Effects of Repeated Psilocybin Dosing in OCD

Effects of Repeated Dosing of Psilocybin on Obsessive-Compulsive Disorder: A Randomized, Waitlist-Controlled Study

This study aims to investigate the effects of repeated dosing of oral psilocybin on obsessive-compulsive disorder (OCD) symptomatology in a randomized, waitlist-controlled design with blinded independent ratings, and assess psychological mechanisms that may mediate psilocybin's therapeutic effects on OCD.

Study Overview

• Status: Recruiting
• Conditions: Obsessive-Compulsive Disorder
• Intervention / Treatment: Drug: Psilocybin

Detailed Description

Aim 1: To examine the effects of two doses of psilocybin on OCD symptoms among participants in the immediate treatment condition, compared to participants in the waitlist control/delayed treatment condition. The investigators hypothesize that participants in the immediate treatment group will report statistically significantly greater symptom improvement from baseline 4 days post-second dose, compared to participants in the waitlist control/delayed treatment group at the same interval during their waitlist phase.

Aim 2: To examine the effects of two doses of psilocybin on OCD symptoms, compared to one dose. The investigators hypothesize that two doses of oral psilocybin will reduce OCD symptoms to a statistically significantly greater extent than one dose.

This study aims to investigate the effects of repeated dosing of oral psilocybin on OCD symptomatology and assess psychological mechanisms that may mediate psilocybin's therapeutic effects on OCD. This study will employ a randomized, waitlist-controlled design with blinded independent ratings, with participants randomized to receive either immediate treatment (two doses oral psilocybin separated by one week) or delayed treatment (7 weeks post-randomization). An adaptive dose selection strategy will be implemented, with the first dose being standardized at 25 mg of psilocybin, and the second dose being either the same or a higher dosage (i.e., 30 mg) on the basis of a clinically significant response from baseline or not, respectively, 4 days post-first dose.

This study is conducted entirely on an outpatient basis with the possibility of remote/virtual follow-up visits after each dosing session. The dosing sessions last the entire day, and participants will be medically cleared prior to being permitted to return home with assistance (e.g., driven by a family member or friend, or ride share).

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Terence Ching, PhD; Phone Number: (203) 974-7731; Email: terence.ching@yale.edu

Study Locations

• United States
  • Connecticut
    • New Haven, Connecticut, United States, 06519
      • Recruiting
      • Connecticut Mental Health Center
      • Principal Investigator: Benjamin Kelmendi, MD
      • Principal Investigator: Terence Ching, PhD
      • Contact: Terence Ching, PhD; Phone Number: 203-974-7731; Email: terence.ching@yale.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Primary DSM-5 diagnosis of OCD, with Y-BOCS-II score of 26 or greater at screening
2. Failed at least one medication and/or therapy trial of standard care treatment for OCD
3. English fluency
4. Agree to sign a medical release for investigators to communicate directly with participants' providers to confirm medication and psychotherapy histories or arrange contingencies in event of crises.
5. Agree to provide an adult contact (relative, spouse, close friend or other caregiver) who is willing and able to be reached by the PI and/or study personnel in the event of an emergency, and who can provide transportation for study visits and independently comment on any changes in the participant's mood or behavior after each administration of psilocybin.
6. Agree to commit to all study procedures.
7. Ability to orally ingest pills for psilocybin dosing visits.
8. Agree to adhere to lifestyle and medication modifications.
9. Must not be on psychotropic medications for OCD or comorbid psychiatric conditions for at least 8 weeks at the time of randomization, and agree to refrain from taking or starting any psychiatric medications until after 4 weeks post-second dose.
10. Must not be in current psychotherapy (CBT or ERP) and must not start new course of psychotherapy (CBT or ERP) for OCD or comorbid psychiatric conditions until after 4 weeks post-second dose.
11. If participant is of childbearing potential, must have a negative pregnancy test at study entry and prior to each dosing session.
12. If participant is of childbearing potential, agree to use adequate birth control and not attempt to become pregnant during study up to 4 weeks post-second dose.

Exclusion Criteria:

1. Personal or immediate (first-degree relative) family history of formally diagnosed schizophrenia or other psychotic disorders, or bipolar I/II disorder
2. Lack of knowledge about biological families' medical history, due to adoption or other circumstance
3. Active suicidal intent or suicidal or non-suicidal self-injurious behaviors
4. Unremitted Tourette syndrome
5. Lifetime diagnosis of autism spectrum disorder
6. Current substance use disorder (except for mild alcohol use disorder)
7. Any neurological condition, including history of seizure(s) or chronic/severe headaches
8. Any history of head injury with loss of consciousness for more than 30 min
9. Any use of classic psychedelic substances within the prior 12 months
10. Unwillingness to abstain from use of classic psychedelics outside of the study up to 4 weeks post-second dose.
11. Use of tobacco products or a THC-containing product more than 2 times per week on average over the past 30 days at screening.
12. Unwilingness or inability to abstain from use of tobacco or THC-containing products from 1 week prior to randomization up to 4 weeks post-second dose.
13. Positive urine drug test for any prohibited substance at screening or days of dosing, or positive breathalyzer test for alcohol on days of dosing
14. Unwillingness or inability to abstain from alcohol use at least 24 hours prior to the days of dosing, up to 24 hours after each dosing day (or corresponding intervals for waitlist group).
15. Any medical conditions that may render study procedures unsafe, including hypertension, history of cardiovascular disease, moderate-to-severe hepatic or renal impairment, diabetes, and hypo- or hyperthyroidism.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Immediate Treatment; Participants randomized to this condition will receive treatment immediately, facilitated by two study staff members, and which consists of two preparatory sessions, followed by the first dosing session and two integration sessions, then the second dosing session and two integration sessions. This is followed by follow-up and long-term follow-up visits up to 12 months post-second dose.	Drug: Psilocybin; The first oral dose will be 25 mg, and the second dose will be either 25 mg or 30 mg, depending on response to first dose. Psilocybin is a naturally occurring hallucinogenic ingredient found in some varieties of mushrooms that can be produced synthetically. It is considered to be a serotonergic psychedelic. We will use synthetically produced oral psilocybin in this study. Other Names: "Magic Mushrooms"
No Intervention: Waitlist Control/Delayed Treatment; Participants randomized to this condition will first enter a waitlist phase that lasts for 7 weeks, after which rater unblinding will occur, and participants will be rescreened. If participants remain eligible at this time, they will begin their treatment phase. During their treatment phase, participants in this condition will receive the same treatment as described for participants in the immediate treatment group. This is followed by follow-up and long-term follow-up visits up to 12 months post-second dose.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Yale-Brown Obsessive-Compulsive Scale-Second Edition (Y-BOCS-II) Severity Scale total score from baseline at 4 days post-second dose	Clinician-administered assessment of severity of OCD symptoms over the past seven days. The most prominent obsessions and compulsions are rated on the Severity Scale from 0 to 4. Total Y-BOCS-II scores range from 0 to 40, with higher scores indicating greater severity of OCD symptoms.	Baseline & 4 days post-second dose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Montgomery-Asberg Depression Scale (MADRS) total score from baseline at 4 days post-second dose	Clinician-administered assessment of severity of depressive symptoms over past month. Total scores range from 0 to 60, with higher scores indicating greater severity of depressive symptoms.	Baseline & 4 days post-second dose
Change in Dimensional Obsessive-Compulsive Scale (DOCS) total score from baseline at 4 days post-second dose	Self-report measure of various OCD symptoms over the modified time frame of the past week. Total scores range from 0 to 140, with higher scores indicating greater severity of OCD symptoms.	Baseline & 4 days post-second dose
Change in Obsessive Beliefs Questionnaire-44 (OBQ-44) total score from baseline at 4 days post-second dose	Self-report measure of various obsessive beliefs implicated in OCD in general. Total scores range from 44 to 308, with higher scores indicating greater severity of obsessive beliefs.	Baseline & 4 days post-second dose
Change in Acceptance and Action Questionnaire for Obsessions and Compulsions (AAQ-OC) total score from baseline at 4 days post-second dose	Self-report measure of experiential avoidance and psychological flexibility in the context of OCD symptoms in general. Total scores range from 13 to 91, with higher scores indicating greater psychological inflexibility.	Baseline & 4 days post-second dose
Change in Tolerance of Uncontrollability Questionnaire (TOUQ) total score from baseline at 4 days post-second dose	Self-report measure of ability to tolerate uncontrollability (or inversely need for control) in general. Total scores range from 19 to 133, with higher scores indicating greater tolerance of uncontrollability.	Baseline & 4 days post-second dose
Change in White Bear Suppression Inventory (WBSI) total score from baseline at 4 days post-second dose	Self-report measure of thought suppression tendencies in general. Total scores range from 15 to 75, with higher scores indicating stronger thought suppression tendencies.	Baseline & 4 days post-second dose
Change in Difficulties in Emotion Regulation Scale (DERS) total score from baseline at 4 days post-second dose	Self-report measure of emotion regulation difficulties in general. Total scores range from 36 to 180, with higher scores indicating greater difficulties with regulating emotions.	Baseline & 4 days post-second dose
Change in Southampton Mindfulness Questionnaire (SMQ) total score from baseline at 4 days post-second dose	Self-report measure of trait mindfulness in regards to distressing thoughts and images. Total scores range from 0 to 96, with higher scores indicating greater trait mindfulness.	Baseline & 4 days post-second dose
Toronto Mindfulness Scale (TMS)	Self-report measure of state mindfulness during dosing session. Total scores range from 0 to 52, with higher scores indicating greater state mindfulness.	Up to 3 weeks for immediate treatment condition, and up to 10 weeks for waitlist condition
Set, Setting, and Intentions (SSI) Scale	Self-report measure of set, setting, and clarity of intentions just prior to dosing session. Total mean scores range from 0 to 100 (after reverse-scoring two items), with higher scores indicating greater preparedness for the dosing session.	Up to 3 weeks for immediate treatment condition, and up to 10 weeks for waitlist condition
Mystical Experience Questionnaire (MEQ)	Self-report measure of acute mystical experiences during dosing. Total mean scores range from 0 to 5, with higher scores indicating greater mystical experiences.	Up to 3 weeks for immediate treatment condition, and up to 10 weeks for waitlist condition
Psychological Insight Questionnaire (PIQ)	Self-report measure of acute psychological insights during dosing. Total mean scores range from 0 to 5, with higher scores indicating greater insightful experiences.	Up to 3 weeks for immediate treatment condition, and up to 10 weeks for waitlist condition
Challenging Experience Questionnaire (CEQ)	Self-report measure of acute challenging experiences during dosing. Total mean transformed scores range from 0 to 1, with higher scores indicating greater challenging experiences.	Up to 3 weeks for immediate treatment condition, and up to 10 weeks for waitlist condition
Ego Dissolution Inventory (EDI)	Self-report measure of acute experiences of ego dissolution during dosing. Total mean scores range from 0 to 100, with higher scores indicating greater ego dissolution.	Up to 3 weeks for immediate treatment condition, and up to 10 weeks for waitlist condition
Emotional Breakthrough Inventory (EBI)	Self-report measure of different experiences of emotional breakthroughs during dosing. Total mean scores range from 0 to 100, with higher scores indicating greater emotional breakthrough.	Up to 3 weeks for immediate treatment condition, and up to 10 weeks for waitlist condition
Change in Self-Compassion Scale (SCS) total mean score from baseline at 4 days post-second dose	Self-report measure of self-compassion in general. Total mean scores range from 1 to 5 (after reverse-scoring 13 items), with higher scores indicating greater self-compassion.	Baseline & 4 days post-second dose
Change in Ten-Item Personality Inventory (TIPI) total score from baseline at 4 days post-second dose	Brief self-report measure of Big Five personality dimensions. Total scores range from 10 to 70 (after reverse-scoring 5 items), with higher scores indicating more positive personality traits.	Screening, 4 days and 12 months post-second dose
Change in Persisting Effects Questionnaire (PEQ) subscale scores from 4 weeks post-second dose at 12 months post-second dose	Self-report measure of persisting effects from dosing in general. Subscale scores range from a minimum of 0 to a maximum of 5 to 85, with higher scores indicating greater positive or negative persisting changes since dosing.	4 weeks post-second dose & 12 months post-second dose
Change in Alcohol Use Disorders Identification Test (AUDIT) total score from baseline at 4 weeks post-second dose	Self-report measure of alcohol use severity. Total scores range from 0 to 40, with higher scores indicating greater alcohol use severity.	Baseline & 4 weeks post-second dose
Change in Drug Use Disorders Identification Test (DUDIT) total score from baseline at 4 weeks post-second dose	Self-report measure of illicit substance use. Total scores range from 0 to 44, with higher scores indicating greater illicit substance use severity.	Baseline & 4 weeks post-second dose
Change in Fagerstrom Test for Nicotine Dependence (FTND) total score from baseline at 4 weeks post-second dose	Self-report measure of nicotine use. Total scores range from 0 to 10, with higher scores indicating greater nicotine use severity.	Baseline & 4 weeks post-second dose
Change in Quality of Life Enjoyment & Satisfaction Questionnaire - Short Form (Q-LES-Q-SF) percentage maximum score from baseline at 4 days post-second dose	Self-report measure of life satisfaction over the past week. Percentage maximum scores range from 0% to 100%, with higher percentages indicating greater life satisfaction.	Baseline & 4 weeks post-second dose
Writing task	Online writing task in which participants describe their perceptions of their OCD symptoms with a short written essay	Baseline & 4 days post-second dose
Columbia Suicide Severity and Risk Scale (C-SSRS) Since Last Visit version	Clinician-administered assessment of suicidal ideation and behaviors since the last study visit	Every study visit through study completion, an average of 12 months and 3 weeks for immediate treatment condition, and an average of 12 months and 10 weeks for waitlist condition
Theoretical Orientation Profile Scale-Revised (TOPS-R)	Clinician-reported measure of theoretical orientation over 11 subscales, each corresponding to a different theoretical orientation. Subscale scores range from 1 to 30, with higher scores indicating greater affiliation with a particular theoretical orientation.	Baseline
Working Alliance Inventory-Short Revised (WAI-SR)	Self-report measure of perceived working alliance with study clinicians. Total scores range from 0 to 60, with higher scores indicating stronger perceived working alliance.	Up to 4 days post-second dose
Change in Symptom Provocation Task (SPT) ratings from baseline at 4 days post-second dose	Behavioral measure of OCD symptoms when provoked with idiosyncratic questions. Scores for compulsive urges range from 0-10 in terms of VAS ratings, with higher VAS ratings indicating greater compulsive urges.	Baseline & 4 days post-second dose
Stanford Expectations of Treatment Scale (SETS)	Self-report measure of treatment expectancy over 2 subscales, corresponding to positive and negative expectancy. Subscale scores range from 7 to 21, with higher scores indicating more positive or negative expectancy.	Baseline
Change in World Health Organization Disability Assessment Scale, v2.0 (WHODAS-2.0) 12-item, self-administered version total score from baseline at 4 days post-second dose	Self-report measure of symptom-related functional impairment in general. Total scores range from 12 to 60, with higher scores indicating greater functional impairment.	Baseline & 4 weeks post-second dose

Collaborators and Investigators

• Sponsor: Yale University
• Collaborators: Steven & Alexandra Cohen Foundation
• Investigators: Principal Investigator: Terence Ching, PhD, Yale University; Principal Investigator: Benjamin Kelmendi, MD, Yale University; Study Director: Christopher Pittenger, MD, PhD, Yale University

Publications and helpful links

General Publications

• Griffiths RR, Johnson MW, Carducci MA, Umbricht A, Richards WA, Richards BD, Cosimano MP, Klinedinst MA. Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial. J Psychopharmacol. 2016 Dec;30(12):1181-1197. doi: 10.1177/0269881116675513.
• Ross S, Bossis A, Guss J, Agin-Liebes G, Malone T, Cohen B, Mennenga SE, Belser A, Kalliontzi K, Babb J, Su Z, Corby P, Schmidt BL. Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial. J Psychopharmacol. 2016 Dec;30(12):1165-1180. doi: 10.1177/0269881116675512.
• Moreno FA, Wiegand CB, Taitano EK, Delgado PL. Safety, tolerability, and efficacy of psilocybin in 9 patients with obsessive-compulsive disorder. J Clin Psychiatry. 2006 Nov;67(11):1735-40. doi: 10.4088/jcp.v67n1110.
• Davis AK, Barrett FS, May DG, Cosimano MP, Sepeda ND, Johnson MW, Finan PH, Griffiths RR. Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder: A Randomized Clinical Trial. JAMA Psychiatry. 2021 May 1;78(5):481-489. doi: 10.1001/jamapsychiatry.2020.3285. Erratum In: JAMA Psychiatry. 2021 Feb 10;:

Study record dates

Study Major Dates

• Study Start (Actual): July 20, 2023
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2027

Study Registration Dates

• First Submitted: April 19, 2022
• First Submitted That Met QC Criteria: May 6, 2022
• First Posted (Actual): May 12, 2022

Study Record Updates

• Last Update Posted (Actual): January 3, 2024
• Last Update Submitted That Met QC Criteria: January 2, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: Psilocybin
• Additional Relevant MeSH Terms: Mental Disorders; Personality Disorders; Anxiety Disorders; Compulsive Personality Disorder; Obsessive-Compulsive Disorder; Physiological Effects of Drugs; Psychotropic Drugs; Hallucinogens; Psilocybin
• Other Study ID Numbers: 2000032623

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No