Recruiting

Electroencephalography

Sponsor:

Colorado State University

Code:

NCT06259916

Conditions

Cannabis Use

Alcohol Use, Unspecified

Eligibility Criteria

Sex: All

Age: 21 - 50

Healthy Volunteers: Accepted

Interventions

Alcohol

Cannabis

Study Details

Brief summary:

This is a randomized, parallel-group study designed to explore the differences between cannabis intoxication, alcohol intoxication and co-intoxication involving both alcohol and cannabis, utilizing electroencephalography (EEG) as well as more traditional intoxication measures such as breath alcohol concentration and balance metrics. If eligible for the study, participants will be randomized to complete one study session in our mobile laboratory, during which they will use either alcohol, cannabis (which will be self-administered, ad libitum) or both alcohol and cannabis.

Conditions

Cannabis Use

Alcohol Use, Unspecified

Study ID

NCT06259916

Start date

Jan 5, 2024

Status verified date

Aug, 2026

Completion date

May 30, 2027

Anticipated

Primary completion date

May 30, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 21 - 50

Healthy Volunteers: Accepted

Inclusion Criteria:

  • 21-50 years old
  • Heavy drinkers (consuming more than 4 drinks/day or more than 14 drinks/week for men, or more than 3 drinks/day or more than 7 drinks/week for women)
  • Regular users of legal-market flower cannabis (at least 2x/week in past 3 months)
  • report simultaneously using alcohol and legal-market flower cannabis at least once per month in the past 3 months
  • English speakers.

Exclusion Criteria:

  • Daily tobacco users
  • Diagnosed with or seeking treatment for alcohol use disorder (AUD) or other substance use disorder (SUD)
  • Females cannot be pregnant, breastfeeding or trying to become pregnant
  • Meet criteria for psychotic, bipolar or major depressive disorder with suicidal ideation, or history of these disorders, 5) Current use of psychotropic (except anti-depressants)
  • Report illicit drug use in past 60-days or fail drug screen on the day of the study appointment
  • Major medical condition contraindicating alcohol and/or cannabis consumption.

Study Design

Enrollment

99 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Cannabis Group

Participants in this group will self-administer their own flower cannabis product (that they purchased for use in the study from a legal-market dispensary) ad libitum inside their homes. Researchers will not handle the product or instruct participants on how much to use during the session.

experimental: Alcohol Group

Participants in this group will be administered a dose of alcohol by researchers in our mobile lab. The dose is designed (based on participant sex and body weight) to bring blood alcohol concentration to .06 g/dL.

experimental: Alcohol + Cannabis Group

Participants in this group will first self-administer their own flower cannabis product (that they purchased for use in the study from a legal-market dispensary) ad libitum inside their homes. Researchers will not handle the product or instruct participants on how much to use during the session. They will then return to the mobile lab which will be parked outside their residence and will be administered a dose of alcohol by researchers. The dose is designed (based on participant sex and body weight) to bring blood alcohol concentration to .06 g/dL.

Interventions

Alcohol

Participants in this condition will receive the standard alcohol dose

Cannabis

Participants in this group will self-administer legal-market flower cannabis

Primary outcome measure

  • Electroencephalography (EEG) Objective Cognitive Function Measures--Amplitude (microvolts) [ Time Frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use ]
  • Electroencephalography (EEG) Objective Cognitive Function Measures--Latency (milliseconds) [ Time Frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use ]
  • Standing postural stability [ Time Frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use ]

Central Contacts and Locations

Central contacts

Hollis C Karoly, PhD

970-491-3677hollis.karoly@colostate.edu

Patricia Davies, PhD

(970) 491-7294patricia.davies@colostate.edu

Locations

Colorado State University

Recruiting

Fort Collins, Colorado, United States, 80523

Principal Investigator:

Hollis C. Karoly, PhD

More Information

Sponsor

Colorado State University

Last update posted

Aug 11, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Colorado State University on 2026-08-11.