Positive Effects of Single-Dose Psilocybin Last Nearly 5 Years

After 4.5 years, 60-80% of the study participants with life-threatening cancer still experienced significantly decreased anxiety or antidepressant effects.


A January 2020 follow-up study published in the Journal of Psychopharmacology reveals the long-lasting beneficial effects of single-dose psilocybin in people with life-threatening cancer.1 This study follows up a 2016 single-dose (0.3 mg/kg), double-blind, placebo-controlled, crossover trial of 29 patients with cancer-related anxiety and depression.2

The Original 2016 Psilocybin Study

Data from the 2016 study indicated that 60-80% of the participants experienced significant antidepressant and anxiolytic (decreased anxiety) effects at their 6.5-month follow-up. They also had beneficial changes in existential stress, quality of life, and attitudes toward death. The data also showed that the mystical experience induced by psilocybin mediated the therapeutic effects.

Results of the Current Follow-Up Psilocybin Study

The current study followed up approximately 3.2 and 4.5 years later, with 15 of the 16 participants who were still alive. At 4.5 years, 60-80% still reported clinically significant antidepressant and anxiolytic effects. They also experienced reduced hopelessness, demoralization, and death anxiety. An overwhelming majority (71-100%) of the participants said that their psilocybin-assisted psychotherapy (PcbAP) experience was responsible for the positive changes. They also “rated it among the most personally meaningful and spiritually significant experiences of their lives.”

Researcher Calls the Results “Mind-Boggling”

Dr. Stephen Ross is Director of Addiction Psychiatry at New York University’s Langone Medical Center. He led the original 2016 psilocybin study in 29 cancer patients. Dr. Ross told NBC News in a recent interview that the follow-up study results are,

Mind-boggling. Psilocybin-assisted therapy appears to both work rapidly and have a sustained benefit for years. If other studies support that, the implication is potentially huge for cancer patients.

Reducing Depression and Anxiety in Cancer Patients

Cancer patients often experience depression and anxiety, which can affect their mental and physical health. It can even be fatal. A 2011 study found that 30-40% of cancer patients have mood disorders regardless of whether they are receiving palliative care.3 Dr. Ross told NBC News that the anxiety and depression experienced by cancer patients and survivors of cancer is,

Very common and very consequential. Distress increases rates of suicide and decreases rates of survival by impairing the immune system.

Barb Bauer Headshot

Barb is the former Editor and one of the founders of Psychedelic Science Review. She is currently a contributing writer. Her goal is making accurate and concise psychedelic science research assessable so that researchers and private citizens can make informed decisions.


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  1. Agin-Liebes GI, Malone T, Yalch MM, et al. Long-term follow-up of psilocybin-assisted psychotherapy for psychiatric and existential distress in patients with life-threatening cancer. J Psychopharmacol. 2020;34(2):155-166. doi:10.1177/0269881119897615
  2. Ross S, Bossis A, Guss J, et al. 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. 2016;30(12):1165-1180. doi:10.1177/0269881116675512
  3. Mitchell AJ, Chan M, Bhatti H, et al. Prevalence of depression, anxiety, and adjustment disorder in oncological, haematological, and palliative-care settings: a meta-analysis of 94 interview-based studies. The Lancet Oncology. 2011;12(2):160-174. doi:10.1016/S1470-2045(11)70002-X