Psilocybin for Prolonged Grief Disorder

March 2, 2026 updated by: Jennifer Kim Penberthy, University of Virginia

Psilocybin-Assisted Therapy for Prolonged Grief

The primary purpose of this study is to explore the feasibility of conducting a clinical trial on the effects of psilocybin for individuals with prolonged grief disorder (PGD).

Study Overview

Detailed Description

The study aims to investigate whether a single dose of 25 mg psilocybin can reduce the symptoms of grief and trauma associated with Prolonged Grief Disorder (PGD). It is hypothesized that psilocybin will significantly reduce the symptoms of PGD, and that the treatment will facilitate subjective mystical, spiritual, or insightful experiences, which in turn may contribute to the alleviation of grief and trauma symptoms. Neuroimaging will be used to help researchers better understand the relationship between grief and brain functions, comparing pre- and post-dose scans. Participants will undergo two MRI (magnetic resonance imaging) where they are asked to look at images (this is called a functional MRI or fMRI).

Study Type

Interventional

Enrollment (Estimated)

12

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Virginia
      • Charlottesville, Virginia, United States, 22903
        • Recruiting
        • University of Virginia

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Ages 18 years old up to and including 65 years of age
  • Negative UDS results for illicit drugs at screening and prior to each drug administration session
  • Consent to all study procedures
  • Have an existing diagnosis of Prolonged Grief Disorder. May also be determined to have Complicated Grief Disorder without official diagnosis as determined by PI or designate based on DSM V criteria
  • Score of greater than 25 on the Inventory of Complicated Grief
  • Agree to abstain from any psychoactive drugs on the day prior to and the day of the drug administration session
  • People of childbearing potential that are sexually active must agree to continue or initiate practice of a highly effective means of birth control, alone or in combination with another, throughout the study. Highly effective options are: implants, intrauterine devices (IUD), and sterilization. Exclusive use of condoms is not effective.
  • Be judged by study team clinicians to be at low risk for suicidality as determined by MINI, Columbia Suicide Severity Scale, and the Patient Health Questionnaire-9.
  • Concurrent psychotherapy or pharmacotherapy with SSRIs, SNRIs, and/or bupropion (< 300 mg bupropion) is allowed if the type and frequency of the therapy has been stable for at least two months prior to screening and is expected to remain stable during participation in the study
  • Be otherwise medically stable as determined by screening for medical problems via a personal interview, a medical questionnaire, a physical examination, an electrocardiogram (ECG), urine beta-HCG, and urine toxicology screen
  • Participant must agree to consume approximately the same amount of caffeine-containing beverage (e.g., coffee, tea) that they consume on a usual morning, before arriving at the research unit on the mornings of drug session days. If the participant does not routinely consume caffeinated beverages, they must agree not to do so on session days
  • Agree not to take any PRN medications on the mornings of drug sessions
  • Agree not to take sildenafil (Viagra®), tadalafil, or similar medications within 72 hours of each drug administration
  • Agree that for one week before each drug session, participant will refrain from taking any nonprescription medication, nutritional supplement, or herbal supplement except when approved by the study investigators. Exceptions will be evaluated by the study investigators and will include acetaminophen, non-steroidal anti-inflammatory drugs, and common doses of vitamins and minerals
  • Willingness and ability to remain within the observation room for the duration of the study visits up to 10 hours
  • Willingness and ability to follow study protocol as directed by research staff
  • Willing and able to attend all sessions in the study and complete follow up assessments
  • Fluent in English
  • Ability to provide one photo of a deceased loved one and one photo of a living loved one, as required for the grief elicitation task.

Exclusion Criteria:

General medical exclusion criteria:

  • Previous use of a psychedelic drug may be exclusionary depending on frequency, context, and participant safety as determined by the PI or designate.
  • Person who is pregnant, nursing, or planning to get pregnant determined at screening and before drug session by urine test or self-report
  • People of childbearing potential that are sexually active who are not practicing an effective means of birth control
  • Cardiovascular conditions: coronary artery disease, stroke, angina, a clinically significant ECG abnormality (e.g., atrial fibrillation), prolonged QTc interval (i.e., QTc > 450 msec), heart valve, or TIA in the past year.
  • History of head trauma with neurological deficit; seizures, or neurologic disorders including cerebrovascular disease, epilepsy, or neurogenerative diseases
  • Type 1 diabetes
  • BMI <18
  • Currently taking on a regular (e.g., daily) basis any antidepressant medications other than SSRIs, SNRIs, or bupropion, or any other medications that have a primary centrally-acting serotonergic effect, including MAOIs. Bupropion dosage must be < 300 mg in order to be included
  • Nicotine dependence that would be incompatible with remaining in study area for the entirety of the visit
  • Prescribed or illicit use of benzodiazepines or opioids within 4 weeks prior to screening
  • Baseline blood pressure greater than 139/79 (after repeat measures) unless stable with medication as determined by PI or PI designate
  • Taking any muscle relaxers, antihistamines, or other medications known to cause lethargy or impair cognitive ability within one day prior to psilocybin session
  • Serious medical comorbidity requiring medical intervention or close supervision
  • History of claustrophobia
  • Any court mandated or legal restrictions that would impair the participant from attending all visits
  • Inability to follow and comply with all study procedures
  • Deemed unable to meaningfully or safely participate in the study
  • Any legal judgement toward subject determined to interfere with study attendance or jeopardize compliance with study protocol determined by PI or designate
  • Individuals who are unable to undergo MRI as determined by MRI pre-screening.

General psychiatric exclusion criteria:

  • Score of less than 25 on the Inventory of Complicated Grief
  • Severe psychiatric disorder (other than depression) within 6 months or lifetime history of serious psychiatric or neurological disorders, including bipolar disorder, or active psychosis
  • Clinically significant suicidal ideation (e.g., with strong intent or means) within past 6 months or lifetime history of suicide attempt based on the MINI, Patient Health Questionnaire-9 or Columbia-Suicide Severity Scale. At any point during the study, a participant may be withdrawn from the study for concerns of suicidality and provided follow-up care by our team or a referral to care if needed.
  • Current or past history of meeting DSM-5 criteria for schizophrenia spectrum or other psychotic disorders, or bipolar I disorder
  • Current or previous history within one year of meeting DSM-5 criteria for a moderate or severe alcohol, or other drug use disorder (excluding tobacco, caffeine, and cannabis)
  • Nicotine dependence that would be incompatible with an individual to be nicotine free for 8-10 hours on a psilocybin session day
  • Have a first degree relative with schizophrenia or other psychotic disorders (except substance/medication-induced or due to another medical condition), or bipolar I disorder

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Open-label, single arm trial
25 mg psilocybin administered to each participant
25 mg psilocybin administered to each participant in single arm, open-label trial
There are two "fMRIs" (functional magnetic resonance imaging) that take place 1-14 days before and 1-14 days after psilocybin administration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Recruitment Rate
Time Frame: Through end of enrollment period
Number of participants enrolled divided by number screened over the recruitment period.
Through end of enrollment period
Dropout Rate
Time Frame: Baseline to 6-month Follow-up
Proportion of enrolled participants who withdraw or are lost to follow-up prior to completing the 6-month assessment.
Baseline to 6-month Follow-up

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Prolonged Grief Disorder Symptoms (ICG)
Time Frame: Baseline (Visit 0 - Screening) to 6-month Follow-up
Change in the Inventory of Complicated Grief (ICG) is a 19-item scale assessing prolonged grief symptoms. Scores range from 0 to 76, with higher scores indicating greater symptom severity.
Baseline (Visit 0 - Screening) to 6-month Follow-up
Change in PTSD Symptoms (DTS)
Time Frame: Baseline (Visit 0 Screening) to 6-month Follow-up
Change in Davidson Trauma Scale (DTS) total score; range 0-136; higher scores indicate more severe PTSD symptoms.
Baseline (Visit 0 Screening) to 6-month Follow-up
Mystical Experience (MEQ)
Time Frame: Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Change in Mystical Experiences Questionnaire (MEQ-30) mean score; range 0-5; higher scores indicate greater mystical-type experience.
Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Altered States of Consciousness (5-D ASC)
Time Frame: Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Change in 5-Dimensions of Altered States of Consciousness score; range 0-100%; higher percentages indicate greater altered-state intensity.
Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Awe Experience (AWE-S)
Time Frame: Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Change in Awe Experience Scale mean score; range 1-7; higher scores indicate greater awe.
Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Challenging Experiences (CEQ)
Time Frame: Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Change in Challenging Experiences Questionnaire mean score; range 0-5; higher scores indicate more intense challenging experiences.
Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Psychological Flexibility (AAQ-II)
Time Frame: Baseline (Visit 2 - Preparation for Treatment) to 6-month Follow-up
Change in Acceptance and Action Questionnaire-II total score; range 7-49; higher scores indicate greater psychological inflexibility.
Baseline (Visit 2 - Preparation for Treatment) to 6-month Follow-up
Closeness to Others (IOS)
Time Frame: Baseline (Visit 0 - Screening) to 6-month Follow-up
Change in Inclusion of Others in the Self single-item score; range 1-7; higher scores indicate greater perceived interpersonal closeness.
Baseline (Visit 0 - Screening) to 6-month Follow-up
Meaning in Life (MIL)
Time Frame: Baseline (Visit 2 - Preparation for Treatment) to 6-month Follow-up
Change in Meaning in Life Questionnaire Presence and Search subscales; each subscale range 5-35; higher scores indicate greater presence of meaning (Presence) or search for meaning (Search).
Baseline (Visit 2 - Preparation for Treatment) to 6-month Follow-up
Psychological Insight (PIQ)
Time Frame: Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Change in Psychological Insight Questionnaire mean score; range 0-5; higher scores indicate greater psychological insight.
Baseline (Visit 3 - Treatment Visit) to 6-month Follow-up
Personality Traits (NEO-FFI)
Time Frame: Baseline (Visit 2 - Preparation for Treatment) to 6-month Follow-up
Change in the NEO Five-Factor Inventory (NEO-FFI) is a 60-item measure assessing five personality domains: Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness. Each domain score ranges from 0-48, with higher scores indicating greater expression of the corresponding personality trait.
Baseline (Visit 2 - Preparation for Treatment) to 6-month Follow-up

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Jennifer K Penberthy, PhD, University of Virginia

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

March 1, 2026

Primary Completion (Estimated)

August 1, 2027

Study Completion (Estimated)

August 1, 2027

Study Registration Dates

First Submitted

December 4, 2024

First Submitted That Met QC Criteria

December 6, 2024

First Posted (Actual)

December 9, 2024

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

March 2, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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