A longitudinal assessment of change in marijuana use with other substance use problems

Longitudinal Associations Between Use of Tobacco and Cannabis Among People Who Smoke Cigarettes in Real-world Smoking Cessation Treatment

OBJECTIVES

Cannabis use is common among people who use tobacco. However, little is known about the relationship between change in use of tobacco and cannabis over time. We examined the longitudinal associations between use of the two substances in a realworld smoking cessation context.

METHODS

This study analyzed data from a 3-month smoking cessation program delivered via Facebook in the San Francisco Bay Area, USA during 2016-2020. The sample included 487 participants who smoked cigarettes ( Mage = 25.4 years old, 39.6% Male, 40.3% White). The regressors (ie, frequency or number of days during the past 30 days using cigarettes, e-cigarettes, and cigars) and the outcome (ie, frequency of cannabis use) were measured at both baseline and 3-month follow-up. Random-effects modeling examined the longitudinal associations between the regressors and the outcome controlling for alcohol use and baseline demographics.

RESULTS

Participants who increased (or decreased) their frequency of use of cigarettes (β = 0.17, 95% confidence interval [CI] = 0.10, 0.24), e-cigarettes (β = 0.11, 95% CI = 0.05, 0.17), or cigars (β = 0.19, 95% CI = 0.06, 0.32) also increased (or decreased) their frequency of cannabis use after 3 months. Sexual minority participants (vs heterosexuals) (β = 2.12, 95% CI = 0.01, 4.24) and those whose education attainment being high school or less (vs higher education) (β = 3.89, 95% CI = 1.25, 6.53) were more likely to increase their frequency of cannabis use over time.

CONCLUSIONS

The findings indicated positive associations between change in use of tobacco and cannabis use. Promoting cessation among people who use tobacco may help to reduce their cannabis use.

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

PURPOSE

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

SEARCH METHODS

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

SEARCH RESULTS

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

DISCUSSION AND CONCLUSIONS

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

The Need for Marijuana Perceived Risk Interventions Targeting College Students at a Historically Black College and University

The purpose of this pilot study was to test a peer-led Hip-Hop Development Model (HHD) prevention intervention designed to increase the perceived risk from drug use for undergraduate college students attending a Historically Black College and University (HBCU). The HHD model was used to develop prevention messaging to increase the perceived risk from drug use. This study examined the following outcomes of peer-group-based development of public service announcements grounded in HHD: (1) feasibility, (2) acceptability, and (3) potential for immediate posttest and 1-year impact on perceived risk from marijuana use. Findings indicated that the college students were able to produce public service announcements over the course of a semester that could be broadcast to other students on campus. At the 1-year follow-up, perceived risk from marijuana use was significantly higher than at baseline. Perceived risk from marijuana use at baseline was low with 36% of participants who responded moderate or great risk which increased to 63% at immediate and 50% at 1-year posttest. This small pilot study provides insights into what is needed to implement and evaluate youth-targeted marijuana prevention messaging, in a context of rapid increase in the liberalization of adult marijuana use across the United States.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of tobacco products/devices for marijuana consumption and association with substance use problems among U.S. young adults (2015-2016)

INTRODUCTION

Given the increased availability of tobacco products and devices, rising trends of vaping, and changing marijuana policies in the United States (U.S.), this study reports the prevalence of U.S. young adults using tobacco products/devices for marijuana consumption and associations with substance use problems.

METHODS

U.S. nationally representative data from Wave 3 (2015-2016) of the Population Assessment of Tobacco and Health Study were used to assess young adults' (18-24 years old, unweighted sample = 8453) ever marijuana use and ever use of electronic nicotine delivery systems (ENDS), hookah, or cigars for marijuana consumption. A multinomial logistic regression predicted the Substance Use Problem subscale of the Global Appraisal of Individual Needs inventory categorized into low (0-1), moderate (2-3) and high (4 or more) symptoms.

RESULTS

Weighted analyses indicated about half of young adults (52.1%) had ever used marijuana. Of this group, the majority (80.1%) ever used any tobacco product/device for marijuana use including: ENDS (24.5%), hookah (25.2%), or cigar (74.0%). Ever use of tobacco products/devices for marijuana significantly predicted moderate (RRR = 1.70, p < 0.01) and high (RRR = 4.67, p < 0.01) substance use problems controlling for sex, race, employment, education, and past 30-day cigarette, cigar, ENDS, hookah, marijuana and alcohol use.

CONCLUSIONS

Use of tobacco products/devices for marijuana consumption is common among U.S. young adults and it is associated with substance use problems. A better understanding of how tobacco devices are being used to support use of both substances and the outcomes of co-use are needed to inform policy and public health interventions.

Brain activation to cannabis- and alcohol-related words in alcohol use disorder

Cannabis abuse commonly co-occurs with alcohol use disorder (AUD). With increased acceptance and accessibility to cannabis in the US, it is imperative to understand the psychological and neural mechanisms of concurrent alcohol and cannabis use. We hypothesized that neural alcohol-cue conditioning may extent to other drug-related stimuli, such as cannabis, and underwrite the loss of control over reward-driven behavior. Task-activated fMRI examined the neural correlates of alcohol- and cannabis-related word cues in 21 abstinent AUD and 18 control subjects. Relative to controls, AUD showed behavioral attentional biases and frontal hypoactivation to both alcohol- and cannabis-related words. This cue-elicited prefrontal hypoactivation was related to higher lifetime alcohol consumption (pcorrected < 0.02) and modulated by past cannabis use histories (p ≦ 0.001). In particular, frontal hypoactivation to both alcohol and cannabis cues was pronounced in AUD without prior cannabis exposure. Overall, frontal control mechanisms in abstinent AUD were not sufficiently engaged to override automatic alcohol and cannabis-related intrusions, enhancing the risk for relapse and potentially for alcohol and cannabis co-use with the increased social acceptance and accessibility in the US.

Older marijuana users in substance abuse treatment: Treatment settings for marijuana-only versus polysubstance use admissions

OBJECTIVE

Growing numbers of older adult marijuana users make understanding the marijuana-related treatment needs and treatment-related characteristics of this age group increasingly important. In this study, we examined four types of marijuana-involved admissions (marijuana as the only substance; marijuana as the primary substance with other secondary/tertiary substances; marijuana as the secondary substance; and marijuana as the tertiary substance) by treatment setting.

METHODS

Data came from the 2012-2017 Treatment Episode Data Set-Admissions (TEDS-A), which includes 851,652 admissions by those aged 55+. Using multinomial logistic regression analysis, we focused on the 120,286 marijuana-involved admissions to test the hypothesis that polysubstance use would be associated with a higher likelihood of using detoxification and rehabilitation settings than ambulatory/outpatient settings.

RESULTS

Of all marijuana-involved admissions, 7.5% were marijuana-only, 12.7% were marijuana-primary, 58.4% were marijuana-secondary, and 21.4% were marijuana-tertiary admissions. Compared to marijuana-only admissions, admissions involving other substances were associated with a higher likelihood of detoxification and rehabilitation than ambulatory/outpatient treatment (e.g., RRR = 5.79, 95% CI = 5.08-6.61 for detoxification and RRR = 3.19, 95% CI = 2.89-3.52 for rehabilitation among marijuana-tertiary admissions). Referral source, first age of marijuana use, race/ethnicity, and homelessness were significant covariates.

CONCLUSIONS

Given increasing numbers of older-adult marijuana users, healthcare providers should screen older adults for marijuana and other substance use, and substance abuse treatment programs should become more responsive to older adults' needs.