Studying How Psilocybin and Risperidone Affect Depression and Anhedonia Using Brain Imaging

What this Trial Is About

Researchers are investigating the potential effects of psilocybin on improving anhedonia, a condition characterized by reduced ability to experience pleasure, in patients with depression. This phase 1 clinical trial also explores how psilocybin influences brain activity during pleasurable experiences using advanced brain imaging techniques. The study compares psilocybin alone and combined with risperidone, a medication that blocks some psychedelic effects, to understand the role of the psychedelic experience in these outcomes. Participants receive two doses of 25 mg psilocybin orally in separate sessions. In one session, they also take 1 mg risperidone beforehand to block the psychedelic effects. The study uses a randomized, open-label, cross-over design where participants undergo psilocybin alone first or with risperidone first, followed by the other treatment in the second session. Additionally, participants have three MRI scans one before treatment and one after each psilocybin session. During the study, participants complete various brain imaging tasks to assess changes in anhedonia, reward processing, and sexual arousal. They also complete questionnaires measuring well-being, depression, pleasure experiences, and resilience. Blood samples are taken to study inflammation and brain-related factors. The total participation includes follow-up assessments up to about 12 weeks after enrollment to monitor the effects and brain activity changes.

Elucidating the Relevance of the Psychedelic Experience to Psilocybin's Anti-Anhedonic Effects