CannabisPhase 1THC-ETOHNCT02404688
Ethanol and Cannabinoid Effects on Simulated Driving and Related Cognition
A Phase 1 study testing Active delta-9-THC and Active Ethanol in people with Cannabis and Alcohol Effect, run by Yale University at 1 site in United States.
Trial summary
The overarching goal of this study is to characterize the effects of ethanol and cannabinoids on simulated driving and related cognition. Read more about this study
- Who is it for?
- Ages 21 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Cannabis, Alcohol Effect, Driving Under the Influence of Alcohol and Other Drugs
- What is being tested?
- Active delta-9-THC and Active Ethanol
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- Dec 2015to Dec 2026
- Phase
- Phase 1
- 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 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Males or females 21 to 55 years of age (extremes included).
- Exposed to cannabis at least once.
- Exposed to alcohol at least once.
- Able to provide informed consent.
Who cannot join
- Cannabis naive.
- Alcohol naive.
- Positive pregnancy screen
- Hearing deficits.
Trial locations and contacts
1 site in 1 country.
United States1 site
Biological Studies Unit, VA Connecticut Healthcare System
West Haven, Connecticut, 06516
About this study
The overarching goal of this study is to characterize the effects of ethanol and cannabinoids on simulated driving and related cognition.
Read the detailed description
To study the effects of ethanol clamped at BAC 0.04% and THC (1.05 mg in a 70 kg individual) on driving.
- Being tested
- Active delta-9-THC, Placebo, Active Ethanol
- Medical subject headings
- Marijuana Abuse
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Active delta-9-THCDrug
Low dose (0.015 mg/kg = 1.05 mg in a 70 kg individual) THC, dissolved in alcohol. This dose is roughly equivalent to smoking approximately 1/4 of a marijuana cigarette, or "joint". Administered over 20 minutes.
PlaceboDrug
Control: small amount of alcohol (quarter teaspoon), with no THC. Administered over 20 minutes.
Active EthanolDrug
Target BrAC of 0.04% reached over 20 minutes and then clamped to maintain this dose for an additional 60 minutes. This dose is equivalent to consuming approximately 2 drinks over 1 hour. Administered over a total of 80 minutes.
PlaceboDrug
Control: no alcohol, administered for a total of 80 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Active THC and Placebo Ethanol | Experimental | Not described Receives: Drug: Active delta-9-THC; Drug: Placebo |
| Active THC and Active Ethanol | Experimental | Not described Receives: Drug: Active delta-9-THC; Drug: Active Ethanol |
| Placebo THC and Active Ethanol | Experimental | Not described Receives: Drug: Placebo; Drug: Active Ethanol |
| Placebo THC and Placebo Ethanol | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Road Tracking Error
changes in road tracking errors between timepoints to assess the effects of alcohol and THC on road tracking errors.
Measured: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Secondary outcomes (6)
Biphasic Alcohol Effects Scale (BAES)
A scale designed to assess the stimulant and sedative effects associated with alcohol intoxication.
Measured: baseline, +20, +50, +120, +180, +240 mins after start of alcohol and THC infusion
Visual Analog Scale (VAS)
Feeling states associated with alcohol and cannabis intoxication will be measured using this self-report scale of feeling states.
Measured: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Cognitive Test Battery
Several computer tasks will be administered to assess alcohol and THC effects on driving related cognition, including: visual vigilance, visual motor function, attention and working memory, and processing speed.
Measured: +40 mins after start of alcohol and THC infusion
Willingness to Drive Scale
Subjects will be asked to rate their willingness to drive at their current state in the context of various scenarios including willingness to drive from testing facility to a number of destinations that are different driving distances.
Measured: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Number of Joints Scale
Subjects will be asked to rate the number of standard joints that they believe they have been administered.
Measured: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Number of Drinks Scale
Subjects will be asked to rate the number of standard drinks that they believe they have been administered.
Measured: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Mar 2015 (estimated)
- Study startDec 2015
- Primary completionDec 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for CannabisStudies of the same condition, open and under way.
- More trials run by Yale UniversityThe sponsor's other registered studies.
- 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 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Deepak C. D'Souza, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02404688
- Sponsor's protocol ID
- 1501015208
- Acronym
- THC-ETOH
- Status last verified
- Apr 2026
- First submitted
- 26 Mar 2015
- Last updated
- 29 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ethanol and Cannabinoid Effects on Simulated Driving and Related Cognition
- ClinicalTrials.gov ID
- NCT02404688
- Acronym / sponsor ID
- THC-ETOH / 1501015208
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Study start
- Dec 2015
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 31 Mar 2015 (estimated)
- 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.
The overarching goal of this study is to characterize the effects of ethanol and cannabinoids on simulated driving and related cognition.
Detailed description
To study the effects of ethanol clamped at BAC 0.04% and THC (1.05 mg in a 70 kg individual) on driving.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Active THC and Placebo Ethanol | Experimental | Drug: Active delta-9-THC, Drug: Placebo |
| Active THC and Active Ethanol | Experimental | Drug: Active delta-9-THC, Drug: Active Ethanol |
| Placebo THC and Active Ethanol | Experimental | Drug: Placebo, Drug: Active Ethanol |
| Placebo THC and Placebo Ethanol | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 21 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Males or females 21 to 55 years of age (extremes included).
- Exposed to cannabis at least once.
- Exposed to alcohol at least once.
- Able to provide informed consent.
Key exclusion criteria (4 listed)
- Cannabis naive.
- Alcohol naive.
- Positive pregnancy screen
- Hearing deficits.
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 |
|---|---|---|
| Active delta-9-THCLow dose (0.015 mg/kg = 1.05 mg in a 70 kg individual) THC, dissolved in alcohol. This dose is roughly equivalent to smoking approximately 1/4 of a marijuana cigarette, or "joint". Administered over 20 minutes. | Drug | Active THC and Active Ethanol, Active THC and Placebo Ethanol |
| PlaceboControl: small amount of alcohol (quarter teaspoon), with no THC. Administered over 20 minutes. | Drug | Placebo THC and Active Ethanol, Placebo THC and Placebo Ethanol |
| Active EthanolTarget BrAC of 0.04% reached over 20 minutes and then clamped to maintain this dose for an additional 60 minutes. This dose is equivalent to consuming approximately 2 drinks over 1 hour. Administered over a total of 80 minutes. | Drug | Active THC and Active Ethanol, Placebo THC and Active Ethanol |
| PlaceboControl: no alcohol, administered for a total of 80 minutes. | Drug | Active THC and Placebo Ethanol, Placebo THC and Placebo Ethanol |
Primary outcome
Road Tracking Error
Time frame: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
changes in road tracking errors between timepoints to assess the effects of alcohol and THC on road tracking errors.
6 secondary outcomes
Biphasic Alcohol Effects Scale (BAES)
Time frame: baseline, +20, +50, +120, +180, +240 mins after start of alcohol and THC infusion
Visual Analog Scale (VAS)
Time frame: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Cognitive Test Battery
Time frame: +40 mins after start of alcohol and THC infusion
Willingness to Drive Scale
Time frame: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Number of Joints Scale
Time frame: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
Number of Drinks Scale
Time frame: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion
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 29 Apr 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Active delta-9-THC and Active Ethanol in people with Cannabis and Alcohol Effect, run by Yale 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 4 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: under way, not looking for participants, as of the sponsor's last update on 29 Apr 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Road Tracking Error (time frame: baseline, +20, +50, +120, +180 mins after start of alcohol and THC infusion). 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 29 Apr 2026.