Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial

Summary & key facts

Researchers gave 51 people with life-threatening cancer and serious depression or anxiety two guided psilocybin sessions: one with a very low dose and one with a high dose, spaced five weeks apart. The high dose led to large drops in doctor-rated and self-rated depression and anxiety, and brought lasting gains in quality of life, meaning, optimism, and lower fear of death. About 80% of people still had meaningful improvements six months later. The study was done in a carefully controlled clinical setting, and the strong effects were linked to having a deep, “mystical-type” experience during the high-dose session, so results may not apply the same way outside this setting or for other groups of people.

Key facts:

• The study included 51 people with life-threatening cancer who also had symptoms of depression or anxiety.
• Each person had two sessions: one with a very low psilocybin dose (about 1 or 3 mg per 70 kg of body weight) and one with a high dose (about 22 or 30 mg per 70 kg), five weeks apart.
• After the high-dose session, both clinician ratings and participants’ own ratings showed large decreases in depressed mood and anxiety.
• Around 80% of participants still showed clinically meaningful decreases in depression and anxiety six months after the high-dose session.
• People also reported higher quality of life, more sense of meaning, greater optimism, and less fear of death after the high-dose session.
• Over 80% of participants said their well-being or life satisfaction was moderately or greatly improved because of the high-dose experience.
• The study found that having a strong “mystical-type” experience during the session partly explained why the high dose led to lasting improvements.

Abstract

Cancer patients often develop chronic, clinically significant symptoms of depression and anxiety. Previous studies suggest that psilocybin may decrease depression and anxiety in cancer patients. The effects of psilocybin were studied in 51 cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety. This randomized, double-blind, cross-over trial investigated the effects of a very low (placebo-like) dose (1 or 3 mg/70 kg) vs. a high dose (22 or 30 mg/70 kg) of psilocybin administered in counterbalanced sequence with 5 weeks between sessions and a 6-month follow-up. Instructions to participants and staff minimized expectancy effects. Participants, staff, and community observers rated participant moods, attitudes, and behaviors throughout the study. High-dose psilocybin produced large decreases in clinician- and self-rated measures of depressed mood and anxiety, along with increases in quality of life, life meaning, and optimism, and decreases in death anxiety. At 6-month follow-up, these changes were sustained, with about 80% of participants continuing to show clinically significant decreases in depressed mood and anxiety. Participants attributed improvements in attitudes about life/self, mood, relationships, and spirituality to the high-dose experience, with >80% endorsing moderately or greater increased well-being/life satisfaction. Community observer ratings showed corresponding changes. Mystical-type psilocybin experience on session day mediated the effect of psilocybin dose on therapeutic outcomes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00465595.

Topics

Pain Management and Placebo Effect Paranormal Experiences and Beliefs Psychedelics and Drug Studies

Categories

Clinical Psychology Psychology Social Sciences

Tags

Alternative medicine Anxiety Clinical psychology Hallucinogen Internal medicine Medicine Mood Pathology Placebo Psilocybin Psychiatry Psychology Randomized controlled trial

Substances

Psilocybin

Conditions & symptoms

Anxiety Depression Anxiety or worry Sadness or low mood