Dopamine D2/D3 receptor binding in treatment-resistant, non-resistant depression, and healthy adults

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This observational imaging project compares striatal and extrastriatal dopamine D2 and D3 receptor binding potential using PET in adults aged 25–55. Participants include medication-free patients with a current DSM-5 major depressive episode (HRSD-17 > 14) classified as treatment-resistant or non-resistant, plus healthy controls, with MRI used for anatomical reference. Non-resistant patients must have a prior history of response to antidepressant treatment to increase contrast with resistant cases. The goal is to define dopaminergic differences across groups to inform clinical characterization and future treatment development for treatment-resistant depression.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Key inclusion criteria for the MDD patients:

  * DSM-5 criteria for a Major Depressive Episode (MDE) within a MDD, confirmed through MINI diagnosis (Sheehan et al, 2015)
  * Age between 25 and 65 years
  * Hamilton Depression Rating Scale - 17 item (HRSD-17; Hamilton, 1960) \> 14 (moderate to severe symptoms)
  * Free of psychotropic medications (with the exception of SSRIs or SNRIs) for at least 5 half-lives before PET scanning per investigator discretion, after which an insignificant amount of drug is circulating through the body and accessing the brain. This determination will be based on self-report from the participant of when their last dose was. Use of benzodiazepines (except for diazepam) or sedative hypnotics (e.g. zopiclone) is allowable, but the last dose must be at least 72 hours prior to scanning.
  * Ability to undergo MRI scanning (absence of metal, pacemakers, etc.)
  * For non-resistant patients: Previous history of response to an antidepressant, in order to increase signal to noise between resistant and non-resistant patients

Key inclusion criteria for the Healthy Controls:

* Ages between 25 and 65 years
* Ability to undergo MRI scanning (absence of metal, pacemakers, etc.)

Exclusion Criteria:

Key exclusion criteria for the MDD patients:

* Pregnancy/lactation
* Medical condition requiring immediate investigation or treatment
* Recent (\< 6 months)/current history of drug abuse/dependence
* Lifetime history of psychosis, other Axis I comorbidities are allowable
* Use of any psychotropic use within 5 half-lives before the PET scanning, with the exception of SSRIs and SNRIs
* For non-resistant patients: Failure of \> 2 antidepressant treatments of adequate dose and duration for current MDE.

Key exclusion criteria for the Healthy Controls:

* Pregnancy/lactation
* Medical condition requiring immediate investigation or treatment
* Lifetime history of any psychiatric disorder
* Lifetime history of receiving an antidepressant

Where it's running

• Unity Health Toronto
  Toronto, Ontario, Canada Recruiting

Study contacts

• Principal investigator: Sakina J Rizvi, PhD — Unity Health Toronto
• Study coordinator: Sakina J Rizvi, PhD
• Email: rizvis@smh.ca
• Phone: 416-864-6060

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.