Amygdala response to emotional faces following acute administration of psilocybin in healthy individuals
Sophia Armand, Kristian Larsen, Martin K Madsen, Brice Ozenne, Katrin H Preller, Gitte M Knudsen, Dea S Stenbæk, Patrick M Fisher
Neuroscience Applied December 30, 2023 DOI: 10.1016/j.nsa.2023.103934 via OpenAlex
Summary
AI-generated from the abstractThe psychedelic drug psilocybin acutely reduces amygdala reactivity to angry faces in healthy individuals, while its subjective intensity is linked to reduced amygdala response to fearful faces. In 26 participants, fMRI scans showed that amygdala response to angry faces was significantly lower under psilocybin compared to baseline. No significant changes occurred for fearful or neutral faces. Higher subjective drug intensity was associated with weaker amygdala response to fearful faces, but plasma psilocin levels showed no such link. These findings align with prior work, suggesting psilocybin alters emotion processing in the brain, with potential implications for treating depression.
Study at a glance
| Characteristics | Within-subjects experimental study with fMRI Peer reviewed |
|---|---|
| Sample size | 26 |
| Population | Healthy individuals |
| Intervention | Psilocybin |
| Keywords | Psilocybin psychedelics Hallucinogens Emotional processing emotion Emotional regulation Affective processing |
| Citations | 7 |
| Key finding | Psilocybin significantly reduced amygdala reactivity to angry faces, and subjective drug intensity was negatively associated with amygdala reactivity to fearful faces. |
Abstract
The serotonergic psychedelic psilocybin acutely induces changes in emotional states. However, it remains unresolved whether psilocybin acutely modulates amygdala reactivity to emotions, a brain region critically involved in emotion processing. Using functional magnetic resonance imaging (fMRI), we examined in 26 healthy individuals whether amygdala responses to angry, fearful and neutral faces differ between acute exposure to psilocybin and at baseline. We also evaluated whether plasma psilocin levels (PPL) and subjective drug intensity (SDI) during psilocybin are related to amygdala responses to the emotional faces. We found that amygdala response to angry faces was significantly reduced during exposure to psilocybin as compared to baseline (mean difference = -0.54, PFWER = 0.03), whereas no significant changes in amygdala responses to fearful or neutral faces were observed. We further found that the amygdala response to fearful faces was significantly negatively associated with SDI (slope = -0.13, PFWER = 0.04), whereas no significant association with PPL was observed. Our findings indicate that psilocybin attenuates amygdala reactivity to angry faces and that a more intense subjective psilocybin response (SDI) is associated with attenuated amygdala reactivity to fearful faces, in accordance with previously reported results. Future studies should investigate whether exposure to psilocybin acutely changes emotion processing in individuals with depression and whether such changes are related to therapeutic outcomes.