Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial.
Level 2 - randomized trial
Double-blind, randomized, placebo-controlled crossover trial
PubMed 27909164 · doi:10.1177/0269881116675512
What was done
In a double-blind, placebo-controlled crossover trial, 29 patients with cancer-related anxiety and depression were randomized to receive single-dose psilocybin (0.3 mg/kg) or niacin, both delivered alongside psychotherapy. Primary outcomes compared anxiety and depression between groups prior to crossover at 7 weeks, with extended follow-up to 6.5 months.
What was found
Prior to crossover, psilocybin resulted in immediate and substantial improvements in anxiety, depression, cancer-related demoralization, hopelessness, spiritual well-being, and quality of life relative to niacin. At the 6.5-month follow-up, approximately 60–80% of participants maintained clinically significant reductions in depression or anxiety, with sustained improvements in existential distress, quality of life, and attitudes toward death. The therapeutic effect was mediated by the psilocybin-induced mystical experience. Exact numerical scores, standard deviations, and p-values were not reported in the abstract.
Why it matters
This study provides early randomized evidence that a single dose of psilocybin alongside psychotherapy can produce durable relief from psychiatric and existential distress in patients with life-threatening cancer.
Limits
The sample size was small (n = 29), and the abstract lacks exact numerical estimates, confidence intervals, and safety data. Crossover designs and the distinct psychoactive effects of psilocybin also pose substantial challenges for maintaining participant blinding despite active placebo control.
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.