.

Results

Binge drinking and cannabis co-consumption in first-year students was significantly associated with poor academic performance and adjustment after 2 years of undergraduate study. Relative to controls, co-consumers (BDCA) reported significantly lower academic and personal-emotional adjustment to university as well as poorer performance. Mediation analysis showed that academic adjustment explains the mechanism by which BDCAs perform less well, mediating the relationship between co-consumption and academic performance, with an indirect effect representing 64.61% of the total effect. Furthermore, the mediating effect of academic adjustment was maintained after controlling for academic adjustment and baseline grade point average (T1).

Conclusion

This prospective follow-up study helps to further our knowledge of how combined binge drinking and cannabis consumption may affect university adjustment and academic success in Spanish university students Overall, the study results should encourage health professionals, educational psychologists and academic institutions to take ownership of the need for support and involvement in prevention, as well as for provision of guidelines for implementing appropriate intervention strategies.

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.

Hypertensive Crisis-Related Hospitalizations and Subsequent Major Adverse Cardiac Events in Young Adults with Cannabis Use Disorder: A Nationwide Analysis

Background and Objectives: With the growing recreational cannabis use and recent reports linking it to hypertension, we sought to determine the risk of hypertensive crisis (HC) hospitalizations and major adverse cardiac and cerebrovascular events (MACCE) in young adults with cannabis use disorder (CUD+). Material and Methods: Young adult hospitalizations (18−44 years) with HC and CUD+ were identified from National Inpatient Sample (October 2015−December 2017). Primary outcomes included prevalence and odds of HC with CUD. Co-primary (in-hospital MACCE) and secondary outcomes (resource utilization) were compared between propensity-matched CUD+ and CUD- cohorts in HC admissions. Results: Young CUD+ had higher prevalence of HC (0.7%, n = 4675) than CUD- (0.5%, n = 92,755), with higher odds when adjusted for patient/hospital-characteristics, comorbidities, alcohol and tobacco use disorder, cocaine and stimulant use (aOR 1.15, 95%CI:1.06−1.24, p = 0.001). CUD+ had significantly increased adjusted odds of HC (for sociodemographic, hospital-level characteristics, comorbidities, tobacco use disorder, and alcohol abuse) (aOR 1.17, 95%CI:1.01−1.36, p = 0.034) among young with benign hypertension, but failed to reach significance when additionally adjusted for cocaine/stimulant use (aOR 1.12, p = 0.154). Propensity-matched CUD+ cohort (n = 4440, median age 36 years, 64.2% male, 64.4% blacks) showed higher rates of substance abuse, depression, psychosis, previous myocardial infarction, valvular heart disease, chronic pulmonary disease, pulmonary circulation disease, and liver disease. CUD+ had higher odds of all-cause mortality (aOR 5.74, 95%CI:2.55−12.91, p < 0.001), arrhythmia (aOR 1.73, 95%CI:1.38−2.17, p < 0.001) and stroke (aOR 1.46, 95%CI:1.02−2.10, p = 0.040). CUD+ cohort had fewer routine discharges with comparable in-hospital stay and cost. Conclusions: Young CUD+ cohort had higher rate and odds of HC admissions than CUD-, with prevalent disparities and higher subsequent risk of all-cause mortality, arrhythmia and stroke.

Delay discounting and neurocognitive performance in young adults with differential patterns of substance use: Findings from the Human Connectome Project

A large proportion of individuals who use psychoactive substances regularly use more than one substance. This pattern of behavior, termed polysubstance use, is associated with greater risks than when consuming only a single substance. The present study examined delay discounting, neurocognitive functioning, and demographic indicators among a large, racially and socioeconomically diverse sample of young adults drawn from the Human Connectome Project who reported either non, mono, or dual use of alcohol, tobacco, and/or cannabis. Univariate and multivariate tests suggested individuals who reported using multiple substances were more likely to be male, experienced higher rates of alcohol use disorder, and, when reporting both alcohol use and cannabis involvement, scored lower on a measure of inhibitory control relative to those who reported mono or dual use of alcohol and/or cigarettes. Individuals who reported currently smoking cigarettes exhibited the steepest discounting irrespective of other substances used; however, we observed additive effects for alcohol use and, to a lesser extent, cannabis involvement. Specifically, steeper discounting occurred when individuals who reported either regular alcohol use or > 100 lifetime instances of cannabis use also reported smoking cigarettes. We discuss several hypotheses for this finding related to the diversity of the sample and substances assessed as well as directions for future programmatic lines of research. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Separate and combined effects of alcohol and cannabis on mood, subjective experience, cognition and psychomotor performance: A randomized trial

Co-use of alcohol and cannabis is associated with increased frequency and intensity of use and related problems. This study examined acute effects of alcohol and cannabis on mood, subjective experience, cognition, and psychomotor performance. Twenty-eight healthy cannabis users aged 19-29 years with recent history of binge drinking completed this within-subjects, double-blind, double-dummy, placebo-controlled, randomized clinical trial. Participants received: placebo alcohol and placebo cannabis (<0.1% THC); alcohol (target breath alcohol content [BrAC] 80 mg/dL) and placebo cannabis; placebo alcohol and active cannabis (12.5% THC); and active alcohol and cannabis over four sessions. Profile of Mood States (POMS), Addiction Research Centre Inventory (ARCI), verbal free recall (VFR), Digit Symbol Substitution Test (DSST), Continuous Performance Test (CPT), and grooved pegboard (GPB) task were administered before and approximately 75 min after drinking alcohol (1 h after smoking cannabis ad libitum). Significant effects of condition were found for the POMS (Tension-Anxiety, Confusion) and ARCI (MBG, LSD, PCAG, Euphoria, Sedation), predominantly with greater increases emerging after cannabis or alcohol-cannabis combined relative to placebo. Significant effects were found for VFR (immediate total and delayed recall, percent retained), DSST (trials attempted, trials correct, reaction time), and GPB (non-dominant hand) predominantly with greater declines in performance after alcohol and alcohol-cannabis combined relative to placebo and/or cannabis. Cannabis appeared to affect mood and subjective experience, with minimal impact on cognitive performance. Alcohol appeared to impair cognitive and psychomotor performance, with minimal impact on mood and subjective experience. Acute effects of alcohol and cannabis combined were additive at most.

Cannabis and cocaine use, drinking outcomes, and quality of life in general hospital inpatients with alcohol use disorder

Background: While associations between cannabis and cocaine use, and heavy drinking and quality of life (QOL), are well-established in the general population, it is unclear whether they are present in hospital inpatients with alcohol use disorder (AUD). The aim of the study was to assess associations between cannabis and cocaine use and two outcomes [heavy drinking days (HDDs) and QOL] among hospital inpatients with AUD. Methods: Hospitalized patients with AUD and at least one past-month HDD participated in this cross-sectional study. Cannabis and cocaine use were assessed using the Alcohol, Smoking, and Substance Involvement Screening Test. HDDs were assessed using the Timeline Followback. QOL was assessed by the WHOQOL-BREF instrument. Multivariable regression models assessed associations. Results: Of 248 participants, 225 (91%) had severe AUD. There were no statistically significant associations between: recent cannabis use and HDDs [Incidence Rate Ratio (IRR) = 0.95; 95% Confidence Interval (95% CI): 0.80, 1.14], cocaine use and HDDs [IRR = 0.88; 95% CI: 0.66, 1.18], or both cannabis and cocaine use and HDDs [IRR = 0.87; 95%CI: 0.70, 1.09], as compared to use of neither cannabis nor cocaine. Use of cannabis, cocaine, and both, were not associated with QOL [(odds ratio (OR) = 0.98; 95% CI:0.55, 1.74), (OR = 0.76; 95% CI:0.30, 1.93), (OR = 1.00; 95%CI: 0.49, 2.03), respectively]. Conclusions: Among hospital inpatients with AUD, there were no significant associations between cannabis and cocaine use, heavy drinking, or QOL. Our findings raise questions regarding how drug use affects AUD and whether similar results would be found among those with milder AUD and in prospective studies.

Smoking trajectories from adolescence to early adulthood as a longitudinal predictor of mental health in adulthood: evidence from 21 years of a nationally representative cohort

AIMS

To measure the prospective relationship between smoking trajectories from adolescence to young adulthood and mental health in later adulthood and test whether this relationship was mediated by concurrent co-use of alcohol and marijuana.

DESIGN

Longitudinal study using data drawn from rounds 1 to 18 of the National Longitudinal Survey of Youth 1997 (NLSY97), a nationally representative cohort study spanning 21 years.

SETTING

United States.

PARTICIPANTS

The analytical sample included those who completed survey items about smoking behaviors on at least half the data collection opportunities in adolescence and young adulthood (n = 8570, 48.9% female, 66.2% white).

MEASUREMENTS

Mental health in adulthood was measured using the five-item Mental Health Inventory (MHI-5; range = 0-100) at round 18. Seven trajectories of smoking from adolescence to young adulthood were identified by group-based multi-trajectory modeling, using data over 11 years from rounds 1 to 11.

FINDINGS

Late-onset moderate smokers [β = -1.95, 95% confidence interval (CI) = -3.61 to -0.29], late-onset accelerated smokers (β = -2.53, 95% CI = -4.28 to -0.78), early-onset heavy smokers (β = -3.72, 95% CI = -5.59 to -1.85) and early-onset moderate smokers (β = -2.66, 95% CI = -4.48 to -0.84) showed poorer regression-adjusted mean MHI-5 scores in later adulthood than stable abstainers, even after controlling for baseline mental health and covariates. Whether or not a difference in MHI-5 scores was present between quitters and stable abstainers was inconclusive. The concurrent co-use of alcohol and marijuana in young adulthood significantly mediated the relationship between smoking trajectory and mental health.

CONCLUSIONS

Continued smoking, especially early-onset and heavy smoking from adolescence to young adulthood, appears to increase the risk of poor mental health later in mid-adulthood, and quitting smoking in young adulthood may mitigate such risk even among early-onset smokers. Mediation analyses underscore the role of using multiple substances in this pathway.

A bibliometric analysis of the cannabis and cannabinoid research literature

Background

Cannabis refers to a plant in the family Cannabaceae, which has been used medically, recreationally, and industrially. The last two decades, in particular, have seen a large increase in the volume of literature on this topic. The present bibliometric analysis aims to capture the characteristics of scholarly journal publications on the topic of cannabis and cannabinoid research.

Methods

Searches were run on the Scopus database on April 02, 2021, as follows “(TITLE (cannabi* OR hashish OR marijuana OR marihuana)) AND ( LIMIT-TO ( DOCTYPE,"ar" ) OR LIMIT-TO ( DOCTYPE,"re" ) )”. Results were exported on the same day to prevent discrepancies between daily database updates. Only “article” and “review” publication types were included; no further search limits were applied. The “article” publication type includes publications featuring original research, whereas “review” includes reviews and conference papers. The following data were collected: number of publications (in total and per year), authors, and journals; open access status; publications per journal; journals publishing the highest volume of literature and their impact factors, language of publication; document type; publication country; author affiliations; funding sponsors; most highly cited publications; and most highly published authors. Trends in this subset of publications were identified and presented. Bibliometric networks were constructed using the software tool VOSviewer.

Results

A total of 29 802 publications (10 214 open access), published by 65 109 authors, were published in 5474 journals from 1829 to 2021. The greatest number of publications was published over the last 20 years. The journal that published the largest number of publications was Drug and Alcohol Dependence (n = 705). The most productive countries included the USA (n = 12 420), the UK (n = 2236), and Canada (n = 2062); many of the most common institutional affiliations and funding sponsors originated from these countries.

Conclusions

The number of publications published on the topic of cannabis follows an upward trend. Over the past 20 years, the volume of cannabis research has grown steeply, which can be attributed to a large amount of funding dedicated to researching this topic. Future research should continue to investigate changes in the publication characteristics of emerging research, as the volume of publications on this topic is expected to rapidly grow.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00133-0.

Are Drinking Cognitions Associated with Marijuana and Concurrent Alcohol and Marijuana Use among Adolescents and Young Adults?

Background

Concurrent use of alcohol and marijuana (i.e., CAM use) is the most common poly-drug use pattern among adolescents and young adults and is associated with negative outcomes. Research indicates that Prototype Willingness Model (PWM) drinking cognitions are associated with alcohol use. This secondary analysis was conducted to explore cross-sectional associations between PWM drinking cognitions, alcohol, marijuana, and CAM use.

Methods

Adolescents and young adults between 15-25 years (N = 124, M age = 18.7) completed a baseline assessment as part of a larger study, including questions on alcohol and marijuana use, and PWM drinking cognitions.

Results

In the social reaction pathway, descriptive norms, perceived vulnerability, and prototype favorability, but not willingness were associated with greater alcohol use, whereas in the reasoned pathway attitudes and intentions were associated with frequency of drinking whereas injunctive norms were not. Both willingness and intention to drink were related to marijuana and CAM use when controlling for alcohol use frequency. Greater willingness to drink was the only significant predictor of marijuana use, and only descriptive norms predicted CAM use. However, of the cognitions within the reasoned pathway, greater attitudes toward drinking and drinking intention were related to greater marijuana and CAM use. Results also indicated that CAM users displayed higher levels of certain risk cognitions than non-users or single substance users.

Conclusions

Findings support and extend the utility of the PWM by indicating that specific alcohol cognitions are associated with alcohol, marijuana, and CAM use in adolescents and young adults.

Towards quantifying the reciprocal associations between frequency of cannabis use and alcohol consumption: a cross-lagged analysis from the CONSTANCES cohort

OBJECTIVE

Disentangle the temporal relationships between frequency of cannabis use and alcohol consumption.

METHODS

A cross-lagged model providing standardised coefficients (SCs)±their standard errors in 13 255 men and 13 696 women enrolled in 2015 or 2016 in the French population-based 'CONSulTANts des Centres d'Examens de Santé' (CONSTANCES) cohort. Cannabis use was categorised as follows: 'No use during the past 12 months', 'Use during the past 12 months but not in the past month' and 'Use in the past month' for cannabis use at baseline, and No use during the past 12 months, 'Use less than once per month' and 'Use once per month or more' for cannabis use at 1 year of follow-up. Alcohol consumption was measured at baseline and at 1 year of follow-up and three categories were determined: low risk (<28 drinks per week in men; <14 drinks per week in women), moderate risk (≥28 and<42 in men; ≥14 and<28 in women) and high risk (≥42 in men; ≥28 in women). Analyses were adjusted for age, sex, education, income, tobacco consumption, self-rated health status and depressive symptoms.

RESULTS

Both associations from alcohol to cannabis and from cannabis to alcohol were significant (SC=0.02±0.01 with p=0.003 and SC=0.06±0.01 with p<0.001, respectively). However, the SC of the association from cannabis to alcohol was three times higher than the opposite association (p<0.001). After stratification for sex, SCs of the association from cannabis to alcohol were more than two times higher than for the opposite association in men, and more than four times higher in women (both p<0.001).

CONCLUSIONS

The association between frequency of cannabis use and subsequent alcohol consumption was stronger than the opposite association. This finding encourages considering the risk of increased alcohol consumption among cannabis users.

Frequencies of emergency department use and hospitalization comparing patients with different types of substance or polysubstance-related disorders

Background

This study measured emergency department (ED) use and hospitalization for medical reasons among patients with substance-related disorders (SRD), comparing four subgroups: cannabis-related disorders, drug-related disorders other than cannabis, alcohol-related disorders and polysubstance-related disorders, controlling for various clinical, sociodemographic and service use variables.

Methods

Clinical administrative data for a cohort of 22,484 patients registered in Quebec (Canada) addiction treatment centers in 2012-13 were extracted for the years 2009-10 to 2015-16. Using negative binomial models, risks of frequent ED use and hospitalization were calculated for a 12-month period (2015-16).

Results

Patients with polysubstance-related disorders used ED more frequently than other groups with SRD. They were hospitalized more frequently than patients with cannabis or other drug-related disorders, but less frequently than those with alcohol-related disorders. Patients with alcohol-related disorders used ED more frequently than those with cannabis-related disorders and underwent more hospitalizations than both patients with cannabis-related and other drug-related disorders. Co-occurring SRD-mental disorders or SRD-chronic physical illnesses, more years with SRD, being women, living in rural territories, more frequent consultations with usual general practitioner or outpatient psychiatrist, and receiving more interventions in community healthcare centers increased frequency of ED use and hospitalization, whereas both adverse outcomes decreased with high continuity of physician care. Behavioral addiction, age less than 45 years, living in more materially deprived areas, and receiving 1-3 interventions in addiction treatment centers increased risk of frequent ED use, whereas living in semi-urban areas decreased ED use. Patients 25-44 years old receiving 4+ interventions in addiction treatment centers experienced less frequent hospitalization.

Conclusion

Findings showed higher risk of ED use among patients with polysubstance-related disorders, and higher hospitalization risk among patients with alcohol-related disorders, compared with patients affected by cannabis and other drug-related disorders. However, other variables contributed substantially more to the frequency of ED use and hospitalization, particularly clinical variables regarding complexity and severity of health conditions, followed by service use variables. Another important finding was that high continuity of physician care helped decrease the use of acute care services. Strategies like integrated care and outreach interventions may enhance SRD services.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13011-021-00421-7.

Single- and cross-commodity discounting among adults who use alcohol and cannabis: Associations with tobacco use and clinical indicators

BACKGROUND

Delay discounting assessments typically involve choices between an immediate outcome and a larger amount of the same outcome after a delay. Real-world choices, however, more often involve qualitatively different alternatives. The primary aim of this study was to examine single- and cross-commodity discounting of money, alcohol, and cannabis, along with clinical measures of alcohol and cannabis use among people who use both alcohol and cannabis, yet differ in tobacco cigarette smoking status (i.e., dual- versus tri-use).

METHODS

An online crowdsourced sample (N = 318) of people who reported using alcohol and cannabis in the past week completed single- and cross-commodity discounting assessments across each combination of money, alcohol, and cannabis. We recruited a balanced number of people who did and did not also use tobacco cigarettes and examined associations between discounting, tobacco use, and clinical indicators.

RESULTS

People who reported using tobacco cigarettes in addition to alcohol and cannabis tended to engage in significantly higher rates of harmful alcohol and cannabis use than those who reported using only alcohol and cannabis. Cross-commodity discounting was significantly associated with patterns of harmful alcohol and cannabis use while no associations emerged for single-commodity discounting.

CONCLUSIONS

Cross-commodity discounting provides a nuanced account of intertemporal choice by incorporating relative commodity valuation and appears to characterize harmful alcohol and cannabis use more clearly than single-commodity arrangements. Further cross-commodity research is needed to better understand the interplay between temporal location and relative commodity value among people who use multiple substances.

Drug addiction co-morbidity with alcohol: Neurobiological insights

Addiction is a chronic disorder that consists of a three-stage cycle of binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. These stages involve, respectively, neuroadaptations in brain circuits involved in incentive salience and habit formation, stress surfeit and reward deficit, and executive function. Much research on addiction focuses on the neurobiology underlying single drug use. However, alcohol use disorder (AUD) can be co-morbid with substance use disorder (SUD), called dual dependence. The limited epidemiological data on dual dependence indicates that there is a large population of individuals suffering from addiction who are dependent on more than one drug and/or alcohol, yet dual dependence remains understudied in addiction research. Here, we review neurobiological data on neurotransmitter and neuropeptide systems that are known to contribute to addiction pathology and how the involvement of these systems is consistent or divergent across drug classes. In particular, we highlight the dopamine, opioid, corticotropin-releasing factor, norepinephrine, hypocretin/orexin, glucocorticoid, neuroimmune signaling, endocannabinoid, glutamate, and GABA systems. We also discuss the limited research on these systems in dual dependence. Collectively, these studies demonstrate that the use of multiple drugs can produce neuroadaptations that are distinct from single drug use. Further investigation into the neurobiology of dual dependence is necessary to develop effective treatments for addiction to multiple drugs.

Higher Emotion Dysregulation and Coping Motives in Alcoholand Marijuana Users

Prior research indicates that difficulties in emotion regulation may contribute to the use of substances (e.g. alcohol and marijuana) to alleviate negative affect. Therefore, we hypothesized that coping motives for alcohol and marijuana use would serve as an intermediary in the relationship between emotion dysregulation and alcohol/marijuana-related outcomes. Methods: The sample comprised 241 college students who used both alcohol and marijuana and 378 college students who used alcohol only. Parallel indirect effects models were estimated to test the hypothesis that emotion dysregulation is associated with alcohol and marijuana use/problems through alcohol and marijuana coping motives. Results: Coping motives were consistently identified as the driving intermediary when it came to alcohol and marijuana problems, as well as marijuana consumption. Enhancement motives were only implicated in the relationship between emotion dysregulation and alcohol consumption among the alcohol-only group. Conclusion: Overall, the pattern of results suggests that, as hypothesized, alcohol and/or marijuana users higher in emotion dysregulation are more likely to use alcohol or marijuana to alleviate negative affect. Although further research is warranted, individuals who use substances for coping purposes may benefit from interventions designed to improve emotion regulation skills.

Multifaceted impulsivity as a moderator of social anxiety and cannabis use during pregaming

Individuals may drink or use cannabis to cope with social anxiety, and drinking or using cannabis prior to social situations (e.g., pregaming) may be a way to limit the experience of anxiety when entering social settings. However, theoretical and empirical work has reported mixed associations between social anxiety and substance use, specifically alcohol and cannabis. Little work has looked at how other variables, such as impulsivity (a central component to high risk drinking such as pregaming), may shed light onto these mixed findings. College students who reported past year pregaming (n = 363) completed self-report surveys. Supporting prior work, we found that social anxiety was associated with fewer pregaming days, even among those high in sensation seeking. However, those reporting higher social anxiety also reported higher cannabis use during pregaming, specifically among those who reported high sensation seeking and high positive urgency. Results suggest specific facets of impulsivity may affect the association between social anxiety and cannabis use during high risk drinking events.

Reductions in alcohol use following medical cannabis initiation: results from a large cross-sectional survey of medical cannabis patients in Canada

BACKGROUND

Evidence details how cannabis can influence the use of other psychoactive substances, including prescription medications, alcohol, tobacco and illicit drugs, but very little research has examined the factors associated with these changes in substance use patterns. This paper explores the self-reported use of cannabis as a substitute for alcohol among a Canadian medical cannabis patient population.

METHODS

Data was derived from a survey of 2102 people enrolled in the Canadian medical cannabis program. We included 973 (44%) respondents who reported using alcohol on at least 10 occasions over a 12 month period prior to initiating medical cannabis, and then used retrospective data on the frequency and amount of alcohol use pre-and post medical cannabis initiation to determine which participant characteristics and other variables were associated with reductions and/or cessation of alcohol use.

RESULTS

Overall, 419 (44%) participants reported decreases in alcohol usage frequency over 30 days, 323 (34%) decreased the number of standard drinks they had per week, and 76 (8%) reported no alcohol use at all in the 30 days prior to the survey. Being below 55 years of age and reporting higher rates of alcohol use in the pre-period were both associated with greater odds of reducing alcohol use, and an intention to use medical cannabis to reduce alcohol consumption was associated with significantly greater odds of both reducing and ceasing alcohol use altogether.

CONCLUSIONS

Our findings suggest that medical cannabis initiation may be associated with self-reported reductions and cessation of alcohol use among medical cannabis patients. Since alcohol is the most prevalent recreational substance in North America, and its use results in significant rates of criminality, morbidity and mortality, these findings may result in improved health outcomes for medical cannabis patients, as well as overall improvements in public health and safety.

Adolescent Substance Use and the Brain: Behavioral, Cognitive and Neuroimaging Correlates

Adolescence is an important ontogenetic period that is characterized by behaviors such as enhanced novelty-seeking, impulsivity, and reward preference, which can give rise to an increased risk for substance use. While substance use rates in adolescence are generally on a decline, the current rates combined with emerging trends, such as increases in e-cigarette use, remain a significant public health concern. In this review, we focus on the neurobiological divergences associated with adolescent substance use, derived from a cross-sectional, retrospective, and longitudinal studies, and highlight how the use of these substances during adolescence may relate to behavioral and neuroimaging-based outcomes. Identifying and understanding the associations between adolescent substance use and changes in cognition, mental health, and future substance use risk may assist our understanding of the consequences of drug exposure during this critical window.

Binge Drinking, Cannabis Co-Consumption and Academic Achievement in First Year University Students in Spain: Academic Adjustment as a Mediator

Little is known about how binge drinking or the combination of binge drinking and cannabis consumption affect academic achievement in students during the transition to university, or about the mechanisms that mediate this relationship. The purpose of this study was to evaluate the association between this pattern of alcohol/cannabis consumption and academic achievement, considering academic adjustment as a possible mediator. A total of 258 Spanish, first-year university students (145 females and 113 males), enrolled in undergraduate degree courses, were categorized into three groups on the basis of their patterns of alcohol/cannabis consumption: control, binge drinkers and co-consumers. The findings showed a significant effect of the combined binge drinking/cannabis consumption, but not of binge drinking alone, upon academic achievement and academic adjustment. Grade point average (GPA) and academic adjustment were lower in the co-consumers than in the other groups. Regarding the mediation effect, 34.33% of the impact of combined alcohol/cannabis use on GPA was mediated by academic adjustment. The combined consumption of alcohol and cannabis led to difficulties in adaptation to academic life, which in turn contributed to poorer performance at university. The implications of the findings are discussed.

Perceived Social Support from Significant Others among Binge Drinking and Polyconsuming Spanish University Students

Sense of acceptance is conceived as a central component of perceived social support and is thought to be a key resilience factor for adjustment during transition to university. The current study examines how a binge drinking pattern of alcohol consumption and the co-consumption of binge drinking and cannabis in first-year university students are related to perceived acceptance from family, mother, father, and friends. The study sample consisted of 268 women and 216 men, of average age 18.25 years (SE = 0.01), enrolled in the first year of different degree courses at the University of Santiago de Compostela. Participants were classified in three groups (control, binge drinking, polyconsuming) on the basis of the Timeline Followback for alcohol and cannabis. Perceived sense of acceptance was measured using the Perceived Acceptance Scale. Analysis of the data revealed that perceived acceptance was lower in polyconsuming students than in the binge drinking and control groups (p < 0.05; with η2 ranging between 0.009 and 0.020). A curvilinear relationship between binge drinking and perceived acceptance from friends was identified. Social support should be considered in future investigations and interventions as a vulnerability marker for detrimental consequences of substance use and risk of consumption disorders, as well as adolescent maladjustment.

Categorizing Cannabis and Alcohol Use Patterns of Emerging Adults in Psychiatric Partial Hospitalization Treatment

BACKGROUND

Emerging adulthood is a common and problematic time for alcohol and cannabis use. Emerging adulthood also represents a vulnerable time period for anxiety and depression. Substance use and mental health issues are highly comorbid, yet substance use is commonly neglected in psychiatric care.

OBJECTIVE

The goal of this study was to categorize the cannabis and alcohol use patterns of emerging adults in psychiatric care and to evaluate relationships with use-related problems, psychiatric symptomatology, and motives for use.

METHODS

Participants were emerging adults who were consecutive admissions to a young adult psychiatric partial hospital program from 2017 to 2018. Of 318 participants who completed questionnaires, 244 (76.7%) reported cannabis and/or alcohol use in the previous month. Cluster analyses and analysis of variance tests were conducted to categorize and differentiate between participants who reported use.

RESULTS

Results from cluster analyses identified 4 categories of use: low cannabis/high alcohol (35.7%), low cannabis/low alcohol (17.6%), high cannabis/low alcohol (29.1%), and high cannabis/high alcohol (17.6%). Individuals in categories with the highest rates of use and co-use reported more alcohol problems (F=24.31, P<0.001), cannabis problems (F=36.75, P<0.001), depression (F=3.60, P=0.01), and motives: social (F=6.12, P<0.001), coping with anxiety (F=20.43, P<0.001), coping with depression (F=17.80, P<0.001), enhancement (F=7.85, P<0.001), and conformity (F=4.92, P<0.01).

CONCLUSIONS/IMPORTANCE

Clear categories of substance use emerged. Participants who were heavier users were more likely to use to alleviate psychiatric symptomatology, yet they also reported greater psychiatric symptomatology and use-related problems. Among a psychiatric sample of emerging adults, cannabis and alcohol use was common and problematic. Thus, substance use should be evaluated for and, if present, targeted with interventions during psychiatric care.

Age Differences in Daily and Nondaily Cannabis Use in the United States, 2002-2014

OBJECTIVE

Adult cannabis use has increased in the United States since 2002, particularly after 2007, contrasting with stable/declining trends among youth. We investigated whether specific age groups disproportionately contributed to changes in daily and nondaily cannabis use trends.

METHOD

Participants ages 12 and older (N = 722,653) from the 2002-2014 National Survey on Drug Use and Health reported past-year cannabis use frequency (i.e., daily = ≥300 days/year; nondaily = 1-299 days/year; none). Multinomial logistic regression was used to model change in past-year daily and nondaily cannabis use prevalence by age group (i.e., 12-17, 18-25, 26-34, 35-49, 50-64, ≥65), before and after 2007. Multinomial logistic regressions estimated change in relative odds of cannabis use frequency over time by age, adjusting for other sociodemographics.

RESULTS

Daily cannabis use prevalence decreased in ages 12-17 before 2007 and increased significantly across adult age categories only after 2007. Increases did not differ significantly across adult ages 18-64 and ranged between 1 and 2 percentage points. Nondaily cannabis use decreased among respondents ages 12-25 and 35-49 before 2007 and increased across adult age categories after 2007, particularly among adults 26-34 (i.e., 4.5 percentage points). Adjusted odds of daily versus nondaily cannabis use increased after 2007 for ages 12-64.

CONCLUSIONS

Increases in daily and nondaily cannabis use prevalence after 2007 were specific to adult age groups in the context of increasingly permissive cannabis legislation, attitudes, and lower risk perception. Although any cannabis use may be decreasing among teens, relative odds of more frequent use among users increased in ages 12-64 since 2007. Studies should assess not only any cannabis use, but also frequency of use, to target prevention efforts of adverse effects of cannabis that are especially likely among frequent users.

Specificity of expectancies prospectively predicting alcohol and marijuana use in adulthood in the Pittsburgh ADHD longitudinal study

Alcohol and marijuana use expectancies are presumed to be drug-specific, but prospective study of this assumption is lacking. In addition, these associations may operate differently for adults with attention-deficit/hyperactivity disorder (ADHD) histories, as expectancies have been found to be less associated with alcohol and marijuana use among this population. The first aim of the present study was to investigate whether associations between alcohol and marijuana expectancies and substance use were specific to the substances they assess. The second aim was to determine whether these associations differed as a function of ADHD history. Participants (N = 491; 281 ADHD, 210 non-ADHD) were young adults followed longitudinally between ages 21 to 23 and 29 as part of the Pittsburgh ADHD Longitudinal Study (PALS). Autoregressive models were estimated separately for positive and negative expectancies for frequency of alcohol and marijuana use and compared between ADHD groups. Although there were exceptions, results generally support the specificity of associations between outcome expectancies and respective substance use both concurrently and prospectively, but this specificity was primarily present for those without a history of ADHD. These findings suggest that young adults perceive and respond distinctly to the effects of alcohol and marijuana, but a history of ADHD may interfere with this process. These findings also extend our prior cross-sectional findings that expectancies are less associated with alcohol and marijuana use for individuals with ADHD histories. Additional research examining implicit cognitions is needed to further examine risk for substance use among those with ADHD histories. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Alcohol and Marijuana use in Undergraduate Males: Between- and Within-Person Associations with Interpersonal Conflict

BACKGROUND

Among college students, interpersonal conflict with others is a common, yet stressful negative interpersonal experience. Research suggests that drinking episodes may contribute to the occurrence of conflict. Marijuana use, independently or in conjunction with alcohol, may also influence the likelihood of subsequent conflict.

OBJECTIVES

We considered the temporal effects of independent and simultaneous alcohol and marijuana use episodes on the occurrence of interpersonal conflict. Use of multilevel modeling allowed us to distinguish the within-person effects of substance use from between-person differences in frequency of use.

METHODS

Within a sample of 427 college freshman males over 56 days of daily reports, we examined the independent and interactive effects of episodes of alcohol and marijuana on the odds of conflict within the next 1-, 2-, 3-, and 4 hours.

RESULTS

Multilevel modeling analyses showed that drinking episodes increased the likelihood of conflict occurring within the next 1, 2, 3, and 4 hours. Marijuana had weaker positive effects, significant only within the 2 hour window. There were no alcohol by marijuana interaction effects in any analysis.

CONCLUSIONS/IMPORTANCE

Both marijuana and alcohol independently increased the likelihood of interpersonal conflict; however, the marijuana effect appeared less robust. As marijuana use becomes more normative and accessible for college students, it is important to understand the extent to which marijuana use results in negative consequences and the contexts under which these effects unfold.

Psychometric evaluation of a lifetime version of the marijuana problems scale

Introduction

The Marijuana Problems Scale (MPS) is a widely-used self-report measure of cannabis-related negative consequences that has a past three-month reporting window. This report describes the psychometric characteristics of a lifetime version (MPS-L).

Methods

As part of a larger study, 119 individuals who had recovered from cannabis use disorder completed the MPS-L on two occasions 2 weeks apart and 91 participant-nominated family and friends also completed a collateral version of the scale.

Results

Item analyses and principal component analysis (PCA) revealed that three of the 19 items were relatively weaker. Omitting these items, the MPS-L showed good internal reliability (α = 0.88, for summed severity total, α = 0.85 for number of consequences identified) and test-retest reliability (r = 0.81 and 0.73). As expected, correlations with collateral reports were moderate (r = 0.33 and 0.29), and collaterals reported significantly fewer negative consequences than participants. MPS total scores also correlated as expected with external validity measures (e.g., number of cannabis use disorder symptoms reported, motives for use, lifetime depression, treatment history). PCA supported the use of a total score summed score, but also revealed two secondary factors, measuring internal consequences (e.g., low self-esteem) and external consequences (e.g., financial difficulties).

Conclusions

These analyses provide good preliminary support for a lifetime version of the MPS, with the summed severity total score performing slightly better than the total number of consequences endorsed.

•

The psychometric qualities of a lifetime version of the Marijuana Problems Scale (MPS-L) were assessed.

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Two scoring methods for the MPS-L total score showed good internal and two-week test-retest reliability.

•

The summed severity total score performing slightly better than the total number of consequences endorsed.

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Collateral reports from family and friends and responses to a variety of related measures supported the validity of the MPS-L.

A pilot trial of text-delivered peer network counseling to treat young adults with cannabis use disorder

Approximately 1.8 million young adults aged 18 to 25 had a Cannabis Use Disorder (CUD) in the past year. Unfortunately, engaging young adults in treatment is very challenging. Creative approaches to treat cannabis disorders such as integrating mobile technology with evidence-based treatments are warranted. In light of these challenges, we developed a text message-delivered version of Peer Network Counseling (PNC-txt), which is a substance use intervention that focuses on peer relations. PNC-txt engages participants in 16 automated, personalized text interactions over 4weeks. We conducted a randomized controlled trial to test the efficacy of PNC-txt against a waitlist control group with 30 treatment seeking young adults (ages 18-25) who met DSM-5 criteria for CUD. Self-report and urine analyses were used to test outcomes at the three-month follow-up. The PNC-txt group significantly reduced their cannabis use related problems as well as cannabis cravings, compared to the control group. PNC-txt participants also had a significantly greater percentage with urines negative for cannabis metabolites compared to controls. Moderation analysis showed that CUD severity level moderated treatment, suggesting that PNC-txt is more effective for participants with medium and high levels of CUD severity. All effect sizes ranged from medium to large. Results from this pilot trial are promising and warrant further research on PNC-txt for addressing cannabis use disorder.

Drosophila: An Emergent Model for Delineating Interactions between the Circadian Clock and Drugs of Abuse

Endogenous circadian oscillators orchestrate rhythms at the cellular, physiological, and behavioral levels across species to coordinate activity, for example, sleep/wake cycles, metabolism, and learning and memory, with predictable environmental cycles. The 21st century has seen a dramatic rise in the incidence of circadian and sleep disorders with globalization, technological advances, and the use of personal electronics. The circadian clock modulates alcohol- and drug-induced behaviors with circadian misalignment contributing to increased substance use and abuse. Invertebrate models, such as Drosophila melanogaster, have proven invaluable for the identification of genetic and molecular mechanisms underlying highly conserved processes including the circadian clock, drug tolerance, and reward systems. In this review, we highlight the contributions of Drosophila as a model system for understanding the bidirectional interactions between the circadian system and the drugs of abuse, alcohol and cocaine, and illustrate the highly conserved nature of these interactions between Drosophila and mammalian systems. Research in Drosophila provides mechanistic insights into the corresponding behaviors in higher organisms and can be used as a guide for targeted inquiries in mammals.

Co-use of Alcohol and Cannabis: A Review

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the existing literature on the relationship between the co-use of cannabis and alcohol including (1) epidemiology, comorbidity, and associated consequences of cannabis and alcohol use disorders; (2) preclinical and clinical laboratory studies examining behavioral pharmacology of cannabis and alcohol co-use; and (3) clinical outcomes related to co-use.

RECENT FINDINGS

Findings from the literature reviewed suggest that the co-use of alcohol and cannabis is associated with additive performance impairment effects, higher and more frequent consumption levels, increased social and behavioral consequences such as driving while impaired, and greater likelihood of the experiencing comorbid substance use and mental health disorders. Furthermore, co-use may be associated with worse clinical outcomes, yet there are few studies examining the development and evaluation of interventions on reducing the co-use of cannabis and alcohol.

SUMMARY

There is a need for more rigorous and longitudinal research studies on the co-use of cannabis and alcohol to glean a more complete understanding of the relationship between the two substances. Findings can be used to develop and refine intervention strategies to successfully reduce cannabis and alcohol co-use.