Alcohol Use and Risk of Related Problems Among Cannabis Users Is Lower Among Those With Medical Cannabis Recommendations, Though Not Due To Health

Cannabis use and alcohol and drug outcomes in a longitudinal sample of sober living house residents in California

INTRODUCTION

Some evidence suggests that cannabis may be a safer substitute for other drugs. Historically, sober living houses (SLHs) have been abstinence-based environments designed for individuals in recovery to live with others in recovery. However, the evolving legal landscape around cannabis use has left SLH operators and managers in a difficult position regarding policies related to cannabis use among residents. The primary aim of this study was to examine how cannabis use relates to alcohol use, other drug use, and related problems among SLH residents.

METHODS

Baseline (N = 557), 6-month (n = 462), and 12-month (n = 457) data came from SLH residents living in 48 houses in Los Angeles, CA from 2018 to 2021. Longitudinal generalized estimating equation models tested associations between any past six-month cannabis use and alcohol and non-cannabis drug outcomes: any use, number of days of use, and any alcohol- or drug-related problems. Final models adjusted for baseline age, sex, race-and-ethnicity, inpatient substance use treatment, and alcohol/drug use days, and time-varying 12-step attendance and percent of social network using drugs/alcohol heavily.

RESULTS

At baseline, 107 (19.2 %) residents reported cannabis use in the past six months. At 12 months, 80 (17.5 %) residents reported cannabis use in the past six months. Across all timepoints, any vs. no past six-month cannabis use was related to significantly (P < 0.05) higher odds of past-month alcohol use (OR = 3.85, 95 % CI: 2.65, 5.59); more drinking days in the past six months (IRR = 1.76, 95 % CI: 1.40, 2.21); higher odds of alcohol problems (OR = 2.74, 95 % CI: 1.99, 3.76); higher odds of past-month drug use (OR = 10.41, 95 % CI: 6.37, 17.00); more drug use days in the past six months (IRR = 1.86, 95 % CI: 1.40, 2.49); and higher odds of drug problems (OR = 14.99, 95 % CI: 9.91, 22.68).

CONCLUSIONS

During each assessment period, almost one-fifth of individuals residing in sample of California sober living houses report using cannabis in the past six months. Cannabis does not appear to work as a substitute for alcohol or other drugs in this population because cannabis use is related to increased risk of alcohol and other drug use and problems. SLH managers and operators should consider potential harm that could result from house policies that fail to address cannabis use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Simultaneous Cannabis and Alcohol Use among Medical Cannabis Patients

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

Medical cannabis authorization and risk of emergency department visits and hospitalization due to psychotic disorders: A propensity score-matched cohort study

Despite evidence showing that recreational cannabis use is associated with a higher risk of psychotic disorders, this risk has not been well characterized for patients using medical cannabis. Therefore, this study assessed the risk of emergency department (ED) visits and hospitalization for psychotic disorders (the study outcome) among adult patients authorized to use medical cannabis. We performed a retrospective cohort study on patients authorized to use medical cannabis in a group of Ontario cannabis clinics between 2014 and 2019. Using clinical and health administrative data, each patient was matched by propensity scores to up to 3 population-based controls. Conditional Cox proportional hazards regressions were used to assess the risk. Among 54,006 cannabis patients matched to 161,265 controls, 39 % were aged ≤50 years, and 54 % were female. Incidence rates for psychotic disorders were 3.00/1000 person-years (95%CI: 2.72-3.32) in the cannabis group and 1.88/1000 person-years (1.75-2.03) in the control group. A significant association was observed, with an adjusted hazard ratio of 1.38 (95%CI: 1.19-1.60) in the total sample and 1.63 (1.40-1.91) in patients without previous psychotic disorders. The results suggest that cannabis authorization should include a benefit-risk assessment of psychotic disorders to minimize the risk of events requiring emergency attention.

Evaluating substance use outcomes of recreational cannabis legalization using a unique co-twin control design

Background: As more states pass recreational cannabis legalization (RCL), we must understand how RCL affects substance use.Objectives: The current study aims to examine the effect of RCL on lifetime and past-year use of cannabis, alcohol, tobacco, and other drugs, frequency of cannabis, alcohol, and tobacco use, co-use of cannabis with alcohol and tobacco, and consequences from cannabis and alcohol use.Methods: We used a unique, co-twin control design of twin pairs who were discordant for living in a state with RCL between 2018 and 2021. The sample consisted of 3,830 adult twins (41% male), including 232 twin pairs discordant for RCL. Problems from alcohol and cannabis use were assessed via the Brief Marijuana Consequences Questionnaire and the Brief Young Adult Alcohol Consequences Questionnaire.Results: Results indicated that the twin living in an RCL state was more likely to endorse past-year cannabis use (OR = 1.56, p = .009), greater number of cannabis use days in the past 6 months (β = 0.47, p = .019), but not more negative consequences from cannabis use (β = 0.21, p = .456) compared to their co-twin in a non-RCL state. There were no differences within-twin pairs in frequency of alcohol use (β=-0.05, p = .601), but the RCL twin reported fewer negative consequences from alcohol use (β=-0.29, p = .016) compared to their co-twin in a non-RCL state. We did not observe any other differences within-twin pairs on other outcomes.Conclusion: These results suggest that living in an RCL state is associated with greater cannabis frequency but not more negative consequences from cannabis use than living in a non-RCL state.

Prevalence of marijuana use in pregnant women with concurrent opioid use disorder or alcohol use in pregnancy

BACKGROUND

A quarter of pregnant women use alcohol, 6.5/1000 deliveries are affected by opioid use disorder (OUD), and the prevalence of cannabis use in pregnant women is increasing. However, marijuana co-exposure in polysubstance-using women is not well described.

METHODS

The well-characterized ENRICH-1 cohort (n = 251), which focused on the effects of two primary exposures of interest-opioids and alcohol, was used to (1) estimate the prevalence/frequency of marijuana use in those with OUD and/or alcohol use, and (2) examined correlates of marijuana use. Participants were classified into an OUD group (n = 125), Alcohol group (n = 69), and concurrent OUD and Alcohol (OUD + Alcohol) group (n = 57). Self-report and biomarkers ascertained substance use. Multivariable logistic regression identified correlates of marijuana use.

RESULTS

The prevalence of any marijuana use in pregnancy was 43.2%, 52.6%, and 46.4% in the OUD, OUD + Alcohol, and Alcohol groups, respectively. Correspondingly, weekly or daily use was reported by 19.4%, 21.0%, and 24.6% of participants. In the OUD and OUD + Alcohol groups, the proportion of women using marijuana was significantly higher in those taking buprenorphine (45.8% and 58.3%, respectively) compared to women using methadone (37.5% and 42.9%, respectively). Mean maternal age was lower in women who used marijuana in all three groups compared to non-marijuana users. Independent correlates of marijuana use (controlling for group, race/ethnicity, education, and smoking) were maternal age (adjusted Odds Ratio (aOR) per 5-year increment 0.61; (95% CI 0.47, 0.79)), and polysubstance use (aOR 2.02; 95% CI 1.11, 3.67). There was a significant interaction between partnership status and group: among women who were not in a partnership, those in the OUD and OUD + Alcohol groups had lower odds of marijuana use relative to the Alcohol group. For women in the Alcohol group, partnered women had lower odds of marijuana use than un-partnered women (aOR 0.12; 95% CI: 0.02, 0.68).

CONCLUSIONS

Results indicate a relatively high prevalence and frequency of marijuana use in pregnant women being treated for OUD and/or women consuming alcohol while pregnant. These results highlight the need for ongoing risk reduction strategies addressing marijuana use for pregnant women receiving OUD treatment and those with alcohol exposure.

Incidence and Predictors of Cannabis-Related Poisoning and Mental and Behavioral Disorders among Patients with Medical Cannabis Authorization: A Cohort Study

OBJECTIVE

As medical cannabis use increases in North America, establishing its safety profile is a priority. The objective of this study was to assess rates of emergency department (ED) visits and hospitalizations due to poisoning by cannabis, and cannabis-related mental health disorders among medically authorized cannabis patients in Ontario, Canada, between 2014 and 2017.

METHODS

This is a retrospective cohort study of patients who received medical cannabis authorization in Ontario, Canada, using data collected in participating cannabis clinics. Outcomes included ED visit/hospitalization with a main diagnosis code for: cannabis/cannabinoid poisoning; and mental/behavioral disorders due to cannabis use. Cox proportional hazard regressions were utilized to analyze the data.

RESULTS

From 29,153 patients who received medical authorization, 23,091 satisfied the inclusion criteria. During a median follow-up of 240 days, 14 patients visited the ED or were hospitalized for cannabis poisoning-with an incidence rate of 8.06 per 10,000 person-years (95% CI: 4.8-13.6). A total of 26 patients visited the ED or were hospitalized for mental and behavioral disorders due to cannabis use-with an incidence rate of 15.0 per 10,000 person-years (95% CI: 10.2-22.0). Predictors of cannabis-related mental and behavioral disorders include prior substance use disorders, other mental disorders, age, diabetes, and chronic obstructive pulmonary disease.

CONCLUSIONS

The results suggest that the incidence of cannabis poisoning or cannabis-related mental and behavioral disorders was low among patients who were authorized to use cannabis for medical care. Identified predictors can help to target patients with potential risk of the studied outcomes.

Effects of cannabis use on alcohol consumption in a sample of treatment-engaged heavy drinkers in Colorado

BACKGROUND AND AIMS

Cannabis is commonly used among people who drink alcohol, but evidence suggests a nuanced relationship between alcohol consumption and cannabis use. In particular, among individuals undergoing alcohol treatment the impact of cannabis on alcohol intake may depend upon cannabis use frequency. We aimed to test the effects of within-day cannabis use on total drinks consumed and likelihood of binge drinking on a given day among all participants and compare these relationships between males and females and between individuals who reported infrequent and frequent cannabis use.

DESIGN

This observational study is a substudy of a larger randomized controlled trial (RCT). Individuals were included from the RCT if they reported any cannabis use and were divided into groups based on cannabis use patterns. Alcohol use was compared within and between groups.

SETTING

Individuals were recruited from 2016 to 2020 from community and university settings in Denver and Boulder, CO, USA.

PARTICIPANTS

Of the 182 individuals enrolled in the RCT, 96 cannabis-using subjects were included in these analyses.

MEASUREMENTS

Subjects completed a time-line follow-back (TLFB) at baseline, 4, 8 (end of treatment) and 20 weeks. Daily data on alcohol and cannabis use from the TLFB at all time-points were analyzed.

FINDINGS

Across the sample (n = 96), individuals drank approximately 29% fewer drinks [95% confidence interval (CI) = 18-39%, P < 0.001] and were 2.06 times (95% CI =1.37-3.08, P < 0.001) less likely to have a binge-drinking episode on days that cannabis was used compared with days that cannabis was not used. These patterns were observed in males, females and the infrequent and frequent cannabis use groups. Findings were inconclusive regarding differences in the association between cannabis use and alcohol outcomes when comparing males and females and when comparing infrequent and frequent cannabis use groups.

CONCLUSIONS

Heavy drinkers engaged in treatment to reduce their alcohol consumption who also use cannabis appear to increase their cannabis use on days when they reduce their alcohol consumption.

Cannabis use frequency, route of administration, and co-use with alcohol among older adults in Washington state

Background

The US national surveys and data from legal adult use cannabis states show increases in the prevalence of cannabis use among older adults, though little is known about their manner of cannabis consumption. Here, we examine cannabis use frequency, routes of cannabis administration, and co-use with alcohol, focusing on adults aged 50–64 and ≥65.

Methods

Data come from a general population survey conducted January 2014–October 2016 (N=5492) in Washington state. We first estimate prevalence and trends in cannabis frequency, routes of administration, and co-use with alcohol in gender by age groups (18–29, 30–49, 50–64, ≥ 65). To test associations between cannabis frequency, route of administration, and co-use with alcohol, we then use sample-weighted multinomial regression adjusted for gender, race/ethnicity, marital status, education, employment, and survey year. Sampling weights are used so results better represent the Washington state population. Regressions focus on the 50–64 and ≥65 age groups.

Results

Among men and women 50–64, the prevalence of no cannabis use in the past 12 months decreased significantly (84.2% in 2014 to 75.1% in 2016 for women, 76.8% in 2014 to 62.4% in 2016 for men). Among those who report past-year cannabis use, oral administration and vaping and other routes of administration increased by 70% and 94%, respectively each year. Almost one-third of women aged 50–64 and one-fifth of women aged ≥65 who use cannabis reported daily/near daily use, and more than one-third of men who use cannabis in all age groups reported daily/near daily use, including 41.9% of those ≥65. Among men, the prevalence of edibles, drinks, and other oral forms of cannabis administration went up significantly with age (6.6% among 18–29, 21.5% among ≥65). Vaping and other administration are more strongly related to regular and daily/near daily use than infrequent use among those ≥65. The pattern of associations between cannabis frequency and co-use with alcohol differed for women vs. men.

Conclusions

In a general population representative sample of adults living in a state with legal adult use cannabis, the prevalence of cannabis use increased among those aged 50–64 between 2014 and 2016, the prevalence of daily use is substantial, and oral administration and vaping are increasing.

Extending the Harm to Others Paradigm: Comparing Marijuana- and Alcohol-Attributed Harms in Washington State

Harms attributed to others' alcohol use have been extensively studied in the US and internationally, but no studies have measured harms from others' marijuana use. We utilize data from five cross-sectional waves of a survey series with representative samples of Washington state residents conducted every 6 months from 2014 to 2016, after the legalization of adult use marijuana. Harms attributed to others' drinking and to others' marijuana use included family and financial problems, assault, harassment, and vandalism experiences, and accidents due to impaired drivers. Past year harms attributed to others' marijuana use were reported by 8.4% of the sample, while 21.3% reported alcohol-attributed harms and 4.3% experienced both. Women were more likely to experience harms from either substance. While heavy drinkers were most likely to experience alcohol harms from others' use, frequent marijuana users reported the least harms from others. About three times as many individuals reported harassment, vandalism, or family problems attributed to someone's alcohol use compared to those harms attributed to someone's marijuana use, with a smaller ratio seen for financial trouble and a wider ratio for physical harm. Harms attributed to other's marijuana use in Washington were found to be substantial, but lower than harms from others' drinking.

The relationship of cannabis decriminalization in Colorado and cannabis use in individuals with alcohol use disorders

OBJECTIVE

Over the past decade, cannabis use has become increasingly popular in states that include Colorado. During this time, alcohol use disorders (AUDs) and alcohol-related medical conditions have also been consistently recognized as public health problems with increasing prevalence in the state. Despite the widespread use of cannabis in Colorado, the epidemiology of cannabis use among those with AUDs has been poorly described. Therefore, we sought to examine cannabis use among individuals with likely AUDs and individuals with low-risk alcohol use during a time of major Colorado legislative changes before and after legalization of recreational cannabis in 2012.

METHODS

This study was a secondary data analysis conducted with information from 303 participants (80% male) in the Denver, CO metropolitan enrolled between August 2007 and April 2016 for studies related to alcohol and lung health. Of these participants, 188 (62%) were completing inpatient alcohol detoxification with likely AUDs. All participants completed the Alcohol Use Disorder Identification Test (AUDIT) to establish their likelihood of an AUD, and all had information on current cannabis use assessed by questionnaire and urine toxicology testing.

RESULTS

Individuals with likely AUDs more commonly used cannabis compared to control participants (42% vs 27%, p = 0.007). In multiple logistic regression analyses, participant type (likely AUD versus control), tobacco smoking, and age were significantly associated with cannabis smoking; however, the year of participant enrollment was not. Adjusted odds for cannabis use among participants with likely AUDs were 2.97 (1.51-5.82), p = 0.002, while odds for cannabis use among tobacco smokers were 3.67 (1.94-6.93), p < 0.0001. Among control participants, tobacco smoking increased odds of cannabis use seven-fold.

CONCLUSIONS

Our findings highlight the exceptionally high odds of cannabis use among individuals with likely AUDs undergoing alcohol detoxification at a Colorado treatment facility before and after legalization of recreational cannabis. Targeted investigations into the medical and psychiatric consequences of combined alcohol and cannabis use are urgently needed to define its health impact in these vulnerable individuals.

Investigating Relationships Between Alcohol and Cannabis Use in an Online Survey of Cannabis Users: A Focus on Cannabinoid Content and Cannabis for Medical Purposes

Cannabis is commonly used among people who drink alcohol, but findings are mixed regarding the direction of this relationship. The type of cannabis used [high-cannabidiol (CBD) vs. high-delta-9tetrahydrocannabinol (THC)] and motives for use (i.e., whether cannabis is used to treat a medical condition) may influence the relationship between cannabis and drinking. Specifically, CBD has shown preclinical promise in reducing alcohol consumption, and medical cannabis users report using cannabis to reduce drinking. This study leverages survey data from cannabis users who drink alcohol (N = 533). Respondents were categorized as using cannabis to treat (CTT) a medical condition or as individuals whose cannabis use is not intended to treat (NCTT) a medical condition and grouped based on the THC/CBD ratio of the flower or edible cannabis they typically use (e.g., "High-THC/CBD," "Medium-THC/CBD" and "Low-THC/CBD"). The CTT group (n = 412) reported drinking significantly less frequently than the NCTT group (n = 121). Cannabinoid content of flower cannabis was associated with alcohol consumed on cannabis-use days, such that individuals in the High-THC/CBD group drink more on cannabis-use days compared to the Medium-THC/CBD group. Cannabinoid content of edible cannabis was associated with drinks per drinking occasion, such that the High-THC/CBD group consumed the most drinks and the Low-THC/CBD group consumed the fewest. For both edible and flower groupings, higher-THC/CBD cannabis was associated with more frequent co-use than lower-THC/CBD cannabis. Results suggest that whether someone uses cannabis to treat a medical condition may impact their drinking frequency, and the cannabinoid content in flower and edible cannabis impacts alcohol consumption.

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.

Subgroup trends in alcohol and cannabis co-use and related harms during the rollout of recreational cannabis legalization in Washington state

BACKGROUND

The US state of Washington legalized recreational cannabis in 2012; how this impacted the co-use of cannabis and alcohol in the population overall and among key subgroups has not been examined. The aim of this study is to investigate changes in patterns of alcohol- and cannabis use and alcohol-related harms during the rollout of retail recreational cannabis stores.

METHODS

Data come from six cross-sectional samples recruited between January 2014-October 2016 via Random Digit Dial procedures (N = 5492). Survey-weighted multivariable regression adjusting for gender, age, race/ethnicity, education, employment, marital status, cannabis use, and survey year were used for statistical analyses.

RESULTS

In the sample overall, no significant changes were observed in any alcohol use measures between 2014-2016, while the prevalence of cannabis use significantly (P < 0.05) increased from 25.0% to 31.7%, the prevalence of alcohol-related harms at home significantly decreased from 2.1% to 1.0%, and the prevalence of alcohol-related financial harms decreased from 1.5% to 0.8%. Both women and men significantly increased any cannabis use, while women also experienced significantly fewer alcohol-related harms at home and financial harms over time, and increases in the prevalence of cannabis users/non-drinkers. Those 18-29 years old significantly reduced the number of drinking days and overall volume in the past 30 days, and those 30-49 years old significantly decreased alcohol-related harms at home and financial harms. Those 50+ years old significantly increased any cannabis use and simultaneous use of cannabis and alcohol. Non-cannabis users slightly decreased average number of drinks/day, and cannabis users significantly decreased alcohol-related financial harms.

CONCLUSIONS

Between 2014-2016, the years during and immediately following the introduction of legal recreational cannabis stores in Washington state, there were no significant changes in cannabis and alcohol co-use or overall alcohol consumption. The only significant changes in the sample overall were an increase in any cannabis use and decreases in alcohol-related harms at home and alcohol-related financial harms.

Spirits purchasing and marijuana use behaviors of risky drinkers in the state of Washington from 2014 to 2016

BACKGROUND

Few studies have evaluated alcoholic beverage purchasing behaviors, which are relevant to the design and effectiveness of alcoholic beverage control policies. Focusing on spirits purchasing among spirits drinkers, this study compares purchasing behaviors between risky and non-risky drinkers and across drinking patterns among those observed drinking at both levels.

METHODS

A rolling panel of 794 spirits drinkers in the state of Washington were surveyed between two and five times at 6-month intervals during 2014, 2015 and 2016 regarding their alcohol use, spirits purchasing and marijuana use frequency. Purchasing behaviors assessed for spirits were the frequency of purchasing and the travel time, unit cost, bottle size and store type from the respondents most recent purchase. Alcohol use was categorized at each measurement as risky or not using US NIAAA guidelines.

RESULTS

Risky drinkers were more likely to purchase spirits, purchase spirits more frequently, purchase larger spirits containers and use marijuana occasionally, but not frequently. Among drinkers who were risky only in some survey waves, during risky waves they were more likely to purchase more frequently, pay less per liter for spirits purchased, buy larger sized containers of spirits and use marijuana occasionally.

CONCLUSIONS

Drinkers chose to purchase lower cost spirits in larger containers when they were drinking more heavily compared to times when they were drinking within US low-risk guidelines. Findings also support complementarity between heavier drinking and marijuana use among spirits drinkers in a state with legal recreational marijuana sales.

Risks Associated with Mid level Cannabis Use Among People Treated for Alcohol Use Disorder

BACKGROUND

The relationships between cannabis use frequency with alcohol use, alcohol-related harms, and persistent alcohol use disorder (AUD) in a general population subsample of individuals previously treated for AUD were examined.

METHODS

Secondary analyses of the 2005, 2010, and 2015 U.S. National Alcohol Surveys, a nationwide general population sample of individuals ages 18+, were performed. The analytic subsample (N = 772) reported 3+ lifetime DSM-IV alcohol dependence criteria and prior AUD treatment. Primary exposure was past 12-month frequency of cannabis use (weekly or more, or "heavy;" more than monthly/less than weekly or "midlevel;" less than monthly or "light;" none). Primary outcomes were past 12-month total volume, average frequency of 5+ drinks/month, past 12-month alcohol-related harms, and past 12-month DSM-IV alcohol dependence.

RESULTS

Multivariable negative binomial and logistic regressions showed that the only cannabis users who consistently differed significantly from cannabis abstainers were midlevel users; specifically, more than monthly/less than weekly cannabis users drank 2.83 times as many drinks (95% CI: 1.43, 5.60); had 2.83 as many 5+ occasions (95% CI: 1.38, 5.79); had 6.82 times the odds of experiencing any harms (95% CI: 2.29, 20.33); and had 6.53 times the odds of persistent AUD as cannabis abstainers (95% CI: 2.66, 16.02; all ps < 0.05). The relationship between midlevel cannabis use and harms remained significant after adjustment for volume and frequency of 5+ (OR = 6.18, 95% CI: 1.35, 28.37).

CONCLUSIONS

Among those with lifetime AUD who have been to treatment, only more than monthly/less than weekly cannabis use is related to more alcohol-related harms and persistent AUD compared to cannabis abstinence. Heavier and lighter cannabis use is not related to worse alcohol outcomes compared to cannabis abstinence.