Assessing the safety and acceptability of psilocybin for Bipolar II depression

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

PHASE2 · The University of Texas Health Science Center, Houston · NCT06706232

This study is testing if giving two doses of psilocybin along with therapy can be a safe and helpful treatment for people with Bipolar II Disorder who are feeling depressed and suicidal.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment10 (estimated)
Ages25 Years to 70 Years
SexAll
SponsorThe University of Texas Health Science Center, Houston (other)
Locations1 site (Houston, Texas)
Trial IDNCT06706232 on ClinicalTrials.gov

What this trial studies

This study evaluates the safety and acceptability of administering two sequential doses of 25 mg psilocybin, combined with therapeutic support, to patients with Bipolar II Disorder experiencing depression and suicidality. Participants will receive psychological support informed by mindfulness-based cognitive behavioral therapy (CBT) alongside the psilocybin treatment. The trial is non-randomized and will measure outcomes related to suicidality and depression using validated questionnaires at various time points. The goal is to determine if this approach can provide a feasible and effective treatment option for individuals with limited current options for managing their condition.

Who should consider this trial

Good fit: Ideal candidates are adults aged 25 to 70 with a confirmed diagnosis of Bipolar II Disorder and experiencing passive suicidal ideation.

Not a fit: Patients with active suicidal plans or intentions may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve outcomes for patients with Bipolar II Disorder who are experiencing depression and suicidality.

How similar studies have performed: While the use of psilocybin in treating mental health conditions is emerging, this specific approach in Bipolar II Disorder is relatively novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Must have completed written informed consent
* Must be at 25 years of age or older at screening (but below age of 70)
* Confirmed Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnosis of BD-II using clinical records and Diagnostic Interview for Anxiety, Mood, and Obsessive-compulsive disorder (OCD) and Related Neuropsychiatric Disorders (DIAMOND)
* Must meet criteria for suicidality according to the INQ cutoff scores: A score of at least 12 on the Perceived Burden (PB) subscale and at least a score of 36 on the Thwarted Belongingness (TB) subscale indicating substantial risk for passive suicidal ideation
* Must meet criteria for depression according to the MADRS cutoff scores: A score of 7-34 indicating mild to moderate depression
* Must pass medical examination (physical exam, personal/family medical history, including consultation with current medical provider, ECG, about 4 tablespoons blood draw, psychiatric/psychological assessments, urine drug test)
* Willingness to taper down mood stabilizers and other relevant medications (including but not limited to: antidepressants, antipsychotics, lithium, benzodiazepines, Monoamine oxidase inhibitors (MAOIs), Selective serotonin reuptake inhibitors (SSRIs), Serotonin and norepinephrine reuptake inhibitors (SNRIs), A serotonin-norepinephrine-dopamine reuptake inhibitors (SNDRIs), Tricyclic antidepressants (TCAs), stimulants, cannabis, and other medications, supplements or therapeutics that affect serotonergic function) for the duration of the study before and during administration days (starting 5 weeks before administration), and be off medication for at least 2 weeks prior to administration
* Willingness to stop allowed medication at least 24 h prior to administration of psilocybin as advised by study physician (e.g., benzodiazepines)
* Ability to complete all protocol required assessment tools without any assistance or alteration to the copyrighted assessments, and to comply with all study visits

Exclusion Criteria:

* Participants who do not read/speak English
* Active suicidal ideation with at least some intent and/or plan (i.e., a current score of 4 or 5 on the C-SSRS)
* History of medically significant suicide attempt in the last 6 months
* Current or past history of Bipolar I disorder, psychotic symptoms or psychotic disorder, (including but not limited to schizophrenia, delusional disorder, schizoaffective disorder) clinically relevant personality disorder (such as borderline, antisocial, narcissistic or paranoid personality disorder), or any serious psychiatric comorbidity considered negatively impacting participation or safety (e.g., PTSD or severe substance use or alcohol disorder) assessed by medical history and/or a structured clinical interview
* Have a first or second degree relative with Bipolar I disorder or a psychotic disorder
* Currently experiencing a hypomanic or mixed-symptom episode
* Have a psychiatric or other condition judged to be incompatible with establishment of rapport or safe exposure to psilocybin
* Any indication of a Personality Disorder (PD) such as but not limited to Borderline, Narcissistic, Antisocial, Paranoid, or Schizotypal PD based on Structured Clinical Interview for DSM-5 for PD and/or clinical judgment

Where this trial is running

Houston, Texas

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Bipolar II Disorder, Depression, Bipolar, Suicidality, Bipolar II Depression, Psilocybin

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.