Probing the Cannabinoid System in Individuals With a Family History of Psychosis

June 5, 2025 updated by: Mohini Ranganathan, Yale University
The overall purpose of this study is to determine whether a family history of psychosis is associated with an altered cannabinoid system. This will be tested by studying individuals with and without a family history of psychosis and comparing their responses to delta 9-tetrahydrocannabinol (THC), a probe of the cannabinoid system. We hypothesize, that compared to controls with no family history of psychoses, individuals with a family history of psychoses will have an altered response to THC.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not 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.
21

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.
  • Early Phase 1

Contacts and Locations

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

Study Locations

  • United States
    • Connecticut
      • West Haven, Connecticut, United States, 06516
        • VA Connecticut Healthcare System

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

18 years to 55 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria FHP:

  • Exposure to cannabis at least once in their lifetime
  • Medically and psychiatrically healthy based on screening
  • Having one relative with a confirmed psychotic disorder

Exclusion Criteria FHP:

  • Current or lifetime major DSM-IV Axis I disorder
  • Current or lifetime treatment (at least 6 months) with psychotropic medications for major psychiatric or neurological illness
  • Major or unstable medical illness that might impact safety of the subject in the study
  • Cannabis naive
  • IQ less than 85
  • Less than a high school diploma or its educational equivalent
  • Pregnancy or lactation
  • Major current or recent (<6 weeks) psychosocial stressors.

Inclusion Criteria FHN :

  • Exposure to cannabis at least once in their lifetime
  • Medically and psychiatrically healthy based on screening

Exclusion Criteria FHN:

  • Having a family member with psychosis
  • Current or lifetime major DSM-IV Axis I disorder
  • Current or lifetime treatment (at least 6 months) with psychotropic medications for major psychiatric or neurological illness
  • Major or unstable medical illness that might impact safety of the subject in the study
  • Cannabis naive
  • IQ less than 85
  • Less than a high school diploma or its educational equivalent
  • Pregnancy or lactation
  • Major current or recent (<6 weeks) psychosocial stressors.

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: Other
  • 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: No Family History of Psychosis (FHN)
Individuals recruited with no history of psychosis in the family. They will receive the placebo, very low dose THC, and low dose THC interventions.
Drug: Placebo
placebo
Drug: Very Low Dose THC
Subjects will receive 0.010mg/kg.
Other Names:
  • delta 9-tetrahydrocannabinol
Drug: Low Dose THC
Subjects will receive 0.018 mg/kg over 20 minutes.
Other Names:
  • delta 9-tetrahydrocannabinol
Experimental: Family History of Psychosis (FHP)
Individuals with a family member with a confirmed diagnosis of psychosis. They will receive the placebo, very low dose THC, and low dose THC interventions.
Drug: Placebo
placebo
Drug: Very Low Dose THC
Subjects will receive 0.010mg/kg.
Other Names:
  • delta 9-tetrahydrocannabinol
Drug: Low Dose THC
Subjects will receive 0.018 mg/kg over 20 minutes.
Other Names:
  • delta 9-tetrahydrocannabinol

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
Positive and Negative Symptom Scale for Schizophrenia (PANSS)
Time Frame: -30 min from administration of THC
Positive, negative and general symptoms will be assessed using the positive, negative and general symptoms subscales of the PANSS.
-30 min from administration of THC
Positive and Negative Symptom Scale for Schizophrenia (PANSS)
Time Frame: +80 min from administration of THC
Positive, negative and general symptoms will be assessed using the positive, negative and general symptoms subscales of the PANSS.
+80 min from administration of THC
Positive and Negative Symptom Scale for Schizophrenia (PANSS)
Time Frame: +150 min of administration of THC
Positive, negative and general symptoms will be assessed using the positive, negative and general symptoms subscales of the PANSS.
+150 min of administration of THC
Positive and Negative Symptom Scale for Schizophrenia (PANSS)
Time Frame: +240 min of administration of THC
Positive, negative and general symptoms will be assessed using the positive, negative and general symptoms subscales of the PANSS.
+240 min of administration of THC

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
Clinician Administered Dissociative Symptoms Scale (CADSS)
Time Frame: -30 min, +15 min, +80 min, +150 min, +240 min
Perceptual alterations will be measured using the CADSS. This is a scale consisting of 19 self-report items and 8 clinician-rated items (0=not at all, 4=extremely). The scale captures alterations in environmental/time/body perception, feelings of unreality, and memory impairment.
-30 min, +15 min, +80 min, +150 min, +240 min
Visual Analog Scale (VAS)
Time Frame: -30 min, +15 min, +80 min, +150 min, +240 min
Feeling states associated with cannabis intoxication will be measured using a self-reported visual analogue scale of four feeling states ("high", "anxious", "calm and relaxed", and "tired") associated with cannabis effects. Subjects will be asked to score the perceived intensity of these feeling states at that moment on a 11 mm line (0=not at all, 100=extremely). These data will be captured to validate that the experiment is relevant to cannabis effects.
-30 min, +15 min, +80 min, +150 min, +240 min
Hopkins Verbal Learning Test (HVLT)
Time Frame: +50 min
The HVLT is a 12 word list that is semantically organized. The task consists of 5 trials, an interference list, and free delayed recall and recognition. A different version of the AVLT will be administered on each test day and counterbalanced across subjects.
+50 min
Psychotomimetic States Inventory (PSI)
Time Frame: -30 min, +240 min
The PSI is a measure of drug induced psychotomimetic states. This self-report scale consists of 28 items rated 0 (not at all) to 3 (extremely) and will facilitate the characterization of a wide range of dissociative/hallucinatory phenomena as well as cognitive disorganization associated with the administration of THC.
-30 min, +240 min

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.
Yale University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Mohini Ranganathan, MD, Yale University

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

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.
January 1, 2014

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.
June 1, 2026

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.
December 1, 2026

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).
March 26, 2014

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.
March 28, 2014

First Posted (Estimated)

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.
April 2, 2014

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.
June 10, 2025

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.
June 5, 2025

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.
August 1, 2024

More Information

Terms related to this study

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.
  • 1310012948

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