Actively Recruiting
Characterizing Dopamine D2 and D3 Receptor Binding in Treatment Resistant Depression
Led by Unity Health Toronto · Updated on 2026-03-16
45
Participants Needed
1
Research Sites
52 weeks
Total Duration
On this page
Sponsors
U
Unity Health Toronto
Lead Sponsor
C
Centre for Addiction and Mental Health
Collaborating Sponsor
AI-Summary
What this Trial Is About
Researchers are investigating the brain function differences in people with Treatment Resistant Depression (TRD) compared to those with non-resistant Major Depressive Disorder (MDD) and healthy individuals. The study focuses on dopamine D2 and D3 receptor activity in specific brain areas to better understand TRD's neurobiology. This research aims to inform future treatment development and improve clinical understanding of TRD. Participants include three groups: individuals with TRD, those with non-resistant MDD, and healthy controls with no psychiatric history. All participants will be unmedicated and undergo diagnostic PET and PHNO scans. The study involves three visits, including a screening assessment, MRI scan, and PET scan, with the scan order balanced among participants. During the study, participants will complete clinical interviews and depression rating scales to confirm diagnosis and severity. Researchers will collect demographic and medication history data. The main outcome measured is dopamine receptor binding potential over three years. The study is observational and includes safety monitoring, with all procedures conducted at two nearby medical centers.
CONDITIONS
Brief Title
Characterizing Dopamine Receptor Binding in Treatment Resistant Depression
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Adults aged 25 to 55 years
- Diagnosis of Major Depressive Disorder with a current Major Depressive Episode confirmed by MINI
- Moderate to severe depression symptoms (HRSD-17 score > 14)
- Free of psychotropic medications for at least 5 half-lives before PET scanning
- Ability to safely undergo MRI scanning (no metal implants or pacemakers)
- For non-resistant patients: previous response to an antidepressant
- Healthy controls aged 25 to 55 years
- Healthy controls able to undergo MRI scanning
You will not qualify if you...
- Pregnancy or lactation
- Medical condition requiring immediate investigation or treatment
- Recent (within 6 months) or current drug abuse or dependence
- Lifetime history of psychosis (for MDD patients)
- Use of any psychotropic medication within 5 half-lives before PET scanning
- For non-resistant patients: failure of more than 2 antidepressant treatments of adequate dose and duration for current episode
- Healthy controls with any lifetime psychiatric disorder
- Healthy controls with any lifetime use of antidepressants
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 1 day
Participants undergo PET and PHNO scans to characterize dopamine receptor binding.
1 visit (in-person)
Duration - 3 years
Participants are followed for up to 3 years to observe dopamine potential.
Periodic assessments during follow-up
Trial Site Locations
Total: 1 location
1
Unity Health Toronto
Toronto, Ontario, Canada, M5B 1M4
Actively Recruiting
Research Team
S
Sakina J Rizvi, PhD
A
Ariel Graff-Guerrero, MD, PhD
How is the study designed?
Study Type
OBSERVATIONAL
Masking
N/A
Allocation
N/A
Model
N/A
Primary Purpose
N/A
Number of Arms
3
Similar Trials
Frequently Asked Questions
Have more questions? Get in touch with our team for quick support
Not the Right Trial for You?
Explore thousands of other clinical trials that might be a better match.
Sign up to get personalized trial recommendations delivered to your inbox.
Already have an account? Log in here