Study of Psilocybin Under Anesthesia Controlled by EEG

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 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.

Timeline

Start

2026-07

Primary completion

2027-07

Completion

2027-08

Publications

• Background 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.
• Background 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.
• Background 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.
• Background 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.
• Background 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.
• Background 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.
• Background 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.
• Background 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.
• Background 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.
• Background 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.
• Background 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.

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