An Early Phase 1 interventional study of High THC/No CBD Marihuana and High THC/High CBD Marihuana in Marijuana Use, Cannabis Use and Cannabis Intoxication, sponsored by Hartford Hospital. Not yet recruiting. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-03-17.
Sponsored by Hartford Hospital · Early Phase 1, Interventional, and Other
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.
With increased legalization and medicalization of marijuana (MJ), there is an urgent need to understand the acute effects of use. One of the most consistently observed cognitive outcomes associated with MJ use is memory dysfunction, which may have a substantial impact on daily life in individuals using MJ for recreational or medicinal purposes. Notably, there are numerous preparations of MJ with varying proportions of cannabinoids, which may differ in behavioral and cognitive effects. For instance, there is emerging evidence that acute administration of delta-9-tetrahydrocannabinol (THC), the main psychoactive constituent of MJ, hinders memory and reduces prefrontal and hippocampal functional magnetic resonance imaging (fMRI) activation, but cannabidiol (CBD) may mitigate some of these impairments. Given the role of glutamate in learning and memory, the investigators suggest that these effects may be subserved, in part, by glutamatergic mechanisms. The investigators will use magnetic resonance spectroscopy (MRS) to non-invasively measure glutamate in order to explore the neurochemical underpinnings of memory-related fMRI response changes following acute administration of THC and CBD in a randomized, double-blind, placebo-controlled, cross-over design. A total of 9 healthy participants ages 18-40 will be enrolled. Participants will first undergo one screening visit (\~4 hours), comprising informed consent, assessment of health history, psychiatric diagnoses, cognitive function, and substance use history, and a structural MRI session. This will be followed by 3 separate MJ dose visits (\~4 hours each), at which participants will complete neuroimaging after administration of one of 3 preparations of vaporized MJ in a randomized, counterbalanced, double-blinded fashion: 1) high THC and no CBD (THC), 2) high THC and high CBD (THC+CBD), and 3) no THC and no CBD (placebo MJ). As in the investigator's ongoing studies, bulk MJ plant material will be provided by the National Institute on Drug Abuse. MJ dose visits will comprise MJ administration, blood collection, MRS/fMRI scan, subjective reports, and a brief cognitive assessment.
33 studies on the registry are indexed under Marijuana Use; 6 are open to participants now.
This study's planned enrollment of 9 is below the median of 104 across 32 interventional studies indexed under Marijuana Use.
Browse Marijuana Use studies →Hartford Hospital is the lead sponsor of 105 studies on the registry; 20 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 5 (36%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
People who smoke marijuana occasionally will be given a dose of high THC high CBD marijuana at the study visit
Drug: High THC/High CBD Marihuana
People who smoke marijuana occasionally will be given a dose of high THC and no CBD marijuana at the study visit
Drug: High THC/No CBD Marihuana
People who smoke marijuana occasionally will be given a dose of marijuana that contains no THC or CBD
Drug: No THC/No CBD Marihuana
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
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).
Time frame: approximately 1 hour following drug administration
Glutamate
Magnetic resonance spectroscopy (MRS)-acquired glutamate containing compounds (Glx).
Time frame: approximately 1 hour following drug administration
HVLT-R performance
The Hopkins Verbal Learning Test-Revised will ascertain verbal list learning and immediate and delayed recall (\~15min); alternate forms have been validated, and the order of versions participants receive will be randomized
Time frame: Approximately 2.50 hours after drug administration
Performance on CHARLIE cognitive task
This is a computer-based cognitive battery that administers the Digit Span and Letter/Number Sequencing Test (working memory) and the Digit Symbol Coding test (processing speed). It should take about 10 minutes to complete.
Time frame: Approximately 3.00 hours after drug administration
Blood THC and CBD concentration testing
A blood sample will be taken once per dose visit to assess the concentration of the following metabolites in ng/mL: delta-9-tetrahydrocannabinol, 11-hydroxy-tetrahydrocannabinol, 11-Nor-9-Carboxy-tetrahydrocannabinol (THCCOOH), tetrahydrocannabinol-Glucuronide, THCCOOH-Glucuronide, cannabinol (CBN), and cannabidiol (CBD).
Time frame: Immediately after drug administration (~0.25 hours after drug administration)
Subjective effects on drug effects questionnaire
This self-report will be used to assess subjective reports every 60 minutes throughout the dose visit days. These subjective ratings will be obtained using rapidly completed Visual Analog Scales (VASs) scored on a 0-100 scale. Items include: Do you feel a drug effect right now?, Are you high right now?, Do you dislike any of the effects you are feeling right now?, Do you like any of the effects you are feeling right now? and Would you like more of the drug you took, right now?
Time frame: Post drug administration at: 0.00 hours (immediately after); 1.0 hours; 2.0 hours; 3.0 hours
No study locations are listed for this record.
Plan to share: No
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.
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