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For people with

Persistent depression

When you have tried many ways to feel better, and still don’t feel like yourself.

If low mood continues to affect your daily life despite therapy, medication or other approaches, you are not alone. ONCE offers a carefully structured psilocybin-assisted pathway with professional screening, clinical support and integration.

Start a confidential preliminary assessment
  • Professional screening
  • Supervised access in Amsterdam
  • No promises, no hype

The ONCE pathway is not a replacement for medical or mental-health care.

A man sitting in an armchair by a window at dusk, looking out over Amsterdam canal houses

You might be in the right place if:

You have tried several approachesTherapy, medication or other approaches that did not bring enough relief.
Low mood limits your lifeIt affects your mood, energy, motivation, relationships or work.
You are looking for a new optionA structured approach with professional support and integration.
You want a professionally supported pathway in AmsterdamWith professional screening and clinical oversight at every step.

About the ONCE pathway

ONCE is a professionally supported pathway that combines psilocybin-assisted sessions with psychological preparation and integration.

It is not a treatment and makes no promise of a particular result. The pathway is built around carefully structured access, professional support and evidence-informed practices.

Everyone begins with a confidential preliminary assessment to help understand your situation and whether this pathway may be appropriate for you.

  • Individual assessmentYou share what brings you here. We look at your mental and physical health, approaches you have tried, and what you hope this process might support.
  • Professional reviewQualified clinicians review your summary to consider suitability and risk. You may be invited for a screening conversation.
  • Preparation & in-person daysIf the pathway is appropriate, you continue with preparation, your in-person session in Amsterdam, and integration support afterwards.
  • Integration & follow-upYou are not alone after the experience. We support you in making sense of it and relating it to everyday life.
Learn how the pathway works

What research suggests

In controlled academic studies, some participants with persistent depressive symptoms reported meaningful improvement after psilocybin-assisted sessions, including people who had not found enough relief with other approaches.

Results vary between individuals and study populations. It is not possible to predict how any one person will respond.

See evidence and sources
50–70%of participants in some clinical studies of treatment-resistant depression responded to psilocybin-assisted therapy.Figure pending source verification
30–40%of participants reached remission (sustained improvement) in several clinical studies.Figure pending source verification

Research is evolving. ONCE does not promise specific outcomes.

Curious if this pathway could be relevant for you?

Start a confidential preliminary assessment

Takes about 4 minutes. You read your full summary before any contact details are requested.