Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial

TLDR

Clinically significant anxiety and depression are common in cancer patients and worsen psychiatric and medical outcomes, and prior research suggests psilocybin may help. In a double‑blind, placebo‑controlled crossover trial, 29 cancer patients received a single 0.3 mg/kg dose of psilocybin or niacin alongside psychotherapy, with anxiety and depression measured at 7 weeks. Psilocybin produced immediate, substantial, and sustained reductions in anxiety and depression, improved quality of life and spiritual wellbeing, and at 6.5 months still yielded 60–80 % clinically significant improvements, with the mystical experience mediating the effect. Trial registered at ClinicalTrials.gov (NCT00957359).

Abstract

Background: Clinically significant anxiety and depression are common in patients with cancer, and are associated with poor psychiatric and medical outcomes. Historical and recent research suggests a role for psilocybin to treat cancer-related anxiety and depression. Methods: In this double-blind, placebo-controlled, crossover trial, 29 patients with cancer-related anxiety and depression were randomly assigned and received treatment with single-dose psilocybin (0.3 mg/kg) or niacin, both in conjunction with psychotherapy. The primary outcomes were anxiety and depression assessed between groups prior to the crossover at 7 weeks. Results: Prior to the crossover, psilocybin produced immediate, substantial, and sustained improvements in anxiety and depression and led to decreases in cancer-related demoralization and hopelessness, improved spiritual wellbeing, and increased quality of life. At the 6.5-month follow-up, psilocybin was associated with enduring anxiolytic and anti-depressant effects (approximately 60–80% of participants continued with clinically significant reductions in depression or anxiety), sustained benefits in existential distress and quality of life, as well as improved attitudes towards death. The psilocybin-induced mystical experience mediated the therapeutic effect of psilocybin on anxiety and depression. Conclusions: In conjunction with psychotherapy, single moderate-dose psilocybin produced rapid, robust and enduring anxiolytic and anti-depressant effects in patients with cancer-related psychological distress. Trial Registration: ClinicalTrials.gov Identifier: NCT00957359