Scientists have used a specially engineered virus to help track the brain changes caused by psilocybin in mice, revealing how the drug could be breaking loops of depressive thinking.

This may explain why psilocybin keeps showing positive results for people with depression in clinical trials.

“Rumination is one of the main points for depression, where people have this unhealthy focus, and they keep dwelling on the same negative thoughts,” says Cornell University biomedical engineer Alex Kwan.