Endocannabinoids in Reward

October 2, 2026 updated by: Erin Martin, Medical University of South Carolina

The Contribution of the Endocannabinoid System to Sex Differences in THC-associated Reward

This study will examine sex differences in the effects of cannabis in people that regularly use it. Men and women that use cannabis at least 4 days a week will participate in a study involving 3 in-person visits. The first visit will be used to determine eligibility for the study. The other two visits will last 7 hours each and take place at least two days apart. Visits include administration of either THC, the chemical responsible for many of the psychoactive effects of cannabis, or a placebo; completion of questionnaires; and a 1-hour brain scan. One visit will also include a blood draw for genetic testing.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
78

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • South Carolina
      • Charleston, South Carolina, United States, 29403
        • Recruiting
        • Medical University of South Carolina
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

21 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Able and willing to provide informed consent
  2. Age 21-45
  3. Meet DSM-5 criteria for CUD
  4. Report cannabis use ≥4 days/week on average in the last 30 days at screening
  5. Provide a THC-positive urine sample at screening
  6. BMI between 18-30 kg/m2
  7. Regular menstrual cycle (females only)
  8. Willing to use non-hormonal birth control for the duration of study participation (females only)

Exclusion Criteria:

  1. Meet DSM-5 criteria for any lifetime psychotic or bipolar disorder
  2. Urinalysis results indicative of recent drug use other than cannabis
  3. Current use of any psychotropic medication or over-the-counter supplements deemed by the investigator to have the potential to interfere with study outcomes
  4. Current treatment-seeking for CUD or other SUDs
  5. Meet DSM-5 criteria for any current psychiatric disorder other than nicotine or caffeine use disorder, mild alcohol use disorder, CUD, or ADHD
  6. Females who are pregnant, nursing, or planning to become pregnant
  7. MRI contraindications (e.g., metallic implants, claustrophobia)
  8. Significant history of nausea associated with the use of cannabis and/or THC
  9. History of cardiac or seizure disorders
  10. Allergy to sesame oil

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: Males
Drug: Dronabinol

Oral dronabinol capsules (40 mg)

Other Names:
  • Marinol
Drug: Placebo

Matched placebo capsules
Other: Females
Drug: Dronabinol

Oral dronabinol capsules (40 mg)

Other Names:
  • Marinol
Drug: Placebo

Matched placebo capsules

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Nucleus accumbens glutamate
Time Frame: 2 hours post-dose

Concentrations of nucleus accumbens glutamate measured via proton magnetic resonance spectroscopy
2 hours post-dose
Drug Effects Questionnaire (DEQ) - Like Drug Effect
Time Frame: 0-7 hours post-dose

Visual Analog Scale rating of subjective drug liking included in the Drug Effects Questionnaire. Score ranges from 0 (not at all) to 100 (extremely) using a 100mm line anchored with none/extreme designation.
0-7 hours post-dose
Sex differences in genetics
Time Frame: Day 1

Blood-based DNA sample will be tested for genetic variants of interest involved in the endocannabinoid system
Day 1

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Dorsal striatal glutamate
Time Frame: 2 hours post-dose

Concentrations of dorsal striatal glutamate measured via proton magnetic resonance spectroscopy
2 hours post-dose
Drug Effects Questionnaire (DEQ) - Want More
Time Frame: 0-7 hours post-dose

Visual Analog Scale rating of subjective desire for more of the same drug included in the Drug Effects Questionnaire. Score ranges from 0 (not at all) to 100 (extremely) using a 100mm line anchored with none/extreme designation.
0-7 hours post-dose
Drug Effects Questionnaire (DEQ) - High
Time Frame: 0-7 hours post-dose

Visual Analog Scale rating of subjective "high" included in the Drug Effects Questionnaire. Score ranges from 0 (not at all) to 100 (extremely) using a 100mm line anchored with none/extreme designation.
0-7 hours post-dose

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Medical University of South Carolina

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute on Drug Abuse (NIDA)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 31, 2031

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 31, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 3, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 8, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 11, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Pro00150333

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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