Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial.
Level 2 - randomized trial
Individual randomized double-blind crossover trial
PubMed 27909165 · doi:10.1177/0269881116675513
What was done
A randomized, double-blind, cross-over trial in 51 patients with life-threatening cancer diagnoses and symptoms of depression or anxiety. Participants received a very low placebo-like dose (1 or 3 mg/70 kg) versus a high dose (22 or 30 mg/70 kg) of psilocybin in a counterbalanced sequence with 5 weeks between sessions and a 6-month follow-up. Participant moods, attitudes, and behaviors were rated by participants, clinical staff, and community observers.
What was found
High-dose psilocybin resulted in large decreases in clinician- and self-rated depressed mood and anxiety, reduced death anxiety, and increased quality of life, optimism, and life meaning. At the 6-month follow-up, about 80% of participants maintained clinically significant decreases in depressed mood and anxiety, and over 80% reported moderately or greater increased well-being or life satisfaction. A mystical-type psilocybin experience on the session day mediated the therapeutic effects. Exact numerical scores, effect sizes, and p-values were not provided in the abstract.
Why it matters
This trial demonstrates that a single high dose of psilocybin can produce rapid, clinically meaningful, and durable relief from cancer-related anxiety and depression. It provides foundational evidence for psychedelic-assisted therapy in palliative and psycho-oncology care.
Limits
The sample size was relatively small (51 participants) from a single study population. Blinding may have been compromised by the distinct subjective effects of the high dose compared to the very low dose. Specific statistical parameters and adverse events were omitted from the abstract.
Cited by
- supports Studies by Roland Griffiths and Stephen Ross showed that a single administration of psilocybin produced antidepressant and anxiolytic responses lasting six months or longer in cancer patients.