Altered States
Eduardo E. Icaza, George A. Mashour
Anesthesiology September 21, 2013 DOI: 10.1097/01.anes.0000435635.42332.ee (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Psilocybin |
| Keywords | Consciousness Neuroimaging Altered state General anesthetics Cognitive science Hallucinogen |
| Citations | 11 |
| Key findings | Psilocybin and general anesthetics produce similar patterns of decreased cerebral blood flow and functional disconnections in the brain, despite generating opposite subjective experiences. |
Abstract
Abstract The psychedelic experience has been reported since antiquity, but there is relatively little known about the underlying neural mechanisms. A recent neuroimaging study on psilocybin revealed a pattern of decreased cerebral blood flow and functional disconnections that is surprisingly similar to that caused by various anesthetics. In this article, the authors review historical examples of psychedelic experiences induced by general anesthetics and then contrast the mechanisms by which these two drug classes generate altered states of consciousness.
Comparable studies
Other narrative reviews on psilocybin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function. General population | 2019 | Integrative review | |
| The pharmacology of psilocybin | 2002 | Review | |
| Serotonin research: contributions to understanding psychoses | 2008 | Review | |
| Psychedelics, Meditation, and Self-Consciousness | 2018 | Review | |
| The abuse potential of medical psilocybin according to the 8 factors of the Controlled Substances Act | 2018 | Review |
Citations in the library
Cited by 6
- Beating pain with psychedelics: Matter over mind? Neuroscience & Biobehavioral Reviews December 16, 2021
- The neurobiology of altered states of consciousness induced by drumming and other rhythmic sound patterns. Annals of the New York Academy of Sciences July 16, 2025
- Psychedelic research, assisted therapy and the role of the anaesthetist: A review and insights for experimental and clinical practices. British Journal of Clinical Pharmacology December 1, 2024
- Scientifically Integrating Psychedelics with Counseling: Education, Guidance, and Implications for Mental Health Practitioners Journal of Creativity in Mental Health July 24, 2023
- Psychedelics, Glutamate, and Neuroimaging Studies Anesthesiology May 21, 2014
and 1 more in the library
Cites 15
- Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin Proceedings of the National Academy of Sciences January 23, 2012
- Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV) PLoS One August 31, 2010
- Breakdown of within- and between-network Resting State Functional Magnetic Resonance Imaging Connectivity during Propofol-induced Loss of Consciousness Anesthesiology September 30, 2010
- Disruption of Frontal–Parietal Communication by Ketamine, Propofol, and Sevoflurane Anesthesiology May 22, 2013
- Psychedelic Effects of Ketamine in Healthy Volunteers Anesthesiology 1998
and 10 more in the library