A multi-institutional investigation of psilocybin’s effects on mouse behavior
bioRxiv (Cold Spring Harbor Laboratory) April 9, 2025 Odilia D Lu, Katrina White, Kendall Raymond et al. 18 citations preprint
Psilocybin, the active compound in magic mushrooms, had several clear and repeatable immediate effects on mouse behavior, including increased anxiety and avoidance and reduced fear expression. However, its effects one day later were not consistent across five different laboratories, and no reliable changes were seen in depression-like behavior, fear extinction learning, social preference, or social reward learning. Using about 200 mice per experiment across five independent labs, the findings show that psilocybin's lasting behavioral effects in mice are more modest and less reliable than previously claimed. This coordinated multi-lab approach highlights the importance of replication for producing trustworthy results.