Subjective features of the psilocybin experience that may account for its self-administration by humans: a double-blind comparison of psilocybin and dextromethorphan.
Theresa M. Carbonaro, Matthew W Johnson, Roland R. Griffiths
Psychopharmacology August 1, 2020 DOI: 10.1007/s00213-020-05533-9 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Double-blind Peer reviewed |
|---|---|
| Sample size | 20 |
| Population | Healthy participants with histories of hallucinogen use |
| Interventions | Psilocybin Dextromethorphan |
| Dose | 10, 20, 30 mg/70 kg for psilocybin; 400 mg/70 kg for DXM |
| Duration | Single acute dose |
| Topics | Mystical experience Psilocybin |
| Keywords | Abuse liability Hallucinogen Humans Insightful experience Mood Psychedelic Reinforcing effects Subjective experience Psilocybin vs dextromethorphan |
| Citations | 51 |
| Key findings | Psilocybin produced significantly greater subjective effects than DXM across multiple domains proposed to be related to reinforcing effects, consistent with higher rates of non-medical use. |
Abstract
Although both psilocybin and dextromethorphan (DXM) produce psychedelic-like subjective effects, rates of non-medical use of psilocybin are consistently greater than DXM. New data are presented from a study of psilocybin and DXM relevant to understanding the features of psilocybin subjective effects that may account for its higher rates of non-medical use. Single, acute oral doses of psilocybin (10, 20, 30 mg/70 kg), DXM (400 mg/70 kg), and placebo were administered under double-blind conditions to 20 healthy participants with histories of hallucinogen use. High doses of both drugs produced similar time courses and increases in participant ratings of peak overall drug effect strength. Nine subjective effect domains are proposed to be related to the reinforcing effects of psilocybin: liking, visual effects, positive mood, insight, positive social effects, increased awareness of beauty (both visual and music), awe/amazement, meaningfulness, and mystical experience. For most ratings, (1) psilocybin and DXM both produced effects significantly greater than placebo; (2) psilocybin showed dose-related increases; 3, DXM was never significantly higher than psilocybin; (4) the two highest psilocybin doses were significantly greater than DXM. These differences were consistent with two measures of desire to take the drug condition again. This analysis provides new information about domains of psilocybin subjective effects proposed to be related to its reinforcing effects (alternatively described as the "motivation" to use). Observed differences on these domains between psilocybin and DXM are consistent with the relative rates of non-medical use of psilocybin and DXM.
Comparable studies
Other randomized controlled trials on psilocybin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial Cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety | 2016 | Randomized controlled trial | n = 51 |
| Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial Patients with cancer-related anxiety and depression | 2016 | Double-blind, placebo-controlled, crossover trial | n = 29 |
| Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance Hallucinogen-naïve adults reporting regular participation in religious or spiritual... | 2006 | Double-blind study | n = 36 |
| Trial of Psilocybin versus Escitalopram for Depression Selected group of patients with depression | 2021 | Randomized controlled trial | |
| Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder Adults aged 21 to 75 years with major depressive disorder, not currently using... | 2020 | Randomized controlled trial | n = 24 |
Citations in the library
Cited by 43
- The Subjective Effects of Psychedelics Are Necessary for Their Enduring Therapeutic Effects. ACS Pharmacology & Translational Science December 10, 2020
- Efficacy and safety of psilocybin-assisted treatment for major depressive disorder: Prospective 12-month follow-up Journal of Psychopharmacology February 1, 2022
- The Therapeutic Potential of Psilocybin Molecules May 15, 2021
- Validation of the Psychological Insight Scale: A new scale to assess psychological insight following a psychedelic experience. Journal of Psychopharmacology January 5, 2022
- Structure–Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice ACS Pharmacology & Translational Science November 2, 2022
and 38 more in the library
Cites 20
- Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance Psychopharmacology July 7, 2006
- Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects. Psychopharmacology December 1, 2011
- Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV) PLoS One August 31, 2010
- Validation of the revised Mystical Experience Questionnaire in experimental sessions with psilocybin Journal of Psychopharmacology October 6, 2015
- The Standardized Psychometric Assessment of Altered States of Consciousness (ASCs) in Humans Pharmacopsychiatry July 1, 1998
and 15 more in the library