THC + CBD and Memory Study
Effects of Marijuana on Memory-Related Neurochemistry and Neural Response
2 other identifiers
interventional
9
0 countries
N/A
Brief Summary
Memory deficits are one of the most consistently observed cognitive effects of marijuana use. There is evidence that some decrements attributable to the primary psychoactive ingredient, delta-9-tetrahydrocannabinol (THC), may be attenuated by cannabidiol (CBD). This study will help us learn more about the relationship between THC and CBD consumption with memory processes. A combination of MRI and neuropsychological tests (which are computer and paper/pencil tasks) will be used to measure the neurocognitive and behavioral impacts of THC and CBD use.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for early_phase_1
Started Dec 2025
Shorter than P25 for early_phase_1
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
April 19, 2021
CompletedFirst Posted
Study publicly available on registry
April 22, 2021
CompletedStudy Start
First participant enrolled
December 1, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
December 30, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
December 30, 2026
March 17, 2025
March 1, 2025
1.1 years
April 19, 2021
March 13, 2025
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
fMRI response
Blood oxygen level dependent functional magnetic resonance imaging (fMRI) response during the relational and item specific encoding task. fMRI response will be evaluated during the encoding phase (relational vs. item encoding), item recognition phase (hits vs. misses for item-specific encoding, and hits vs. misses for relational encoding), and associative recognition phase (hits vs. misses).
approximately 1 hour following drug administration
Glutamate
Magnetic resonance spectroscopy (MRS)-acquired glutamate containing compounds (Glx).
approximately 1 hour following drug administration
Secondary Outcomes (4)
HVLT-R performance
Approximately 2.50 hours after drug administration
Performance on CHARLIE cognitive task
Approximately 3.00 hours after drug administration
Blood THC and CBD concentration testing
Immediately after drug administration (~0.25 hours after drug administration)
Subjective effects on drug effects questionnaire
Post drug administration at: 0.00 hours (immediately after); 1.0 hours; 2.0 hours; 3.0 hours
Study Arms (3)
Occasional Users - High THC and High CBD Dose
EXPERIMENTALPeople who smoke marijuana occasionally will be given a dose of high THC high CBD marijuana at the study visit
Occasional Users - High THC and No CBD Dose
EXPERIMENTALPeople who smoke marijuana occasionally will be given a dose of high THC and no CBD marijuana at the study visit
Occasional Users - No THC and No CBD Dose
EXPERIMENTALPeople who smoke marijuana occasionally will be given a dose of marijuana that contains no THC or CBD
Interventions
high THC (65 mg THC) and no CBD (0 mg CBD)
high THC (65 mg THC) and high CBD (50 mg CBD)
no THC (0 mg THC) and no CBD (0 mg CBD); placebo drug
Eligibility Criteria
You may qualify if:
- Right-handed
- Prior MJ users (has used MJ at least once in the past year, but no more than 1x/month in the past 12 months)
- Medically healthy (as determined by medical history and treatment)
- Adequate comprehension of English in order to complete study materials
- Acceptable birth control method for women (i.e., no copper IUD or any device that is not MRI safe)
You may not qualify if:
- Participant currently uses psychoactive medications or substances
- Psychiatric diagnoses (determined by DSM-V)
- Participant heavily or regularly uses MJ (more than 1x/month in the past year)
- Current or past substance dependence (including MJ)
- Positive urine toxicology screens
- Positive pregnancy screens
- MRI contraindications (e.g., heart pacemaker)
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Hartford Hospitallead
- Yale Universitycollaborator
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Godfrey Pearlson, MD
Hartford Hospital - Olin Neuropsychiatry Research Center; Yale University
- PRINCIPAL INVESTIGATOR
Alecia Dager, PhD
Hartford Hospital - Olin Neuropsychiatry Research Center; Yale University
- PRINCIPAL INVESTIGATOR
Michael Stevens, PhD
Hartford Hospital - Olin Neuropsychiatry Research Center
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- early phase 1
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- OTHER
- Intervention Model
- CROSSOVER
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Founding Director Olin Neuropsychiatry Research Center; Professor Yale University
Study Record Dates
First Submitted
April 19, 2021
First Posted
April 22, 2021
Study Start
December 1, 2025
Primary Completion (Estimated)
December 30, 2026
Study Completion (Estimated)
December 30, 2026
Last Updated
March 17, 2025
Record last verified: 2025-03
Data Sharing
- IPD Sharing
- Will not share