Daily associations between cannabis use and alcohol use among people who use cannabis for both medicinal and nonmedicinal reasons: Substitution or complementarity?

Objective: People who use cannabis for medicinal (versus nonmedicinal) reasons report greater cannabis use and lower alcohol use, which may reflect a cannabis–alcohol substitution effect in this population. However, it is unclear whether cannabis is used as a substitute or complement to alcohol at the day level among people who use cannabis for both medicinal and nonmedicinal reasons. This study used ecological momentary assessment (EMA) to examine this question. Method: Participants (N = 66; 53.1% men; mean age 33 years) completed daily surveys assessing previous-day reasons for cannabis use (medicinal versus nonmedicinal), cannabis consumption (both number of different types of cannabis used and grams of cannabis flower used), and number of standard drinks consumed. Results: Multilevel models revealed that, in general, greater cannabis consumption on a given day was associated with greater same-day alcohol use. Further, days during which cannabis was used for medicinal (versus exclusively nonmedicinal) reasons were associated with reduced consumption of both cannabis and alcohol. Finally, the day-level association between medicinal reasons for cannabis use and lower alcohol consumption was mediated by using fewer grams of cannabis on medicinal cannabis use days. Conclusions: Day-level cannabis-alcohol associations may be complementary rather than substitutive among people who use cannabis for both medicinal and nonmedicinal reasons, and lower (rather than greater) cannabis consumption on medicinal use days may explain the link between medicinal reasons for cannabis use and reduced alcohol use. Still, these individuals may use greater amounts of both cannabis and alcohol when using cannabis for exclusively nonmedicinal reasons.This research was supported by grants from the Canadian Institutes of Health Research Canadian HIV Trials Network (CTN PT037; PIs: Jeffrey D. Wardell and Sergio Rueda) and from the Canadian Institutes of Health Research (159754; PIs: Jeffrey D. Wardell and Christian S. Hendershot). The views expressed herein do not necessarily represent the official policy of the Canadian Institutes of Health Research. Sergio Rueda holds an Innovator Award from the Ontario HIV Treatment Network

Examining differential responses to the Take Care of Me trial: A latent class and moderation analysis

Given prevalent alcohol misuse-emotional comorbidities among young adults, we developed an internet-based integrated treatment called Take Care of Me. Although the treatment had an impact on several secondary outcomes, effects were not observed for the primary outcome. Therefore, the goal of the current study was to examine heterogeneity in treatment responses. The initial RCT randomized participants to either a treatment or psychoeducational control condition. We conducted an exploratory latent class analysis to distinguish individuals based on pre-treatment risk and then used moderated regressions to examine differential treatment responses based on class membership. We found evidence for three distinct groups. Most participants fell in the “low severity” group (n = 123), followed by the “moderate severity” group (n = 57) who had a higher likelihood of endorsing a previous mental health diagnosis and treatment and higher symptom severity than the low group. The “high severity” group (n = 42) endorsed a family history of alcoholism, and the highest symptom severity and executive dysfunction. Moderated regressions revealed significant class differences in treatment responses. In the treatment condition, high severity (relative to low) participants reported higher alcohol consumption and hazardous drinking and lower quality of life at follow-up, whereas moderate severity (relative to low) individuals had lower alcohol consumption at follow-up, and lower hazardous drinking at end-of-treatment. No class differences were found for participants in the control group. Higher risk individuals in the treatment condition had poorer responses to the program. Tailoring interventions to severity may be important to examine in future research

Efficacy of a novel online integrated treatment for problem gambling and tobacco smoking: Results of a randomized controlled trial

Background and aimsProblem gambling and tobacco use are highly comorbid among adults. However, there are few treatment frameworks that target both gambling and tobacco use simultaneously (i.e., an integrated approach), while also being accessible and evidence-based. The aim of this two-arm open label RCT was to examine the efficacy of an integrated online treatment for problem gambling and tobacco use.MethodsA sample of 209 participants (M$_{age}$ = 37.66, SD = 13.81; 62.2% female) from North America were randomized into one of two treatment conditions (integrated [n = 91] or gambling only [n = 118]) that lasted for eight weeks and consisted of seven online modules. Participants completed assessments at baseline, after treatment completion, and at 24-week follow-up.ResultsWhile a priori planned generalized linear mixed models showed no condition differences on primary (gambling days, money spent, time spent) and secondary outcomes, both conditions did appear to significantly reduce problem gambling and smoking behaviours over time. Post hoc analyses showed that reductions in smoking and gambling craving were correlated with reductions in days spent gambling, as well as with gambling disorder symptoms. Relatively high (versus low) nicotine replacement therapy use was associated with greater reductions in gambling behaviours in the integrated treatment condition.Discussion and conclusionsWhile our open label RCT does not support a clear benefit of integrated treatment, findings suggest that changes in smoking and gambling were correlated over time, regardless of treatment condition, suggesting that more research on mechanisms of smoking outcomes in the context of gambling treatment may be relevant

Correlates of self-reported medicinal cannabis use for physical health, mental health, and sleep-related conditions in a population-based survey of Canadian youth

Objective: Medicinal cannabis use (MCU) among youth is correlated with frequent cannabis use and several substance use and health-related indicators. This study examined whether correlates of self-reported MCU among youth varied as a function of the primary health condition for which cannabis is used. Method: Data came from the 2017 Canadian Tobacco, Alcohol, and Drugs Survey. Youth (ages 15-24) who reported past year cannabis use were included in analyses. Regression analyses (controlling for age and sex) compared youth reporting only non-medicinal cannabis use (NMCU-only, n=2082) to youth reporting MCU primarily for physical health conditions (n=227), mental health conditions (n=271), or insomnia (n=98). Results: Relative to youth reporting NMCU-only, youth reporting MCU for physical or mental health conditions had greater odds of reporting daily cannabis use, cannabis problems, vaporization and oral ingestion of cannabis, and tobacco use. Youth reporting MCU for physical health reasons also had greater odds of both illicit drug use and prescription pain medication use, whereas youth reporting MCU for mental health reasons had greater odds of prescription sedative use. Youth reporting MCU for insomnia only had greater odds of cannabis problems relative to youth in the NMCU-only group. Youth in both the physical health and mental health MCU groups reported poorer health and mental health compared with the NMCU-only group. Some, but not all, differences were accounted for by greater frequency of cannabis use among youth reporting MCU. Conclusions: Findings provide new insight into the correlates of MCU among youth in the general population, suggesting that these correlates vary as a function of the primary reason for MCU

Characterizing heterogeneity among people who use cannabis for medicinal reasons: A latent class analysis of a nationally representative Canadian sample

Background: Many individuals who use cannabis report doing so for medicinal reasons. Few studies have explored heterogeneity within this population, which may be important to inform targeted interventions. This study used latent class analysis to identify subgroups of people who use cannabis for medicinal reasons and their sociodemographic and cannabis-risk-related correlates. Method: Data came from the 2019 Canadian Alcohol and Drugs Survey, which is a representative survey of Canadians ages 15 years and older. Data from 814 individuals reporting past-year use of cannabis for medicinal or mixed medicinal and non-medicinal reasons were included. Latent class analysis was conducted with forms of cannabis used, cannabis use frequency, concurrent non-medicinal cannabis use, and the medical conditions and symptoms cannabis was used to manage as indicators. Results: Four distinct latent classes of medicinal cannabis use were identified: a non-daily cannabis flower for mental health and sleep class (39.56% of the sample), a non-daily cannabis flower for pain class (26.41% of the sample), a non-daily cannabis oil for physical health class (20.15% of the sample), and a daily multi-form cannabis for mental health and non-medical reasons class (13.88% of the sample). Sociodemographic factors and risk level for cannabis-related harms were associated with latent class membership. Conclusions: Results of this study reveal considerable heterogeneity among people reporting medicinal cannabis use and suggest that the distinct patterns of cannabis use behaviors and motives observed may be important for understanding risk for cannabis-related harms in this population. Findings underscore a need for harm reduction interventions tailored toward specific patterns of medicinal cannabis use

Randomized controlled trial of a smartphone app designed to reduce unhealthy alcohol consumption

Background and aimsUnhealthy alcohol use is common and causes tremendous harm. Most people with unhealthy alcohol use will never seek formal alcohol treatment. As an alternative, smartphone apps have been developed as one means to provide help to people concerned about their alcohol use. The aim of this study was to test the efficacy of a smartphone app targeting unhealthy alcohol consumption in a general population sample.MethodsParticipants were recruited from across Canada using online advertisements. Eligible participants who consented to the trial were asked to download a research-specific version of the app and were provided with a code that unlocked it (a different code for each participant to prevent sharing). Those who entered the code were randomized to one of two different versions of the app: 1) the Full app containing all intervention modules; or 2) the Educational only app, containing only the educational content of the app. Participants were followed-up at 6 months. The primary outcome variable was number of standard drinks in a typical week. Secondary outcome variables were frequency of heavy drinking days and experience of alcohol-related problems.ResultsA total of 761 participants were randomized to a condition. The follow-up rate was 81 %. A generalized linear mixed model revealed that participants receiving the full app reduced their typical weekly alcohol consumption to a greater extent than participants receiving the educational only app (incidence rate ratio 0.89; 95 % confidence interval 0.80 to 0.98). No significant differences were observed in the secondary outcome variables (p > .05).Discussion and conclusionThe results of this trial provide some supportive evidence that smartphone apps can reduce unhealthy alcohol consumption. As this is the second randomized controlled trial demonstrating an impact of this same app (the first one targeted unhealthy alcohol use in university students), increased confidence is placed on the potential effectiveness of the smartphone app employed in the current trial