An interventional study of Alcohol and Cannabis in Cannabis Use and Alcohol Use, Unspecified, sponsored by Colorado State University. Recruiting at 1 site in United States. Open to participants aged 21 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-11.
Sponsored by Colorado State University · Not applicable, Interventional, and Other
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.
701 studies on the registry are indexed under Alcohol Drinking; 133 are open to participants now.
This study's planned enrollment of 99 is below the median of 122 across 607 interventional studies indexed under Alcohol Drinking.
Browse Alcohol Drinking studies →Colorado State University is the lead sponsor of 117 studies on the registry; 19 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 3 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
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.
Other: Cannabis
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.
Other: Alcohol
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.
Other: Alcohol · Other: Cannabis
Participants in this condition will receive the standard alcohol dose
Participants in this group will self-administer legal-market flower cannabis
Electroencephalography (EEG) Objective Cognitive Function Measures--Amplitude (microvolts)
The EEG amplitude (measured in microvolts) will be obtained while participants perform the speeded visual flanker task
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)
The EEG latency (measured in milliseconds) will be obtained while participants perform the speeded visual flanker task
Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use
Standing postural stability
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.
Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use
Breath Alcohol Concentration
Measured using hand-held breathalyzer device
Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use
Blood Delta-9-tetrahydrocannabinol (THC) Levels
THC measured from blood samples
Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use
Blood Cannabidiol (CBD) Levels
CBD measured from blood samples
Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use
Blood Levels of 11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH)
THC-COOH measured from blood samples
Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use
Blood Levels of 11-Hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC)
11-OH-THC measured from blood samples
Time frame: Immediately pre-substance use, 1-hour post-use, 2-hours post-use, 4-hours post-use
Started Jan 2024 (actual). Primary completion is estimated for May 2027, 40 months after the start.
Of 328 non-industry interventional studies with no phase under Alcohol Drinking, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 45. This study's planned 40 months is above that.
Counting every sponsor, half of 336 studies reached it within 24 months; a quarter within 10 and three quarters within 45.
How these figures are worked out, and which studies are left out of them.
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