60 Participants Needed
Centre for Addiction and Mental Health logo

Psilocybin for Depression

(PSI-RIS Trial)

MI
NL
AC
Overseen ByAlexandria Coles, MSc
No Placebo GroupAll trial participants will receive the active study treatment (no placebo)
Prior Safety DataThis treatment has passed at least one previous human trial
Approved in 2 JurisdictionsThis treatment is already approved in other countries

Trial Summary

What is the purpose of this trial?

This trial uses a magic mushroom substance and therapy to treat people with depression that hasn't improved with other treatments. It aims to understand if the mind-altering effects are needed for its antidepressant benefits. Psilocybin, a compound derived from magic mushrooms, has shown potential in early trials for treating depression with relatively low side effects.

Will I have to stop taking my current medications?

Yes, you will need to stop taking your current antidepressant and antipsychotic medications, as well as certain enzyme inhibitors, for at least two weeks before starting the trial and throughout its duration, if your doctor confirms it's safe for you to do so.

What data supports the effectiveness of the drug psilocybin for depression?

Several clinical trials have shown that psilocybin can reduce symptoms of depression, and it has been well tolerated with limited side effects. Some patients with treatment-resistant depression have experienced significant, long-term improvements after just one or a few sessions.12345

Is psilocybin generally safe for humans?

Psilocybin has been studied for its safety in humans, showing that it can be used safely under controlled conditions, although higher doses may pose risks. In healthy adults, escalating doses of psilocybin were generally well-tolerated, and extracts from magic mushrooms did not worsen certain heart conditions in lab studies.23678

How is the drug psilocybin different from other treatments for depression?

Psilocybin is unique because it is a naturally occurring compound found in certain mushrooms and acts quickly to reduce depression symptoms, often with just one or two doses, unlike traditional antidepressants that require prolonged use. It works by affecting serotonin receptors in the brain, which can lead to psychedelic experiences that may help in therapeutic settings.125910

Research Team

MI

Ishrat Husain, MD

Principal Investigator

Centre for Addiction and Mental Health

Eligibility Criteria

Adults aged 18-65 with treatment-resistant depression, defined as not responding to two or more antidepressants, can join this trial. They must be able to consent and communicate in English, have normal bloodwork, use effective contraception if applicable, and safely stop current medications affecting the study.

Inclusion Criteria

I can safely stop my antidepressant and antipsychotic meds for the study.
I am between 18 and 65 years old.
Able to provide informed consent and read and communicate in English
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Exclusion Criteria

I have a history of heart rhythm issues or risk factors for it.
I do not have a severe heart, kidney, liver condition, or an allergy to psilocybin.
Have a DSM-5 diagnosis of substance use disorder (recreational use of tobacco, alcohol, cannabis and prescribed opioids are permitted) within the preceding 6-months
See 9 more

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks
1 visit (in-person)

Washout

Participants undergo a washout period where they are tapered off concomitant medication over a period of 4 to 6 weeks.

4-6 weeks
Weekly visits (in-person)

Baseline

Participants complete clinical measures and undergo a preparatory session with study therapists.

Up to 7 days
1-2 visits (in-person)

Treatment

Participants receive psilocybin 25 mg plus risperidone 1 mg, or psilocybin 25 mg plus placebo, or placebo plus risperidone 1 mg during a 5-6 hour dosing session.

1 day
1 visit (in-person)

Integration

Participants attend two 1-hour integration sessions post-dosing.

1 week
2 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment.

4 weeks
3 visits (in-person)

Treatment Details

Interventions

  • Psilocybin
Trial OverviewThe trial is testing whether psilocybin's effects on depression require its psychedelic aspect by comparing three groups: one taking psilocybin with risperidone (which may block psychedelic effects), another taking psilocybin with a placebo, and a third group receiving placebo plus risperidone.
Participant Groups
3Treatment groups
Experimental Treatment
Active Control
Group I: Risperidone 1 mg plus Psilocybin 25 mgExperimental Treatment2 Interventions
Risperidone 1 mg plus Psilocybin 25 mg
Group II: Placebo plus Psilocybin 25 mgExperimental Treatment2 Interventions
Placebo plus Psilocybin 25 mg
Group III: Risperidone 1 mg plus PlaceboActive Control2 Interventions
Risperidone 1 mg plus Placebo

Psilocybin is already approved in United States, European Union for the following indications:

🇺🇸
Approved in United States as Psilocybin for:
  • Treatment-resistant depression (TRD) under Breakthrough Therapy designation
🇪🇺
Approved in European Union as Psilocybin for:
  • Treatment-resistant depression (TRD) under PRIME designation

Find a Clinic Near You

Who Is Running the Clinical Trial?

Centre for Addiction and Mental Health

Lead Sponsor

Trials
388
Recruited
84,200+

Findings from Research

Psilocybin has shown promise in clinical trials for reducing symptoms of depression, indicating its potential as a novel treatment option.
Patients with treatment-resistant depression (TRD) may benefit the most from psilocybin therapy, although the risks associated with its use are still not fully understood.
Assessing potential of psilocybin for depressive disorders.Kozak, Z., Johnson, MW., Aaronson, ST.[2023]
Psilocybin, a hallucinogenic compound found in certain mushrooms, has been associated with increasing rates of drug abuse, highlighting the need for comprehensive pharmacological understanding.
Despite its historical use in the 1960s for experimental medical purposes, recent research has only begun to uncover the pharmacological properties of psilocybin, indicating a gap in knowledge that needs to be addressed.
The pharmacology of psilocybin.Passie, T., Seifert, J., Schneider, U., et al.[2016]
In a study involving 12 healthy adults, escalating doses of psilocybin (0.3, 0.45, and 0.6 mg/kg) were administered safely, with no serious adverse events reported, indicating a favorable safety profile for this psychedelic compound.
The pharmacokinetics of psilocin, the active metabolite of psilocybin, were linear across the tested doses, with an elimination half-life of about 3 hours, suggesting that no dose adjustments are necessary for individuals with mild to moderate renal impairment.
Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults.Brown, RT., Nicholas, CR., Cozzi, NV., et al.[2022]

References

Assessing potential of psilocybin for depressive disorders. [2023]
The pharmacology of psilocybin. [2016]
Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults. [2022]
[Treatment with psilocybin: applications for patients with psychiatric disorders]. [2021]
Single-dose psilocybin-assisted therapy in major depressive disorder: A placebo-controlled, double-blind, randomised clinical trial. [2023]
[Hallucinogenic mushrooms]. [2018]
Intravenous mushroom poisoning. [2019]
Effects and safety of Psilocybe cubensis and Panaeolus cyanescens magic mushroom extracts on endothelin-1-induced hypertrophy and cell injury in cardiomyocytes. [2021]
A Proposal to Study the Safety and Efficacy of Psilocybe cubensis in Preclinical and Clinical Studies as a Therapeutic Alternative for Major Depressive Disorder. [2023]
10.United Statespubmed.ncbi.nlm.nih.gov
Structure-Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice. [2023]