SchizophreniaPhase 1NCT06058702
Genetic Basis of the Risk and Consequences of Cannabis Exposure in Humans
A Phase 1 study testing Delta-9-THC Very Low Dose and Delta-9-THC Medium Dose in people with Schizophrenia and Cannabis Use Disorder, run by Yale University at 1 site in United States.
Trial summary
Cannabis is widely used worldwide and is associated with negative outcomes including cannabis use disorder (CanUD), psychosis, and cognitive impairment amongst others. Given the legalization of "recreational" and "medical" cannabis globally, the increasing availability of cannabis, the higher potency of cannabis, the… Read more about this study
- Who is it for?
- Ages 21 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Schizophrenia, Cannabis Use Disorder
- What is being tested?
- Delta-9-THC Very Low Dose and Delta-9-THC Medium Dose
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 215 participants
- Where
- 1 siteUnited States
- Study dates
- 16 Sep 2024to 31 Dec 2028
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- -Ages 21-60 years old
Who cannot join
- Major or unstable medical conditions based on history, the Structured Clinical Interview for DSM-5, collateral information, physical and laboratory examinations, ECG, and vital signs.
- Cannabis naïve individuals
- Positive pregnancy test
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
West Haven Veterans Affairs Medical Center
West Haven, Connecticut, 06516
Deepak C D'Souza, MD, 2039325711 ext. 12594, deepak.dsouza@yale.edu
About this study
Cannabis is widely used worldwide and is associated with negative outcomes including cannabis use disorder (CanUD), psychosis, and cognitive impairment amongst others. Given the legalization of "recreational" and "medical" cannabis globally, the increasing availability of cannabis, the higher potency of cannabis, the availability of highly potent cannabinoid products, the commercialization of cannabis, and the rising rates of cannabis use, it is critical to understand how genetic factors influence 1) an individual's vulnerability for addiction and psychosis, 2) the response to cannabinoids, 3) the response to novel treatments for CanUD. CanUD is strongly genetically influenced; the investigators published the first CanUD genomewide association study (GWAS) with genomewide-significant results; however, the precise nature of the contribution of genetic factors in the development of CanUD is still not clear. Cannabis exposure has also been linked to a number of psychosis outcomes including schizophrenia (SCZ). SCZ is highly heritable and population-based and genetics studies both support a bidirectional genetic relationship between SCZ and CanUD. However, the precise contribution of genetic factors in the development of psychosis outcomes related to cannabis are not clear.
- Conditions
- Schizophrenia, Cannabis Use Disorder
- Being tested
- Delta-9-THC Very Low Dose, Placebo, Delta-9-THC Medium Dose
- Medical subject headings
- Schizophrenia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Delta-9-THC Very Low DoseDrug
Active Delta-9-THC administered intravenously over 20 minutes.
PlaceboDrug
Control: Small amount of sterile 190 proof USP ethanol (1-2 mLs), with no THC, administered intravenously over 20 minutes.
Delta-9-THC Medium DoseDrug
Active Delta-9-THC administered intravenously over 20 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Delta-9-THC Very Low Dose | Active comparator | Active delta-9-THC administered intravenously over 20 minutes. Receives: Drug: Delta-9-THC Very Low Dose |
| Placebo | Placebo comparator | Control: small amount of alcohol administered intravenously (quarter teaspoon), with no delta-9-THC, over 20 minutes. Receives: Drug: Placebo |
| Delta-9-THC Medium Dose | Active comparator | Active delta-9-THC administered intravenously over 20 minutes. Receives: Drug: Delta-9-THC Medium Dose |
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual Analog Scale (VAS)
The VAS is a scale to document perceived reward. A higher score reflects a positive response.
Measured: Measured at baseline, 20 minutes, 45 minutes, 90 minutes, 140 minutes, 165 minutes, 210 minutes, 270 minutes, and 360 minutes after the start of the initial THC/placebo drug infusion.
Positive and Negative Symptom Scale (PANSS)
The Positive and Negative Syndrome Scale is a 30-item scale to assess both the positive and negative symptom symptoms of schizophrenia. The range total score is 30-210. An improvement in symptoms is reflected by a lower score.
Measured: Measured at baseline, 45 minutes, 90 minutes, 165 minutes, 210 minutes, and 360 minutes after the start of the initial THC/placebo drug infusion.
Clinician Administered Dissociative Symptoms Scale (CADSS),
Perceptual alterations will be measured using scales such as the Clinician Administered Dissociative Symptoms Scale (CADSS), a scale consisting of 19 self-report items and 8 clinician-rated items (0 = not at all, 4 = extremely) that we have shown to be sensitive to THC effects. The scale captures alterations in environmental/time/body perception, feelings of unreality, and memory impairment.
Measured: Measured at baseline, 45 minutes, 90 minutes, 165 minutes, 210 minutes, and 360 minutes after the start of the initial THC/placebo drug infusion.
CogState Battery
The CogState Battery measures cognition including verbal learning and recall and episodic memory.
Measured: Measured at baseline, 45 minutes, and 165 minutes after the start of the initial THC/placebo drug infusion.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Sep 2023
- Study start16 Sep 2024
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SchizophreniaStudies of the same condition, open and under way.
- More trials run by Yale UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 215 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Responsible party
- Principal investigator, Deepak C. D'Souza, Yale University
- Investigators
- Deepak D'Souza, MD, Principal investigator, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06058702
- Sponsor's protocol ID
- 2000036194
- Other IDs
- RO1
- Status last verified
- Sep 2026
- First submitted
- 15 Sep 2023
- Last updated
- 2 Sep 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Genetic Basis of the Risk and Consequences of Cannabis Exposure in Humans
- ClinicalTrials.gov ID
- NCT06058702
- Acronym / sponsor ID
- 2000036194
- Conditions
- Schizophrenia, Cannabis Use Disorder
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 215 participants (estimated)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Study start
- 16 Sep 2024 (actual)
- Primary completion
- 31 Dec 2028 (estimated)
- Study completion
- 31 Dec 2028 (estimated)
- First posted
- 28 Sep 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Cannabis is widely used worldwide and is associated with negative outcomes including cannabis use disorder (CanUD), psychosis, and cognitive impairment amongst others. Given the legalization of "recreational" and "medical" cannabis globally, the increasing availability of cannabis, the higher potency of cannabis, the availability of highly potent cannabinoid products, the commercialization of cannabis, and the rising rates of cannabis use, it is critical to understand how genetic factors influence 1) an individual's vulnerability for addiction and psychosis, 2) the response to cannabinoids, 3) the response to novel treatments for CanUD. CanUD is strongly genetically influenced; the investigators published the first CanUD genomewide association study (GWAS) with genomewide-significant results; however, the precise nature of the contribution of genetic factors in the development of CanUD is still not clear. Cannabis exposure has also been linked to a number of psychosis outcomes including schizophrenia (SCZ). SCZ is highly heritable and population-based and genetics studies both support a bidirectional genetic relationship between SCZ and CanUD. However, the precise contribution of genetic factors in the development of psychosis outcomes related to cannabis are not clear.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Delta-9-THC Very Low Dose | Active comparator | Drug: Delta-9-THC Very Low DoseActive delta-9-THC administered intravenously over 20 minutes. |
| Placebo | Placebo comparator | Drug: PlaceboControl: small amount of alcohol administered intravenously (quarter teaspoon), with no delta-9-THC, over 20 minutes. |
| Delta-9-THC Medium Dose | Active comparator | Drug: Delta-9-THC Medium DoseActive delta-9-THC administered intravenously over 20 minutes. |
Who may qualify
- Ages
- 21 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- -Ages 21-60 years old
Key exclusion criteria (3 listed)
- Major or unstable medical conditions based on history, the Structured Clinical Interview for DSM-5, collateral information, physical and laboratory examinations, ECG, and vital signs.
- Cannabis naïve individuals
- Positive pregnancy test
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Delta-9-THC Very Low DoseActive Delta-9-THC administered intravenously over 20 minutes. | Drug | Delta-9-THC Very Low Dose |
| PlaceboControl: Small amount of sterile 190 proof USP ethanol (1-2 mLs), with no THC, administered intravenously over 20 minutes. | Drug | Placebo |
| Delta-9-THC Medium DoseActive Delta-9-THC administered intravenously over 20 minutes. | Drug | Delta-9-THC Medium Dose |
Primary outcome
Visual Analog Scale (VAS)
Time frame: Measured at baseline, 20 minutes, 45 minutes, 90 minutes, 140 minutes, 165 minutes, 210 minutes, 270 minutes, and 360 minutes after the start of the initial THC/placebo drug infusion.
The VAS is a scale to document perceived reward. A higher score reflects a positive response.
Positive and Negative Symptom Scale (PANSS)
Time frame: Measured at baseline, 45 minutes, 90 minutes, 165 minutes, 210 minutes, and 360 minutes after the start of the initial THC/placebo drug infusion.
The Positive and Negative Syndrome Scale is a 30-item scale to assess both the positive and negative symptom symptoms of schizophrenia. The range total score is 30-210. An improvement in symptoms is reflected by a lower score.
Clinician Administered Dissociative Symptoms Scale (CADSS),
Time frame: Measured at baseline, 45 minutes, 90 minutes, 165 minutes, 210 minutes, and 360 minutes after the start of the initial THC/placebo drug infusion.
Perceptual alterations will be measured using scales such as the Clinician Administered Dissociative Symptoms Scale (CADSS), a scale consisting of 19 self-report items and 8 clinician-rated items (0 = not at all, 4 = extremely) that we have shown to be sensitive to THC effects. The scale captures alterations in environmental/time/body perception, feelings of unreality, and memory impairment.
CogState Battery
Time frame: Measured at baseline, 45 minutes, and 165 minutes after the start of the initial THC/placebo drug infusion.
The CogState Battery measures cognition including verbal learning and recall and episodic memory.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2026.
Related trials for Schizophrenia
RecruitingPhase 3
A Study to Evaluate the Long-term Safety and Tolerability of Xanomeline and Trospium Chloride for the Treatment of Psychiatric Disorders in Children and Adolescents
Schizophrenia, Autism-Related Irritability
Not yet recruiting
Deep Brain Stimulation for Treatment-Resistant Schizophrenia
Treatment Resistant Disorders
Not yet recruitingObservational study
Sleep Monitoring for Early Detection of Relapse in People With Schizophrenia or Bipolar Disorder Receiving Usual Treatment
Bipolar Disorder (BD), SCHIZOPHRENIA 1 (Disorder)
Not yet recruitingPhase 1
Pharmacokinetics and Relative Bioavailability of Intranasal vs Intramuscular Olanzapine in Healthy Adult Participants
Healthy Adult Participants
Active, not recruiting
Designing and Evaluating a Classroom-Based Mental Health Programme for Adolescents.
Mental Health Promotion
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Deepak D'Souza, MD principal investigator
Yale University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Delta-9-THC Very Low Dose and Delta-9-THC Medium Dose in people with Schizophrenia and Cannabis Use Disorder, run by Yale University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Erik Zorrilla, PhD (203-932-5711 ext. 15758, erik.zorrilla@yale.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Visual Analog Scale (VAS) (time frame: Measured at baseline, 20 minutes, 45 minutes, 90 minutes, 140 minutes, 165 minutes, 210 minutes, 270 minutes, and 360 minutes after the start of the initial THC/placebo drug infusion.). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2026.