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Depression

Neurobiological Effects of Psilocybin in Treatment Resistant Bipolar Depression

Recruiting · Toronto, Ontario

Study treatment at no costPHASE1

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Study care at no cost to you

For your time and travel

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Most need no insurance or papers

Legal status usually isn't required; we'll tell you each study's requirements

Interpreters available

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Your choice

Voluntary — you can stop anytime

What is this study?

This study is an open-label, single-arm, proof-of-concept study, wherein treatment resistant bipolar depression (TRBD) participants will receive one 25 mg dose of oral psilocybin accompanied by preparatory, monitoring, and integration psychotherapy sessions (psilocybin-assisted psychotherapy, or PAP). Using fMRI (functional magnetic resonance imaging), the findings of this study will provide data on the neurobiological mechanism of psilocybin in TRBD.

It is , overseen by an independent and licensed medical staff.

Read the full clinical description

This study is an open-label, single-arm, proof-of-concept study, wherein treatment resistant bipolar depression (TRBD) participants will receive one 25 mg dose of oral psilocybin accompanied by preparatory, monitoring, and integration psychotherapy sessions (psilocybin-assisted psychotherapy, or PAP). Using fMRI (functional magnetic resonance imaging), the findings of this study will provide data on the neurobiological mechanism of psilocybin in TRBD. The primary objective is to understand the dynamic role of amygdala activity by evaluating the neurobiological effects of a single psychedelic dose (25 mg) of oral psilocybin in individuals with a moderate to severe major depressive episode and a primary diagnosis of Bipolar II Disorder, with 2 or more failed treatment trials (i.e., treatment resistant bipolar depression \[TRBD\]). Neurobiological effects will be determined by evaluating the association between post-treatment right amygdala activity during the facial affect task (determined by fMRI one day after the psilocybin dose) and antidepressant effects (determined by changes in the Montgomery-Åsberg Depression Rating Scale \[MADRS\] scores over time, during the one-week period post-psilocybin dose). This is a single-arm, open-label clinical trial wherein all participants will receive the same study intervention. Hypothesis: Increased right amygdala activity on fMRI with emotional stimuli one day after psilocybin treatment will be associated with greater antidepressant effects in the one-week period post-treatment in individuals with TRBD.

Who this study is looking for

In plain language, from the study's own rules. The study team confirms the full details with you — this isn't a final yes or no.

✅ You may be able to join if…

  • Adults age 18 to 65
  • Bipolar II Disorder as their main diagnosis, and they are in a current major depressive episode without psychotic features
  • Their current depressive episode is moderate to severe, and they did not improve after two or more past bipolar-depression treatment trials
  • They can take pills by mouth
  • They are able to use highly effective birth control (if capable of becoming pregnant) or use condoms/other methods with a partner (if capable of fathering a child)

🚫 You may not be able to join if…

  • They are pregnant, planning to become pregnant during the study, or breastfeeding
  • They have had mania, hypomania, or mixed symptoms right now (YMRS score greater than 12), or they had mania/hypomania in the past 6 months
  • They have a past-year diagnosis of substance use disorder (not counting tobacco) or have active suicidal thoughts/risk that requires urgent care
  • They have ever been diagnosed with schizophrenia-spectrum or other psychotic disorders, bipolar I disorder, or a neurocognitive disorder
  • They cannot have an MRI/brain scan for safety reasons, have a history of seizures, or cannot take lamotrigine as required during the study

Are you a good fit?

Simplified highlights. The study team always confirms the full details with you.

  • Adults roughly 18–65
  • Have Depression
  • !Some conditions may not be a fit: Heart / cardiovascular disease, High blood pressure
  • !Not for people who are pregnant or breastfeeding

What to expect, step by step

  1. 1

    Usually a few weeks

    The study team checks whether the study is a good fit for you, with a visit and sometimes lab tests. You can ask any questions before deciding.

  2. 2

    Treatment

    If you join and choose to continue, you receive the study treatment and are watched closely by medical staff.

  3. 3

    Follow-up

    After treatment, the team checks on your health and confirms the visit schedule with you. You can leave the study at any point.

Has this treatment been tested before?

This is an early-stage study. The treatment has gone through laboratory and preliminary testing before being studied in people here.

What you need to know before you apply

What is this study testing?+

This study is an open-label, single-arm, proof-of-concept study, wherein treatment resistant bipolar depression (TRBD) participants will receive one 25 mg dose of oral psilocybin accompanied by preparatory, monitoring, and integration psychotherapy sessions (psilocybin-assisted psychotherapy, or PAP). Using fMRI (functional magnetic resonance imaging), the findings of this study will provide data on the neurobiological mechanism of psilocybin in TRBD.

Is it safe? Who makes sure of that?+

This is an early study (Phase 1), focused mostly on safety. Every study is reviewed and monitored by an independent ethics board (called an IRB) whose job is to protect participants, and care is overseen by licensed medical staff. You'll be told the known risks before you agree to anything, and you can stop at any time.

Will I get a placebo instead of the real treatment?+

Some studies compare a treatment against a placebo (an inactive version), and some don't. If this one does, the study team will explain your chances of receiving the active treatment before you decide. Nothing is hidden from you.

Do I have to stop taking my current medications?+

It depends on the study. Some let you stay on your current medications and some ask you to adjust them. Never stop a medication on your own — the study team will review everything with you first.

Does it cost anything? Will I be paid?+

The study treatment and study-related visits are provided at no cost to you. Some studies also pay for your time; the coordinator can tell you if this one does. You should never be asked to pay to take part.

Do I need insurance? Will anyone ask about my immigration status?+

No. You do not need health insurance to take part in a research study, and you will not be asked about your immigration status to join. Taking part is about whether you're a medical fit for the study.

What if English isn't my first language?+

You have the right to understand everything before you agree. Study sites can often provide materials or an interpreter in your language — you can ask the coordinator for one.

Is my information private?+

Yes. Your health information is only shared with the study sites you choose to be contacted by, and only to help match and enroll you. It is never sold, and you can ask us to delete it at any time.

Some requirements (like specific lab values or timing) are confirmed directly by the study team, not by us.

Source: ClinicalTrials.gov · NCT06506019 · Locations: Ontario