fMRI pilot: how THC affects memory and learning in young to middle-aged adults
Official title: Pilot fMRI Studies of Aging-Related Effects of THC
Run by Yale University · NCT06647524 · Data updated 2026-11-12
This will see if a single dose of THC temporarily impairs memory and learning in young to middle-aged adults who use cannabis.
Quick facts
| Phase | Phase 2 |
|---|---|
| Study type | Interventional |
| Ages | 18 Years to 75 Years |
| Sex | All |
| Enrollment | 10 (estimated) |
| Sponsor | Yale University Academic / other |
| Locations | 1 site (Hartford, Connecticut) |
| Status | Recruiting |
| Started | July 1, 2025 |
| Main results expected | December 2027 |
| Study ends | December 2027 |
| Registry record updated | October 9, 2025 |
| Trial ID | NCT06647524 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates are young to middle-aged adults who have used cannabis within the past two years, can undergo MRI, read and speak English, and meet cognitive and safety screening criteria.
✕Probably not a fit
People with current heavy tolerance or active desire to cut down, those abstaining from cannabis, pregnant or breastfeeding individuals, anyone with MRI contraindications, serious medical/neurological illness, or IQ/readability below thresholds would not qualify and are unlikely to benefit from participation.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This is a double-blind, randomized, placebo-controlled, two-session crossover pilot using functional MRI to measure how acute THC changes brain activity during memory and learning tasks. Participants complete an initial screening with cognitive testing and a structural MRI, then attend two counterbalanced assessment sessions (THC and placebo) with standardized breaks, vital-sign monitoring, and on-site supervision until intoxication resolves. During each active session subjects rate their intoxication and perform two fMRI paradigms (Card Guessing and Complex Working Memory Span) plus a computer-based effort-for-reward task to probe motivation and cognitive effort. The design aims to link task performance changes with alterations in underlying neural circuitry caused by THC.
Why it matters
Potential benefit: If successful, this could clarify how THC causes temporary memory and learning problems and help guide safer use and future interventions.
How similar studies have gone: Prior behavioral and some imaging studies have shown that acute THC can impair memory and alter brain activation patterns, but combined fMRI task paradigms in this specific user population are relatively limited and this pilot builds on that existing work.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * CNB use within past 2 years and felt "high" when used. * Able to read, speak, and understand English. * Able and willing to provide written informed consent, and willing to commit to the study protocol. Exclusion Criteria: * Current marijuana tolerance, desire to cut down, or cravings to use during periods of abstinence. * Positive screen for drug or alcohol (except CNB) on test day will result in rescheduling the appointment * History of adverse effects with CNB * CNB users who are abstaining * IQ \<80 on the Wechsler Abbreviated Scale of Intelligence * Inability to comprehend written instructions using the WRAT 4 reading achievement test * Pregnant, breastfeeding, and ineffective birth control methods * Unable or unsafe to have an MRI * Serious medical, neuro-ophthalmological, or neurological illness (e.g. cancer, seizure disorders, encephalopathy * History of head trauma with loss of consciousness \> 30 minutes or concussion lasting 30 days * Focal brain lesion seen on structural MRI * Any medical/neurological condition that could compromise neurocognitive performance (e.g. epilepsy, multiple sclerosis, fetal alcohol syndrome) * Anyone deemed unsafe to study personnel for any reason * Hearing loss such that subject cannot hear sounds at the levels (dB) or pitches (Hz) to be used in the study * Significant pain and/or reduced mobility in the arms
Where it's running
-
Olin Neuropsychiatric Research Center at Hartford Healthcare
Hartford, Connecticut, United States Recruiting
Study contacts
- Principal investigator: Godfrey Pearlson, M.D — Founding Director, Olin Neuropsychiatry Center; Yale University
- Study coordinator: Godfrey Pearlson, MD
- Email: godfrey.pearlson@yale.edu
- Phone: 860-305-8921
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.