The Impact of Oral Cannabis Administration and Co-Administration of Alcohol on Impairment

October 2, 2025 updated by: Johns Hopkins University
This study will evaluate the individual and interactive effects of oral cannabis and alcohol on subjective and behavioral measures of impairment.

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

This clinical laboratory study will be double-blind, placebo-controlled and will utilize a within-subjects experimental design. Participants will complete 7 outpatient drug administration sessions that will consist of self-administration of oral cannabis (0, 10 or 25mg THC) and alcohol (either placebo or active; BAC of 0.05 percent); participants will always receive both an alcohol drink (active or placebo) and dose of cannabis (active or placebo). Participants will also complete a condition in which they administer alcohol (BAC: 0.08 percent) with placebo cannabis, as a positive control. Primary outcomes include performance on field sobriety tests, cognitive and psychomotor impairment, subjective drug effects, and simulated driving performance. Blood concentrations of THC and THC metabolites will also be determined.

Study Type

Interventional

Enrollment (Actual)

60

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Johns Hopkins Behavioral Pharmacology Research Unit

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years to 55 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Have provided written informed consent
  2. Be between the ages of 21 and 55
  3. Be in good general health based on a physical examination, medical history, vital signs, and screening urine and blood tests
  4. Not be pregnant or nursing (if female). All females must have a negative serum pregnancy test at the screening visit and a negative urine pregnancy test at each study visit.
  5. Have a body mass index (BMI) in the range of 19 to 36 kg/m2
  6. Blood pressure at Screening Visit does not exceed a systolic blood pressure (SBP) of 150 mmHg or a diastolic blood pressure (DBP) of 90 mmHg
  7. Have not donated blood in the prior 30 days.
  8. Report at least 2 days of binge drinking in the past 90 days (greater than 4 or 5 drinks on a single occasion for women and men, respectively)
  9. Report ≥ 1 use of cannabis in the past year
  10. Provide negative urine test for illicit drug use (excluding THC) and negative breath alcohol test (0% BAC) at screening and before study sessions
  11. Report at least 1 instance of simultaneous alcohol and use in the past year.

Exclusion Criteria:

  1. Psychoactive drug use (aside from cannabis, nicotine, alcohol, or caffeine) in past month
  2. Current use of over-the-counter (OTC) drugs, supplements/vitamins, or prescription medications that, in the opinion of the investigator or medical staff, will impact the participant's safety
  3. History of or current evidence of significant medical condition
  4. Evidence of current psychiatric condition [(MINI for Diagnostic and Statistical Manual (DSM)-V)]
  5. Meet criteria for severe alcohol use disorder (MINI for DSM-V)
  6. Clinical Institute Withdrawal Assessment for Alcohol scale (CIWA-Ar) score > 9
  7. Been in treatment previously for alcohol or cannabis use disorder
  8. Use of cannabis, on average, more than 2 times/week over past 3 months
  9. Liver function tests more than 2x normal range
  10. Enrollment in another clinical trial or receiving of any drug as part of research within past 30 days
  11. Shipley vocabulary score <18 (corresponds to 5th grade reading level).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo cannabis + placebo alcohol
Participants administer oral cannabis containing 0mg THC in combination with a placebo alcohol drink.
Cannabis will be orally ingested via a brownie
Alcohol will be orally ingested via a flavored drink
Experimental: low dose cannabis with placebo alcohol
Participants administer oral cannabis containing 10mg THC in combination with a placebo alcohol drink.
Cannabis will be orally ingested via a brownie
Alcohol will be orally ingested via a flavored drink
Experimental: high dose cannabis with placebo alcohol
Participants administer oral cannabis containing 25mg THC in combination with a placebo alcohol drink.
Cannabis will be orally ingested via a brownie
Alcohol will be orally ingested via a flavored drink
Experimental: low dose cannabis with low dose alcohol
Participants administer oral cannabis containing 10mg THC in combination with an alcohol drink (0.05 percent BAC).
Cannabis will be orally ingested via a brownie
Alcohol will be orally ingested via a flavored drink
Experimental: high dose cannabis with low dose alcohol
Participants administer oral cannabis containing 25mg THC in combination with an alcohol drink (0.05 percent BAC).
Cannabis will be orally ingested via a brownie
Alcohol will be orally ingested via a flavored drink
Experimental: Placebo cannabis + low dose alcohol
Participants administer oral cannabis containing 0mg THC in combination with an alcohol drink (0.05 percent BAC).
Cannabis will be orally ingested via a brownie
Alcohol will be orally ingested via a flavored drink
Experimental: Placebo cannabis + high dose alcohol
Participants administer oral cannabis containing 0mg THC in combination with an alcohol drink (0.08 percent BAC).
Cannabis will be orally ingested via a brownie
Alcohol will be orally ingested via a flavored drink

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
DRUID application global impairment score
Time Frame: 7.5 hours
Acute cognitive and behavioral impairment will be assessed with global impairment score(range 0-100) on the DRUID app (higher scores indicate greater impairment).
7.5 hours
Correct Trials on Paced Auditory Serial Addition Task (PASAT)
Time Frame: 7.5 hours
Computerized version of Paced Auditory Serial Addition Task will be administered to assess working memory performance. Will report the total correct trials out of 90 recorded (lower scores indicate worse performance).
7.5 hours
Correct Trials on the Digit Symbol Substitution Task (DSST)
Time Frame: 7.5 hours
Computerized version of Digit Symbol Substitution Task will be administered to assess psychomotor performance. Will report the total correct trials in 90 seconds (lower scores indicate worse performance).
7.5 hours
Cumulative score on Field Sobriety Tests
Time Frame: 7.5 hours
Impairment will be assessed using a battery of standard field sobriety tests including: the Horizontal Gaze Nystagmus Test (HGN), the Walk and Turn, the One Leg Stand, and the Modified Romberg Balance. We will report the cumulative amount of clues observed across these tasks (out of a possible 22 clues).
7.5 hours
Drug Effect Questionnaire (DEQ) - Feel Drug Effect
Time Frame: 7.5 hours
The DEQ will be used to obtain subjective ratings of "feel drug effects". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
7.5 hours
Drug Effect Questionnaire - Feel High
Time Frame: 7.5 hours
The DEQ will be used to obtain subjective ratings of "feel high". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
7.5 hours
Drug Effect Questionnaire - Confidence to Drive
Time Frame: 7.5 hours
The DEQ will be used to obtain subjective ratings of "confidence to drive". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
7.5 hours
Drug Effect Questionnaire - Willingness to Drive
Time Frame: 7.5 hours
The DEQ will be used to obtain subjective ratings of "willingness to drive". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
7.5 hours
Biphasic alcohol effects scale (BAES) - Sedative Score
Time Frame: 7.5 hours
The BAES is used to assess sedative and stimulant subjective effects of alcohol. There are 7 sedative-related questionnaire items, each presented on a scale of 0 (not at all) to 10 (extremely), which are integrated to produce an overall sedative score (0-70).
7.5 hours
Biphasic alcohol effects scale (BAES) - Stimulant Score
Time Frame: 7.5 hours
The BAES is used to assess sedative and stimulant subjective effects of alcohol. There are 7 stimulant-related questionnaire items, each presented on a scale of 0 (not at all) to 10 (extremely), which are integrated to produce an overall stimulant score (0-70).
7.5 hours
Subjective high assessment scale (SHAS)
Time Frame: 7.5 hours
For the SHAS, participants are presented with 13 questionnaire items, displayed on a visual analog scale anchored from 0 (normal) to 10 (extremely), which assess subjective effects of alcohol. These items are integrated to produce an overall SHAS score (0-130)
7.5 hours
Driving performance as assessed by standard deviation of lateral position (SDLP)
Time Frame: 7.5 hours
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. SDLP (measured in cm) will be determined during each drive. This measure is a composite index of lateral control and incorporates lane weaving, swerving, and over-correcting. SDLP is the gold standard of quantifying the magnitude of driving impairment from drugs and alcohol and has excellent predictive validity to actual driving. Scores range from 0 to no upper limit. Higher scores represent higher magnitude of driving impairment.
7.5 hours
Driving performance as assessed by composite drive score
Time Frame: 7.5 hours
Driving impairment will be assessed via a composite drive score (higher scores indicate greater impairment). The composite drive score is derived by integrating various driving outcomes (see primary and secondary driving outcomes). There is no upper or lower limit to possible scores
7.5 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Driving performance as assessed by standard deviation of speed (SDSP)
Time Frame: 7.5 hours
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. SDSP will be determined during each drive; this measure quantifies the variability in speed (in MPH) observed.
7.5 hours
Driving performance (mean speed)
Time Frame: 7.5 hours
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. Mean speed (in MPH) over the course of each drive will be determined.
7.5 hours
Driving performance (number of speed exceedances)
Time Frame: 7.5 hours
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The cumulative number of times participants exceed the allowable speed limit during each drive.
7.5 hours
Driving performance (number of accidents)
Time Frame: 7.5 hours
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The cumulative number of accidents (including car collisions, pedestrians hit, etc.) during each drive.
7.5 hours
Driving performance (total rule violations)
Time Frame: 7.5 hours
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The cumulative number of rule violations (including number of missed stop signs, illegal turns, speed exceedances, etc.) during each drive.
7.5 hours
Driving performance (distance to lead vehicles)
Time Frame: 7.5 hours
The STISIM Drive® M4000-R Console system will be used to assess driving performance, a state-of-the-art technology that has been independently validated to reflect real-world driving conditions. The mean distance (in meters) maintained to lead vehicles during car-following segments of each drive.
7.5 hours
Attempted Trials on the Digit Symbol Substitution Task (DSST)
Time Frame: 7.5 hours
Computerized version of Digit Symbol Substitution Task will be administered to assess psychomotor performance. The number of attempted trials will be recorded
7.5 hours
Percentage Correct on attempted trials on the Digit Symbol Substitution Task (DSST)
Time Frame: 7.5 hours
Computerized version of Digit Symbol Substitution Task will be administered to assess psychomotor performance. Percentage of correct trials out of those attempted will be recorded
7.5 hours
Reaction time on Paced Auditory Serial Addition Task
Time Frame: 7.5 hours
Computerized version of Paced Auditory Serial Addition Task will be administered to assess working memory performance. The mean reaction time (in milliseconds) to select correct responses will be recorded.
7.5 hours
Field Sobriety Test - Score on Horizontal Gaze Nystagmus Test
Time Frame: Up to 7.5 hours
Impairment will be assessed using performance on the Horizontal Gaze Nystagmus Test (HGN). Total score will be recorded (out of possible 6 clues) with higher scores indicating higher impairment.
Up to 7.5 hours
Field Sobriety Test - Score on Walk and Turn test
Time Frame: Up to 7.5 hours
Impairment will be assessed using performance on the the Walk and Turn. Total score will be recorded (out of a possible 8 clues) with higher scores indicating higher impairment.
Up to 7.5 hours
Field Sobriety Test - Score on One Leg Stand
Time Frame: Up to 7.5 hours
Impairment will be assessed using performance on the One Leg Stand test. Total score will be recorded (out of a possible 4 clues) with higher scores indicating higher impairment.
Up to 7.5 hours
Field Sobriety Test - Score on Modified Romberg Balance
Time Frame: Up to 7.5 hours
Impairment will be assessed using performance on the Modified Romberg Balance test. Total score will be recorded (out of a possible 4 clues) with higher scores indicating higher impairment.
Up to 7.5 hours
Drug Effect Questionnaire - Like Drug Effect
Time Frame: 7.5 hours
The DEQ will be used to obtain subjective ratings of "like drug effect". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
7.5 hours
Drug Effect Questionnaire - Want more
Time Frame: 7.5 hours
The DEQ will be used to obtain subjective ratings of "want more". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
7.5 hours
Drug Effect Questionnaire - Dislike Drug Effect
Time Frame: 7.5 hours
The DEQ will be used to obtain subjective ratings of "dislike drug effect". Score range from 0 (none) to 100 (extreme) using a 100mm line anchored with none/extreme designation.
7.5 hours
Pharmacokinetics - CMax for THC and THC metabolites
Time Frame: 7.5 hours
Whole blood concentrations of THC, 11-OH- THC, and THCCOOH will be measured using quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis. The maximum concentration (Cmax) is determined as the highest concentration reached for each individual. Characterizing these cannabinoids will allow for adequate control for individual differences in drug absorption and metabolism in statistical analyses and assist with interpretation of subjective and behavioral outcomes.
7.5 hours
Pharmacokinetics - AUC for THC and THC metabolites
Time Frame: Up to 7.5 hours
Whole blood concentrations of THC, 11-OH- THC, and THCCOOH will be measured using quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis. The area under the curve (AUC) is calculated across all timepoints, minus the baseline. Characterizing these cannabinoids will allow for adequate control for individual differences in drug absorption and metabolism in statistical analyses and assist with interpretation of subjective and behavioral outcomes.
Up to 7.5 hours
Pharmacokinetics - Breath Alcohol Concentration (BAC)
Time Frame: Up to 7.5 hours
BAC will be measured using the Alco-Sensor IV. Measuring BAC is needed to confirm that participants reached the targeted BAC for a given session and to confirm adherence to pre-session alcohol abstinence requirements.
Up to 7.5 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Tory Spindle, PhD, Johns Hopkins University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 17, 2022

Primary Completion (Actual)

August 15, 2025

Study Completion (Actual)

August 15, 2025

Study Registration Dates

First Submitted

June 11, 2021

First Submitted That Met QC Criteria

June 11, 2021

First Posted (Actual)

June 18, 2021

Study Record Updates

Last Update Posted (Estimated)

October 3, 2025

Last Update Submitted That Met QC Criteria

October 2, 2025

Last Verified

October 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • IRB00290015
  • 1R01DA052295-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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