Researchers from Acadia University and The University of British Columbia, including Dayna Forsyth and Dr. Suzie Currie, have found that a low dose of psilocybin significantly reduces aggressive “swimming bursts” in mangrove rivulus fish. This finding was published in the journal Frontiers in Behavioral Neuroscience.

This study provides the first evidence that psilocybin can selectively diminish aggression in a vertebrate model without disrupting other social interactions. The results suggest new possibilities for understanding and potentially treating aggression, drawing on the evolutionary conservation of serotonin pathways in living organisms. However, researchers caution that these findings are not directly transferable to humans.

What the records show

Following psilocybin exposure, the treated fish exhibited a significant decrease in aggressive “swimming bursts,” which are described as high-energy attack behaviors or rapid, aggressive darts towards other fish without making physical contact. Crucially, the fish continued to engage in lower-energy social behaviors, such as head-on communication, which are considered displays for social assessment. While overall activity levels also decreased in dosed fish, researchers emphasized that the effect was “calming, not sedating,” meaning the fish remained socially engaged but less combative.

The timeline

What changed and for whom

What the researchers said publicly

What we could not confirm