Study on How THC- and CBD-Dominant Cannabis Affect Alcohol Drinking in Adults Aged 21 to 50

What this Trial Is About

Researchers are evaluating the effects of different types of cannabis on alcohol consumption in heavy episodic drinkers who use cannabis weekly. This study compares the impact of THC-dominant cannabis, CBD-dominant cannabis, and placebo on subsequent drinking behavior using a repeated measures experimental design. Participants will receive cannabis simultaneously with either an alcohol-priming dose or an alcohol placebo, aiming to better understand how specific cannabinoids influence alcohol use and related risks. Participants will be randomized to receive one of several interventions a THC-dominant cannabis dose 9.53% THC and 0.09% CBD, a CBD-dominant cannabis dose 0.35% THC and 11.27% CBD, or a placebo cannabis dose, all smoked using a handheld pipe. Alcohol will be given as a priming drink designed to raise blood alcohol levels to 0.03 gdl or as a placebo beverage consisting mainly of juice with a trace of alcohol for masking. The study includes a baseline session, three experimental sessions, and a four-week follow-up period using a smartphone application to monitor participants in their natural environment. During the study, participants will complete alcohol choice tasks to measure the amount of alcohol consumed after smoking cannabis or placebo. Researchers will assess drinking behavior over two hours after cannabis use and track participants alcohol use and related behaviors during the four-week follow-up. Safety measures include breath alcohol tests at each visit and monitoring for adherence to study protocols. The study aims to enroll up to 350 participants to achieve a final sample of 200 with complete data.

Cannabis' Impact on Alcohol Consumption