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Active, Not Recruiting

NCT Number: NCT02102113

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

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Psychosis Cannabis Use Chemically-Induced Disorders Marijuana Marijuana Abuse Mental Disorders Psychotic Disorders Schizophrenia Schizophrenia Spectrum and Other Psychotic Disorders Substance-Related Disorders THC

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

VA Connecticut Healthcare System

West Haven, Connecticut, 06516, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Placebo

Drug

placebo

Very Low Dose THC

Drug

Subjects will receive 0.010mg/kg.

Other names: delta 9-tetrahydrocannabinol

Low dose THC

Drug

Subjects will receive 0.018 mg/kg over 20 minutes.

Other names: delta 9-tetrahydrocannabinol

Primary outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

Secondary outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

Sponsors and collaborators

Lead sponsor

Yale University

Other

Registry information

Important dates

Study start
2014
Primary completion
2026
Study completion
2026
First posted
Apr 2, 2014
Registry last updated
Jun 10, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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