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Psilocybin-Assisted Therapy for Treatment-Resistant Depression in Bipolar II Disorder

Psilocybin-Assisted Therapy for Treatment-Resistant Depression in Bipolar II Disorder: A Randomized Controlled Trial

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06943573
Acronym
PAT-BD-01
Enrollment
90
Registered
2025-04-24
Start date
2026-06-15
Completion date
2028-12-01
Last updated
2026-09-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bipolar II Depression

Keywords

Bipolar Disorder, Mood Disorder, Psychedelic-assisted therapy, Psychedelics, Treatment resistant, Psilocybin, Depression

Brief summary

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.

Detailed description

Bipolar disorders (BD) are lifelong conditions characterized by recurrent episodes of depression and (hypo)mania. Statistics Canada data indicate over a million Canadians are affected by this illness. Bipolar II disorder is characterised by recurrent episodes of hypomania and depression and individuals with BD-II are symptomatic about 50% of the time despite treatment. The majority of this time is spent being depressed thus there is an urgent need to develop new treatments that are safe and effective. Psilocybin, a naturally occurring psychedelic compound found in mushrooms, has been noted to result in an increase in psychological well-being in healthy volunteers as well as have antidepressant effects when administered in conjunction with psychological support. Two recent open-label pilot trials of Psilocybin-Assisted Therapy (PAT) in treatment-resistant depression, including BD-II participants, demonstrated high response rates and excellent tolerability, thereby providing strong justification for the current study.

Interventions

DRUGpsilocybin (25 mg)

Single-dose psilocybin (25 mg)-assisted therapy (PAT)

DRUGpsilocybin 1mg micro-dose

Single dose active placebo psilocybin-assisted therapy

Sponsors

Lakshmi N Yatham
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

Study Therapist

Intervention model description

Double-blind, Active Placebo controlled, Randomized Clinical Trial

Eligibility

Sex/Gender
ALL
Age
19 Years to 65 Years
Healthy volunteers
No

Inclusion criteria

1. You are male or female aged 19 to 65 years inclusive. 2. You have a diagnosis of bipolar disorder type II, and are currently in a major depressive episode. 3. 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. 4. 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. 5. Your current medications have been at a stable dose for two weeks prior to the dosing visit.

Exclusion criteria

1. You have a history of psychotic symptoms. 2. You have a history of seizures. 3. 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). 4. You have a current unstable or inadequately treated medical illness, especially cardiovascular illness, except for the current depression. 5. You recently (i.e., within the past 6 weeks) started taking treatment for your acute bipolar depressive episode. 6. 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). 7. You have a history of nonresponse or intolerance to psilocybin. 8. You have, in the past 6 months, used any psychedelic drugs, including ketamine, LSD, or psilocybin-containing mushrooms. 9. You have a history of non-response to electroconvulsive therapy. 10. You are pregnant or lactating.

Design outcomes

Primary

MeasureTime frameDescription
Change in depressive symptomsBaseline to Week 3The Montgomery Asberg Depression Rating Scale (MADRS) will be used to measure change in depressive symptoms. Scores range from 0 to 60, and lower scores reflect better clinical outcomes.

Secondary

MeasureTime frameDescription
Response RatesWeek 3, Week 6, Week 12Patients showing ≥50% reduction in the Montgomery Asberg Depression Rating Scale (MADRS) scores from Baseline. Scores range from 0 to 60, and lower scores reflect better clinical outcomes.
Remission RatesEndpointDefined as Montgomery Asberg Depression Rating Scale (MADRS) scores ≤ 10 and Young Mania Rating Scale (YMRS) scores ≤ 8. Scores for the MADRS range from 0 to 60, with lower scores reflecting better clinical outcomes. Scores for the YMRS range from 0 to 60, with lower scores reflecting better clinical outcomes.
Treatment-emergent manic/hypomanic events12 weeksThe Young Mania Rating Scale (YMRS) will be used to determine the presence of any treatment-emergent manic or hypomanic events from baseline to endpoint. Scores range from 0 to 60, and lower scores reflect better clinical outcome
Mean change in depressive symptomsWeek 6 and 12The Montgomery Asberg Depression Rating Scale (MADRS) will be used to measure mean change in depressive symptoms. Scores range from 0 to 60, and lower scores reflect better clinical outcomes.
Subjective depressive symptoms12 weeksThe Quick Inventory of Depressive Symptomatology-Self Report (QIDS-SR) will be used to measure change in subjective depressive symptoms from baseline to endpoint. Scores on the QIDS-SR range from 0 to 27; lower scores on the QIDS-SR reflect better clinical outcomes.
Symptoms of anhedonia12 weeksThe Snaith-Hamilton Pleasure Scale (SHAPS) will be used to measure change in subjective symptoms of anhedonia from baseline to endpoint. Scores on the SHAPS range from 0 to 42; higher SHAPS scores indicate a reduced ability to experience pleasure and reduced capacity to feel pleasure.
Objective anxiety symptoms12 weeksThe Hamilton Anxiety Rating Scale (HAM-A) will be used to measure change in objective anxiety symptoms from baseline to endpoint. Scores range from 0 to 56 and lower scores reflect better clinical outcomes.
Overall psychiatric status12 weeksThe Clinical Global Impression - severity \& change scales will be used to measure change in global severity and global improvement in symptoms from baseline to endpoint. Scores range from 3 to 42, and higher scores reflect worsening in overall psychiatric status.
Psychotic symptoms12 weeksThe Positive and Negative Syndrome Scale (PANSS) will be used to measure change in psychotic symptoms from baseline to endpoint. Scores range from 7 to 49, and lower scores reflect better clinical outcomes.
Subjective cognitive functioning12 weeksThe Cognitive Complaints in Bipolar Disorder Risk Assessment (COBRA) scale will be used to measure change in subjective cognitive functioning from baseline to endpoint. COBRA scores range from 0 to 48, and lower scores reflect better outcomes.
Objective cognitive functioning12 weeksThe Screen for Cognitive Impairment in Psychiatry (SCIP) will be used to measure change in objective cognitive functioning from baseline to endpoint. Higher scores reflect better outcomes.
Sleep quality12 weeksThe Pittsburgh Sleep Quality Index (PSQI) will be used to measure changes in sleep quality and disturbance from baseline to endpoint. Lower scores reflect better sleep quality.
Quality of Life assessed by QoL.BD12 weeksThe Brief Quality of Life in Bipolar Disorder (QoL.BD) will be used to measure change in quality of life from baseline to endpoint. Higher scores reflect higher quality of life.
Daily functioning12 weeksThe Functioning Assessment Short Test (FAST) will be used to measure change in daily functioning from baseline to endpoint. Scores range from 0 to 72 with lower scores reflecting better daily functioning.
Suicidal thoughts and behaviours12 weeksThe Columbia-Suicide Severity Rating Scale (C-SSRS) will be used to measure change in suicidal thoughts and behaviours from baseline to endpoint. Scores range from 0 to 37, and lower scores reflect better clinical outcomes.
MEQ30Dosing Visit (Day 0)Psychedelic experience will be measured by the MEQ30. Scores range from 30 to 150; higher scores reflect stronger (more profound) experiences.
Clinician's perspective on the therapeutic relationshipBaseline and Week 1The Therapeutic Relationship will be measured with the Scale to Assess the Therapeutic Relationship - Clinician version (STAR-C). Scores range from 0 to 48 respectively; higher scores reflect better therapeutic relationships.
Patient's perspective on the therapeutic relationshipBaseline and Week 1The Therapeutic Relationship will be measured with the Scale to Assess the Therapeutic Relationship - Patient version (STAR-P). Scores range from 0 to 48 respectively; higher scores reflect better therapeutic relationships.

Countries

Canada

Contacts

CONTACTVy Ngo, B.Sc
vy.ngo@ubc.ca604-822-3769
CONTACTNazlin Walji, B.Sc, CCRC
nazlin.walji@ubc.ca604-822-7294
PRINCIPAL_INVESTIGATORDr. Lakshmi N Yatham

UBC Department of Psychiatry

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 16, 2026