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Major DepressionPhase 2SPACENCT07479550

Study of Psilocybin Under Anesthesia Controlled by EEG

A Phase 2 study testing Psilocybin (Usona Institute) and Propofol in people with Major Depression, run by Stanford University at 1 site in United States.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
Search all trials

Trial summary

Major depressive disorder (MDD) affects millions of Americans and remains difficult to treat. Psilocybin, a psychedelic compound, has shown promise for reducing depression symptoms, but a key challenge in psychedelic research is that participants can usually tell whether they received the active drug - making it hard… Read more about this study

Who is it for?
Ages 25 to 65 years
Conditions the study is for
Major Depression
What is being tested?
Psilocybin (Usona Institute) and Propofol
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
10 participants
Where
1 siteUnited States
Study dates
Jul 2026to Aug 2027
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 25 to 65 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • A participant will be eligible for inclusion when all of the following criteria are met:
  • People 25 to 65 years of age at screening;
  • Able to read, understand, and provide dated, informed consent, either in writing or electronically, prior to screening. Patients will be deemed likely to comply with study protocol and communicate with study staff about adverse events and other clinically important information;
  • Fluent in English;
  • Able to commit to attend all study visits and participate in all remote data collection procedures;
  • Be stable in background psychotherapy for at least 4 weeks prior to enrollment outside of the study and able to access mental healthcare for the duration of the study;
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  • Body mass index between 17-35 kg/m2.
  • Participant has a current diagnosis of MDD during a current Major Depressive Episode (MDE) (single or recurrent episode as defined by DSM-5-TR [if single episode, duration of ≥4 weeks] and verified after evaluation by a qualified member of the investigative team using the QuickSCID-5 (Quick Structured Clinical Interview for DSM-5 Disorders).
  • Able to physically tolerate general anesthesia, as determined by American Society of Anesthesiologists (ASA) Physical Status Class I or II. ASA Class III participants whose functional impairment is directly related to a psychiatric diagnosis (depression) will be included.
  • Agree that for one week preceding the psilocybin sessions and throughout the study, they will refrain from taking any nonprescription medication, nutritional supplement, or herbal supplement except when approved by the study staff. Exceptions will be evaluated by the study staff and will include acetaminophen, non-steroidal anti-inflammatory drugs, and common doses of vitamins and minerals.
  • Agree not to consume any food or drink after midnight preceding dosing days.
  • Agree not to consume alcoholic beverages for 48 hours prior to and 24 hours following the dosing sessions.
  • Agree not to use cannabis in any form for the duration of the study.
  • Non-smoker, or abstained at least 6 weeks.
  • For people who can become pregnant: agree to use highly effective contraception from entry into the trial through the end of the study.
  • A person with a uterus is considered of childbearing potential, i.e. fertile, following menarche and until becoming post-menopausal unless permanently sterilized (i.e. has had a hysterectomy, bilateral salpingectomy or bilateral oophorectomy).
  • A person with a uterus who is not of childbearing potential is considered to be postmenopausal after at least 12 months without menstruation.
  • Highly effective contraception (typical use failure rate of less than 1%) is defined i. combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation
  • <!-- -->
  • oral
  • intravaginal
  • Transdermal
  • Double-barrier method ii. progestogen-only hormonal contraception associated with inhibition of ovulation:
  • 1. oral 2. injectable 3. implantable iii. intrauterine device (IUD) iv. intrauterine hormone-releasing system (IUS) v. bilateral tubal occlusion vi. vasectomized partner vii. sexual abstinence
  • Periodic abstinence (i.e., calendar, symptothermal, or postovulation methods, and tubal ligation/occlusion) are not an acceptable form of contraception for this study.
  • The PI will use his judgement and familiarity with the participant's preferred and usual lifestyle to understand if reporting of abstinence may be trusted to achieve 100% effectiveness.
  • 15. Negative urinary pregnancy test at screening and again immediately before dosing sessions.

Who cannot join

  • A potential participant will NOT be eligible for participation in this study if any of the following criteria are met:
  • Has any ongoing legal or disability claim such as Worker's Compensation
  • Is taking a medication belonging to any of the following classes:
  • TCAs, MAOIs, SSRIs, SNRIs. (Other antidepressants including mirtazapine, nefazodone, trazodone, vilazodone, vortioxetine, and bupropion are allowed.) b. Typical or atypical antipsychotics c. Anticonvulsants such as valproate, topiramate, oxcarbazepine, carbamazepine. (Gabapentinoids and lamotrigine are allowed.) d. Other agents that may be associated with serotonin syndrome: i. St. John's Wort ii. S-adenosyl-methionine (SAM-e) iii. 5-Hydroxytryptophan (5-HTP) iv. Lithium v. Dextromethorphan vi. Linezolid vii. Buspirone viii. Efavirenz ix. Lorcaserin e. Agents that may interact with psilocybin metabolism/effects: i. Modulators of uridine diphosphate (UDP) or glucuronosyltransferase (UGT) (e.g., COMT inhibitors, ethinyl estradiol, valproate, diclofenac, mefenamic acid, verapamil, ketoconazole, itraconazole, probenecid, phenobarbital, protease inhibitors) ii. L-Methylfolate (>/= 7.5mg/day) iii. Alcohol or aldehyde dehydrogenase inhibitors
  • Is taking benzodiazepine medication such that patient cannot tolerate withholding doses 8 hours before through 6 hours after planned study intervention
  • Is taking agents that may interact with psilocybin metabolism effects such that the patient cannot tolerate withholding doses 8 hours before through 6 hours after planned study intervention.
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  • For individuals who can become pregnant:
  • Currently pregnant (confirmed or suspected) b. Currently breastfeeding c. Positive urinary pregnancy test at screening or immediately before dosing d. Unwilling or unable to use highly effective contraception (defined as methods with failure rate <1% per year) from the time of consent through 30 days following the last dosing session e. Planning to become pregnant within 30 days following the psilocybin or placebo administration sessions
  • Participation in a clinical trial within 30 days of entry into this trial, or during the trial, or treatment with another investigational drug or other intervention within 30 days or 5 half-lives, whichever is longer, that may interfere with psilocybin metabolism/effects.
  • Currently receiving electroconvulsive therapy (ECT). Previous treatment with ECT is permitted; last treatment must be at least 30 days prior to entry into this trial.
  • History of schizophrenia or schizoaffective disorders, or any history of psychotic symptoms, mania, or bipolar affective disorder
  • A positive urine toxicology screen including amphetamines, cocaine, MDMA, cannabis, opioids, ketamine, and benzodiazepines at screening visit and on the morning of the dosing session.
  • Use of psychedelics in the previous 6 months prior to screening (psilocybin, LSD, DMT, 5-Meo-DMT, MDMA, Ibogaine).
  • History of meeting DSM-5 criteria for Hallucinogen Use Disorder (Moderate or Severe) or Hallucinogen Persisting Perception Disorder (HPPD),or has ever had a negative reaction to or experience with a psychedelic (e.g., "bad trip").
  • Current diagnosis of a Substance Use Disorder over the last 12 months (SUD; Abuse or Dependence, as defined by DSM-V) per QuickSCID-5. Participants who are at risk of alcohol or cannabis withdrawal will be excluded (e.g. those who endorse tolerance or who have experienced previous withdrawal). The following categories of SUD will NOT be excluded: nicotine dependence; alcohol or cannabis substance use disorder rated "mild".
  • Current diagnosis of a psychiatric disorder or mental health status that in the judgement of the study staff increases the risk of the intervention or would interfere with the patient's ability to engage in the intervention at any time within the six months prior to screening.
  • History of suicide attempt requiring hospitalization or suicidal ideation with intent in the last 10 years.
  • In the judgment of the study staff, the participant is at significant risk for suicidal behavior during the course of their participation in the study per Columbia Suicide Severity Rating Scale (C-SSRS), rated 'High Risk'.
  • A neurological disorder including:
  • Dementia, delirium, amnestic, or any other cognitive disorder.
  • Lifetime history of surgical procedures involving the brain or meninges,
  • Encephalitis, meningitis, degenerative central nervous system disorder (e.g., Alzheimer's or Parkinson's Disease), epilepsy, mental retardation
  • Any other disease/procedure/accident/intervention associated with significant injury to or malfunction of the central nervous system (CNS),
  • History of significant head trauma within the past two years.
  • A cardiovascular disorder including:
  • Elevated blood pressure defined as systolic blood pressure (SBP) >140 or diastolic blood pressure (DBP) >90 averaged over two separate measurements taken during the screening period b. Tachycardia defined as heart rate (HR) >90 beats per minute averaged over two separate measurements taken during the screening period c. Bradycardia defined as heart rate (HR) <50 beats per minute averaged over two separate measurements taken during the screening period d. Angina e. Clinically significant EKG abnormality (e.g., atrial fibrillation, QTcF >450 ms for males or >470 ms for females) f. Any other significant current or history of a cardiovascular condition that would preclude safe participation in the study based on the clinical judgment of the investigators.
  • Clinically significant pulmonary/respiratory disorder including
  • History of difficult airway or difficult mask ventilation, or predictors of difficult airway such as Mallampati Score 3 or 4, limited mouth opening, thyromental distance <6cm, restricted neck mobility, or significant retrognathia.
  • COPD requiring systemic steroid use. c. Obstructive Sleep Apnea, moderate or severe (Apnea-Hypopnea Index >=15), or requiring regular CPAP use
  • Clinically significant liver disease, determined by Liver Function Tests (LFTs) within the past 6 months: Hepatic dysfunction as indicated by any of the following values:
  • AST > 3 x upper limit of normal
  • ALT > 3 x upper limit of. Normal
  • Total bilirubin > 3.0 mg/dl
  • Known allergy or hypersensitivity to propofol or any of its components (unless they have a documented propofol exposure without complication), including:
  • Eggs or egg products
  • Soybeans, soy products, or soy lecithin
  • Peanuts or other legumes
  • History of anaphylaxis, angioedema, bronchospasm, or other serious allergic reaction to any of the above substances.
  • Known allergy or hypersensitivity to psilocybin or its metabolites.
  • History of severe lipid disorder or recent pancreatitis
  • Is taking a GLP-1 agonist class drug like tirzepatide, or has taken a dose within the past 7 days prior to propofol dosing.
  • Has symptomatic gastroesophageal reflux disease, or other delayed gastric emptying conditions.
  • Clinically significant kidney disease determined by creatinine/glomerular filtration rate within the past 6 months. Renal insufficiency (creatinine clearance < 40 ml/min using Cockraft and Gault equation)
  • Any endocrine disorder or any thyroid disorder treated (medically or surgically) within the past 6 months prior to screening:
  • Uncontrolled diabetes, type 1 or 2 (well-controlled diabetes is allowed).
  • Hyperthyroidism or hypothyroidism diagnosed within the past six months prior to screening (stable treatment with a thyroid hormone replacement therapy is allowed).
  • Other medical condition(s) or diagnosis, physical exam finding, EKG or laboratory abnormality that precludes participation in study procedures due to safety concerns at the discretion of the study staff.
  • -

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Dr. Boris Heifets, MD, PhD contact

4157161585

bheifets@stanford.edu

Dr. Pilleriin Sikka, PhD contact

sikka@stanford.edu

United States1 site

  • Stanford University

    Stanford, California, 94304

    Dr. Pilleriin Sikka, PhD, 6506808801, sikka@stanford.edu

    Dr. Boris Heifets, MD, PhD, bheifets@stanford.edu

Other trials in United States

About this study

Official title: A Phase 2 Randomized Study Examining the Safety, Feasibility, and Effectiveness of Masking Psilocybin Therapy With General Anesthesia in Major Depressive Disorder

Major depressive disorder (MDD) affects millions of Americans and remains difficult to treat. Psilocybin, a psychedelic compound, has shown promise for reducing depression symptoms, but a key challenge in psychedelic research is that participants can usually tell whether they received the active drug - making it hard to conduct fully blinded studies.

This study (Studying Psilocybin with Anesthesia Controlled by EEG [SPACE]) tests a new approach: administering psilocybin while participants are under general anesthesia, so that the noticeable psychological effects of psilocybin are masked. This allows both participants and outcome assessors to remain unaware of whether psilocybin or placebo was given, improving the scientific rigor of the research.

Participants with MDD will be randomly assigned to receive either psilocybin or placebo across four dosing sessions conducted under general anesthesia. The study will assess whether this approach is safe and feasible, and will collect early data on whether it may reduce depression symptoms.

Read the detailed description

Participants will receive four dosing sessions spaced one week apart. Each session involves taking an oral capsule containing either psilocybin (10 mg or 25 mg) or placebo, followed by general anesthesia with propofol.

All sessions take place at Stanford Hospital under the supervision of a board-certified anesthesiologist. Between and after sessions, participants complete questionnaires about mood, sleep, wellbeing, and anxiety. Participants may also wear a consumer-grade EEG headband at home to track sleep patterns.

The total study duration per participant is approximately 7 weeks, across around 25 visits, most of which are conducted remotely. Psilocybin is not FDA-approved and is administered under an FDA Investigational New Drug (IND) authorization for research purposes only.

Being tested
Psilocybin (Usona Institute), Propofol, Placebo
Keywords
psilocybin, major depressive disorder, anesthesia, propofol, psychedelic-assisted therapy, blinding, masking
Medical subject headings
Depressive Disorder, Major

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Psilocybin (Usona Institute)Drug

    Oral psilocybin capsules administered at doses not disclosed to participants to preserve blinding. Each dose is administered approximately 30 minutes prior to induction of general anesthesia with propofol. Participants receive psilocybin or placebo across four weekly dosing sessions.

  • PropofolDrug

    Intravenous propofol administered by a board-certified anesthesiologist to induce and maintain general anesthesia during each of the four dosing sessions. Propofol is co-administered with psilocybin or placebo to mask the psychoactive effects of psilocybin and enable participant blinding.

  • PlaceboDrug

    Oral placebo capsule identical in appearance to the psilocybin capsules, administered prior to induction of general anesthesia with propofol during one of the four dosing sessions.

Study groups in NCT07479550
Study groupRoleWhat they receive
Sequence AExperimentalParticipants are randomized 1:1 to one of two dosing sequences. All participants receive all four dosing conditions across weekly sessions: placebo (0 mg), psilocybin 10 mg, and psilocybin 25 mg administered in two separate sessions. Sequences differ only in the order of the first two sessions. Specific sequence assignments are not disclosed to preserve blinding.
Receives: Drug: Psilocybin (Usona Institute); Drug: Propofol; Drug: Placebo
Sequence BExperimentalParticipants are randomized 1:1 to one of two dosing sequences. All participants receive all four dosing conditions across weekly sessions: placebo (0 mg), psilocybin 10 mg, and psilocybin 25 mg administered in two separate sessions. Sequences differ only in the order of the first two sessions. Specific sequence assignments are not disclosed to preserve blinding.
Receives: Drug: Psilocybin (Usona Institute); Drug: Propofol; Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Blinding Success - Correct Identification of Psilocybin at Final Dosing Session

    Percentage of participants who correctly guess whether they received a full dose of psilocybin during the final dosing session (Visit 20), assessed using the Blinding Survey at Visit 21.

    Measured: 1 day after the final dosing session (Visit 21, Week 4)

  2. Blinding Success - Accuracy of Guessed Psilocybin Dose at Final Dosing Session

    The dose of psilocybin guessed by participants at Visit 21 compared to the dose actually received at Visit 20, assessed using the Blinding Survey.

    Measured: 1 day after the final dosing session (Visit 21, Week 4)

Secondary outcomes (3)

  1. Acute Drug Effects by Dose - Drug Effects Questionnaire (DEQ)

    Mean differences in acute subjective drug effects between psilocybin doses and placebo, assessed using the Drug Effects Questionnaire (DEQ; Morean et al., 2013) after emergence from anesthesia at each dosing session. The DEQ consists of 5 items rated on visual analog scales; scores are expressed as the mean across items. Minimum score: 0 (no drug effects); Maximum score: 100 (maximum drug effects). Higher scores indicate greater perceived drug effect.

    Measured: Immediately after emergence at each of the 4 dosing sessions (Visits 5, 10, 15, 20; Weeks 1-4)

  2. Mystical-Type Experiences by Dose - Mystical Experiences Questionnaire (MEQ-30)

    Mean changes in overall and subsection scores of the Mystical Experiences Questionnaire (MEQ-30; Maclean et al., 2012) compared between psilocybin doses and placebo, assessed after emergence from anesthesia at each dosing session. The MEQ-30 consists of 30 items rated on a 0-5 scale across four subscales: Mystical, Positive Mood, Transcendence of Time and Space, and Ineffability. Total scores are calculated by summing all individual items. Minimum score: 0 (no mystical-type experience); Maximum score: 150 (extreme mystical-type experience). Higher scores indicate greater mystical experience intensity.

    Measured: Immediately after emergence at each of the 4 dosing sessions (Visits 5, 10, 15, 20; Weeks 1-4)

  3. Altered States of Consciousness by Dose - Three-Dimensional Altered States of Consciousness Scale (3D-ASCr)

    Mean changes in overall and dimension scores of the Three-Dimensional Altered States of Consciousness Rating Scale - Revised (3D-ASCr; Stocker et al., 2025) compared between psilocybin doses and placebo, assessed after emergence from anesthesia at each dosing session. The 3D-ASCr consists of 42 items rated on visual analog scales, organized into three higher-order dimensions: Positive Effects (PosE), Distressing Effects (DisE), and Perceptual Effects (PerE). Dimension scores are calculated as means of their constituent subscale means. Minimum score: 0 (no alteration); Maximum score: 100 (maximum alteration). Higher scores indicate greater alteration of consciousness in each dimension; higher PosE scores reflect more positive experiential effects, higher DisE scores reflect more distressing effects, and higher PerE scores reflect greater perceptual effects.

    Measured: Immediately after emergence at each of the 4 dosing sessions (Visits 5, 10, 15, 20; Weeks 1-4)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Mar 2026
  2. Study startJul 2026 (estimated)
  3. Primary completionJul 2027 (estimated)
  4. Study completionAug 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Model description
This is a within-subject, randomized sequence crossover design. Each participant receives all four dosing conditions - placebo (0 mg), psilocybin 10 mg, and psilocybin 25 mg administered across two separate sessions - in a randomized order. Dosing sessions are spaced one week apart.
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
10 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07479550
Sponsor's protocol ID
72097
Acronym
SPACE
Status last verified
Apr 2026
First submitted
8 Mar 2026
Last updated
6 May 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No: Individual participant data will not be shared due to the small sample size (N=10) and the sensitive nature of the data collected, including psychiatric diagnoses, psychedelic drug administration, and detailed psychological assessments. Sharing IPD could compromise participant confidentiality. Aggregate findings will be reported in peer-reviewed publications.

Publications

  • Stocker K, Hartmann M, Schmid Y, Vogt SB, Becker AM, Ley L, Straumann I, Arikci D, Klaiber A, Erne L, Vizeli P, Holze F, Liechti ME. The 3D-ASCr scale: A revalidation of the core dimensions of the Altered States of Consciousness Rating Scale 5D(11)-ASC for psychedelic research. J Psychopharmacol. 2026 May;40(5):850-862. doi: 10.1177/02698811251397328. Epub 2025 Dec 26.

    PubMed 41451514

  • Maclean KA, Leoutsakos JM, Johnson MW, Griffiths RR. Factor Analysis of the Mystical Experience Questionnaire: A Study of Experiences Occasioned by the Hallucinogen Psilocybin. J Sci Study Relig. 2012 Dec;51(4):721-737. doi: 10.1111/j.1468-5906.2012.01685.x.

    PubMed 23316089

  • Yerubandi A, Thomas JE, Bhuiya NMMA, Harrington C, Villa Zapata L, Caballero J. Acute Adverse Effects of Therapeutic Doses of Psilocybin: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2024 Apr 1;7(4):e245960. doi: 10.1001/jamanetworkopen.2024.5960.

    PubMed 38598236

  • Johnson M, Richards W, Griffiths R. Human hallucinogen research: guidelines for safety. J Psychopharmacol. 2008 Aug;22(6):603-20. doi: 10.1177/0269881108093587. Epub 2008 Jul 1.

    PubMed 18593734

  • Lii TR, Smith AE, Flohr JR, Okada RL, Nyongesa CA, Cianfichi LJ, Hack LM, Schatzberg AF, Heifets BD. Randomized trial of ketamine masked by surgical anesthesia in patients with depression. Nat Ment Health. 2023 Nov;1(11):876-886. doi: 10.1038/s44220-023-00140-x. Epub 2023 Oct 19.

    PubMed 38188539

  • Szigeti B, Heifets BD. Expectancy Effects in Psychedelic Trials. Biol Psychiatry Cogn Neurosci Neuroimaging. 2024 May;9(5):512-521. doi: 10.1016/j.bpsc.2024.02.004. Epub 2024 Feb 20.

    PubMed 38387698

  • Aday JS, Heifets BD, Pratscher SD, Bradley E, Rosen R, Woolley JD. Great Expectations: recommendations for improving the methodological rigor of psychedelic clinical trials. Psychopharmacology (Berl). 2022 Jun;239(6):1989-2010. doi: 10.1007/s00213-022-06123-7. Epub 2022 Apr 1.

    PubMed 35359159

  • Carhart-Harris RL, Bolstridge M, Rucker J, Day CM, Erritzoe D, Kaelen M, Bloomfield M, Rickard JA, Forbes B, Feilding A, Taylor D, Pilling S, Curran VH, Nutt DJ. Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study. Lancet Psychiatry. 2016 Jul;3(7):619-27. doi: 10.1016/S2215-0366(16)30065-7. Epub 2016 May 17.

    PubMed 27210031

  • von Rotz R, Schindowski EM, Jungwirth J, Schuldt A, Rieser NM, Zahoranszky K, Seifritz E, Nowak A, Nowak P, Jancke L, Preller KH, Vollenweider FX. Single-dose psilocybin-assisted therapy in major depressive disorder: A placebo-controlled, double-blind, randomised clinical trial. EClinicalMedicine. 2022 Dec 28;56:101809. doi: 10.1016/j.eclinm.2022.101809. eCollection 2023 Feb.

    PubMed 36636296

  • Goodwin GM, Aaronson ST, Alvarez O, Arden PC, Baker A, Bennett JC, Bird C, Blom RE, Brennan C, Brusch D, Burke L, Campbell-Coker K, Carhart-Harris R, Cattell J, Daniel A, DeBattista C, Dunlop BW, Eisen K, Feifel D, Forbes M, Haumann HM, Hellerstein DJ, Hoppe AI, Husain MI, Jelen LA, Kamphuis J, Kawasaki J, Kelly JR, Key RE, Kishon R, Knatz Peck S, Knight G, Koolen MHB, Lean M, Licht RW, Maples-Keller JL, Mars J, Marwood L, McElhiney MC, Miller TL, Mirow A, Mistry S, Mletzko-Crowe T, Modlin LN, Nielsen RE, Nielson EM, Offerhaus SR, O'Keane V, Palenicek T, Printz D, Rademaker MC, van Reemst A, Reinholdt F, Repantis D, Rucker J, Rudow S, Ruffell S, Rush AJ, Schoevers RA, Seynaeve M, Shao S, Soares JC, Somers M, Stansfield SC, Sterling D, Strockis A, Tsai J, Visser L, Wahba M, Williams S, Young AH, Ywema P, Zisook S, Malievskaia E. Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression. N Engl J Med. 2022 Nov 3;387(18):1637-1648. doi: 10.1056/NEJMoa2206443.

    PubMed 36322843

  • Raison CL, Sanacora G, Woolley J, Heinzerling K, Dunlop BW, Brown RT, Kakar R, Hassman M, Trivedi RP, Robison R, Gukasyan N, Nayak SM, Hu X, O'Donnell KC, Kelmendi B, Sloshower J, Penn AD, Bradley E, Kelly DF, Mletzko T, Nicholas CR, Hutson PR, Tarpley G, Utzinger M, Lenoch K, Warchol K, Gapasin T, Davis MC, Nelson-Douthit C, Wilson S, Brown C, Linton W, Ross S, Griffiths RR. Single-Dose Psilocybin Treatment for Major Depressive Disorder: A Randomized Clinical Trial. JAMA. 2023 Sep 5;330(9):843-853. doi: 10.1001/jama.2023.14530.

    PubMed 37651119

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Psilocybin (Usona Institute) and Propofol in people with Major Depression, run by Stanford University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 27 inclusion and 48 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 6 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Dr. Boris Heifets, MD, PhD (4157161585, bheifets@stanford.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Blinding Success - Correct Identification of Psilocybin at Final Dosing Session (time frame: 1 day after the final dosing session (Visit 21, Week 4)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07479550, which also lists 11 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 May 2026; AzTrials last refreshed its copy on 31 Oct 2026.

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