Cannabis Observations on Brain Waves, Retrieval, and Attention: Experiment 3

Recruiting

• Conditions: Cannabis; Memory; Electroencephalography

• Registration Number: NCT06669585
• Lead Sponsor: L. Cinnamon Bidwell

Brief Summary

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 two 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.

Detailed Description

Previous research has established cannabis's harmful cognitive impact, with particularly robust and consistent effects in the domain of 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 pictures as stimuli. Participants complete the same memory task while intoxicated one day and not intoxicated another day. A THC-dominant strain and a strain containing both THC and CBD are included in the study. Participants self-administer one of the two 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.

Study Timeline

• Status Verified: 2024-10
• Study Start: 2024-10-09
• Study First Submitted: 2024-10-23
• Study First Submitted QC: 2024-10-30
• Study First Posted: 2024-11-01
• Last Update Submitted: 2024-12-04
• Last Update Posted: 2024-12-09
• Primary Completion: 2026-01
• Study Completion: 2026-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 64

Inclusion Criteria

1. Must be between the ages of 21 and 40 and provide informed consent;
2. Must be right-handed (Laterality Quotient > 60 on Edinburgh Handedness Inventory - Short Form);
3. Must use cannabis at least 4 days during the month;
4. Must be a cannabis user for at least a year;
5. Must self-report not using other illicit recreational drugs (e.g., cocaine, benzodiazepines (non-prescription), opiates (non-prescription), MDMA, sedatives, or methamphetamine) in the past 30 days, during the Pre-Screening;
6. Must not test positive on a urine toxicology test for drugs of abuse at the Baseline appointment;
7. Must not be using psychotropic medications, however anti-depressant, non-benzodiazepine anti-anxiety, and ADHD medications are ok. ADHD medication users must be willing to abstain from ADHD medication use on appointment days;
8. Must not be a regular nicotine user (≤4 days per week; cigarette, E-cigs, or smokeless);
9. Must not have used caffeine or nicotine (cigarette, E-cigs, or smokeless) for 4 hours before each appointment;
10. Must have a breath alcohol level of 0 at Baseline appointment (to sign consent form);
11. Must not be actively seeking or in treatment for any substance use disorder;
12. Female subjects must not be or trying to become pregnant (as indicated by a pregnancy test administered at Baseline appointment);
13. Must not be in treatment for psychotic disorder or bipolar disorder; or have a history with these disorders;
14. Must not have any physical characteristics (e.g., thick hair, head size exceeding the limit of the net, dyed hair) or experience any technical difficulties during testing that result in a poor-quality EEG recording.

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Difference in ERP amplitude (FN400)	Intoxicated session and not-intoxicated session (about 1 week)	Electroencephalography is used to quantify FN400.
Difference in ERP amplitude (parietal)	Intoxicated session and not-intoxicated session (about 1 week).	Electroencephalography is used to quantify parietal ERP effects.
Difference in retrieval memory performance	Intoxicated session and not-intoxicated session (about 1 week)	Reaction time will be used to assess task performance.
Difference in retrieval memory accuracy	Intoxicated session and not-intoxicated session (about 1 week)	Accuracy will be used to assess task performance.

Secondary Outcome Measures

Name	Time	Method
Change in Positive and Negative Affect Schedule (PANAS)	Before and after acute cannabis use during intoxicated session	The PANAS is Self-report measurement of positive and negative affect. Both subscales range from 1 - 50, with a higher score on the positive affect scale indicating higher positive affect and a higher score on the negative affect scale indicating higher negative affect.
Change in Drug Effects Questionnaire (DEQ)	Before and after acute cannabis use during intoxicated session	The DEQ is a visual analogue scale of measure of acute drug effects. Participants are asked 5 questions on the DEQ, each of which range from 0 - 100, with higher values for each item indicating greater drug effect.
Change in Addiction Research Center Inventory (ARCI-M)	Before and after acute cannabis use during intoxicated session	The ARCI-M is a self-report measure of subjective effects of marijuana. This is a 12-item true-false task, in which higher (true) scores indicate greater intoxication.
Change in Marijuana Craving Questionnaire	Before and after acute cannabis use during intoxicated session	The Marijuana Craving Questionnaire is a self-report measure of marijuana craving. Participants complete 8 questions ranging from 0 - 10, with a higher score indicating greater cannabis craving and somatic symptoms.
Change in Profile of Mood States (POMS)	Before and after acute cannabis use during intoxicated session	The POMS is a self-report measure of mood. Participants complete 27 mood-related items ranging from 0 - 4, with higher scores indicating greater levels of specific mood states.
Change in Alcohol Craving Questionnaire	Before and after acute cannabis use during intoxicated session	The Alcohol Craving Questionnaire is a self-report measure of alcohol craving. This is a 2-item scale with each item ranging 0 - 10, with higher scores indicating greater alcohol craving.
Change in State Adapted Paranoia Checklist-Brief (SAPC-B)	Before and after acute cannabis use during intoxicated session	The SAPC-B is a self-report measure of paranoia. Participants complete 5 items each ranging from 0 - 10, with higher scores indicating greater feelings of paranoia.
Difference in circulating cannabinoid concentration	Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)	Blood levels of THC and CBD will be quantified.

Trial Locations

Locations (1)

Center for Innovation and Creativity (CINC); 🇺🇸 Boulder, Colorado, United States