Examining how cannabis affects alcohol consumption

Cannabis' Impact on Alcohol Consumption: Integrating Laboratory and Ecological Momentary Assessment Methods

PHASE2 · Brown University · NCT05389930

This study is testing how different types of cannabis affect drinking habits in heavy drinkers who use cannabis regularly.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment350 (estimated)
Ages21 Years to 50 Years
SexAll
SponsorBrown University (other)
Locations1 site (Providence, Rhode Island)
Trial IDNCT05389930 on ClinicalTrials.gov

What this trial studies

This study investigates the effects of THC-dominant and CBD-dominant cannabis on alcohol consumption among heavy episodic drinkers who use cannabis weekly. Participants will engage in an alcohol choice task where they can choose to drink or receive monetary rewards for abstaining from alcohol. The study will enroll up to 350 participants, with a focus on understanding the impact of specific cannabinoids and the context of cannabis-alcohol co-use. Data will be collected through a combination of experimental sessions and a smartphone application over a four-week period.

Who should consider this trial

Good fit: Ideal candidates are English-speaking adults aged 21 to 50 who are heavy episodic drinkers and have used cannabis in the past two months.

Not a fit: Patients who are pregnant, nursing, or seeking treatment for alcohol or cannabis use may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into effective strategies for reducing alcohol consumption among heavy drinkers using cannabis.

How similar studies have performed: Other studies have explored the relationship between cannabis and alcohol use, but this specific approach examining the effects of different cannabinoid profiles is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 21 to 50
* English-speaking
* cannabis smoking in past two months
* heavy drinking in past two months
* in good physical health and weighing \< 250 lbs
* zero breath alcohol at each visit

Exclusion Criteria:

* positive pregnancy test
* nursing
* positive urine toxicology screen for drugs other than cannabis
* interest to quit or receive treatment for cannabis or alcohol use

Where this trial is running

Providence, Rhode Island

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Alcohol Drinking, Cannabis Use, Cannabis, Alcohol Use Disorder, alcohol, cannabis, marijuana, addiction

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.