An observational study in Cannabis, Memory and Electroencephalography, sponsored by University of Colorado, Boulder. Completed at 1 site in United States. Open to participants aged 21 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-12-20.
Sponsored by University of Colorado, Boulder · Observational
This study investigates the impact of ∆9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on recognition memory in healthy, regular cannabis users. Participants complete the same recognition memory task after self-administering one of three different strains of cannabis flower one day and while not intoxicated another day. Event-related potentials (ERPs) are measured via electroencephalogram (EEG) during the recognition memory task. Blood is collected to quantify THC and CBD exposure. Participants also complete self-report measures of medical history, sleep quality, subjective cognitive function, physical activity, psychological functioning, substance use, and acute drug effects.
Previous research has established cannabis's harmful cognitive impact, with particularly robust and consistent effects in the domain of verbal episodic memory. However, prior work has not sufficiently considered that the memory effects of cannabis are the compound action of different cannabinoids, which vary in their pharmacology and effects. Specifically, CBD, a non-psychotomimetic component of cannabis (doesn't produce a "high"), is thought to have cognitively protective properties and may mitigate some of the harmful effects of THC. Further, few prior studies have tested the effects of high potency strains that are commonly available.
This study tests the effects of commercially available cannabis flower strains on recognition memory performance and ERPs that are related to different underlying memory processes in healthy, regular cannabis users. An episodic memory task is used to assess recognition memory, which asks participants to discriminate between previously studied and non-studied items using words as stimuli. Participants complete the same memory task while intoxicated one day and not intoxicated another day. A THC-dominant, a CBD-dominant, and a strain containing both THC and CBD are included in the study. Participants self-administer one of the three cannabis strains prior to memory encoding and retrieval.
Blood is collected to determine THC and CBD exposure, as well as to explore how genetic variation in genes related to cannabinoid metabolism, cannabis-related behavior, and neurocognitive function associate with memory function before and after cannabis use. Participants also complete self-report measures of medical history, sleep quality, subjective cognitive function, physical activity, psychological functioning, substance use, and acute drug effects.
517 studies on the registry are indexed under Marijuana Abuse; 114 are open to participants now.
This study's enrollment of 96 is close to the median of 100 across 78 observational studies indexed under Marijuana Abuse.
Browse Marijuana Abuse studies →University of Colorado, Boulder is the lead sponsor of 86 studies on the registry; 20 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Community Sample
Inclusion Criteria:
Self-Directed Use (ad-libitum)
Difference in ERP amplitude
Electroencephalography is used to quantify FN400 and parietal ERP effects.
Time frame: intoxicated session and not-intoxicated session
Difference in recognition memory performance
Accuracy and reaction time will be used to assess task performance.
Time frame: intoxicated session and not-intoxicated session (about 1 week)
Difference in Flanker Task performance
Accuracy and reaction time will be used to assess task performance.
Time frame: intoxicated session and not-intoxicated session (about 1 week)
Difference in Flanker Task ERPs
Electroencephalography is used to quantify ERN effects.
Time frame: intoxicated session and not-intoxicated session (about 1 week)
Change in Positive and Negative Affect Schedule (PANAS)
The PANAS is Self-report measurement of positive and negative affect.
Time frame: before and after acute cannabis use (about 30 minutes)
Change in Drug Effects Questionnaire (DEQ)
The DEQ is a visual analogue scale of measure of acute drug effects.
Time frame: before and after acute cannabis use (about 30 minutes)
Change in Addiction Research Center Inventory (ARCI-M)
The ARCI-M is a self-report measure of subjective effects of marijuana.
Time frame: before and after acute cannabis use (about 30 minutes)
Change in Marijuana Craving Questionnaire
The Marijuana Craving Questionnaire is a self-report measure of marijuana craving.
Time frame: before and after acute cannabis use (about 30 minutes)
Change in Profile of Mood States (POMS)
The POMS is a self-report measure of mood.
Time frame: before and after acute cannabis use (about 30 minutes)
Change in Alcohol Craving Questionnaire
The Alcohol Craving Questionnaire is a self-report measure of alcohol craving.
Time frame: before and after acute cannabis use (about 30 minutes)
Change in State Adapted Paranoia Checklist-Brief (SAPC-B)
The SAPC-B is a self-report measure of paranoia.
Time frame: before and after acute cannabis use (about 30 minutes)
Difference in circulating cannabinoids
Blood levels of THC and CBD will be quantified.
Time frame: baseline, intoxicated session, and not-intoxicated session (about 3 weeks)
Exploratory: Associations between genes related to cannabinoid metabolism, cannabis-related behavior, and neurocognitive function with ERPs and recognition memory performance
DNA samples are collected from a baseline blood sample.
Time frame: baseline, intoxicated session, and not-intoxicated session (about 3 weeks)
Exploratory: Moderation of primary effects by baseline health and psychological functioning
Baseline health and psychological function include measures of sleep quality, affective symptoms, and substance use history.
Time frame: baseline, intoxicated session, and not-intoxicated session (about 3 weeks)
Plan to share: No
This study is completed, as verified in Dec 2024. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University of Colorado, Boulder