Consuming oral cannabidiol prior to a standard alcohol dose has minimal effect on breath alcohol level and subjective effects of alcohol

Rationale: Cannabidiol (CBD) is found in the cannabis plant and has garnered attention as a potential treatment for alcohol use disorder (AUD). CBD reduces alcohol consumption and other markers of alcohol dependence in rodents, but human research on CBD and alcohol is limited. It is unknown whether CBD reduces drinking in humans, and mechanisms through which CBD could impact behavioral AUD phenotypes are unknown.

Objectives: This study explores effects of oral CBD on breath alcohol level (BrAC), and subjective effects of alcohol in human participants who report heavy drinking.

Methods: In this placebo-controlled, crossover study, participants consumed 30 mg CBD, 200 mg CBD, or placebo CBD before receiving a standardized alcohol dose. Participants were blind to which CBD dose they received at each session and completed sessions in random order. Thirty-six individuals completed at least one session and were included in analyses.

Results: Differences in outcomes across the three conditions and by sex were explored using multilevel structural equation models. BrAC fell fastest in the placebo condition, followed by 30 mg and 200 mg CBD. Stimulation decreased more slowly in the 200 mg CBD condition than in placebo (b = - 2.38, BCI [- 4.46, - .03]). Sedation decreased more slowly in the 30 mg CBD condition than in placebo (b = - 2.41, BCI [- 4.61, - .09]). However, the magnitude of condition differences in BrAC and subjective effects was trivial.

Conclusions: CBD has minimal influence on BrAC and subjective effects of alcohol. Further research is needed to test whether CBD impacts alcohol consumption in humans, and if so, what mechanism(s) may explain this effect.