Psilocybin-Assisted Psychotherapy for Treatment-Resistant Depression: Comparing One Versus Two Doses of Psilocybin (PSI-1V2)

This interventional trial (n=92) aims to evaluate the efficacy and safety of Psilocybin-Assisted Psychotherapy (PAP/PAT, 25mg, 2x) involving family members in adults with treatment-resistant major depressive disorder (TRMDD).

Participants will be divided into two groups: one group receiving PAT involving family members and another with PAT conducted solely with therapists. Each participant will receive two doses of 25 mg of psilocybin three weeks apart.

The primary outcome, measured using the Hamilton Depression Rating Scale (HDRS) and the Montgomery–Åsberg Depression Rating Scale (MADRS), will be assessed 12 months following the last psychotherapy session.

This trial aims to determine whether one or two doses of psilocybin are more effective in relieving depressive symptoms in patients with treatment-resistant depression. The primary objective is to assess antidepressant efficacy by measuring the change in MADRS score between baseline and Week 8.

Safety and tolerability will also be evaluated. The trial is being conducted by the University Health Network, Toronto, and is currently recruiting participants aged 18 to 65 years old who meet specific criteria for major depressive disorder.

The estimated primary completion date is February 2028, with an estimated enrollment of 92 participants.

This trial is also registered with Health Canada.

Topic Depression Treatment-Resistant Depression Safety
Compound Psilocybin
Country Canada
Visit trial
Status Recruiting
Results Published No
Start date 05 February 2024
End date 01 August 2028
Phase Phase II
Design Blinded
Type Interventional
Generation First
Participants 92
Sex All
Age 18- 65
Therapy Yes

Trial Details

The purpose of this study is to see if one or two doses of psilocybin is more effective in relieving depressive symptoms in patients with treatment-resistant depression (TRD). Researchers also want to know if a second dose of psilocybin is safe and well-tolerated. This study will see if psilocybin is effective, safe, and well-tolerated by tracking changes in depressive symptoms, suicidality, and side effects. This study will also see if a second dose of psilocybin has an effect on quality of life, functioning, cognition (thinking, reasoning, remembering), and how long depressive symptoms improve (or worsen) after psilocybin is administered.

NCT Number NCT06341426

Sponsors & Collaborators

University Health Network Toronto
University Health Network is a public research and teaching hospital network in Toronto. The Nikean Psychedelic Psychotherapy Research Centre was established in 2021.

Data attribution

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