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

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
• Conditions: Alcohol Intoxication; Cannabis Intoxication
• Intervention / Treatment: Drug: Cannabis; Drug: Alcohol

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): 70
• Phase: Phase 1

Contacts and Locations

Study Locations

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

Participation Criteria

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

How is the study designed?

Design Details

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

Number of Arms

7

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.	Drug: Cannabis; Cannabis will be orally ingested via a brownie; Drug: Alcohol; 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.	Drug: Cannabis; Cannabis will be orally ingested via a brownie; Drug: Alcohol; 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.	Drug: Cannabis; Cannabis will be orally ingested via a brownie; Drug: Alcohol; 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).	Drug: Cannabis; Cannabis will be orally ingested via a brownie; Drug: Alcohol; 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).	Drug: Cannabis; Cannabis will be orally ingested via a brownie; Drug: Alcohol; 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).	Drug: Cannabis; Cannabis will be orally ingested via a brownie; Drug: Alcohol; 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).	Drug: Cannabis; Cannabis will be orally ingested via a brownie; Drug: Alcohol; Alcohol will be orally ingested via a flavored drink

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Peak Change From Baseline DRUID Application Global Impairment Score	Acute cognitive and behavioral impairment will be assessed with global impairment score (range 0-100) on the DRUID app (higher scores indicate greater impairment). Results are mean change from baseline.	7.5 hours, assessed at baseline (prior to drug administration) and again 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours after oral cannabis ingestion.
Cumulative Score on Field Sobriety Tests	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 0-22 clues). Higher scores indicate greater/worse impairment. These assessments were completed once after 7.5 hours.	7.5 hours
Mean Peak Change From Baseline Scores on the Drug Effect Questionnaire (DEQ) - Feel Drug Effect	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. Results are mean change from baseline and a higher score indicates a more extreme/worse drug effect.	7.5 hours, assessed at baseline (prior to drug administration) and again 0.5, 1, 1.25, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours after oral cannabis ingestion
Drug Effect Questionnaire - Feel High	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. Higher score greater "feel high" rating.	7.5 hours
Drug Effect Questionnaire - Confidence to Drive (Change From Baseline)	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. Higher scores indicate higher confidence to drive. Results expressed as change from baseline	7.5 hours
Drug Effect Questionnaire - Willingness to Drive	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. Higher score indicates higher willingness to drive.	7.5 hours
Biphasic Alcohol Effects Scale (BAES) - Sedative Score	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). Higher scores indicating greater sedative effects of alcohol. Scores presented show the change from baseline to 7.5 hours.	Baseline, 7.5 hours
Biphasic Alcohol Effects Scale (BAES) - Stimulant Score	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). Higher scores indicating greater stimulant effects of alcohol.	7.5 hours
Subjective High Assessment Scale (SHAS)	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). Higher score indicates greater effects of alcohol.	7.5 hours
Driving Performance as Assessed by Standard Deviation of Lateral Position (SDLP)	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) was calculated across all drives to get a composite index of lateral control and reported as peak change from baseline. 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.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Driving Performance as Assessed by Composite Drive Score	Driving impairment will be assessed via a composite drive score. The composite drive score is derived by integrating various driving outcomes (see primary and secondary driving outcomes). Higher z-score indicates worse performance. The score is on a z-score scale, meaning a score of 1 equates to 1 standard deviation outside of the participants' mean baseline performance and a Z-score of 0 represents the mean baseline performance. This was calculated across all drives and reported as peak change from baseline.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Driving Performance as Assessed by Standard Deviation of Speed (SDSP)	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 calculated across all drives to get a composite index of the variability in speed (measured in MPH) and is reported as peak change from baseline. Scores range from 0 to no upper limit. Higher scores represent higher magnitude of driving impairment.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Total Run Length	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. Total run length will be calculated across all drives and measured as peak change from baseline score (in seconds). Higher scores represent higher magnitude of driving impairment.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Driving Performance (Number of Speed Exceedances)	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. Driving performance will be calculated across all drives to get a cumulative number of times participants exceed the allowable speed limit and reported as peak change from baseline. Scores range from 0 to no upper limit. Higher scores represent higher numbers of speed exceedances.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Driving Performance (Number of Accidents)	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. Driving performance will be calculated across all drives to get a cumulative number of accidents (including car collisions, pedestrians hit, etc.) and reported as peak change from baseline. Scores range from 0 to no upper limit. Higher scores represent higher numbers of accidents.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Driving Performance (Total Rule Violations)	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. Driving performance will be calculated across all drives to get a cumulative number of total rule violations (including number of missed stop signs, illegal turns, speed exceedances, etc.) and reported as peak change from baseline. Scores range from 0 to no upper limit. Higher scores represent higher numbers of rule violations. All scores reported are relative to baseline, thus negative values represent a lower number of rule violations than at baseline.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Driving Performance (Distance to Lead Vehicles)	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. Driving performance will be calculated across all drives to get the mean distance (in meters) maintained to lead vehicles during car-following segments and reported as peak change from baseline. Scores range from 0 to no upper limit. Higher scores represent greater distance maintained to lead vehicles. All scores reported are relative to baseline, thus negative values represent a shorter distance maintained than at baseline.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Change in Field Sobriety Test - Score on Horizontal Gaze Nystagmus Test	Impairment will be assessed using performance on the Horizontal Gaze Nystagmus Test (HGN). Total score will be recorded (out of possible 0-6 clues) with higher scores indicating higher impairment. Assessed at baseline and 7.5 hours, change from baseline to 7.5 hours reported	Baseline, 7.5 hours
Change in Field Sobriety Test - Score on Walk and Turn Test	Impairment will be assessed using performance on the the Walk and Turn. Total score will be recorded (out of a possible 0-8 clues) with higher scores indicating higher impairment. Assessed at baseline and 7.5 hours, change from baseline to 7.5 hours reported	Baseline, 7.5 hours
Change in Field Sobriety Test - Score on One Leg Stand	Impairment will be assessed using performance on the One Leg Stand test. Total score will be recorded (out of a possible 0-4 clues) with higher scores indicating higher impairment. Assessed at baseline and 7.5 hours, change from baseline to 7.5 hours reported	Baseline, 7.5 hours
Change in Field Sobriety Test - Score on Modified Romberg Balance	Impairment will be assessed using performance on the Modified Romberg Balance test. Total score will be recorded (out of a possible 0-4 clues) with higher scores indicating higher impairment. Assessed at baseline and 7.5 hours, change from baseline to 7.5 hours reported	Baseline, 7.5 hours
Drug Effect Questionnaire - Like Drug Effect	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. Higher score indicating greater "liked drug effect" rating.	7.5 hours
Drug Effect Questionnaire - Dislike Drug Effect	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. Higher score indicating greater "dislike drug effect" rating.	7.5 hours
Pharmacokinetics - CMax for THC and THC Metabolites	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 (ng/mL) across all timepoints.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Pharmacokinetics - AUC for THC and THC Metabolites	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 cumulative across all timepoints.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Pharmacokinetics - CMax for Alcohol	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 (g/210L). The maximum concentration (Cmax) is determined as the highest concentration reached for each individual (ng/mL) across all timepoints.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours
Pharmacokinetics - AUC for Alcohol	Whole blood concentrations of Alcohol will be measured using quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis. The area under the curve (AUC) is calculated cumulative across all timepoints.	Baseline, 1, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, and 7.5 hours

Collaborators and Investigators

• Sponsor: Johns Hopkins University
• Collaborators: National Institute on Drug Abuse (NIDA)
• Investigators: Principal Investigator: Tory Spindle, PhD, Johns Hopkins University

Publications and helpful links

General Publications

• Zamarripa CA, Lin S, Klausner M, Rastogi K, Roche DJO, Novak M, Antoine D, Wolinsky D, Marcotte TD, Weerts EM, Vandrey R, Spindle TR. Impact of Cannabis Edibles Combined With Alcohol on Driving, Field Sobriety Performance, and Subjective Effects: A Within-Participant Crossover Trial. JAMA Netw Open. 2026 May 1;9(5):e269842. doi: 10.1001/jamanetworkopen.2026.9842.

Study record dates

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 (Actual): August 3, 2026
• Last Update Submitted That Met QC Criteria: July 29, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Substance-Related Disorders; Chemically-Induced Disorders; Alcohol-Related Disorders; Alcoholic Intoxication; Organic Chemicals; Alcohols; Ethanol; nabiximols
• 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