Papers

Research literature with structured metadata.

Trials

Registered studies by status, phase, and compound.

Topics

Indications and themes psychedelics are researched for.

Compounds

Evidence across molecules with rich data.

Countries

Regulation, access, and research activity by region.

Stakeholders

Organizations shaping the space across research, policy, and funding.

People

Investigators, clinicians, and authors with mapped output.

Courses

Training programs and certifications across modalities.

Events

Conferences, workshops, and convenings by date and focus.

Results

Compare outcome data across trials and publications.

Research Snapshot

One-page overview of trials, participants, papers, and research networks.

Clinical Guidelines

Trial-anchored manuals and protocol guidance with competency mapping.

Research recaps

Monthly evidence summaries with key takeaways.

Map of research

Landscape view of trials, compounds, and outcomes.

Newsletter

Weekly or daily updates on trials, publications, analysis, and more.

Research Groups

Worldwide map of psychedelic research centres by region.

Road to Access

Science, regulation, and economics on the path to patient access.

Research Network

Interactive co-authorship map of psychedelic researchers.

Top papers

Find needles in the haystack of psychedelic research per topic.

AskBeta
Pricing

The intelligence layer for psychedelic research.

Company

  • About
  • Contact
  • Newsletter

Product

  • Feedback
  • Roadmap
  • Changelog
  • API
  • Partners
  • Clinical Guidelines

Legal

  • Privacy
  • Terms

© 2026 Blossom. All rights reserved.

Home/Research/Psilocybin/Bipolar Disorder

Psilocybin for Bipolar Disorder

20 papers and 6 clinical trials exploring psilocybin as a treatment for bipolar disorder.

CompoundClassic Psychedelic

Psilocybin

Psilocybin is a naturally occurring tryptamine psychedelic that acts as a prodrug to psilocin, a potent 5-HT2A receptor agonist. It is the furthest advanced psychedelic in clinical development, with two positive Phase III trials in treatment-resistant depression and expanding regulated access in Australia, Germany, and US states.

Full Psilocybin profile
Indication45 million worldwide

Bipolar Disorder

Bipolar disorder, characterised by extreme fluctuations in mood, is a complex mental health condition that affects approximately 45 million people worldwide. Current research on psychedelics as a potential treatment is limited due to concerns about inducing manic episodes, but emerging evidence, particularly regarding ketamine, suggests promise for alleviating depressive symptoms associated with the disorder.

Full Bipolar Disorder profile

Academic Research

20 papers
Open Accessindividual

Cognitive outcomes following psilocybin-assisted therapy in treatment-resistant depression: A post-hoc analysis of a randomized, waitlist-controlled trial

This secondary analysis (n=26) of adults with treatment-resistant depression from an open-label psilocybin-assisted psychotherapy trial found statistically significant improvements in processing speed and executive function at two weeks post-treatment, with gains on Trail Making Tests remaining significant after adjusting for depressive symptoms; however, reliable change indices showed that the proportion of participants achieving meaningful improvement (4.2–12.5%) did not exceed chance expectations, suggesting observed gains may reflect practice effects rather than genuine procognitive benefits.

Published
December 1, 2025
Journal
Progress in Neuro-Psychopharmacology and Biological Psychiatry
Authors
Johnson, D. E., Meshkat, S., Kaczmarek, E. S., Rabin, J. S., Brudner, R. M., Chisamore, N., Doyle, Z., Bawks, J., Riva-Cambrin, J., Mansur, R. B., Lipsitz, O., McIntyre, R. S., Lanctôt, K. L., Rosenblat, J. D.
Open Accessindividual

An open-label, dose-escalation trial of psilocybin-assisted therapy for bipolar 2 depression

In an open-label, single-arm dose-escalation pilot (n=14) of psilocybin-assisted therapy for bipolar II depression, psilocybin (10 mg, with 25 mg if needed) was generally well tolerated and produced significant, sustained reductions in depressive symptoms and improved quality of life up to 90 days, with adverse events (including transient anxiety, nausea, headache and three notable psychiatric events) broadly comparable to other psilocybin studies. The authors conclude that randomised, placebo-controlled trials are needed to confirm efficacy and refine dosing protocols in this vulnerable population.

Published
July 7, 2025
Journal
OSF Preprints
Authors
Downey, A. E., Szigeti, B., Bradley, E. R., Fernandes-Osterhold, G., Sakai, K., Llerena, K., Nerayo, J., Fredenburg, L., Nielsen, B., Krystal, A. D., O'donovan, A., Gard, D. E., Woolley, J. D.
Open Accessindividual

Examining mystical experiences as a predictor of psilocybin-assisted psychotherapy for treatment-resistant depression

In a clinical sample of 31 people with treatment‑resistant major depressive disorder or Bipolar II disorder who received one to three 25 mg psilocybin‑assisted psychotherapy sessions, greater mystical experiences during the first dosing session predicted larger reductions in depressive symptoms at two weeks, whereas this relationship was not observed for second or third doses. These findings provide preliminary support that mystical‑type experiences may contribute to the therapeutic effects of psilocybin‑assisted psychotherapy for treatment‑resistant depression.

Published
July 1, 2025
Journal
Journal of Psychopharmacology
Authors
Brudner, R. M., Kaczmarek, E., Blainey, M. G., Schulz-Quach, C., Meshkat, S., Doyle, Z., Lipsitz, O., Offman, H., Sethi, R., Weiglein, G., Mcintyre, R. S., Rosenblat, J. D.
Paywallindividual

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

In a subgroup analysis of four adults with treatment-resistant bipolar II disorder, one or two 25 mg psilocybin-assisted psychotherapy sessions produced rapid reductions in depressive symptoms (mean MADRS 32.5 → 20.3 at two weeks, 21.3 at six months). No treatment-emergent mania, hypomania or psychosis was observed, indicating preliminary safety and potential antidepressant efficacy that requires confirmation in larger trials.

Published
February 27, 2025
Journal
Psychedelic Medicine
Authors
Meshkat, S., Kaczmarek, E., Doyle, Z., Brudner, R. M., Gomes, F. A., Blainey, M. G., Weiglein, G., McIntyre, R. S., Mansur, R. B., Rosenblat, J. D.
Paywallmeta

Adverse Events in Studies of Classic Psychedelics: A Systematic Review and Meta-Analysis

This systematic review and meta‑analysis of 214 studies (3,504 participants with analysable adverse‑event data) found that high‑dose classic psychedelics were generally well tolerated in clinical/research settings, with serious adverse events occurring mainly in ~4% of participants who had preexisting neuropsychiatric disorders and no reports in contemporary trials of suicide, persistent psychotic disorder or hallucinogen‑persisting perception disorder. Common non‑serious adverse events (headache, anxiety, nausea, fatigue, dizziness) had similar prevalences for psilocybin and LSD, but substantial heterogeneity and limited systematic adverse‑event monitoring across studies highlight the need for improved pharmacovigilance.

Published
December 1, 2024
Journal
JAMA Psychiatry
Authors
Hinkle, J. T., Graziosi, M., Nayak, S., Yaden, D. B.
Open Accessmeta

Reconsidering evidence for psychedelic-induced psychosis: an overview of reviews, a systematic review, and meta-analysis of human studies

This systematic review (2024) and meta-analysis (s=131) examines the incidence of psychedelic-induced psychosis, focusing on individuals with schizophrenia. It finds an incidence of 0.002% in population studies, 0.2% in UCTs, and 0.6% in RCTs, with 3.8% of UCT participants with schizophrenia developing long-lasting psychotic symptoms. It also reports that 13.1% of those with psychedelic-induced psychosis later developed schizophrenia.

Published
November 27, 2024
Journal
Molecular Psychiatry
Authors
Sabé, M., Sulstarova, A., Glangetas, A., De Pieri, M., Mallet, L., Curtis, L., Richard-Lepouriel, H., Penzenstadler, L., Seragnoli, F., Thorens, G., Zullino, D., Preller, K., Böge, K., Leucht, S., Correll, C. U., Solmi, M., Kaiser, S., Kirschner, M.

Clinical Trials

6 trials
Not yet recruitingPhase III

Psilocybin-Assisted Therapy for Treatment-Resistant Depression in Bipolar II Disorder (PAT-BD-01)

This randomised, quadruple-blind, placebo-controlled Phase III trial (n=90) will study the effectiveness, safety, and tolerability of psilocybin (25 mg)–assisted therapy compared to an active placebo (1 mg psilocybin) in individuals with treatment-resistant depression associated with bipolar II disorder.

Started
June 1, 2025
Type
interventional
Blinding
quadruple
Randomized
Yes
Registry ID
NCT06943573
RecruitingPhase II

Acceptability & Safety of Two Sequential Doses of Psilocybin in Bipolar Disorder II Depression

Non-randomised, single-group Phase II trial (n=10) assessing safety and acceptability of up to two 25 mg oral psilocybin administrations with therapeutic support in individuals with Bipolar II depression and suicidal ideation (second dose optional, 4 weeks apart).

Started
January 1, 2025
Type
interventional
Blinding
none
Randomized
No
Registry ID
NCT06706232
RecruitingPhase I

Neurobiological Effects of Psilocybin in Treatment Resistant Bipolar Depression (Psilo-BD)

Open-label, single-arm proof-of-concept study (n=30) evaluating neurobiological effects of a single 25 mg oral psilocybin dose with accompanying psychotherapy in treatment-resistant bipolar depression (BD-II).

Started
August 1, 2024
Type
interventional
Blinding
none
Randomized
No
Registry ID
NCT06506019
CompletedPhase II

Psilocybin for Treatment-Resistant Depression

Randomised, parallel-group Phase II trial (n=30) comparing immediate vs delayed point-of-care psilocybin for treatment-resistant depression; single dosing with up to two repeat doses permitted for relapse.

Started
November 19, 2021
Type
interventional
Blinding
none
Randomized
Yes
Registry ID
NCT05029466
Active not recruitingPhase II

Psilocybin Therapy for Depression in Bipolar II Disorder (BAP)

The purpose of this study is to determine the safety, tolerability, and feasibility of psilocybin therapy in people with Bipolar II Disorder.

Started
November 11, 2021
Type
interventional
Blinding
none
Randomized
No
Registry ID
NCT05065294
Unknown statusPhase II

The Safety and Efficacy of Psilocybin in Participants With Type 2 Bipolar Disorder (BP-II) Depression

Open-label, single-group Phase II study (n=15 actual) evaluating a single 25 mg dose of psilocybin with supportive therapy in adults with BP-II current depressive episode.

Started
January 3, 2021
Type
interventional
Blinding
none
Randomized
No
Registry ID
NCT04433845

Explore further

Search all Psilocybin papers Search all Bipolar Disorder trials Full Psilocybin profile Full Bipolar Disorder profile