Recruiting
Phase 2

THC

Sponsor:

Yale University

Code:

NCT06647524

Conditions

THC

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

THC

Placebo

Study Details

Brief summary:

The purpose of this study is to begin investigating acute impairment of various forms of memory and learning by Tetrahydrocannabinol (THC) in cannabis (CNB) compared to placebo, in a 2-session per subject double-blind, random assignment, placebo-controlled counterbalanced design in young to middle-aged adults.

Conditions

THC

Study ID

NCT06647524

Start date

Jul 1, 2025

Status verified date

Oct, 2025

Completion date

Dec, 2027

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

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

Study Design

Enrollment

10 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: THC then Placebo

Participants in this arm will receive THC then placebo in a 2-session per subject double-blind, random assignment, placebo-controlled counterbalanced design. (Participants randomized to receive THC in the first session will receive placebo at the 2nd session.) Sessions will be scheduled at least one week apart. Tasks tapping each of the major cognitive memory-related domains will be performed in the MRI scanner, to reveal the relevant underlying circuitry and its disruption by drug using functional MRI.

placebo comparator: Placebo then THC

Participants in this arm will receive placebo then THC in a 2-session per subject double-blind, random assignment, placebo-controlled counterbalanced design. (Participants randomized to receive placebo in the first session will receive THC at the 2nd session.) Sessions will be scheduled at least one week apart. Tasks tapping each of the major cognitive memory-related domains will be performed in the MRI scanner, to reveal the relevant underlying circuitry and its disruption by drug using functional MRI.

Interventions

THC

Participants will be administered 0.5g of vaporized THC cannabis (12% THC cannabis)

Placebo

Participants will be administered identical plant material from which all THC has been removed by solvent extraction.

Primary outcome measure

  • The Complex Working Memory Span (CWMS) Task- Items Recalled [ Time Frame: At sessions 1 and 2 while under fMRI, immediately post drug administration ]
  • The Complex Working Memory Span (CWMS) Task- fMRI measure [ Time Frame: At sessions 1 and 2 while under fMRI, immediately post drug administration ]
  • The Effort Expenditure for Reward Task (EEfRT) [ Time Frame: At sessions 1 and 2 immediately post drug administration ]
  • The Card-Guessing fMRI task [ Time Frame: At sessions 1 and 2 while under fMRI, immediately post drug administration ]
  • The Zibrio SmartScale [ Time Frame: At sessions 1 and 2 while under fMRI, immediately post drug administration ]

Central Contacts and Locations

Central contacts

Godfrey Pearlson, MD

860-305-8921godfrey.pearlson@yale.edu

Ariana Caruso

ariana.caruso2@hhchealth.org

Locations

Olin Neuropsychiatric Research Center at Hartford Healthcare

Recruiting

Hartford, Connecticut, United States, 06106

More Information

Sponsor

Yale University

Last update posted

Oct 9, 2025

Last verified

Oct, 2025

Keywords

  • Memory Impairment
  • Learning Impairment

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Yale University on 2025-10-09.