When alcohol is only part of the problem: An event-level analysis of negative consequences related to alcohol and other substance use

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/58685.

E-cigarettes in college: Associations between mental health and e-cigarette use with other substances

INTRODUCTION

College students are a priority population for substance use prevention, and other studies have reported associations between mental health and e-cigarette use. This study described the association of mental health to e-cigarette and other substance use (ECIG+ use) among US college students.

METHODS

We used Fall 2018 and Spring 2019 National College Health Assessment data among undergraduate students aged 18-24 years (n=55654) at 138 institutions. We characterized substance use patterns and used multinomial regression to model adjusted odds of past 30-day ECIG use type [no substance use (reference); sole e-cigarette use; e-cigarette use and other substance use (ECIG+ use); no e-cigarette use but other substance use] by mental health characteristics, past 12-month diagnosis/treatment and psychological distress, individual characteristics, and college characteristics.

RESULTS

Alcohol was the most prevalent substance (58%) used, followed by cannabis (23%) and e-cigarettes (15%). Nearly all (95%) students who used e-cigarettes reported using another substance. Adjusted odds of ECIG+ use (vs no substance use) were higher among students with past 12-month mental health diagnosis/treatment (AOR=1.5; 95% CI: 1.4-1.6) and higher psychological distress (AOR=1.1; 95% CI: 1.1-1.2). Other characteristics significantly associated with ECIG+ use included gender identity, sexual orientation, race and ethnicity, self-rated health, year in school, cumulative grade average, fraternity/sorority membership, and current residence.

CONCLUSIONS

Most students who used e-cigarettes also reported other substance use, and this pattern of use was associated with poorer mental health outcomes than no substance use. Clarifying the relationship between mental health and ECIG+ use may enhance health interventions for college students.

Long-term impact of familismo and ethnic identity on latinx college student drinking and high-risk consequences

Familismo, ethnic pride, and ethnic shame were examined as longitudinal predictors of Latinx college student alcohol use and high-risk alcohol-related consequences. Latinx students completed measures during the fall of their first (T1), second (T2), and fourth (T4) year of college. T1 familismo was positively associated with T2 ethnic pride and negatively associated with T2 ethnic shame. T2 ethnic pride was negatively associated with T4 drinking, while T2 ethnic shame was positively associated with T4 drinking. T4 drinking was positively associated with T4 consequences. Results suggest that Latinx ethnic pride and ethnic shame during the second-year of college act as mediators between first-year familismo and fourth-year drinking and consequences.

Daily Stress, Drinking Motives and Alcohol Co-Use with Other Drugs

Background: Recent evidence indicates that alcohol and other substance co-use, compared to alcohol-only use, might be more closely associated with negative reinforcement processes, and thus more likely during periods of increased stress. The present study examined this possibility by using data from an intensive longitudinal (daily) study of college student drinkers (N = 1461, 54% women). We also examined individual differences in coping and enhancement drinking motives as predictors of alcohol and other substance co-use. Results: We used multilevel multinomial logistic regression to predict, relative to alcohol-only days, the likelihood of alcohol co-use with either cigarettes or marijuana, along with alcohol use with multiple substances and other substance-only use from daily interpersonal and academic stress, day-of-the-week, sex, and individual differences in coping and enhancement drinking motives. We found that, relative to alcohol-only, alcohol and marijuana co-use was more likely, and non-alcohol related substance use was less likely, on weekends. Alcohol and marijuana co-use was less likely, and other substance-only use was more likely, on days characterized by greater academic stress, whereas alcohol and cigarette co-use was more likely on days characterized by greater interpersonal stress. Individuals with higher levels of drinking to cope motivation were more likely to engage in alcohol and cigarette co-use, other substance-only use, and alcohol plus multiple substances, relative to alcohol-only. Individuals with higher levels of enhancement motives were more likely to engage in all types of alcohol and other substance co-use and other substance-only use relative to alcohol-only. Conclusions: Findings are discussed in terms of the complex nature of different patterns of co-use patterns when evaluating indicators of positive- and negative-reinforcement processes.

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.

A pilot study of the acceptability, efficacy, and iatrogenic effects of a brief dynamic norms intervention for reducing young adult alcohol use

BACKGROUND

Alcohol use and its related consequences are a public health problem among young adults. Building upon efficacious personalized normative feedback interventions, dynamic norms can be used to highlight the decreasing prevalence of alcohol use over time among young adults' peers, thereby increasing their motivation to change drinking consistent with the trend. Because limited research has examined dynamic norms feedback interventions for alcohol use, we examined the acceptability and initial efficacy of such an intervention, and potential iatrogenic effects of showing norms feedback about drinking to light drinkers and nondrinkers.

METHODS

Participants were 546 unvaccinated young adults ages 18-24 who completed a baseline survey, intervention, and 1-month follow-up assessment. Participants were block randomized to receive a brief web-based dynamic norms intervention, with feedback content focused on either (a) alcohol-related behaviors (intervention) or (b) COVID-19 vaccine behaviors (the attention-matched control for the present study).

RESULTS

On average, participants who received the alcohol intervention rated it as generally engaging, helpful, and acceptable, with the majority (90.8%) indicating that they would recommend it to a friend. Supporting initial efficacy, in generalized linear models controlling for demographics and baseline alcohol outcomes, at 1-month follow-up the alcohol intervention was associated with statistically and clinically significant reductions in all indices of perceived drinking norms, drinking quantity, drinking frequency, and driving after drinking occasions. Lighter drinkers showed no adverse iatrogenic effects.

CONCLUSIONS

Presenting alcohol-related personalized normative feedback using dynamic trends is a promising intervention for reducing alcohol use in a community sample of young adults. Further research clarifying the optimal presentation of dynamic norms is needed.

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.

Daily Relations Among Alcohol and Cannabis Co-Use, Simultaneous Use, and Negative Consequences: A Day-Level Latent Profile Analysis

Objective

Concurrent and simultaneous cannabis and alcohol co-use confers risk for daily negative alcohol consequences. However, studies often treat co-use as a dichotomy, precluding examination of higher- and lower-risk co-use days. Additionally, little is known about specific alcohol consequences associated with daily co-use. Therefore, the current study 1) differentiated days based upon alcohol consumption, co-use, and simultaneous use, and 2) tested whether certain day-level use patterns conferred risk for daily alcohol consequences.

Methods

College student co-users (N=489) completed an online Timeline Followback, reporting daily alcohol consumption, negative alcohol consequences, concurrent cannabis and alcohol co-use, and simultaneous co-use (SAM) on drinking days over the past month. Day-Level Latent Profile Analysis differentiated days based upon drinking quantity, co-use, and simultaneous use, and tested whether patterns of use conferred risk for overall and specific negative alcohol consequences.

Results

Four day-level profiles emerged, including moderate consumption of alcohol-only days (57.5%), moderate consumption SAM use days (29.1%), higher consumption alcohol-only days (7.4%), and higher consumption SAM use days (6%). Higher consumption SAM use days were associated with more negative alcohol consequences than all other days; however, higher consumption SAM use days differed from higher consumption alcohol-only days in acute dependence symptoms. Higher consumption alcohol-only days were associated with more negative alcohol consequences than moderate consumption SAM days, particularly those that were action-oriented (i.e., dependence symptoms, blackout drinking, impaired control, risky behavior, social/interpersonal consequences).

Conclusions

Findings suggest that there are in fact lower-risk co-use days, and that links with unique negative alcohol consequences depend on levels of alcohol consumption and co-use.

Does it really matter that I do not remember my night? Consequences related to blacking out among college student drinkers

BACKGROUND

Alcohol-induced blackouts (AIBs) are experienced frequently by college student drinkers and are more likely to occur on days with high-intensity drinking (HID; 8+ for females/10+ for males) than non-HID days. Research suggests that AIBs are associated with experiencing other alcohol-related consequences (ARCs), including more serious ARCs (SARCs; e.g., legal and sexual consequences), but we do not know whether individuals experience more ARCs and more SARCs on occasions when they black out than when they do not black out. This study examines the associations between AIBs and the total number of both ARCs and SARCs.

METHODS

Students (N = 462, 51.7% female, 87.7% White, Mage  = 20.1) were assessed across 6 weekends via e-surveys (80%-97% response rate). Multilevel models were used to test for main effects, controlling for drinking (HID or estimated blood alcohol concentration; eBAC) and sex.

RESULTS

Drinking days when an AIB was experienced were associated with more total ARCs (b = 3.54, 95% CI: 3.10, 3.99) and more SARCs (b = 0.77, 95% CI: 0.60, 0.95) per day than non-AIB days. The more frequently a person experienced an AIB, the more total ARCs (b = 5.33, 95% CI: 4.40, 6.25) and SARCs (1.05, 95% CI: 0.80, 1.30) they reported on average.

CONCLUSION

Alcohol-induced blackout days were associated with higher levels of harm than non-AIB days, even at the same levels of drinking. Interventions that focus on reducing the occurrence of AIBs and factors that contribute to them, in addition to reducing alcohol consumption, may help reduce total harm associated with drinking among college students.

Dynamic relations among simultaneous alcohol and cannabis use, subjective responses, and problem drinking during naturally occurring drinking episodes

BACKGROUND

Simultaneous alcohol and cannabis use (SAM) is associated with riskier drinking. However, little is known regarding mechanisms of risk during drinking episodes. The current study tested whether subjective responses to simultaneous vs. alcohol-only use (i.e., high arousal positive/reward, high arousal negative/aggression, low arousal positive/relaxation, low arousal negative/impairment) were mechanisms through which SAM use was associated with daily drinking.

METHODS

Emerging adults who co-use alcohol and cannabis (N=85) completed 21 days of ecological momentary assessment with drink-contingent reports during drinking episodes. Participants reported on their simultaneous use and current subjective effects during drink reports and past-night total drinks consumed and negative consequences experienced the next morning. Three-level multilevel models (momentary, daily, person level) tested whether SAM use predicted subjective responses, and whether subjective responses mediated associations between SAM use, heavier drinking and negative consequences.

RESULTS

At the momentary and day-level, SAM (vs. alcohol-only) use predicted increased high arousal positive/rewarding, low arousal positive/relaxing, and low arousal negative/impairing subjective effects. SAM use indirectly predicted heavier day-level drinking and further negative consequences through high arousal positive/rewarding response. SAM use also indirectly predicted day-level negative consequences through low arousal negative/impairing response. At the person-level, more frequent SAM use predicted higher person-average high arousal positive/rewarding and low arousal positive/relaxing responses, and high arousal positive/rewarding response mediated relation between SAM frequency and heavier drinking.

CONCLUSIONS

Simultaneous use was associated with reward, relief, and impairment, and reward and impairment were mechanisms of risk between SAM use and riskier drinking. Findings may inform theory and just-in-time interventions seeking to reduce alcohol misuse.

Alcohol-induced blackouts among college student drinkers: A multilevel analysis

OBJECTIVE

To identify factors (manner of drinking, combined alcohol and other substance use, physiology) that are associated with alcohol-induced blackouts (AIBs) over and above estimated blood alcohol concentration (eBAC).

METHODS

Students (N = 462, 51.7 % female, 87.7 % White, Mage = 20.1) were assessed across 6 weekends via e-surveys (80-97 % response rate). eBAC was calculated using standard number of drinks, drinking duration, sex, and weight. Three-level multilevel models (days, weeks, persons) were conducted to test for main effects, controlling for eBAC.

RESULTS

Protective behavioral strategies (PBS) were associated with decreased odds of AIBs on the daily (OR = 0.64, 95 % CI: 0.53, 0.77), weekly (OR = 0.84, 95 % CI: 0.72, 0.98), and person-levels (OR = 0.62, 95 % CI: 0.51, 0.74). Combined cannabis with alcohol was associated with increased odds of AIBs on the weekly (OR = 2.13, 95 % CI 1.13, 4.07) and person-levels (OR = 3.56, 95 % CI 1.60, 7.93). People who more frequently played drinking games (OR = 1.41, 95 % CI: 1.12, 1.77), pregamed (OR = 1.55, 95 % CI: 1.19, 2.03), and showed higher tolerance (OR = 1.22, 95 % CI: 1.08, 1.37) showed increased risk of AIBs, over and above eBAC levels.

CONCLUSION

We identified a number of daily-, weekly-, and person-level factors that uniquely contribute to the prediction of AIBs even at equivalent eBACs. Many of these factors were behavioral, suggesting that they may serve as malleable prevention targets for AIBs in college student drinkers.

Adolescent Polysubstance Use and Co-Occurring Weapon Carrying, Bullying Victimization, and Depressive Symptomology: Patterns and Differences in the United States

Adolescent substance use commonly co-occurs with poor mental health, bullying victimization and risky behaviors that may lead to violence. The purpose was to describe the United States (US) national prevalence of polysubstance use and co-occurring characteristics and associated demographic characteristics among youth. Middle and high school students in the 2019 CDC YRBS survey reported their demographics and current ( ≥ 1 days in the last 30 days) substances used (alcohol, cigarette, e-cigarette, cannabis); polysubstance combinations were generated. Cross-sectional weighted logistic regression estimated odds of polysubstance use and frequent use ( ≥ 6 days in the last 30 days) by weapon carrying, depressive symptoms, bullying victimization, and demographics. Mean age of the sample was 16 years, 51% were boys, 51% were non-Hispanic White. While accounting for 21% of the sample, 22-40% of Multiracial youth reported polysubstance use and frequent use. Odds of frequent polysubstance use (all combinations) were highest for weapon carrying youth.

A qualitative examination of positive and negative consequences young adults experience from simultaneous alcohol and cannabis use

OBJECTIVE

Alcohol and cannabis are two of the most commonly used substances among young adults, and most individuals who use both substances use them simultaneously, that is, on the same occasion such that their effects overlap. Given the high prevalence of simultaneous alcohol and cannabis use, it is important to understand the relationship between simultaneous use and consequences. This study presents a qualitative examination of positive and negative consequences of simultaneous use.

METHOD

We conducted individual interviews among 36 young adults who engage in simultaneous use (23 women, 12 men, 1 trans man). Interviews included open-ended questions examining negative and positive consequences of simultaneous use and how simultaneous use differed from single substance use (alcohol only use, cannabis only use). Interviews were analyzed using applied thematic analysis.

RESULTS

Young adults reported numerous negative and positive consequences of simultaneous use, many overlapping with single substance use. Yet, they also reported unique combinations of positive consequences not experienced by single substance use. Young adults discussed patterns of use that were sometimes approached intentionally (e.g., quantity of substances used, order) that influenced consequences.

CONCLUSIONS

Together these findings provide further insight into young adults' simultaneous use experiences. Next steps should include quantitative exploratory research to identify and determine the frequency of specific consequences experienced during simultaneous use and examine the relationship between simultaneous use consequences and particular patterns of use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Associations between alcohol and cannabis use order, frequency, quantity, and consequences in a college sample of individuals who co-use alcohol and cannabis

BACKGROUND AND OBJECTIVES

Using both alcohol and cannabis (either at the same time or at different times) is common among college students, and is called "co-use." Using these substances simultaneously, such that their effects overlap, is thought to be an especially risky co-use pattern. Gaining a better understanding of how co-use patterns relate to substance use and consequences could aid prevention and intervention efforts.

METHODS

We examined college students (N = 401) who reported using both alcohol and cannabis at least once in the past 30 days. Path analysis was used to explore relations among co-use patterns (number of days in a typical week that participants used both alcohol and cannabis; the number of days using alcohol first, cannabis first, alcohol last, and cannabis last; the number of days of simultaneous use), past-30-day alcohol and cannabis consequences, use frequency, and typical quantities used.

RESULTS

Each additional day of using alcohol first was associated with fewer past-30-day cannabis consequences. Each additional day of using cannabis first was associated with fewer alcohol-related consequences. Each additional day of using alcohol and cannabis on the same day and each additional day of simultaneous use were both associated with less cannabis used and alcohol consumed in a typical week.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

This study is among the first to identify associations between alcohol and cannabis order and outcomes (i.e., consequences and consumption). Results suggest that modifying which substance is used first on a given day could be a practical intervention strategy for individuals who co-use alcohol and cannabis.

Acute Consequences Associated With Co-use of Alcohol and Cannabis: A Daily Survey Analysis

OBJECTIVE

Co-use of alcohol and cannabis has been associated with more total negative consequences than single-substance use, but results have been mixed depending on whether the single substance was alcohol or cannabis. The present study used within-person analyses to examine whether co-use increased the risk for experiencing specific acute negative consequences.

METHOD

College students who were co-users of alcohol and cannabis (N = 341; M age = 19.8 years; 51.3% female; 74.8% White) completed 56 days of five daily surveys across two bursts. We used generalized linear mixed effects models to examine the effects of type of substance use day on specific negative consequences, controlling for consumption and covariates.

RESULTS

Relative to both alcohol-only and co-use days, cannabis-only days were associated with decreased likelihood of experiencing hangover, blackout, nausea/vomiting, injury, rude/aggressive behavior, and unwanted sex. Relative to alcohol-only days, cannabis-only and co-use days were associated with an increased likelihood of driving high/drunk. Finally, there was an increased likelihood of hangovers on alcohol-only days compared with co-use days.

CONCLUSIONS

Days with different types of substance use differed in specific consequences. Most of the negative co-use consequences investigated here appear to be driven by alcohol consumption rather than cannabis use. The results also indicated that these young adults were more likely to endorse driving under the influence of cannabis than alcohol. Interventions for co-use should target alcohol consumption to reduce negative consequences such as blackout, injury, rude/aggressive behavior, and unwanted sex and highlight the dangers of driving under the influence of cannabis.

Prevalence and correlates of alcohol-induced blackout in a diverse sample of veterans

BACKGROUND

Alcohol-induced blackouts have been associated concurrently and prospectively with alcohol-related harm. Although rates of heavy drinking among military samples tend to be comparable or higher than rates among civilian samples, the prevalence and correlates of blackout in the military population are understudied.

METHODS

Veterans (N = 241, 29% female, 39% Black) reported on their alcohol consumption and mental health as part of a larger health-related study among veterans. In this secondary analysis, we tested theoretically and empirically informed predictors (gender, drinking quantity, and other drug use) and consequences [depression, posttraumatic stress disorder (PTSD)] of alcohol-induced blackout. Given the diversity of the sample, potential roles of racial/ethnic discrimination and drinking to cope in alcohol-induced blackout were also tested.

RESULTS

Past-year prevalence of alcohol-induced blackout was 53% among veterans who drank alcohol and 68% among those who screened positive for hazardous drinking. Everyday experience of racial discrimination was the strongest concurrent predictor of alcohol-induced blackout. Drinking quantity and use of other drugs were significant correlates only in bivariate models. Controlling for gender, race, drinking quantity, other drug use, and discrimination, blackout frequency was significantly associated with symptoms of depression, but not symptoms of PTSD. Both blackout and racial discrimination were associated with drinking to cope.

CONCLUSIONS

The prevalence and correlates of alcohol-induced blackout among veterans are largely consistent with those documented in civilian and young adult populations. Among racially diverse groups, racial discrimination may be more strongly associated with mental health symptoms than alcohol consumption or acute alcohol consequences such as blackout.

Sexual Victimization in the Digital Age: A Population-Based Study of Physical and Image-Based Sexual Abuse Among Adolescents

Adolescents increasingly use social media platforms, and these practices open up new forms of sexual victimization, in particular image-based sexual abuse (IBSA). Few studies have examined prevalence rates and correlates of both physical sexual victimization (PSV) and these new forms of victimization in representative samples. We used data from 5,245 adolescent girls (53%) and 4,580 adolescent boys (47%) from the population-based Young in Oslo Study (mean age 17.1 years, SD = 0.9). Of all respondents, 2.9% had experienced IBSA, 4.3% PSV, and 1.7% both IBSA and PSV in the course of the previous 12 months. Multivariate analyses revealed that PSV victims, after control for other variables, had many characteristics described in previous studies of sexual victimization. Girls had higher prevalence rates than boys, many had been victims of other types of violence, and were part of peer groups with much use of alcohol and drugs. PSV victims also reported early intercourse onset and a higher proportion had been commercially sexually exploited. Lesbian, gay, and bisexual adolescents had higher victimization rates. Victims of both PSV and IBSA had a similar but even more pronounced profile. The IBSA victims were different: They lacked many of the traditional risk factors for sexual victimization, there were no significant gender differences in this group, and IBSA victims more often came from high socioeconomic backgrounds. In conclusion, we observe a reconfigured landscape of sexual victimization patterns among Norway adolescents due to their increasing participation on social media and digital platforms.

Risky Drinking in Adolescents and Emerging Adults: Differences between Individuals Using Alcohol Only versus Polysubstances

BACKGROUND

Factors related to risky drinking (e.g., motives, protective behavioral strategies [PBS]) may vary between youth who engage in polysubstance use compared to those who consume alcohol only. We examined differences in factors among youth who consume alcohol only compared to alcohol with other substances (i.e., polysubstance use), and correlates associated with risky drinking between the groups.

METHODS

Participants (N = 955; ages 16-24; 54.5% female) who reported recent risky drinking completed measures of alcohol/substance use, alcohol-related consequences, drinking motives, alcohol PBS, mental health symptoms, and emotion dysregulation. Participants were in the polysubstance group if they reported using at least one other substance (e.g., cannabis, stimulants) in addition to alcohol in the past three months. Chi-square and t-tests examined differences between the two groups and multiple regression analyses examined correlates of risky drinking.

RESULTS

Most participants (70.4%, n = 672) reported polysubstance use; these individuals engaged in riskier patterns of drinking, experienced more alcohol-related consequences, used fewer PBS, had stronger drinking motives (enhancement, social, coping), endorsed more mental health symptoms, and reported more emotion dysregulation. Regression models showed that emotion dysregulation significantly associated with risky drinking in the alcohol-only group; conformity and coping motives, alcohol PBS, and anxiety symptoms significantly associated with risky drinking in the polysubstance group.

CONCLUSIONS

Among risky drinking youth, results indicated youth engaging in polysubstance use have greater comorbidities and individual-level factors associated with risky drinking than youth who consume alcohol only. These findings may inform the tailoring of interventions for individuals who engage in risky drinking and polysubstance use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Examining the heterogeneity of polysubstance use patterns in young adulthood by age and college attendance

Substance use in young adulthood and polysubstance users (PSU), in particular, pose unique risks for adverse consequences. Prior research on young adult PSU has identified multiple classes of users, but most work has focused on college students. We examined PSU patterns by age and college attendance during young adulthood in two nationally representative samples. Using National Epidemiological Survey on Alcohol and Related Conditions (NESARC) Wave 1 and NESARC-III data sets, multigroup latent class analysis (MG-LCA) was employed to examine PSU patterns based on age (18-24 vs. 25-34) and determine whether solutions were similar (i.e., statistically invariant) by college attendance/graduation. Classes were estimated by binary past-year use of sedatives, tranquilizers, opioids/painkillers, heroin, amphetamines/stimulants, cocaine, hallucinogens, club drugs, and inhalants, and past-year frequency of alcohol, cigarette, and cannabis use. PSU patterns are largely replicated across waves. Model fit supported 3-class solutions in each MG-LCA: Low frequency-limited-range PSU (alcohol, cigarettes, and cannabis only), medium-to-high frequency limited-range PSU (alcohol, cigarettes, and cannabis only), and extended-range PSU (ER PSU; all substances). Apart from one model, MG-LCA solutions were not invariant by college attendance/graduation, suggesting important differences between these groups. Except for alcohol, cannabis, and cigarette use frequency, results showed that probabilities of illicit and prescription drug use declined in the older age group. Findings also supported examining college and noncollege youth separately when studying PSU. ER PSU may be uniquely vulnerable to coingesting substances, particularly for nongraduates, warranting future research to classify patterns of simultaneous PSU and identify predictors and consequences of high-risk combinations (e.g., alcohol and opioids). (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Examining the impact of early college experiences on the cumulative number of alcohol-related consequences

OBJECTIVE

To estimate the total number of alcohol-related consequences students experience during 4 years of college and examine early college indicators that result in higher rates of consequences.

METHOD

Undergraduate drinkers (N = 1,744; 58% female; 87% White; 5% Hispanic) at a large northeastern university completed an online survey at the end of the fall and spring semesters during their first (T1, T2), second (T3, T4), third (T5, T6), and fourth (T7, T8) years of college (87% retention across the study). First, descriptive statistics were calculated to estimate the total number of alcohol-related consequences students experienced across all 4 years of college. Second, a structural equation model was examined to identify early college indicators that influence individuals experiencing more cumulative consequences.

RESULTS

Students experienced an average of 102 (SD = 89.91) alcohol-related consequences during 4 years of college. Next, early parental approval of consequences, but not peer drinking norms, were positively associated with students' willingness to experience consequences, which in turn, were positively associated with higher alcohol consumption and greater total consequences.

CONCLUSIONS

Results estimated that, on average, students experienced 102 alcohol-related consequences across all 4 years of college. Parental approval of consequences influenced students' total consequences through their willingness to experience consequences and drinking behaviors. Findings from the current study have several important implications for interventions.

Substance Use, Risky Sex, and Peer Interactions Predict Sexual Assault Among College Women: An Ecological Momentary Assessment (EMA) Study

Sexual assault is an unfortunately common experience among women in college campuses. This study used ecological momentary assessment (EMA) to gain a better understanding of the contextual determinants of sexual assault among college women. EMA reports inquired about sexual assault experiences, risky sex (sex without a condom and regretted hookups), and substance use (alcohol and cannabis use), as well as what activities participants were engaged in (e.g., pregaming, drinking with peers, and drinking with a casual sexual partner), and whether they experienced peer pressure to engage in casual sex. Participants were 103 freshman undergraduate women (18-24 years old) at a Southwestern university in the United States, who were unmarried, interested in dating opposite-sex partners, engaged in binge drinking (defined as having 3 or more drinks on one occasion) in the past month, and reported at least one experience of sexual intercourse in their lifetime. Participants completed reports (one random and two time-contingent) via EMA three times a day over a 42-day period. Compliance in completing EMA reports was good (84.2% of prompted reports were completed), and time-to-completion of reports once signaled was acceptable (mean = 26 minutes, median = 5.75 minutes). During the 42 days, 40 women (38.8%) reported 75 occasions of sexual assault. The odds of experiencing sexual assault were significantly greater during occasions of regretted hookups and unprotected sex. Additionally, drinking with peers and peer pressure to engage in casual sex were each associated significantly with occasions of sexual assault. Reducing risk for sexual assault among undergraduate women may be possible by targeting these behaviors and contextual features in near real-time via momentary intervention.

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

PURPOSE

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

SEARCH METHODS

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

SEARCH RESULTS

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

DISCUSSION AND CONCLUSIONS

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

Stress and Affect as Daily Risk Factors for Substance Use Patterns: an Application of Latent Class Analysis for Daily Diary Data

At the population level, use of multiple substances (or "co-use") is prevalent in young adulthood and linked with increased risk for experiencing substance-related harms. Less understood is the heterogeneity of substance use behaviors within individuals and across days, as well as the proximal predictors of these daily use patterns. The present study applied latent class analysis to daily diary data to identify daily substance use patterns and compare day-level class membership based on day-level stress and positive and negative affect among a higher-risk sample of young adult substance users. Participants (n = 152) completed up to 13 daily assessments of stress, affect, and substance use behavior. Among substance use days, five classes of days were identified: cannabis (some alcohol; 43% of days), alcohol-only (26%), vaping (some alcohol, cannabis; 24%), stimulant + alcohol (some cannabis, vaping; 4%), and cigarette-only (3%) days. Days with lower levels of perceived stress were significantly more likely to be alcohol-only Days relative to being days characterized by cigarette use, cannabis use, or multiple drug combinations. Days with higher levels of stress and negative affect were more likely to be cigarette-only days relative to cannabis and vaping days. Study findings document the wide range of substance use and co-use behaviors exhibited among young adults in daily life and highlight the importance of considering risk factors that correspond to days of problematic use patterns.

Associations between social network characteristics and alcohol use alone or in combination with cannabis use in first-year college students

OBJECTIVE

Simultaneous use of alcohol and cannabis is common among young adults, but little research has examined social ties and their relation to simultaneous use. This study investigated the social network characteristics of college students at two time points in the first year of college. Participants were categorized into those who used alcohol and cannabis, such that their effects overlap (simultaneous users), those who used both substances without overlapping effects (concurrent users), and those who used alcohol only.

METHOD

First-year college students (N = 1,294) completed online questionnaires during the fall and spring semester. At both assessments, participants nominated up to 10 important peers in their class, reported on peers' alcohol and cannabis use, and reported their own use of alcohol or cannabis with each peer.

RESULTS

Concurrent and simultaneous users reported a greater proportion of drinking buddies than those who used alcohol only. A greater proportion of friends who used alcohol or cannabis, but not the proportion who were "drinking buddies" or "cannabis buddies," was associated with increased odds of simultaneous use relative to concurrent use. Participants nominated network ties that paralleled their own substance use (e.g., the majority of simultaneous users' networks ties were also simultaneous users).

CONCLUSION

Having a larger percentage of friends who use cannabis and alcohol is associated with increased odds of using both substances at the same time, perhaps because it gives access to both substances at the same time. Interventions should account for amount of exposure to alcohol and cannabis use from network members. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Drinking less on cannabis use days: The moderating role of UPPS-P impulsive personality traits

Objective: Several studies suggest that alcohol and cannabis co-users are heavier drinkers and experience more alcohol-related consequences. However, day-level associations between co-use and drinking levels are mixed. One reason may be that individual characteristics moderate the daily impact of using alcohol alone or in conjunction with cannabis. The theory would suggest that highly impulsive individuals may drink more on co-use days, yet this assertion remains untested. Therefore, the current study tested whether impulsivity moderated the effect of co-use on same-day drinking quantity within veterans, a high-risk sample for substance use and impulsivity. Method: In a longitudinal observational study, co-using veterans (N = 139) completed three semi-annual assessments reporting on their daily drinking quantity and cannabis use via Timeline Followback (Observations = 19,245) and impulsivity via the UPPS-P. Mixed effect modeling was used to test hypotheses that co-use (compared to alcohol-only) days would be associated with heavier drinking for those high (but not low) in positive and negative urgency. Results: Significant interactions were found for positive urgency (PU) and lack of perseverance (LP), such that individuals at mean and low levels of PU and LP drank less on co-use (compared to alcohol-only) days. There were no significant interactions for other UPPS-P impulsivity facets. Conclusion: Findings are consistent with a substitution/compensatory effect for individuals at mean and low levels of both UPPS-P facets, and may be a byproduct of frequent cannabis use in veterans. In contrast, findings suggest that co-use and alcohol-only days may be characterized by similarly high levels of drinking for highly impulsive individuals. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Alcohol and cannabis co-use and social context as risk pathways to sexual assault

Objective: Simultaneous use of alcohol in combination with cannabis ("co-use") is common among young adults, and associated with myriad consequences. Yet no studies have examined how co-use may confer vulnerability for sexual assault (SA). Further, though both co-use and SA commonly occur in social settings, there have been no examinations of the role that co-use may play in the broader social context that leads to assault risk. This was the objective of the present study. Method: In a community sample of young adult women, (N = 174; Mage = 22.6), we examined risk pathways to SA, guided by Routine Activities Theory (Mustaine & Tewksbury, Criminal Justice Review, 2002, 27, 89). Using a longitudinal burst design with 27 daily assessments across 1 year, women reported on their own and others' alcohol, cannabis, and co-use, and on social context and assault experiences. Results: Multilevel path model results showed alcohol and cannabis co-use to confer unique risk for SA, above and beyond the influence of use of either substance alone. Intoxication and components of the co-use social context (proximity to offenders) mediated this risk. Importantly, we observed a key role for co-use by others within the social context in assault risk. Conclusions: This study adds to the literature by providing a nuanced and contextual account of how cannabis-alcohol co-use may lead to assault vulnerability in young adult women. Findings underscore the need for intervention efforts that expand their focus to include the broader social context, and the role that the use and co-use behaviors of others may play within this context. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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

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

Ordering in alcohol and cannabis co-use: Impact on daily consumption and consequences

BACKGROUND

Co-use of alcohol and cannabis is highly prevalent among young adults and college students. Between-person reports suggest that co-use is associated with the experience of more frequent consumption and related consequences, compared to single substance use. However, recent studies have found conflicting evidence regarding the impact of co-use use on consumption and consequences in daily or event-level investigations. Conflicting evidence may be due to understudied factors, such as the order in which alcohol and cannabis are used. The current study aimed to examine the effect of substance use order on a) alcohol consumption; b) cannabis consumption; and c) negative alcohol and cannabis consequences.

METHODS

Data were collected from U.S. undergraduate college student alcohol and cannabis users (N = 258) who completed two 28-day longitudinal online assessment bursts examining alcohol and cannabis co-use patterns. Data were collected five times per day during both bursts (three months apart).

RESULTS

Controlling for between-person alcohol and cannabis use, within-person mixed-effects models indicated that using cannabis first within a co-use day was associated with lower daily alcohol consumption, but greater daily cannabis consumption. Substance use ordering was not linked to consequences, whereas between-person levels of alcohol consumption and within-person number of drinks in a day were positive predictors of consequences.

CONCLUSIONS

Overall, results highlighted that order of substance use is a robust predictor of consumption on co-use days. Therefore, future research on co-use use should consider patterns of use in addition to level of use.

College students' using marijuana to sleep relates to frequency, problematic use, and sleep problems

OBJECTIVE

Given the rising rates of insufficient sleep and the popularity of marijuana, we investigated using marijuana as a sleep aid, marijuana use frequency, problematic marijuana use, and sleep problems. Participants: Participants included a convenience sample of college students who endorsed using marijuana in the past year from May to December 2013 (N = 354; 68% female, 57% White). Methods: Path analyses investigated if using marijuana to sleep predicted: (1) marijuana use outcomes and (2) sleep problems; and if sleep problems predicted marijuana use outcomes. Results: Using marijuana to sleep was related to increased use and problematic use, as well as worse sleep efficiency. Daytime dysfunction related to sleepiness was associated with elevated levels of marijuana use and problematic use. Similar associations were found across sex and race. Conclusions: College students should be informed of the potential misconceptions between marijuana and improved sleep and provided with evidence-based alternatives to improve their sleep.

Motivations to combine alcohol and nicotine in college students: A validation of the Alcohol and Nicotine Motives Scale

INTRODUCTION

Research on combining alcohol and nicotine (ALCNIC) has shown this risky behavior results in significantly more consequences than using either alcohol or nicotine alone. No measures currently exist to assess ALCNIC motives limiting intervention and prevention efforts. The present study developed a psychometrically sound and multidimensional measure of ALCNIC motives (the ANMS).

METHODS

An initial item pool of ALCNIC items was developed from literature on college student drinking, focus groups, and individual interviews. Study 1 involved students from a northeastern university who completed an online survey on the ALCNIC items (N = 55; 57.1% female; Mage = 20.3). Analysis focused on reliability (exploratory factor analysis). Study 2 involved a cross-validation national sample of college students (N = 336; 49.7% female; Mage = 21.2) completing the same survey items. Confirmatory factor analysis, criterion-related validity (ALCNIC/weekend drinking), and discriminant validity (social desirability) were assessed using structural equation modeling.

RESULTS

Results across two studies revealed three factors to engage in ALCNIC: antagonistic (party longer), synergistic (enhanced effects), and social (peer pressure); and one factor to avoid ALCNIC: negative effects (feeling anxious) (all alphas > 0.7). In study 2, criterion-related validity revealed that synergistic motives were significantly positively associated with ALCNIC use; and negative effects motives were significantly negatively associated with ALCNIC use. Discriminant validity showed ALCNIC subscales were not significantly associated with social desirability (except social).

CONCLUSIONS

The study developed a reliable and valid measure of motives for ALCNIC use. Results were robust to cross-validation across two samples of college students. These measures provide targets for intervention and prevention efforts.

Intentions and motives to experience alcohol-induced blackout among young adults in college

Blackouts are typically considered a negative consequence of alcohol use. Yet some college students report consuming alcohol with the intention of blacking out. This study examined intentions and motives for blackout drinking among young adults in college. College students with a past-year history of blackout (N = 350, 56% female, 73% White) completed an anonymous online survey. Descriptive statistics were used to examine the incidence of blackout intentions, and individuals who did and did not report future blackout intentions were then compared on drinking patterns, depressive symptoms, social norms, and outcome expectancies. Overall, 135 participants (39%) reported consuming alcohol in the past 30 days with the intention of losing memory of the night's events, and 107 (31%) reported blackout intentions in the next 30 days. When asked (via open text box) to indicate their motives for past blackout intentions, the majority of participants provided responses that fit with coping, social, or enhancement drinking motives. A larger proportion of men than women reported blackout intentions. As a group, those reporting future blackout intentions reported heavier, more frequent, and more problematic drinking, as well as more symptoms of depression and more positive (but not negative) outcome expectancies. A substantial subset of college students reporting a blackout in the past year also endorsed intentions to experience a blackout in the next 30 days. Given strong associations between intentions and subsequent behavior, interventions targeting blackout styles of drinking are warranted. The extent to which "blackout" drinking motives differ from traditional drinking motives is unclear. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Characterizing symptoms of cannabis use disorder in a sample of college students

Since legalization of marijuana in several U.S. states in 2012, there has been concern about increases in the development of cannabis use disorder (CUD). The current study examined rates of CUD in Colorado college students who reported regular marijuana use and assessed a range of factors associated with CUD symptoms, including coping motives, concentrate/dab use, mental health concerns (depression, anxiety), age of regular marijuana use, and alcohol use. College students were recruited from a mid-sized university and completed a baseline assessment that included a marijuana urine screen. Participants reported a median of five CUD symptoms and 90% met criteria for CUD. After adjusting for covariates, age of regular marijuana use was negatively associated with number of CUD symptoms, while average daily alcohol drinks was positively associated with number of symptoms. Prevention and intervention efforts at the university level should be increased to reduce negative outcomes associated with problem marijuana use.

Alcohol and marijuana co-use: Consequences, subjective intoxication, and the operationalization of simultaneous use

BACKGROUND

Alcohol and marijuana are frequently co-used with overlapping effects. However, the absence of consistent operational definitions delineating simultaneous alcohol and marijuana use (SAM) from concurrent use (CAM) challenges consistent inferences about these behaviors. This study first examined whether daily alcohol and marijuana co-use predicted substance-use related consequences and subjective intoxication; and then evaluated whether competing operationalizations of SAM and CAM were associated with differences in these outcomes on co-use days.

METHODS

A sample of 341 young adult college students who reported past-month use of both alcohol and marijuana "at the same time so that their effects overlapped" completed a two-wave survey with paired 28-day daily experience sampling bursts examining alcohol and marijuana co-use. Outcomes were (a) daily substance-use related consequences; and (b) daily subjective intoxication. Focal predictors were daily drinks and marijuana uses; daily co-use versus single-substance use (Aim 1) or CAM versus SAM (Aim 2); and their interaction.

RESULTS

Participants reported more negative consequences on co-use days versus marijuana-only days and greater subjective intoxication relative to alcohol or marijuana-only days. Competing operationalizations of SAM, defined as daily co-use occurring within 1-240 min in increments of 1 min, found no difference in consequences or subjective intoxication regardless of operationalization.

CONCLUSION

Co-use days involve greater risk than alcohol-only or marijuana-only days. Although there was no evidence of additional daily risk from simultaneous use regardless of the timeframe used to operationalize it, investigating these effects remains challenging due to the generally small timeframe between substances on co-use days in this sample.

Consequences of alcohol and marijuana use among college students: Prevalence rates and attributions to substance-specific versus simultaneous use

College students who use alcohol and marijuana often use them simultaneously, so that their effects overlap. The present study examined whether negative consequences experienced by simultaneous alcohol and marijuana (SAM) users vary from those experienced by individuals who use alcohol and marijuana concurrently but not simultaneously (CAM) or single-substance users. We considered 9 types of consequences: cognitive, blackout, vomiting, academic/occupational, social, self-care, physical dependence, risky behaviors, and driving under the influence (DUI). Further, we examined whether consequences experienced by SAM users are attributed to using alcohol, marijuana, or both simultaneously. The sample included past-year alcohol and marijuana users age 18-24 (N = 1,390; 62% female; 69% White; 12% Hispanic) recruited from 3 U.S. college campuses. SAM users experienced a greater overall number of consequences than CAM or alcohol-only users, even controlling for frequency and intensity of alcohol and marijuana use and potentially confounding psychosocial and sociodemographic factors. Experiencing specific consequences differed between simultaneous and concurrent users, but after adjusting for consumption and other covariates, only blackouts differed. In contrast, SAM users were more likely to experience each consequence than alcohol-only users, with strongest effects for DUI, blackouts, and cognitive consequences. Among SAM users, consequences were most likely to be attributed to alcohol and were rarely attributed to simultaneous use. Being a user of both alcohol and marijuana and using alcohol and marijuana together so that their effects overlap each contribute to risk, suggesting there is value in targeting the mechanisms underlying type of user as well as those underlying type of use. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Drinking contexts and their association with acute alcohol-related harm: A systematic review of event-level studies on adults' drinking occasions

ISSUES

Event-level alcohol research can inform prevention efforts by determining whether drinking contexts-such as people or places-are associated with harmful outcomes. This review synthesises evidence on associations between characteristics of adults' drinking occasions and acute alcohol-related harm.

APPROACH

We systematically searched Ovid MEDLINE, Ovid PsycInfo and the Web of Science Social Sciences Citation Index. Eligible papers used quantitative designs and event-level data collection methods. They linked one or more drinking contexts to acute alcohol-related harm. Following extraction of study characteristics, methods and findings, we assessed study quality and narratively synthesised the findings.

PROSPERO ID

CRD42018119701.

KEY FINDINGS

Searches identified 95 eligible papers, 65 (68%) of which study young adults and 62 (65%) of which are set in the United States, which limits generalisability to other populations. These papers studied a range of harms from assault to drink driving. Study quality is good overall although measures often lack validation. We found substantial evidence for direct effects of drinking context on harms. All of the contextual characteristics types studied (e.g. people, place, timing, psychological states, drink type) were consistently associated with harms. Certain contexts were frequently studied and associated with harms, in particular, weekend drinking, drinking in licensed premises and concurrent illicit drug use.

IMPLICATIONS

The findings of our review indicate target drinking contexts for prevention efforts that are consistently associated with increased acute alcohol-related harm.

CONCLUSION

A large range of contextual characteristics of drinking occasions are directly associated with acute alcohol-related harm, over and above levels of consumption.

A Daily Study Comparing Alcohol-Related Positive and Negative Consequences for Days With Only Alcohol Use Versus Days With Simultaneous Alcohol and Marijuana Use in a Community Sample of Young Adults

BACKGROUND

Alcohol and marijuana are psychoactive substances commonly used by young adults and are independently associated with numerous acute and long-term consequences. Many young adults engage in simultaneous alcohol and marijuana (SAM) use to cross-fade (i.e., to enhance the effects of intoxication), although the extent to which alcohol use and alcohol-related consequences increase on SAM occasions compared to alcohol-only occasions is unclear. This study examines daily data among a sample of SAM users comparing SAM days to other days when young adults only used alcohol.

METHODS

A sample of 409 young adults (age 18 to 25; M_age  = 21.6, SD = 2.2; 50.9% women) who reported SAM use in the past month completed 2 bursts of 14 days of daily surveys (28 days in total) assessing alcohol use, alcohol-related consequences, and SAM use.

RESULTS

Multilevel models based on alcohol-only and SAM days (n = 3,016 days; 391 individuals) indicated young adults drank more alcohol on SAM days compared to alcohol-only days (with no marijuana use). Similarly, days with SAM use were associated with more alcohol-related positive and negative consequences. The daily association between SAM use and positive consequences was statistically significant, after accounting for the amount of alcohol consumed; in contrast, the association between SAM use and negative consequences was diminished and nonsignificant.

CONCLUSIONS

Among young adult SAM users, days with SAM use were associated with more alcohol use and positive consequences compared to days they only drank alcohol. Further examination of the motivational context for engaging in SAM use, as well as potential physiological interactions between alcohol and marijuana use on alcohol's effects, is warranted. Alcohol interventions might benefit from addressing increased alcohol use and alcohol-related consequences as risks associated with SAM use.

A longitudinal examination of daily patterns of cannabis and alcohol co-use among medicinal and recreational veteran cannabis users

BACKGROUND

Prompted by the ongoing debate regarding whether cannabis serves as a complement to or substitute for alcohol, this study uses prospective data to examine daily associations between medicinal versus recreational cannabis and alcohol use in veterans.

METHODS

Three semi-annual waves of Timeline Followback Interview data were collected from a sample of veterans who reported co-using alcohol and cannabis on at least one day (N = 115; 56% medicinal users; 93% male; 62,100 observations). Linear mixed effects models were used to examine the association between daily cannabis use and number of drinks consumed across time for both medicinal and recreational users and to examine the frequency medicinal cannabis used to substitute for alcohol.

RESULTS

Compared to medicinal users, recreational users were more likely to drink more on cannabis use days relative to non-use days. Among medicinal users, those endorsing more frequent use of cannabis as a substitute for alcohol reported fewer number of drinks consumed on days when cannabis was used relative to non-use days.

CONCLUSIONS

Among veterans, recreational users are at greater risk for increased drinking when co-using cannabis at the daily level, an association that is stable over time. Medicinal users may be at lower risk for increased drinking on days when cannabis is also used, especially those who endorse using cannabis to substitute for alcohol. Findings help clarify the debate on cannabis-alcohol substitution or complementary associations in a sample of veterans and suggests that alcohol interventions should address cannabis use as a risk factor, especially for recreational users.

Demographic differences in perceived social norms of drug and alcohol use among Hispanic/Latinx and non-Hispanic White college students

Social norms are a modifiable treatment target that can decrease problematic alcohol use among college students. However, little is known about how social norms may be related to cannabis, opioid, and stimulant use. Further, it is not known how these relations might differ by gender and race/ethnicity. This study sought to examine the role of descriptive social norms of two peer reference groups (close friend and acquaintance) in relation to personal substance use among four substances (opioids, alcohol, cannabis, and stimulants), and if these relations may be moderated by gender or race/ethnicity in a sample of Hispanic/Latinx (H/L) and Non-Hispanic White (NHW) students. Participants were primarily H/L (58%), women (70%), and freshman (47%). Findings indicated that higher perceived peer substance use was associated with higher personal use for alcohol and cannabis. Higher perceived close friend stimulant use was associated with higher personal stimulant use, although perceived acquaintance stimulant use was not associated with personal stimulant use. There was no association between perceived peer opioid use and personal opioid use. Men had a stronger positive association between perceived peer cannabis use and personal use. Women had a stronger positive association between perceived acquaintance stimulant use and personal use. H/L students had a stronger positive association between perceived peer cannabis use and personal use. NHW had no significant association between perceived peer opioid use and personal use. Findings suggest that men and H/L students may be more susceptible to peer influences on cannabis and opioid use.

Event-Level Correlates of Drinking Events Characterized by Alcohol-Induced Blackouts

BACKGROUND

Prior research identifies a range of potential predictors of blackouts and suggests that blackouts increase risk for additional negative consequences. However, these studies are based on epidemiological work that allows us to draw conclusions about groups of people but not within-person processes. The present study examined within-person, event-level correlates of blackouts.

METHODS

Ninety-six heavy drinking college students (52% female) completed 28 days of daily reports of alcohol use and consequences, including blackouts. Thirty-three participants reported 56 blackouts. Hierarchical linear modeling compared morning reports of drinking events on which participants did versus did not report a blackout, controlling for total drinks at the event.

RESULTS

Blackout likelihood increased as a function of total drinks consumed and of crossing thresholds for heavy episodic drinking (4+/5+ drinks for women/men) and high-intensity drinking (8+/10+). Participants reported a higher total number of additional negative consequences on blackout events. Specific consequences that were more likely included embarrassing oneself and hangover. Blackouts were associated with morning ratings of less positive mood and a less favorable drinking event. Motives for drinking and simultaneous use of marijuana were not associated with blackouts.

CONCLUSIONS

Event-level findings of this study document that events leading to alcohol-induced memory loss are associated with other adverse experiences relative to drinking events that do not result in blackout, and offer potentially motivational levers for preventive interventions.

Simultaneous Use of Alcohol and Marijuana: Patterns and Individual Differences

Background: Simultaneous alcohol and marijuana (SAM) use, or using alcohol and marijuana in such a way that their effects overlap, is associated with negative health and behavioral outcomes. Objectives: Our study sought to fill gaps in our knowledge on this emerging public health concern by comparing SAM users and alcohol-only users on individual-level factors and substance use outcomes as well as examining associations of SAM use frequency, within users. Methods: Participants were recruited through online postings. Our analytic sample consisted of 1017 young adults (18-25 years) who reported past-month alcohol use. Most were male (67.8%), Caucasian (71.5%), and had attended at least some college (74.8%). Results: Past-year SAM users reported higher levels of sensation seeking and greater perceptions of their close friends' drinking behavior in comparison to alcohol-only users. SAM users reported heavier and more frequent alcohol use than alcohol-only users. Within past-year SAM users, 70% reported SAM use at least weekly. More frequent SAM use was associated with all alcohol use outcomes (e.g., weekly quantity, frequency, alcohol-related problems) and marijuana use outcomes (e.g., quantity, frequency, peak use) and higher drinking norms. Conclusions/Importance: It is clear that SAM users are a vulnerable sub-population of young adult drinkers. SAM users are differentiated from alcohol-only users in terms of their personality characteristics and perceptions of peer groups' drinking. SAM users and more frequent users are also at heightened risk for substance use outcomes. Prevention and intervention efforts targeting high-risk drinking may benefit from also assessing whether they simultaneously use alcohol and marijuana.

Simultaneous Alcohol and Marijuana Use Among College Students: Patterns, Correlates, Norms, and Consequences

BACKGROUND

Alcohol and marijuana users often engage in simultaneous alcohol and marijuana (SAM) use (i.e., using the 2 substances together so that their effects overlap), which can result in more negative consequences than using either substance alone. Nevertheless, little is known about SAM use among contemporary college students to aid in the development of preventive interventions. This study examined SAM use patterns, demographic correlates of SAM use, and normative influences on SAM use and related negative consequences among college students.

METHODS

Students who had used alcohol and marijuana in the past year were recruited from 3 state universities in states with different laws regarding recreational marijuana use (N = 1,389). They completed an online survey, which assessed their own alcohol, marijuana, and SAM use and related consequences, their perceptions of the proportion of same-gender peers and close friends who engaged in SAM use, marijuana access, and demographic characteristics.

RESULTS

About three-fourths of participants reported at least 1 occasion of SAM use in the past year with an average frequency of twice per month among SAM users. There were significant differences in SAM use prevalence and frequency by sociodemographic characteristics controlling for past-year alcohol and marijuana frequency. Students in a state with decriminalized recreational marijuana use reported higher frequency of past-year SAM use than students in states with legalized or criminalized use. There were significant demographic differences in perceived norms regarding SAM use among close friends and same-gender peers. SAM users endorsed significantly higher perceived peer and friend norms than nonusers. Also, higher perceived norms predicted more frequent SAM use and more negative consequences of use.

CONCLUSIONS

Results indicate a need for prevention programs on college campuses that address SAM use. Interventions that use personalized normative feedback may be effective.

Are Co-users of Alcohol and Marijuana More Willing to Experience Consequences From Drinking? A Longitudinal Examination Among First-Year College Students

BACKGROUND

Alcohol and marijuana co-users are at heightened vulnerability for experiencing a variety of negative alcohol use outcomes including heavier alcohol use and driving under the influence. The current study explored willingness to experience negative consequences as a potential factor underlying the association between co-user status and negative consequences in an effort to guide future intervention work. From a longitudinal study of first-year college students, we examined willingness to experience consequences at Time 2 as a mediator of co-user status at Time 1 and experience of negative consequences at Time 3.

METHODS

First-year college student drinkers (n = 1,914) at a large university completed surveys in the fall and spring of their freshman year and the fall of their sophomore year.

RESULTS

Alcohol and marijuana co-users reported higher willingness to experience consequences than alcohol-only users. Willingness to experience consequences partially explained the association between alcohol and marijuana couse and consequences.

CONCLUSIONS

The current study was the first to compare co-users of alcohol and marijuana to alcohol-only users on willingness to experience consequences, and examine the role of willingness as a mediator between co-user status and consequences experienced. Co-users were more willing to experience adverse effects from drinking, in turn predicting more consequences. Intervention work targeting consequences may be less effective for co-users; thus, additional work is needed to identify other potential mechanisms for change for this at-risk group.

An examination of consequences among college student drinkers on occasions involving alcohol-only, marijuana-only, or combined alcohol and marijuana use

This event-level study examined within-person differences in consequences for college students who engaged in alcohol-only, marijuana-only, or simultaneous alcohol and marijuana (SAM) use across 18 weekend days. Participants (n = 451) were asked to report consequences they experienced on each occasion across five different types of events: (a) heavier alcohol combined with marijuana; (b) lighter alcohol combined with marijuana; (c) heavier alcohol only; (d) lighter alcohol only; and (e) marijuana only. Occasions involving heavy drinking, alone and in combination with marijuana, were associated with higher rates of consequences relative to lighter alcohol-only occasions, lighter alcohol combined with marijuana occasions, and marijuana-only occasions. Light alcohol-only occasions did not significantly differ on consequences from lighter alcohol combined with marijuana occasions or marijuana-only occasions. Past research has shown SAM use is associated with more consequences compared with alcohol-only use. The current findings suggest that SAM use is not necessarily riskier than drinking or using marijuana alone. Results suggested that on heavy drinking occasions, the number of consequences did not significantly change by also using marijuana. Findings suggest the benefit of targeted intervention strategies to reduce harms associated with heavy drinking occasions with and without SAM use. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Marijuana use is associated with alcohol use and consequences across the first 2 years of college

College entry is associated with marijuana initiation, and co-use of alcohol and marijuana is associated with problematic outcomes, including alcohol-related consequences. The present study explored if: (a) use of marijuana on a given day would be associated with greater alcohol use within the same day; (b) use of marijuana within a given week would be associated with increased alcohol-related consequences in that same week; and (c) the association between marijuana use and alcohol consumption and consequences varies across time or by precollege level of problematic alcohol use. Participants (N = 488 college student drinkers, 59% female) completed assessments of marijuana use, alcohol use, and alcohol consequences across 2 years. Analyses revealed: (a) daily marijuana use predicted greater number of daily drinks and estimated breath alcohol concentration; (b) weekly marijuana use predicted more weekly positive and negative alcohol consequences; (c) the effect of daily marijuana use on alcohol use strengthened over time, while the effect of weekly marijuana use on positive alcohol consequences reduced over time; and (d) precollege level of problematic alcohol use moderated the association between daily marijuana and alcohol use and weekly marijuana use and negative consequences. This study provides the first longitudinal evidence of the association between marijuana use and greater alcohol use and consequences in college students. Future research examining event-level measurement of alcohol and marijuana co-use is important for the prevention of alcohol-related consequences. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

College student knowledge of blackouts and implications for alcohol intervention: A qualitative analysis

Blackouts (periods of alcohol-induced anterograde amnesia) are common among young adults and place individuals at significant risk for alcohol-related harm; thus, researchers have advocated for increased efforts to educate young adults on blackouts. This qualitative study examined college student knowledge of blackouts as well as their ideas for intervening on blackout drinking behavior in order to inform prevention and intervention efforts. College students who had experienced a blackout in the past 6 months participated in eight focus groups, stratified by gender (N = 50, five to eight/group, 56% female). Discussions followed a semistructured agenda. Audio recordings were transcribed verbatim and coded using applied thematic analysis. Themes related to knowledge were reviewed in comparison to the empirical literature. Empirically derived risk factors for blackouts included biology (e.g., genetics, biological sex), drinking behavior (i.e., rate of consumption), other drug use, and "indirect" influences (e.g., pregaming, drinking location). Participants' knowledge of the risk factors for blackout was inconsistent and, in some cases, inaccurate. While participants generally understood the behavioral risk factors for blackouts, they demonstrated less understanding of the role of genetics, biological sex, drinking speed (vs. quantity), and other drug use. They also identified dehydration and sleep as perceived risk factors for blackout. They suggested avenues for intervention at the policy (e.g., amnesty policies), peer (e.g., expressing concern), and individual (e.g., education) levels. College students with a history of blackout have limited understanding of the biological risk factors for blackout. These knowledge gaps represent targets for intervention. Findings indicate promise for blackout-specific interventions. (PsycINFO Database Record (c) 2018 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.

An event- and network-level analysis of college students' maximum drinking day

BACKGROUND

Heavy episodic drinking is common among college students and remains a serious public health issue. Previous event-level research among college students has examined behaviors and individual-level characteristics that drive consumption and related consequences but often ignores the social network of people with whom these heavy drinking episodes occur. The main aim of the current study was to investigate the network of social connections between drinkers on their heaviest drinking occasions.

METHODS

Sociocentric network methods were used to collect information from individuals in the first-year class (N=1342) at one university. Past-month drinkers (N=972) reported on the characteristics of their heaviest drinking occasion in the past month and indicated who else among their network connections was present during this occasion.

RESULTS

Average max drinking day indegree, or the total number of times a participant was nominated as being present on another students' heaviest drinking occasion, was 2.50 (SD=2.05). Network autocorrelation models indicated that max drinking day indegree (e.g., popularity on heaviest drinking occassions) and peers' number of drinks on their own maximum drinking occasions were significantly associated with participant maximum number of drinks, after controlling for demographic variables, pregaming, and global network indegree (e.g., popularity in the entire first-year class).

CONCLUSION

Being present at other peers' heaviest drinking occasions is associated with greater drinking quantities on one's own heaviest drinking occasion. These findings suggest the potential for interventions that target peer influences within close social networks of drinkers.

Characteristics of prospectively identified negative alcohol-related events among college students

BACKGROUND

Throughout the first two years of college, the majority of drinkers experience one or more alcohol-related consequences. Research that examines the characteristics surrounding negative consequences typically utilizes global retrospective survey methods. The objective of the current study was to apply an event-based methodology to describe the circumstances of a recent drinking episode that resulted in one or more alcohol-related consequences among first- and second-year college students.

METHODS

We used a prospective web-based survey method to identify participants (N=296) who had one or more alcohol-related consequences in the past week. Shortly after reporting the consequence(s), participants attended an in-person interview during which they described the circumstances that preceded and followed the consequence(s), including the use of alcohol and other substances, proximal contextual factors including peer drinking, the characteristics of the negative alcohol-related consequence(s), and the reaction of others to the event.

RESULTS

The majority of participants reported experiencing the event at either their own (32.4%) or a friend's (32.8%) residence, and 87.1% of participants were with peers when the event happened. Most (85.0%) of the sample indicated that their closest friend knew about their event.

CONCLUSION

The high peer involvement at all stages of the event suggest the potential for training college students to help each other avoid or prevent consequences.