Alcohol DrinkingPhase 2NCT05389930
Cannabis' Impact on Alcohol Consumption
A Phase 2 study testing THC-dominant cannabis, CBD-dominant cannabis and Alcohol in people with Alcohol Drinking and Cannabis Use, run by Brown University at 1 site in United States.
Trial summary
This study employs a repeated measures experimental design to examine the effect of THC-dominant dose of cannabis and CBD-dominant dose of cannabis, relative to placebo, on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not… Read more about this study
- Who is it for?
- Ages 21 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Alcohol Drinking, Cannabis Use, Cannabis
- What is being tested?
- THC-dominant cannabis, CBD-dominant cannabis and Alcohol
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 350 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Mar 2023to 31 Dec 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
Who cannot join
- positive pregnancy test
- nursing
- positive urine toxicology screen for drugs other than cannabis
- interest to quit or receive treatment for cannabis or alcohol use
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Brown University
Providence, Rhode Island, 02912
Jane Metrik, PhD, 401-863-6650, Jane_Metrik@brown.edu
About this study
Official title: Cannabis' Impact on Alcohol Consumption: Integrating Laboratory and Ecological Momentary Assessment Methods
This study employs a repeated measures experimental design to examine the effect of THC-dominant dose of cannabis and CBD-dominant dose of cannabis, relative to placebo, on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consumed. Cannabis will be administered simultaneously with an alcohol-priming dose or alcohol placebo.
The study will enroll up to 350 nontreatment-seeking heavy episodic alcohol drinkers who use cannabis weekly.
Read the detailed description
This study employs a repeated measures experimental design to examine the effect of THC-dominant (9.53% THC and 0.09% CBD) dose of cannabis and CBD-dominant (0.35% THC and 11.27% CBD) dose of cannabis, relative to placebo, on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consumed. Cannabis will be administered simultaneously with an alcohol-priming dose or alcohol placebo. The study will enroll up to 350 nontreatment-seeking heavy episodic alcohol drinkers who use cannabis weekly to obtain the final sample of 200 with complete data. Participants will be tested at a baseline session, during three experimental sessions, and then during a subsequent 4-week period in the natural environment using a smart-phone application. Findings have important implications for cannabis regulatory science and alcohol use disorder treatment by addressing the relative impact of specific cannabinoids as well as contextual risk in cannabis-alcohol co-use.
- Conditions
- Alcohol Drinking, Cannabis Use, Cannabis, Alcohol Use Disorder
- Being tested
- THC-dominant cannabis, CBD-dominant cannabis, Cannabis placebo, Alcohol, Alcohol placebo
- Keywords
- alcohol, cannabis, marijuana, addiction, cannabinoid, tetrahydrocannabinol, cannabidiol
- Medical subject headings
- Alcohol Drinking, Marijuana Abuse, Alcoholism, Behavior, Addictive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
THC-dominant cannabisDrug
Smoked cannabis with 9.53% THC and 0.09% CBD
CBD-dominant cannabisDrug
Smoked cannabis with 0.35% THC and 11.27% CBD
Cannabis placeboDrug
Smoked placebo cannabis plant material
AlcoholDrug
Drink containing 0.3 g/kg of alcohol
Alcohol placeboDrug
Placebo beverage contains only juice and a negligible trace of alcohol for masking
| Study group | Role | What they receive |
|---|---|---|
| THC-dominant cannabis dose | Experimental | 367 mg of cannabis plant material with 9.53% THC and 0.09% CBD and 217 mg of placebo cannabis plant material will be mixed and smoked in a handheld pipe Receives: Drug: Alcohol; Drug: Alcohol placebo |
| CBD-dominant cannabis dose | Experimental | 367 mg of cannabis plant material with 11.27% CBD and 0.35% THC and 217 mg of placebo cannabis plant material will be mixed and smoked in a handheld pipe Receives: Drug: Alcohol; Drug: Alcohol placebo |
| Placebo | Placebo comparator | 584 mg of cannabis plant material will be smoked in a handheld pipe Receives: Drug: Alcohol; Drug: Alcohol placebo |
| Alcohol priming dose | Experimental | Alcohol: 0.3 g/kg. Alcohol priming drink is designed to raise blood alcohol levels to 0.03 g/dl and be consumed in 5 minutes. The drink is mixed using 80-proof liquor and juice. Participants are randomized to receive either the experimental alcohol priming dose or alcohol placebo. Receives: Drug: THC-dominant cannabis; Drug: CBD-dominant cannabis; Drug: Cannabis placebo |
| Alcohol placebo dose | Placebo comparator | Placebo beverage contains only juice and a negligible trace of alcohol for masking. The weight and sex-adjusted volume of alcohol and non-alcohol containing beverages will be equal. Participants are randomized to receive either the experimental alcohol priming dose or alcohol placebo. Receives: Drug: THC-dominant cannabis; Drug: CBD-dominant cannabis; Drug: Cannabis placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
ml of alcohol consumed
ml of alcohol consumed during the alcohol choice task
Measured: post-smoking during two-hours of the alcohol choice task
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 May 2022
- Study start16 Mar 2023
- Primary completion31 Aug 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Alcohol DrinkingStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Factorial
- Model description
- Mixed factorial design will use a 3 (within-subjects; cannabinoid dose: 9.53% THC/0.06% CBD, 11.27% CBD/0.35% THC, placebo) X 2 (between-subjects; cannabis + an alcohol-priming dose (0.3 g/kg) versus cannabis + alcohol placebo)
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 350 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Brown University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Alcohol Abuse and Alcoholism (NIAAA)
- Responsible party
- Sponsor
- Investigators
- Jane Metrik, PhD, Principal investigator, Brown University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05389930
- Sponsor's protocol ID
- 2022003195
- Other IDs
- R01AA029711
- Status last verified
- Oct 2026
- First submitted
- 20 May 2022
- Last updated
- 5 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cannabis' Impact on Alcohol Consumption: Integrating Laboratory and Ecological Momentary Assessment Methods
- ClinicalTrials.gov ID
- NCT05389930
- Acronym / sponsor ID
- 2022003195
- Conditions
- Alcohol Drinking, Cannabis Use, Cannabis, Alcohol Use Disorder
- Keywords
- alcohol, cannabis, marijuana, addiction, cannabinoid, tetrahydrocannabinol, cannabidiol
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 350 participants (estimated)
- Lead sponsor
- Brown UniversityUniversity, hospital or other
- Collaborators
- National Institute on Alcohol Abuse and Alcoholism (NIAAA)
- Study start
- 16 Mar 2023 (actual)
- Primary completion
- 31 Aug 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 25 May 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study employs a repeated measures experimental design to examine the effect of THC-dominant dose of cannabis and CBD-dominant dose of cannabis, relative to placebo, on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consumed. Cannabis will be administered simultaneously with an alcohol-priming dose or alcohol placebo.
The study will enroll up to 350 nontreatment-seeking heavy episodic alcohol drinkers who use cannabis weekly.
Detailed description
This study employs a repeated measures experimental design to examine the effect of THC-dominant (9.53% THC and 0.09% CBD) dose of cannabis and CBD-dominant (0.35% THC and 11.27% CBD) dose of cannabis, relative to placebo, on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consumed. Cannabis will be administered simultaneously with an alcohol-priming dose or alcohol placebo. The study will enroll up to 350 nontreatment-seeking heavy episodic alcohol drinkers who use cannabis weekly to obtain the final sample of 200 with complete data. Participants will be tested at a baseline session, during three experimental sessions, and then during a subsequent 4-week period in the natural environment using a smart-phone application. Findings have important implications for cannabis regulatory science and alcohol use disorder treatment by addressing the relative impact of specific cannabinoids as well as contextual risk in cannabis-alcohol co-use.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 5
- Model description
- Mixed factorial design will use a 3 (within-subjects; cannabinoid dose: 9.53% THC/0.06% CBD, 11.27% CBD/0.35% THC, placebo) X 2 (between-subjects; cannabis + an alcohol-priming dose (0.3 g/kg) versus cannabis + alcohol placebo)
| Arm | Type | Receives |
|---|---|---|
| THC-dominant cannabis dose | Experimental | Drug: Alcohol, Drug: Alcohol placebo367 mg of cannabis plant material with 9.53% THC and 0.09% CBD and 217 mg of placebo cannabis plant material will be mixed and smoked in a handheld pipe |
| CBD-dominant cannabis dose | Experimental | Drug: Alcohol, Drug: Alcohol placebo367 mg of cannabis plant material with 11.27% CBD and 0.35% THC and 217 mg of placebo cannabis plant material will be mixed and smoked in a handheld pipe |
| Placebo | Placebo comparator | Drug: Alcohol, Drug: Alcohol placebo584 mg of cannabis plant material will be smoked in a handheld pipe |
| Alcohol priming dose | Experimental | Drug: THC-dominant cannabis, Drug: CBD-dominant cannabis, Drug: Cannabis placeboAlcohol: 0.3 g/kg. Alcohol priming drink is designed to raise blood alcohol levels to 0.03 g/dl and be consumed in 5 minutes. The drink is mixed using 80-proof liquor and juice. Participants are randomized to receive either the experimental alcohol priming dose or alcohol placebo. |
| Alcohol placebo dose | Placebo comparator | Drug: THC-dominant cannabis, Drug: CBD-dominant cannabis, Drug: Cannabis placeboPlacebo beverage contains only juice and a negligible trace of alcohol for masking. The weight and sex-adjusted volume of alcohol and non-alcohol containing beverages will be equal. Participants are randomized to receive either the experimental alcohol priming dose or alcohol placebo. |
Who may qualify
- Ages
- 21 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (4 listed)
- positive pregnancy test
- nursing
- positive urine toxicology screen for drugs other than cannabis
- interest to quit or receive treatment for cannabis or alcohol use
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| THC-dominant cannabisSmoked cannabis with 9.53% THC and 0.09% CBD | Drug | Alcohol placebo dose, Alcohol priming dose |
| CBD-dominant cannabisSmoked cannabis with 0.35% THC and 11.27% CBD | Drug | Alcohol placebo dose, Alcohol priming dose |
| Cannabis placeboSmoked placebo cannabis plant material | Drug | Alcohol placebo dose, Alcohol priming dose |
| AlcoholDrink containing 0.3 g/kg of alcohol | Drug | CBD-dominant cannabis dose, Placebo, THC-dominant cannabis dose |
| Alcohol placeboPlacebo beverage contains only juice and a negligible trace of alcohol for masking | Drug | CBD-dominant cannabis dose, Placebo, THC-dominant cannabis dose |
Primary outcome
ml of alcohol consumed
Time frame: post-smoking during two-hours of the alcohol choice task
ml of alcohol consumed during the alcohol choice task
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Oct 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jane Metrik, PhD principal investigator
Brown University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing THC-dominant cannabis, CBD-dominant cannabis and Alcohol in people with Alcohol Drinking and Cannabis Use, run by Brown University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 5 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jane Metrik, PhD (401-863-6650, Jane_Metrik@brown.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
ml of alcohol consumed (time frame: post-smoking during two-hours of the alcohol choice task). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Oct 2026.