Psychedelic medicine (New Rochelle, N.Y.)
March 1, 2025
Daniel J Kruger, Jacob S Aday, Christopher W Fields et al.
19 citations
In an anonymous online survey of 1,221 people who reported past psychedelic use, most described adverse experiences: 74.3% felt frightened, 58.6% sadness, 54.3% body shaking or trembling, and 51.6% loneliness. About half reported some other adverse experience, and one in ten had adverse physical reactions. One-third knew someone arrested for possession or use of psychedelics; 8% reported that they or someone they know was the victim of inappropriate sexual contact by a psychedelic sitter, guide, or practitioner; and one-quarter knew someone who experienced a severe adverse event other than inappropriate sexual contact or arrest. The findings indicate that despite beneficial effects, psychedelic experiences can be challenging, distressing, or harmful, highlighting the need to prevent, identify, manage, and treat adverse events.
Journal of psychoactive drugs
January 1, 2023
Daniel J Kruger, Nicolas G Glynos, Christopher W Fields et al.
10 citations
People who use psychedelics and have higher education, lower age, greater frequency of use, male gender, White/Caucasian identity, higher income, and experience with more types of psychedelics tend to know more about legal status, active compounds, and therapeutic efficacy. A survey of 1,435 participants recruited at a psychedelic advocacy event and online showed overall high knowledge, but gaps remain, highlighting the need for targeted education and harm reduction outreach, especially in under-represented communities.
bioRxiv : the preprint server for biology
October 15, 2025
Rolf J Skyberg, Christopher W Fields, Dylan M Martins et al.
preprint
Psychedelics like DOI alter visual perception by increasing how often mice actively sample their visual environment during free movement, yet they reduce the neural responses in the primary visual cortex that these behaviors generate. The effects vary widely across individual neurons and depend on the type of visual input, with stronger suppression of responses to unpredictable stimuli than to predictable ones. This dissociation suggests that predictability of visual events influences how psychedelics disrupt sensory processing, offering insights into the neural basis of altered perceptual states.
Anesthesia and analgesia
June 1, 2022
Michael A Brito, Duan Li, Christopher W Fields et al.
Cortical acetylcholine levels correlate with neurophysiologic complexity and frontoparietal connectivity during altered states of consciousness. In rats under isoflurane anesthesia, subanesthetic ketamine (10 mg/kg/h) produced sustained increases in brain complexity and high gamma connectivity, accompanied by progressive rises in prefrontal (104%) and parietal (159%) acetylcholine. Nitrous oxide caused a transient increase in complexity and connectivity with smaller acetylcholine increases (prefrontal 56%, parietal 43%), followed by a later phase of decreased acetylcholine, reduced complexity, and weaker connectivity. These findings link cortical acetylcholine to changes in consciousness level.