Psilocybin Reduces Aggression and Increases Laziness in Fish

Scientists discovered a surprising effect of magic mushrooms. The key ingredient, psilocybin, reduces aggression in aggressive fish. It also makes them lazier. Researchers from Canada studied mangrove rivulus fish. These animals are naturally very aggressive. Therefore, even small behavior changes are easy to spot. The team gave the fish a low dose of psilocybin. As a result, the fish moved less. They also showed fewer high‑energy attacks. “Psilocybin’s calming effect selectively reduces escalated conflict,” says Dayna Forsyth, first author. Importantly, normal social interaction continued. The fish still communicated with each other.

The Experiment

The researchers used genetically identical fish. This helped isolate psilocybin’s effects. First, they observed baseline behavior. Then, they exposed the same fish to dissolved psilocybin for 20 minutes. After treatment, the fish displayed fewer swimming bursts. Those bursts represent aggressive attacks. However, low‑energy displays like head‑on looks stayed unchanged. This suggests the compound targets only harmful aggression. “Psilocybin reduces energetically costly behaviors,” explains Dr. Suzie Currie. “But it does not shut down social behavior altogether.”

This Discovery Matters

This study provides the first evidence in a vertebrate model. Psilocybin reduces aggression without stopping social ties. That could help future therapeutic research. For example, scientists want to understand which brain pathways control aggression. Fish studies can answer questions that are difficult to study in humans. However, the team warns that findings do not directly apply to people. More research is needed. Future work should explore long‑term effects and repeated doses. Nevertheless, this discovery opens a new door. A natural compound from mushrooms might one day inspire calmness therapies.