Psilocybin-Assisted Therapy for Cancer-Related Psychological and Existential Distress in Adults with Cancer: An Integrative Systematic Review
Athanasios Pitis, Maria Nikoloudi, Nikos C. Stefanis, Kyriaki Mystakidou
Journal of Pain & Palliative Care Pharmacotherapy November 3, 2026 DOI: 10.1080/15360288.2026.2756950 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Qualitative Peer reviewed |
|---|---|
| Population | Adults with cancer experiencing depression, anxiety, and existential distress |
| Intervention | Psilocybin-assisted therapy |
| Dose | 25-30 mg/70 kg |
| Duration | Benefits lasting 2-6 months, in some cases up to 4.5 years |
| Measures | Mixed Methods Appraisal Tool (MMAT) |
| Topics | End-of-life distress Psilocybin |
| Key findings | Across 11 reports from six clinical cohorts, psilocybin-assisted therapy was associated with rapid and enduring reductions in depression, anxiety, existential distress, and fear of death, with benefits lasting 2-6 months and in some cases up to 4.5 years. No psilocybin-related serious adverse events were reported, though transient cardiovascular changes, headache, nausea, anxiety, emotional distress, and occasional brief psychotic-like symptoms occurred. The authors conclude the approach may be promising but remains investigational. |
Abstract
Psilocybin-assisted therapy has reemerged as a promising intervention for distress associated with cancer and life-threatening illness. This integrative systematic review evaluated evidence on the safety, efficacy, and therapeutic impact of psilocybin-assisted therapy in adults with cancer experiencing depression, anxiety and existential distress. Following PRISMA guidelines, PubMed, Scopus, Google Scholar, and CINAHL databases were searched from 10 August 2025 to 31 October 2025. Eleven eligible reports derived from six independent clinical cohorts met inclusion criteria. Psilocybin was generally administered as a single supervised moderate-to-high dose (25-30 mg/70 kg), within structured preparation, dosing, and integration. Across all designs, psilocybin produced rapid and enduring reductions in depression, anxiety, existential distress, and fear of death, with benefits lasting 2-6 months and, in some cases, up to 4.5 years. Qualitative findings highlighted enhanced emotional clarity, acceptance, spiritual well-being, and reconnection with meaning. Five of the 11 reports met Mixed Methods Appraisal Tool (MMAT) criteria; concerns in others involved assessor blinding, representativeness, confounding control, or mixed-methods integration. No psilocybin-related serious adverse events were reported; transient cardiovascular changes, headache, nausea, anxiety or emotional distress, and occasional brief psychotic-like symptoms occurred. Psilocybin-assisted therapy may be promising but still investigational palliative pharmacotherapy-related intervention for cancer-related psychological and existential distress.
Comparable studies
Other systematic reviews and meta-analyses on psilocybin for end-of-life distress, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Evaluating the effectiveness of psilocybin in alleviating distress among cancer patients: A systematic review. Patients with life-threatening cancer | 2025 | Systematic review | |
| Psilocybin-assisted therapy for individuals with palliative care needs: A systematic review of safety and efficacy Adult participants in palliative care settings | 2025 | Systematic review | n = 74 |
Citations in the library
Cites 42
- Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial Journal of Psychopharmacology November 30, 2016
- Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial Journal of Psychopharmacology November 30, 2016
- The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs Frontiers in Human Neuroscience 2014
- Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder JAMA Psychiatry November 4, 2020
- Pilot Study of Psilocybin Treatment for Anxiety in Patients With Advanced-Stage Cancer Archives of General Psychiatry September 7, 2010
and 37 more in the library