BACKGROUND: Psychological distress is a common problem near the end of life, for which we lack effective, timely and scalable treatments. No previous study has assessed whether microdose psilocybin can improve symptoms in this population.
AIM: To determine whether microdose psilocybin is safe, feasible and potentially efficacious in a palliative setting.
DESIGN: Open label, single-arm clinical trial of a 3-week oral psilocybin intervention, starting with 1 mg daily in week 1, increased to 2 mg in week 2 and 3 mg in week 3.
CLINICALTRIALS: gov NCT04754061.
SETTING/PARTICIPANTS: Two-center study in Ottawa, Canada of adults with advanced, incurable illness and an estimated prognosis of 1-12 months, experiencing severe psychological distress.
RESULTS: We enrolled 20 participants (59% of those screened) between January 2024 and April 2025, of which 17 began and 13/17 (76%) completed the intervention. Participants were 40-84 years old, 53% female, and 82% had cancer. There were no serious adverse events reported, and nine mild or moderate adverse events. Four participants withdrew due to disease progression or poor response. Of the 13 remaining participants, nine (69%) reported a meaningful global improvement (Patient Global Impression of Change ⩾ 5); 8 (62%) reported >50% improvement in Hamilton Depression Rating Scale scores, 7 (54%) reported >50% improvement in Hospital Anxiety and Depression Scale scores and 9 (72%) reported a meaningful improvement in Demoralization Scale II scores.
CONCLUSIONS: Microdose psilocybin is a safe, feasible and potentially efficacious treatment for psychological distress in people with advanced illness.
