Psilocybin with therapy for bipolar depression not helped by earlier treatments
Tests psilocybin with therapy in adults with hard-to-treat bipolar depression.
Plain-language title generated from the registry record
Registry title: Psilocybin-Assisted Therapy for Treatment-Resistant Depression in Bipolar II Disorder
Key facts
- Where
- Ottawa, Toronto, and Vancouver, CanadaSee the 3 sites
- Phase
- Phase 2
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults aged 19 to 65 with bipolar II disorder who are in a major depressive episode and have not improved with at least two standard treatments.
- Age
- 19 to 65 years
- Sex
- Men and women
- Disease stage
- Bipolar II disorder, currently in a major depressive episode. Depression has not responded to at least two first or second-line treatments.
- Earlier treatment
- No response to at least two treatments for bipolar II depression (for example quetiapine, lithium, lamotrigine, sertraline, venlafaxine or bupropion). Current medicines must be at a stable dose for two weeks before dosing. Cannot have started treatment for the current episode in the past 6 weeks, or structured psychotherapy in the past 8 weeks.
Main reasons for not taking part
- History of psychotic symptoms or seizures
- Parent, sibling or child with a primary psychotic disorder
- Unstable or inadequately treated medical illness, especially heart disease
- Psychedelic drug use (including ketamine, LSD, psilocybin mushrooms) in the past 6 months
- Pregnant or breastfeeding
Read by machine on 12 November 2026.
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 19 and 65 years old?
Source: NCT06943573, who can take part
Where in Canada
- Department of Psychiatry, University of Ottawa, The Ottawa HospitalOttawa, CanadaContact: Nicole EdgarNot yet recruiting
- Department of Psychiatry, University of Toronto, University Health Network,Toronto, CanadaContact: Zoe DoyleNot yet recruiting
- Djavad Mowafaghian Centre for Brain HealthVancouver, CanadaContact: Vy NgoTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorTrial details
- Who runs it
- Lakshmi N Yatham
- Trial code
- NCT06943573
- Record updated
- 15 September 2026
- Original description
This study is a 12-week (in addition to up to 30 days of screening) randomized, double-blind, placebo-controlled, parallel-group trial. The primary objective of this study is to assess the effectiveness, safety, and tolerability of single-dose psilocybin (25 mg)-assisted therapy in comparison to active placebo (1 mg micro-dose) psilocybin-assisted therapy in patients with bipolar II depression who have not responded to adequate trials with at least two first or second-line treatments for bipolar II depression (i.e. quetiapine, lithium, lamotrigine, sertraline, or venlafaxine as monotherapy or adjunctive therapy, or bupropion adjunctive therapy). The active placebo is a substance that looks identical to the study medication but contains less therapeutic ingredients, and thus is less capable of producing the transformative and meaningful aspects of psychedelic experience compared to the 25 mg dose. Participants will have a total of 11 study visits over a period of up to 16 weeks, which includes 5 therapy sessions from trained study therapists.Read full original descriptionShow less
Psilocybin-Assisted Therapy for Treatment-Resistant Depression in Bipolar II Disorder: A Randomized Controlled Trial
This study is a 12-week (in addition to up to 30 days of screening) randomized, double-blind, placebo-controlled, parallel-group trial. The primary objective of this study is to assess the effectiveness, safety, and tolerability of single-dose psilocybin (25 mg)-assisted therapy in comparison to active placebo (1 mg micro-dose) psilocybin-assisted therapy in patients with bipolar II depression who have not responded to adequate trials with at least two first or second-line treatments for bipolar II depression (i.e. quetiapine, lithium, lamotrigine, sertraline, or venlafaxine as monotherapy or adjunctive therapy, or bupropion adjunctive therapy). The active placebo is a substance that looks identical to the study medication but contains less therapeutic ingredients, and thus is less capable of producing the transformative and meaningful aspects of psychedelic experience compared to the 25 mg dose. Participants will have a total of 11 study visits over a period of up to 16 weeks, which includes 5 therapy sessions from trained study therapists.
Inclusion: You are male or female aged 19 to 65 years inclusive; You have a diagnosis of bipolar disorder type II, and are currently in a major depressive episode; You are willing, for the entire duration of the study, to practice highly effective methods of contraception (e.g., contraceptive pills, intrauterine device or system, vasectomy and tubal ligation, or double-barrier methods of contraception) OR agree to completely abstain from heterosexual intercourse. Females who do not have childbearing potential are required to be postmenopausal for at least 1 year before the screening visit (confirmed by an FSH test) OR surgically sterile; You have sufficient English language skills to understand, consent to, and comply with study requirements, study visits, and to return to the clinic for follow-up evaluations; Your current medications have been at a stable dose for two weeks prior to the dosing visit.
Exclusion: You recently (i.e., within the past 8 weeks) began structured psychotherapy (e.g., cognitive-behavioral therapy, interpersonal psychotherapy, family-focused therapy, or interpersonal and social rhythm therapy); You have, in the past 6 months, used any psychedelic drugs, including ketamine, LSD, or psilocybin-containing mushrooms; You have a history of psychotic symptoms; You have a history of seizures; You have a first-degree relative, such as your parent, sibling, or child, with a diagnosis of a primary psychotic disorder (e.g., schizoaffective disorder, schizophrenia); You have a current unstable or inadequately treated medical illness, especially cardiovascular illness, except for the current depression; You have a history of nonresponse or intolerance to psilocybin; You have a history of non-response to electroconvulsive therapy; You recently (i.e., within the past 6 weeks) started taking treatment for your acute bipolar depressive episode; You are pregnant or lactating.