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
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