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NCT Number: NCT06259916

Distinguishing Alcohol Intoxication, Cannabis Intoxication and Co-intoxication Using Electroencephalography (EEG)

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.

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Key information

Conditions

Cannabis Use Alcohol Drinking Alcohol Use, Unspecified Behavior Drinking Behavior

Age range

21 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Colorado State University

Fort Collins, Colorado, 80523, United States

Location status: Recruiting

Location contact

Hollis C. Karoly, PhD

CONTACT

Hollis C. Karoly, PhD

PRINCIPAL_INVESTIGATOR

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Alcohol

Other

Participants in this condition will receive the standard alcohol dose

cannabis

Other

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

Primary outcomes

  1. 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

    The EEG amplitude (measured in microvolts) will be obtained while participants perform the speeded visual flanker task

  2. 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

    The EEG latency (measured in milliseconds) will be obtained while participants perform the speeded visual flanker task

  3. Standing postural stability

    Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use

    An iPod Touch will be attached to each participant's hip with a simple elastic/Velcro strap. An app on the device will record fine grained movements while they try to stand as still as possible for 30-60 seconds under four conditions that vary in terms of demand on the proprioceptive system (eyes open, eyes closed), and on a stable vs. soft (foam) surface.

Other outcomes

  1. Breath Alcohol Concentration

    Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use

    Measured using hand-held breathalyzer device

  2. Blood Delta-9-tetrahydrocannabinol (THC) Levels

    Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use

    THC measured from blood samples

  3. Blood Cannabidiol (CBD) Levels

    Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use

    CBD measured from blood samples

  4. Blood Levels of 11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH)

    Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use

    THC-COOH measured from blood samples

  5. Blood Levels of 11-Hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC)

    Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use

    11-OH-THC measured from blood samples

Study contacts

Contact information is provided by the study sponsor or research team.

Hollis C Karoly, PhD

CONTACT

[email protected]

970-491-3677

Patricia Davies, PhD

CONTACT

[email protected]

(970) 491-7294

Sponsors and collaborators

Lead sponsor

Colorado State University

Other

Registry information

Official study title

Developing Predictive Models to Distinguish Alcohol Use, Cannabis Use and Co-use: An Exploration of Electroencephalography (EEG) Metrics and Traditional Intoxication Measures

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Feb 14, 2024
Registry last updated
Nov 13, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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