Simultaneous versus concurrent use of alcohol and cannabis in the National Alcohol Survey

Prenatal ethanol and cannabis exposure have sex- and region-specific effects on somatostatin and neuropeptide Y interneurons in the rat hippocampus

BACKGROUND

Cannabis is increasingly being legalized and socially accepted around the world and is often used with alcohol in social settings. We recently showed that in utero exposure to both substances can alter the density of parvalbumin-expressing interneurons in the hippocampus. Here we investigate the effects of in utero alcohol and cannabis exposure, alone or in combination, on somatostatin- and neuropeptide Y-positive (NPY) interneurons. These are separate classes of interneurons important for network synchrony and inhibition in the hippocampus.

METHODS

A 2 (Ethanol, Air) × 2 (tetrahydrocannabinol [THC], Vehicle) design was used to expose pregnant Sprague-Dawley rats to either ethanol or air, in addition to either THC or the inhalant vehicle solution, during gestational days 5-20. Immunohistochemistry for somatostatin- and NPY-positive interneurons was performed in 50 μm tissue sections obtained at postnatal day 70.

RESULTS

Exposure to THC in utero had region-specific and sex-specific effects on the density of somatostatin-positive interneurons in the adult rat hippocampus. A female-specific decrease in NPY interneuron cell density was observed in the CA1 region following THC exposure. Combined exposure to alcohol and THC reduced NPY neurons selectively in the ventral dentate gyrus hippocampal subfield. However, overall, co-exposure to alcohol and cannabis had neither additive nor synergistic effects on interneuron populations in other areas of the hippocampus.

CONCLUSIONS

These results illustrate how alcohol and cannabis exposure in utero may affect hippocampal function by altering inhibitory processes in a sex-specific manner.

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.

Interpretations and experiences of subjective effects for alcohol alone and when combined with cannabis: A mixed-methods approach

Subjective effects generally describe the feelings one has when consuming substances. There are several tools available for measuring alcohol-related subjective effects but there are reasons to believe that effects are interpreted differently across participants. The assessment of alcohol-related subjective effects is further complicated by the fact that many people use other substances with alcohol, including cannabis. The present study used a mixed-methods approach to evaluate interpretations of 21 subjective effects used in common assessments among a college student sample (N = 99; primarily White [79%], Hispanic [60%] women [74%], 72% of which reported lifetime couse of alcohol and cannabis). We sought to (a) estimate the prevalence of each effect and the amount of alcohol/number of drinks (and, for those with simultaneous use, amount of cannabis/number of hits) required to experience each effect and (b) evaluate how participants interpreted each effect that they had ever experienced when drinking (for our sample who had used only alcohol) or when simultaneously using alcohol and cannabis (for our sample who had reported simultaneous use). Across both samples, we found that several effects were far more common than others and participants had varied interpretations of each subjective effect. Further, qualitative results demonstrated that participants interpreted some subjective effects in a way that differed from the original intention of the measure. Results suggest a degree of measurement error when using common subjective effects assessment tools. Findings lay the groundwork for standardized measures of subjective effects for simultaneous use and have implications for future real-world assessment and intervention work. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Alcohol and cannabis use and co-use among Whites and Hispanics on and off the U.S./Mexico border in California

This paper examines self-reported rates of drinking and cannabis use and co-use among White and Hispanic adults randomly selected in four counties in California: Imperial on the border; and Kern, Tulare, and Madera in California's Central Valley. Co-use was significantly higher among the U.S. born than among those born abroad, and in the Central Valley than on the border. Co-users were heavier drinkers, had higher rates of alcohol use disorder, other alcohol problems, and a positive history of illicit drug use than drinkers only.

Drinking contexts, coping motive, simultaneous cannabis use, and high-intensity drinking among adults in the United States

AIMS

High-intensity drinking (HID), extreme drinking considerably above the level of heavy episodic drinking (HED), is associated with long-term health and social consequences. There is limited understanding of HID beyond young adulthood. This study aims to identify concurrent risk factors for HID, comparing age differences among all adults.

METHODS

Multinomial logistic and linear regression modeling was performed using a nationally-representative sample of adults (analytic n = 7956) from the 2015 and 2020 National Alcohol Surveys. The outcomes were any HID of 8-11 drinks and 12+ drinks for men, and 8+ drinks for women, and corresponding frequencies. Concurrent risk factors included coping motive, sensation seeking, simultaneous use of alcohol and cannabis (SAC), and drinking at a bar or party. Analyses were stratified by age (18-29 vs. older) and sex.

RESULTS

For younger men, sensation-seeking was significantly associated with HID (vs. no HED) at both levels and frequency of HID 8-11 drinks, while drinking to cope was only significant for 12+ drinks. For older men, drinking to cope was a consistent predictor for both HID level and its frequency, but sensation-seeking was not significant. Both coping and sensation-seeking were significantly associated with any HID for all women, while coping was significant for HID frequency for younger women. Frequent drinking at bars and parties were associated with greater odds of HID for all adults. With HED as referent, similar patterns of (though fewer significant) associations were observed.

CONCLUSIONS

Younger and older adults share similar risk factors for HID, with coping more consistent for older men.

Interactive effects of alcohol and cannabis quantities in the prediction of same-day negative consequences among young adults

BACKGROUND

Simultaneous alcohol and cannabis use is common, but observational studies examining negative consequences of simultaneous use have rarely considered dose-related interactions between alcohol and cannabis. This study examined interactions between quantities of cannabis and alcohol consumed in predicting negative consequences on simultaneous use days.

METHODS

Young adults (N = 151; 64% female; 62% White) reporting recent simultaneous use and at least weekly alcohol and cannabis use completed 21 daily, smartphone-based surveys assessing previous day quantities of cannabis and alcohol used, types of cannabis used (flower, concentrates, edibles), and negative substance-related consequences. Multilevel models examined: (1) whether negative consequences differed within-person across simultaneous use days and single-substance use days; and (2) whether quantities of alcohol and cannabis consumed on simultaneous use days interacted, within-person, to predict negative consequences. We focused on quantities of cannabis flower (grams) in primary analyses and explored quantities of other forms of cannabis (concentrates, edibles) in supplementary analyses.

RESULTS

Participants reported fewer negative consequences on alcohol-only (243 observations) and cannabis-only (713 observations) days than they did on simultaneous use days (429 observations). On simultaneous use days involving cannabis flower use (313 observations across 81 participants), the within-person association between number of standard drinks and negative consequences was weaker on days during which larger (vs. smaller) amounts of cannabis flower were consumed. Inspection of simple slopes revealed that decreased alcohol use was associated with less of a decline in negative consequences when combined with relatively greater amounts of cannabis flower.

CONCLUSIONS

Although simultaneous use was associated with more negative consequences than alcohol-only and cannabis-only use, negative consequences on simultaneous use days varied as a function of the interaction between alcohol and cannabis quantities. As findings suggest that using larger amounts of cannabis may attenuate declines in negative consequences associated with lighter drinking, interventions for higher-risk simultaneous use patterns may benefit from a focus on quantities of both alcohol and cannabis.

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.

Probing the Paradox: Investigating the Impact of Affect, Exercise Type, and Cannabis Use on the Alcohol-Exercise Relationship in College Students

Alcohol has previously shown a paradoxical positive relationship with exercise behaviors. However, the relationship has not been explored according to type of exercise (aerobic vs. anaerobic), nor has the research considered other contextual variables that commonly co-occur with alcohol use, such as cannabis and mood. This study sought to expand upon previous research to understand how the alcohol-exercise relationship may vary based on exercise type. Additionally, this study included cannabis use and mood as moderators of the alcohol-exercise association. Cross-sectional survey data was collected from college students (N = 335). Negative binomial regression was used to test associations between exercise and alcohol consumption, cannabis use, positive affect (PA), negative affect (NA), and moderating effects of these factors on the alcohol-exercise relationship. Effect sizes are reported from an Incidence Rate Ratio (IRR). Sex assigned at birth (male = 1, female = 0; IRR = 1.34, p = .017), PA (IRR = 1.57, p = .001), and alcohol consumption (IRR = 1.94, p = .037) exhibited positive relationships with exercise. Significant main effects were not observed for negative affect (IRR = 1.17, p = .230), or cannabis use (IRR = 1.00, p = .988). There was a significant interaction between positive affect and alcohol consumption (IRR = 0.87, p = .044) predicting exercise minutes. Alcohol was positively associated with exercise for those with low positive affect (n = 42, b = 12.61, p = .096) and this effect was attenuated as levels of positive affect increased (mean positive affect: n = 232, b = 0.55, p = .926; high positive affect: n = 61, b = -15.86, p = .146). These findings suggest that low positive affect may contribute to the positive link between alcohol use and exercise (especially aerobic exercise) in young people.

Is there a relationship between abuse of alcohol and illicit drugs seen in hair results?

Combined use of alcohol and illicit drugs is a serious health and social problem. In this study, it was examined, whether a relationship between alcohol and drug abuse can be ascertained by comparison of alcohol marker and drug concentrations in hair. In the frame of a social support system for families with parental abuse of illicit drugs, hair samples were analyzed between 2011 and 2022 for methadone, heroin (6-acetylmorphine), cocaine, amphetamine, ecstasy (MDMA), cannabinoids (THC), and the alcohol markers ethyl glucuronide (EtG) and ethyl palmitate (EtPa). For 1314 hair samples from adolescent and adult family members, the hair results show a prevalence of combined occasional or regular drug use and social or abusive alcohol use of 41%-60% except heroin (35%). The drug concentrations were statistically compared in the three categories of abstinence or moderate drinking, social drinking, and alcohol abuse. For the most frequently detected drug cocaine (n = 703), a significant increase of the concentrations with rising alcohol consumption was found. The frequent detection of cocaethylene proved the preferred simultaneous intake of both substances. For THC (n = 489), no significant difference between the alcohol consumer groups was seen. Concerning the less frequently detected methadone (n = 89), 6-acetylmorphine (n = 92), amphetamine (n = 123), and MDMA (n = 105), no clear trend between drug and alcohol marker results was determined. It is concluded that the evaluation of hair results is an appropriate way to study the extent of combined drug-alcohol consumption and complements other studies based on acquisition of consumption data by interview or questionnaire.

The association between single and dual use of cannabis and alcohol and driving under the influence and riding with an impaired driver in a large sample of Canadian adolescents

OBJECTIVE

Dual use of cannabis and alcohol has increased in adolescents, but limited research has examined how it relates to impaired driving or riding with an impaired driver (IDR) compared to single substance use. This study aimed to examine the odds of alcohol- and/or cannabis-IDR among adolescents based on their use of alcohol and/or cannabis, and whether associations differed by gender and age.

METHODS

Cross-sectional survey data were used from a sample of 69,621 students attending 182 Canadian secondary schools in the 2021/22 school year. Multilevel logistic regression estimated the odds of exclusive alcohol-IDR, exclusive cannabis-IDR, and both alcohol and cannabis IDR (alcohol-cannabis-IDR). Substance use interactions with gender and age were tested.

RESULTS

Overall, 14.7% of participants reported IDR; 7.5% reported exclusive alcohol-IDR, 3.2% reported exclusive cannabis-IDR, 4.0% reported alcohol-cannabis-IDR, and 7.4% were unsure if they had experienced IDR. The prevalence of IDR varied across substance use groups, 8.0% among nonuse, 21.9% among alcohol-only use, 35.9% among cannabis-only use, and 49.6% among dual use groups. Gender diverse, older, and students with lower socioeconomic status exhibited a higher likelihood of reporting alcohol-cannabis-IDR. Dual use was significantly associated with 9.5 times higher odds of alcohol-cannabis-IDR compared to alcohol-only use, and 3.0 times higher odds compared to cannabis-only use. Dual use was also associated with an increased likelihood of either alcohol- or cannabis-IDR.

CONCLUSIONS

This study highlights that all students, regardless of substance use, are at risk of IDR, but students engaged in dual use of alcohol and cannabis face an elevated risk compared to both peers who do not use substances and those who use only a single substance. These findings emphasize the importance of targeted interventions that address the risks associated with IDR.

Reduced fetal cerebral blood flow predicts perinatal mortality in a mouse model of prenatal alcohol and cannabinoid exposure

BACKGROUND

Children exposed prenatally to alcohol or cannabinoids individually can exhibit growth deficits and increased risk for adverse birth outcomes. However, these drugs are often co-consumed and their combined effects on early brain development are virtually unknown. The blood vessels of the fetal brain emerge and mature during the neurogenic period to support nutritional needs of the rapidly growing brain, and teratogenic exposure during this gestational window may therefore impair fetal cerebrovascular development.

STUDY DESIGN

To determine whether prenatal polysubstance exposure confers additional risk for impaired fetal-directed blood flow, we performed high resolution in vivo ultrasound imaging in C57Bl/6J pregnant mice. After pregnancy confirmation, dams were randomly assigned to one of four groups: drug-free control, alcohol-exposed, cannabinoid-exposed or alcohol-and-cannabinoid-exposed. Drug exposure occurred daily between Gestational Days 12-15, equivalent to the transition between the first and second trimesters in humans. Dams first received an intraperitoneal injection of either cannabinoid agonist CP-55,940 (750 µg/kg) or volume-equivalent vehicle. Then, dams were placed in vapor chambers for 30 min of inhalation of either ethanol or room air. Dams underwent ultrasound imaging on three days of pregnancy: Gestational Day 11 (pre-exposure), Gestational Day 13.5 (peri-exposure) and Gestational Day 16 (post-exposure).

RESULTS

All drug exposures decreased fetal cranial blood flow 24-hours after the final exposure episode, though combined alcohol and cannabinoid co-exposure reduced internal carotid artery blood flow relative to all other exposures. Umbilical artery metrics were not affected by drug exposure, indicating a specific vulnerability of fetal cranial circulation. Cannabinoid exposure significantly reduced cerebroplacental ratios, mirroring prior findings in cannabis-exposed human fetuses. Post-exposure cerebroplacental ratios significantly predicted subsequent perinatal mortality (p = 0.019, area under the curve, 0.772; sensitivity, 81%; specificity, 85.70%) and retroactively diagnosed prior drug exposure (p = 0.005; AUC, 0.861; sensitivity, 86.40%; specificity, 66.7%).

CONCLUSIONS

Fetal cerebrovasculature is significantly impaired by exposure to alcohol or cannabinoids, and co-exposure confers additional risk for adverse birth outcomes. Considering the rising potency and global availability of cannabis products, there is an imperative for research to explore translational models of prenatal drug exposure, including polysubstance models, to inform appropriate strategies for treatment and care in pregnancies affected by drug exposure.

An examination of cannabis use motives among couples with intimate partner violence and alcohol use disorder

BACKGROUND AND OBJECTIVES

Cannabis use is highly prevalent among individuals with a history of intimate partner violence (IPV) and among people who drink alcohol. Motives for cannabis use are important correlates of consumption and problem severity. However, no research has examined cannabis use motives among couples with IPV. The goals of the study were to examine (1) the associations between a person and their partner's cannabis use motives; and (2) examine the extent to which each partners' cannabis use motives are related to their own and their partner's cannabis consumption.

METHODS

Participants were 100 couples (n = 92 different-sex couples, n = 8 same-sex couples) who reported physical IPV in their current relationship.

RESULTS

Certain cannabis motives (coping and conformity) and behaviors (cannabis use frequency, quantity and drug-related problems) were positively associated between intimate partners. One's own higher coping motives were associated with greater frequency of cannabis consumption; higher conformity motives were associated with less quantity of consumption; higher social motives were associated with greater quantity of cannabis consumption; and one's partner's social motives were associated with less quantity of cannabis consumption. DISCUSSION AND CONCLUSIONS: Findings suggest that couples report similar motives for cannabis use, and that one's own and their partner's motives may differentially influence frequency and quantity of use.

SCIENTIFIC SIGNIFICANCE

This study provides novel information on congruency between cannabis use motives and behaviors between intimate partners, as well as how both an individual and their partner's motives for use can influence an individual's cannabis use behaviors.

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.

Association between non-medical cannabis legalization and alcohol sales: Quasi-experimental evidence from Canada

BACKGROUND

There is increasing interest in understanding the impact of non-medical cannabis legalization on use of other substances, especially alcohol. Evidence on whether cannabis is a substitute or complement for alcohol is both mixed and limited. This study provides the first quasi-experimental evidence on the impact of Canada's legalization of non-medical cannabis on beer and spirits sales.

METHODS

We used the interrupted time series design and monthly data on beer sales between January 2012 and February 2020 and spirits sales between January 2016 and February 2020 across Canada to investigate changes in beer and spirits sales following Canada's cannabis legalization in October 2018. We examined changes in total sales, nationally and in individual provinces, as well as changes in sales of bottled, canned and kegged beer.

RESULTS

Canada-wide beer sales fell by 96 hectoliters per 100,000 population (p=0.011) immediately after non-medical cannabis legalization and by 4 hectoliters per 100,000 population (p>0.05) each month thereafter for an average monthly reduction of 136 hectoliters per 100,000 population (p<0.001) post-legalization. However, the legalization was associated with no change in spirits sales. Beer sales reduced in all provinces except the Atlantic provinces. By beer type, the legalization was associated with declines in sales of canned and kegged beer but there was no reduction in sales of bottled beer.

CONCLUSIONS

Non-medical cannabis legalization was associated with a decline in beer sales in Canada, suggesting substitution of non-medical cannabis for beer. However, there was no change in spirits sales following the legalization.

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.

Trajectories of alcohol and cannabis use among emerging adults with a history of unstable housing: Associations with functioning over a two-year period

INTRODUCTION

Research has documented high rates of alcohol and cannabis use among emerging adults experiencing homelessness. However, little is known about trajectories of use over time or how trajectories are associated with functioning (e.g., risk behaviors, mental and physical health, social functioning, economic well-being).

METHODS

Data come from a cohort of 18-25 year olds experiencing homelessness who were surveyed 5 times over 24 months. Parallel process growth mixture models were used to model heterogeneity in alcohol and cannabis use across the 5 timepoints, which allowed for the extraction of classes based on both alcohol and cannabis use trajectories. Classes were compared on demographics and functioning at baseline and 24-months.

RESULTS

Two trajectory classes of alcohol and cannabis use emerged: moderate decreasing cannabis and low stable alcohol use (75% of the sample) and heavy cannabis and alcohol use (25% of the sample). The heavy cannabis and alcohol use class reported a significantly higher likelihood for any non-cannabis drug use at baseline and 24-months, as well as greater depression and physical ailments at 24-months. In addition, at 24-months this class had a marginally higher likelihood of a positive screen for at least moderate anxiety and being recently unhoused.

CONCLUSIONS

The effects of heavy continued cannabis and alcohol co-use on multiple domains of functioning (e.g., risk behavior, mental and physical health) highlight the importance of a coordinated systems approach that addresses the often complex and interrelated challenges facing emerging adults with a history of homelessness.

Psychiatric and substance use disorders among adults over age 50 who use cannabis: A matched cohort study using electronic health record data

INTRODUCTION

Adults over age 50 increasingly use cannabis, but few studies have examined co-occurring psychiatric and substance use disorders (SUDs) in this population. The current study utilized electronic health record (EHR) data to compare adults age 50 + with ICD-10 cannabis codes (cases) and matched controls on common psychiatric and SUDs from 2016 to 2020.

METHOD

Patients age 50 + from an integrated healthcare system in Hawai'i were identified using ICD-10 codes for cannabis (use, abuse, and dependence) from 2016 to 2018. In a matched cohort design, we selected non-cannabis-using controls (matched on sex and age) from the EHR (n = 275) and compared them to cases (patients with an ICD-10 cannabis code; n = 275) on depressive and anxiety disorders and SUDs (i.e., tobacco, opioid, and alcohol use disorders) over a two-year follow-up period.

RESULTS

Participants were 62.8 years (SD = 7.3) old on average; and were White (47.8 %), Asian American (24.4 %), Native Hawaiian or Pacific Islander (19.3 %), or Unknown (8.5 %) race/ethnicity. Conditional multiple logistic regression was used to estimate odds ratios comparing cases vs controls. Participants with an ICD-10 cannabis code had a significantly greater risk of major depressive disorder (OR = 10.68, p < 0.0001) and any anxiety disorder (OR = 6.45, p < 0.0001), as well as specific anxiety or trauma-related disorders (e.g., generalized anxiety disorder, PTSD) and SUDs (ORs 2.72 - 16.00, p < 0.01 for all).

CONCLUSIONS

Over a two-year period, diverse adults age 50 + in Hawai'i with ICD-10 cannabis codes experienced higher rates of subsequent psychiatric and SUDs compared to controls. These findings can guide efforts to inform older adults about possible cannabis-related risks.

Age-related patterns in high-risk alcohol and cannabis use and their associations with positive and negative affect in young adulthood

OBJECTIVE

We examined age-varying associations between young adult simultaneous alcohol and marijuana/cannabis use (SAM) and heavy episodic drinking (HED) and positive and negative affect to inform harm reduction efforts.

METHODS

Young adults reporting past-year alcohol use (n = 556; ages 19-25) were recruited in a state where alcohol and nonmedical cannabis use was legal for those 21 +. Participants provided 24 repeated monthly assessments. Among those reporting past-month cannabis use on at least one survey, logistic time-varying effect models estimated (1) the age-varying prevalence of and associations between past-month SAM and HED and (2) age-varying unique associations of affect with SAM and HED.

RESULTS

There was a positive age-varying association between HED and SAM over time that was highest at age 19 (OR = 7.56), decreased until age 20.7 (OR = 3.39), increased until age 23.0 (OR = 4.85), and decreased until the association became non-significant by age 25. Negative affect was positively associated with SAM from ages 20.7 to 23.0, peaking at age 21.8 (OR = 1.36). Positive affect was positively associated with HED from ages 19.4 to 20.4 (peak OR = 1.25) and ages 22.5 to 24.5 (peak OR = 1.38). In contrast, positive affect was not uniquely associated with SAM nor negative affect with HED across ages 19-25.

CONCLUSIONS

While HED and SAM were positively associated throughout young adulthood and interventions could target them in tandem, their associations with affect suggest differential etiologic processes. Preventive intervention and harm reduction efforts should attend to psychological context in which these behaviors occur.

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.

Risk Factors for Quantity of Cannabis Use Per Day among College Students Who Violated Their University Drug Use Policy

Background

Cannabis use among college students represents a continued public health issue. The objective was to assess risk factors and reasons for cannabis use among students who violated their university's drug use policy, and whether risk factors influenced cannabis use quantity.

Methods

This cross-sectional survey study included 99 college students enrolled at a large U.S. public university. Descriptive statistics were calculated, and an ordinary least squares regression analysis was conducted.

Results

Students reported using cannabis an average of 7.4 (SD = 10.2) days in the past month, with 8% reporting daily use. On average, students consumed slightly over 0.25 (SD = 0.25) grams per day, with 40% reporting greater than one gram per day. The average age of onset of cannabis use was 16.8 (SD = 1.8) years old. The top reasons for cannabis use were to: relax or relieve tension (75.8%), feel good or get high (62.6%), and have a good time with friends (60.6%). Students perceived an average of 47% of their peers engaged in past-month cannabis use and only slight risk was associated with regular use. Students perceived their loved ones would mostly approve of a reduction in their cannabis use. Regression results indicated past-month cannabis frequency (p = .002) and being of racial/ethnic minority descent (p = .05) were positively associated with quantity of cannabis per day, while perceived risk of regular cannabis use (β = -0.21) was negatively associated.

Conclusion

Evidence-based cannabis interventions for students who violate their university's drug use policies are critically needed that aim to reduce cannabis use and mitigate its associated negative 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.

Prevalence and Frequency of Cannabis Use Among Adults Ages 50-80 in the United States

Introduction: Legal access to and attitudes toward cannabis are changing rapidly. Most of the United States and territories allow adults to use medical and/or recreational cannabis. Recent trends demonstrate increasing cannabis use among older U.S. adults. However, little research has examined cannabis use among older adults since 2019, when the COVID-19 pandemic caused major changes in patterns of substance use. Methods: The National Poll on Healthy Aging is a nationally cross-sectional survey that asked U.S. adults ages 50-80 in January 2021 about their cannabis use in the past year. Multivariable logistic regression was used to identify demographic and health characteristics associated with cannabis use. Results: Among 2023 participants aged 50-80 (52.7% female), 12.1% reported cannabis use in the past year. Among those who reported cannabis use, 34.2% reported using cannabis products 4 or more days per week. In multivariable logistic regression, cannabis use was less likely among people who identified as Hispanic ethnicity or as "other" races compared with non-Hispanic white respondents. Cannabis use was more likely among unmarried/unpartnered and unemployed respondents. Those who consumed alcohol were more likely to use cannabis. Conclusions: More than one in 10 U.S. adults aged 50-80 used cannabis in the 1st year of the COVID-19 pandemic, and many used cannabis frequently. As access to and use of cannabis continue to increase nationally, clinicians and policymakers should monitor and address the potential risks among older adults.

Daily diary study of associations between alcohol, cannabis, co-use and sleep quality in individuals with intentions to use cannabis to cope with anxiety

INTRODUCTION

Sleep problems and anxiety conditions are common comorbidities and may be influenced by cannabis and alcohol use. This study examined daily within-person variation in subjective sleep quality among individuals with anxiety symptoms after cannabis or alcohol were used alone, and after co-use.

METHODS

A total of 347 individuals with intentions to use cannabis to cope with anxiety reported their cannabis and alcohol use in the previous 24 h and their previous nights' sleep quality for 30 consecutive days. Mixed-effects models examined whether the within-person daily variation in use of cannabis and alcohol (alone and co-use) was associated with subjective sleep quality. Models also examined whether daily cannabis and alcohol use associations with sleep were moderated by frequency of cannabis, alcohol and co-use during the study period.

RESULTS

Compared to non-use, participants reported better sleep after cannabis-use-only and after co-use, but not after alcohol-use-only. People who more frequently use alcohol and cannabis reported sleeping better after cannabis-use-only days compared to those who use cannabis and alcohol less frequently.

DISCUSSION AND CONCLUSIONS

The study's utilisation of naturalistic data among individuals with anxiety symptoms replicated previously reported experimental findings among individuals without sleep and anxiety problems that overall, cannabis is associated with higher subjective sleep quality. The results expand upon other research to suggest that more frequent use of alcohol and cannabis may moderate daily associations of cannabis use and sleep, potentially through pharmacokinetics and cross-sensitisation.

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.

Are you thinking what I'm thinking? Defining what we mean by "polysubstance use."

The rise in drug overdoses and harms associated with the use of more than one substance has led to increased use of the term "polysubstance use" among researchers, clinicians, and public health officials. However, the term retains no consistent definition across contexts. The current authors convened from disciplines including sociology, epidemiology, neuroscience, and addiction psychiatry to propose a recommended definition of polysubstance use. An iterative process considered authors' formal and informal conversations, insights from relevant symposia, talks, and conferences, as well as their own research and clinical experiences to propose the current definition. Three key concepts were identified as necessary to define polysubstance use: (1) substances involved, (2) timing, and (3) intent. Substances involved include clarifying either (1) the number and type of substances used, (2) presence of more than one substance use disorder, or (3) primary and secondary substance use. The concept of timing is recommended to use clear terms such as simultaneous, sequential, and same-day polysubstance use to describe short-term behaviors (e.g., 30-day windows). Finally, the concept of intent refers to clarifying unintentional use or exposure when possible, and greater attention to motivations of polysubstance use. These three components should be clearly defined in research on polysubstance use to improve consistency across disciplines. Consistent definitions of polysubstance use can aid in the synthesis of evidence to better address an overdose crisis that increasingly involves multiple substances.

Characterizing Alcohol Consumption and Positive and Negative Consequences During Simultaneous Alcohol and Cannabis Use Events

OBJECTIVE

Young adults who engage in simultaneous alcohol and cannabis use report heavy use of both substances. Event-level studies examining differences between consequences experienced on simultaneous use compared with single substance use days have been mixed. Although studies often control for alcohol use levels, few have examined how quantity of alcohol may influence consequences experienced on simultaneous use days. Furthermore, little research has examined the relationship between simultaneous use and positive consequences or explored individual consequences. This study examined differences in consequences experienced on simultaneous use versus single substance use days (alcohol-only, cannabis-only) including endorsement of specific consequences and examined the relationship among simultaneous use, consequences, and alcohol consumption.

METHOD

Young adults who engage in simultaneous use (N = 86) completed 30 days of daily surveys reporting substance use and positive and negative consequences.

RESULTS

Simultaneous use days were associated with more negative and positive consequences than single substance use (alcohol-only and cannabis-only) days. We also examined endorsement of specific positive and negative consequences on alcohol-only, cannabis-only, and simultaneous use days. The effect of day type (simultaneous use vs. alcohol-only) on consequences was moderated by alcohol quantity. On lighter drinking days, more positive and negative consequences were endorsed if it was a simultaneous use versus alcohol-only day. On heavier drinking days, number of consequences did not differ between simultaneous use and alcohol-only days.

CONCLUSIONS

Findings from this study point to simultaneous use as both reinforcing and high risk and highlight the importance of intervening even on lighter drinking simultaneous use occasions to reduce harms.

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.

Is pre-college interpersonal trauma associated with cannabis use?

OBJECTIVE

To examine the prevalence and correlates of lifetime cannabis use (i.e., experimental [use 1-5 times] and non-experimental [use ≥ 6 times]) in relation to interpersonal trauma (IPT) above and beyond relevant covariates.

PARTICIPANTS

A large (n = 9,889) representative sample of college students at an urban university in the southeastern part of the United States.

METHODS

Participants were 4 cohorts of first-year college students who completed measures of demographics, cannabis, alcohol, nicotine, and IPT. Associations were estimated using multinomial logistic regressions.

RESULTS

The prevalence of lifetime cannabis use was 28.1% and 17.4% for non-experimental and experimental cannabis use, respectively. IPT was significantly associated with experimental and non-experimental cannabis use above and beyond effects of sex, race, cohort, alcohol, and nicotine.

CONCLUSIONS

Results show that cannabis use is prevalent among college students and is associated with IPT above and beyond associations with sex, race, and other substance use.

Predicting moderate drinking behaviors in National Health and Nutrition Examination Survey participants using biochemical and demographical factors with machine learning

Recent studies revealed that any amount of alcohol consumption is an overall health detriment to multiple populations, contrary to popular beliefs. In addition, very few alcohol use studies utilized machine learning methods to compare the biological health of moderate drinkers compared to those that abstain from alcohol consumption, opting instead to focus on binge drinking and heavy drinking. Using participant data of multiple factor types from the National Health and Nutrition Examination Survey, we created prediction models with stacked ensembles and gradient boosting models. Machine learning models were used to identify which factors most enabled the prediction of moderate drinking behaviors. Our combined factor runs produced a cross-validation area under the curve (AUC) of 0.929 and a validation area under the curve of 0.806. Runs that only included biochemical or demographical factors received cross-validation AUC values of 0.825 and 0.925, and validation AUC values of 0.757 and 0.783, respectively. The top predictive factors for our machine learning runs, including gamma glutamyl transferase, gender, iron levels, and cigarette and marijuana usage, corroborate past studies that link those factors to alcohol consumption. Our findings identified key differences in the biological health of moderate drinkers compared to those that abstain from drinking. These results reveal a need to further explore the health effects of moderate drinking, especially for vulnerable populations.

The role of sex in daily levels of high-risk alcohol and cannabis co-use

Background

Co-use of alcohol and cannabis is highly prevalent and may be associated with negative outcomes. The intersection between alcohol and cannabis use remains poorly understood. The present study assessed this intersection and the moderating effects of sex on the daily levels of high-risk alcohol and cannabis co-use.

Methods

A secondary analysis of an experimental pharmacology study specifically designed to recruit individuals using both alcohol and cannabis was conducted. Thirty-three non-treatment seeking subjects (19 M/14F) reporting high-risk levels of alcohol and cannabis use completed a 30-day Timeline Follow-back (TLFB) assessment for alcohol and cannabis use, resulting in a total of N = 990 observations. Logistic models tested the probability of same day cannabis use as predicted by alcohol use (any use, total drinking, and binge drinking), sex, and alcohol use by sex interactions.

Results

Drinking any alcohol on a given day was associated with a significant increase in the likelihood of same-day cannabis use (b = 0.61, p = 0.001) as was amount of alcohol consumed on a given day (b = 0.083, p = 0.012). These relations were significantly moderated by sex (b = 1.58, p<0.001; b = 0.14, p = 0.044). Male-identifying individuals demonstrated an increased probability of concurrent cannabis use with any alcohol use on a given day, and this relationship increased linearly as the number of drinks consumed increased.

Conclusions

The present study investigated the patterns associated with co-using alcohol and cannabis in individuals reporting high-risk levels of both alcohol and cannabis use. The sex-dependent findings suggest that males are at higher risk for co-using alcohol and cannabis compared with females.

Sex and Gender Differences in Simultaneous Alcohol and Cannabis Use: a Narrative Review

Purpose of Review

The aim is to review recent literature on sex and gender differences in patterns of use, motives, pharmacological effects, and consequences of simultaneous alcohol and cannabis use (SAC).

Recent Findings

Men engage in SAC more frequently than women. Women may have more substance-specific motives for use, while men tend to consistently endorse social/enhancement motives for both alcohol and cannabis. Regarding pharmacological effects, women experience the same subjective effects as men do at lower levels of use, with some evidence that women modulate cannabis use during simultaneous use episodes to avoid greater subjective intoxication. Finally, women appear more vulnerable to experiencing a range of positive and negative consequences from SAC relative to men.

Summary

Research has identified several important sex/gender differences in SAC and its correlates and consequences. However, research has primarily focused on white and cisgender populations, with a need for more research among racial/ethnic and gender minorities.

Examining Differences in Emotion Dysregulation Between Emerging Adult Alcohol-Only Users, Abstainers, and Simultaneous Users

Objective

Simultaneous use of alcohol and cannabis is associated with more negative consequences than use of either substance alone. Research suggests that emotion dysregulation is linked to alcohol, cannabis, and polysubstance use. However, no previous research has examined whether emotion dysregulation scores differ among individuals without past month substance use (abstainers), individuals who report past-month alcohol use only (no past month cannabis or simultaneous use; alcohol-only users), and individuals who engage in past-month simultaneous alcohol and cannabis use (simultaneous users). Our aim was to examine differences in overall levels of emotion dysregulation and emotion dysregulation subscales between these groups.

Methods

The sample included 468 college students. Participants completed an online survey assessing demographics, emotion dysregulation, average number of drinks per week, days of monthly cannabis use, and simultaneous use of alcohol and cannabis.

Results

A one-way ANOVA showed significant differences in emotion dysregulation between alcohol-only users, abstainers, and simultaneous users. A Bonferroni post hoc analysis revealed significant differences in emotion dysregulation for simultaneous users (p = .004) compared to alcohol-only users and abstainers. A series of ANOVAs were run to examine emotion dysregulation subscale scores and significant differences were found for impulse control difficulties (p = .003) and limited access to emotion regulation strategies (p = .005) for simultaneous users compared to alcohol-only users and abstainers, and for non-acceptance of emotional responses (p = .018) for simultaneous users compared to and alcohol-only users.

Conclusion

These findings indicate that simultaneous users have higher levels of emotion dysregulation, higher levels of impulse control difficulties, greater non-acceptance of emotions, and greater lack of access to emotion regulation strategies compared to abstainers and alcohol-only users.

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.

Cultural and Psychosocial Correlates of co-use among Black-White Biracial Adults

INTRODUCTION

Biracial individuals, a subset of the fastest growing population segment in the United States, frequently experience conflict with ethnic identity, according to marginality theory. Ethnic identity is associated with perceived discrimination and self-esteem, and each of these factors is associated with alcohol and marijuana use. Some research suggests that Black-White biracial individuals have specific challenges with ethnic identity, discrimination, and self-esteem, as well as have disproportionate rates of alcohol and marijuana use separately. Co-use of these substances is linked to more risk behaviors and greater quantity/frequency of use compared to singular use of alcohol or marijuana. However, research examining these cultural and psychosocial factors as correlates of recent co-use among Black-White biracial individuals is limited.

METHOD

The current study examined past-year cultural (i.e., ethnic identity, perceived discrimination) and psychosocial (i.e., age, gender, self-esteem) factors associated with past 30-day co-use (i.e., alcohol, marijuana) among a sample of 195 biracial (Black-White) adults recruited and surveyed via MTurk. We analyzed data using a hierarchical logistic regression.

RESULTS

Results of the final step of logistic regression indicate increases in perceived discrimination were significantly associated with a 1.06 times greater likelihood in 30-day co-use (95% CI [1.002, 1.10]; p = .002). Further, co-use is more common among women than men (OR = 0.50, 95% CI [0.25, 0.98]; p = .04).

CONCLUSIONS

Findings indicate discrimination experienced among Black-White biracial adults is the most culturally relevant correlate of recent co-use in this study, of the factors measured given the framework. As such, substance use treatment with this population may focus on experiences of and coping with discrimination. Since women were also at greater risk for co-use, gender-specific treatments may be beneficial for this population. The article also discussed other culturally relevant treatment considerations.

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.

The interaction of genetic sex and prenatal alcohol exposure on health across the lifespan

Prenatal alcohol exposure (PAE) can reprogram the development of cells and tissues, resulting in a spectrum of physical and neurobehavioral teratology. PAE immediately impacts fetal growth, but its effects carry forward post-parturition, into adolescence and adulthood, and can result in a cluster of disabilities, collectively termed Fetal Alcohol Spectrum Disorders. Emerging preclinical and clinical research investigating neurological and behavioral outcomes in exposed offspring point to genetic sex as an important modifier of the effects of PAE. In this review, we discuss the literature on sex differences following PAE, with studies spanning the fetal period through adulthood, and highlight gaps in research where sex differences are likely, but currently under-investigated. Understanding how sex and PAE interact to affect offspring health outcomes across the lifespan is critical for identifying the full complement of PAE-associated secondary conditions, and for refining targeted interventions to improve the quality of life for individuals with PAE.

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.

Risky drinking and other drug use in adults with chronic conditions in the United States: differential associations by race/ethnicity

Co-use of multiple drugs may prolong or increase heavy drinking, even for individuals with health conditions adversely affected by it. Patterns of alcohol and drug use may vary across racial/ethnic groups, with differential implications for health. This study examines racial/ethnic differences in the associations between risky drinking and other drug use in adults with diabetes, hypertension, heart disease, or cancer. Multiple logistic regression modeling, stratified by condition, was performed using a nationally representative sample of adults drawn from the 2015 to 2019 National Survey on Drug and Health. The outcome was risky drinking (consuming more than 7/14 drinks weekly). Other drugs considered were tobacco, marijuana, illicit drugs, and non-medical prescription drugs. Covariates included age, sex, education, income, marital/cohabitation status, health insurance coverage, and self-rated health status. Each drug category was positively associated with risky drinking across all four conditions. Racial/ethnic minority adults were less likely than White adults to engage in risky drinking, with this pattern most consistent for those with hypertension. Other drug use in minority adults (i.e. tobacco and illicit drug use in Black and Hispanic adults, and marijuana and prescription drug use in Asian adults) was associated with disproportionately greater odds of risky drinking compared with White adults. This pattern was more prominent for those with a heart condition, and not found for those with cancer. Future interventions might address co-use of alcohol and other drugs in adults with chronic conditions, with special attention to racial/ethnic minority adults.

Emerging adult perceptions of higher-risk cannabis consumption behaviours

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Alignment in local approaches to alcohol and cannabis control policy: A case study of California cities and counties

BACKGROUND

Public health experts have urged governments around the world to regulate newly legalized cannabis as they do alcohol to effectively and efficiently protect health. However, research evaluating the alignment of alcohol and cannabis policies is sparse. We assessed similarities and differences in local alcohol and cannabis control policies across California, and characterized localities adopting distinct policy approaches.

METHODS

Using standard legal epidemiologic techniques, we collected and coded local alcohol and cannabis control policies relevant to public health for 12 California counties and all incorporated cities within them (N=241). We assessed whether localities were equally stringent on alcohol and cannabis policies by comparing overall restrictiveness (summed policy scores) and 9 specific provisions that applied to both substances. We captured distinct local alcohol-cannabis policy approaches using latent class analysis, and examined this classification in relation to local demographic, socioeconomic, political, and retail market characteristics.

RESULTS

All 241 localities permitted alcohol sales, while 71% banned cannabis sales. Among those that did not ban cannabis sales, more stringent alcohol policy scores were associated with more stringent cannabis policy scores (linear regression coefficient: 0.16 [95% CI: 0.07, 0.25]). Local governments rarely adopted the same provisions for alcohol and cannabis (e.g., limits on hours of sale, advertising restrictions), and only two regulated the co-location of cannabis and alcohol outlets. Localities that were restrictive on alcohol yet permissive on cannabis (12%) were more urban, politically progressive, and had more low-income and racial/ethnic minority residents. Localities that were more permissive on alcohol and restrictive on cannabis (51%) were more socioeconomically advantaged.

CONCLUSION

We found few similarities between local alcohol and cannabis control policies. California's experience suggests that, as governments around the world legalize cannabis, lessons learned from regulating alcohol are not routinely applied to cannabis, particularly in communities distinguished by high social and economic advantages.

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.

The effects of alcohol and marijuana co-use patterns on intimate partner aggression perpetration

Alcohol and marijuana are two of the most widely used substances in the U.S, with rates of alcohol and marijuana co-use increasing in recent years. Despite this increase, little is known about the effects of alcohol and marijuana co-use patterns (e.g., simultaneous, concurrent) on intimate partner aggression (IPA) perpetration. The purpose of the current study was to examine differences in IPA among simultaneous and concurrent alcohol and marijuana use groups and an alcohol-only group. Participants were 496 individuals (57% identifying as a woman) recruited nationally in April 2020 via Qualtrics Research Services who reported being in a current relationship and recently consuming alcohol. Individuals completed an online survey that included demographics, measures of COVID-19 stress, alcohol and marijuana use, and physical and psychological IPA perpetration. Based on survey responses, individuals were categorized as belonging to the alcohol use only group (n = 300), the concurrent alcohol and marijuana use group (n = 129), or the regular simultaneous alcohol and marijuana use group (n = 67). Due to inclusion criteria, there was no marijuana use only group. Individuals with regular simultaneous or concurrent alcohol and marijuana co-use reported more frequent physical and psychological IPA perpetration compared to those who only used alcohol. Neither physical nor psychological IPA perpetration frequency differed between individuals who reported regular simultaneous versus concurrent alcohol and marijuana co-use. Results suggest that alcohol and marijuana co-use in general, and not the specific pattern of use, is associated with an increased likelihood of IPA perpetration.

Adolescent simultaneous use of alcohol and marijuana by trends in cigarette and nicotine vaping from 2000 to 2020

BACKGROUND

Simultaneous alcohol and marijuana (SAM) use is associated with adverse consequences for youth. While SAM use is overall declining among youth, prior studies indicate increasing marijuana use among US adolescents who ever used cigarettes, suggesting possible moderation of the alcohol-marijuana relationship by cigarette use.

METHODS

We included 43,845 12-th grade students participating in Monitoring the Future data (2000-2020). A 5-level alcohol/marijuana measure was used, including past-year SAM, alcohol-only, marijuana-only, non-simultaneous alcohol and marijuana, or no use. Multinomial logistic regressions estimated associations between time periods (categorized based on sample size: 2000-2005, 2006-2009, 2010-2014, 2015-2020) and the 5-level alcohol/marijuana measure. Models adjusted for sex, race, parental education and survey mode and included interactions of time periods and lifetime cigarette or vaped nicotine use.

RESULTS

While overall SAM among 12th graders decreased from 23.65% to 18.31% between 2000 and 2020, SAM increased among students who never used cigarettes or vaped nicotine (from 5.42% to 7.03%). Among students who ever used cigarettes or vaped nicotine, SAM increased from 39.2% in 2000-2005-44.1% in 2010-2014 then declined to 37.8% in 2015-2020. Adjusted models controlling for demographics indicated that among students with no lifetime cigarette or vaped nicotine use, students in 2015-2020 had 1.40 (95% C.I. 1.15-1.71) times the odds of SAM, and 5.43 (95% C.I. 3.63-8.12) times the odds of marijuana-only (i.e., no alcohol use) compared to students who used neither in 2000-2005. Alcohol-only declined over time in both students who ever and never used cigarettes or nicotine vape products.

CONCLUSION

Paradoxically, while SAM declined in the overall adolescent US population, the prevalence of SAM increased among students who have never smoked cigarettes or vaped nicotine. This effect arises because of a substantial decline in the prevalence of cigarette smoking; smoking is a risk factor for SAM, and fewer students smoke. Increases in vaping are offsetting these changes, however. Preventing adolescent use of cigarettes and nicotine vaped products could have extended benefits for other substance use, including SAM.

The Alcohol and Polysubstance Behaviors of Mandated College Students Prior to Collegiate Sporting Events: An Assessment of Pregaming

Background: Despite a litany of education and prevention efforts seeking to curtail alcohol and other drug (AOD) use behaviors of United States (U.S.) college students, AOD use remains pervasive among the American college student population. Socio-cultural reinforcement of AOD behaviors, such as pregaming (PG), are often considered normative aspects of the collegiate experience, potentially introducing, and/or exacerbating, AOD use among U.S. college students. Objective: Due to the unique relationship PG has with the U.S. college experience and sports culture, this study explored the relationship between PG prior to a live sporting event and frequency of alcohol use, and the likelihood of persons who pregame also engaging in polysubstance use (>1 substance during drinking/use event). Methods: This study was conducted with college students (n = 816) attending a large public university in the Southeastern Conference (SEC) who violated campus alcohol use policies. Results: Beyond the influence of important demographic covariates, PG (p < .001) was significantly associated with a greater frequency of alcohol use. Moreover, students who participated in PG festivities were nearly 2.5 times more likely to participate in polysubstance use. Discussion: PG prior to live collegiate sporting events has clear public health and policy implications. Future efforts should institute and enforce risk-management policies on college campuses and employ event-specific alcohol and polysubstance use prevention and intervention strategies.

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.

Comparing the Efficacy of Mindfulness-Based Relapse Prevention Versus Relapse Prevention for Alcohol Use Disorder: A Randomized Control Trial

OBJECTIVE

This study compared the efficacy of mindfulness-based relapse prevention (MBRP) with relapse prevention (RP) on reducing alcohol consumption. Secondary, exploratory aims assessed moderation of treatment effects by sex and cannabis use.

METHOD

A total of 182 individuals (48.4% female; 21-60 years old) who reported drinking more than 14/21 drinks/week (for women and men, respectively) in the past 3 months but who wished to quit/reduce their drinking were recruited from Denver and Boulder, Colorado. Individuals were randomly assigned to 8 weeks of individual-based MBRP or RP treatment. Participants completed substance use assessments at baseline, halfway through and at the end of treatment, and 20 and 32 weeks after treatment. Primary outcomes were Alcohol Use Disorders Identification Test-consumption questions (AUDIT-C) scores, heavy drinking days (HDD), and drinks per drinking day (DDD).

RESULTS

Across treatments, drinking decreased over time (ps < .001), with a significant time-by-treatment interaction found for HDD (F = 3.50, p < .01). HDD initially decreased in both treatments but remained stable or increased after treatment for MBRP and RP participants, respectively. At follow-up, MBRP participants had significantly less HDD than RP participants. Sex did not moderate treatment effects (ps > .17), whereas cannabis use moderated treatment effects on DDD and HDD (F = 4.89, p < .001, and F = 4.30, p < .005, respectively). High cannabis use frequency was associated with continued posttreatment decreases in HDD/DDD for MBRP participants but increased HDD for RP participants. At low cannabis use frequency levels, HDD/DDD remained stable after treatment across groups.

CONCLUSIONS

Drinking decreases were comparable across treatments, but HDD improvements diminished for RP participants after treatment. In addition, cannabis use moderated treatment efficacy for HDD/DDD.