A psychedelic drug found in mushrooms could work as an antidepressant, new research shows.

Psilocybin, a compound that naturally occurs in some mushrooms, may be able to increase the long-lasting connections between neurons in the brain by 10 percent.

A research team from Yale University believes these connections can reduce the effects of depression on a person.

The study, which will be published in the journal Neuron on Monday, also found that the strength of neuron connections increases as well.

'We not only saw a 10 percent increase in the number of neuronal connections, but also they were on average about 10 percent larger, so the connections were stronger as well,' Alex Kwan, senior author of the study and associate professor of psychiatry and of neuroscience at Yale.

Researchers tested the drug in mice.

They found that within 24 hours of receiving the drug, mice were showing increased number of dendritic spines, the part of neurons that transmit information to one another.

Mice who had the drug administered on them also showed behavioral improvements. 

The effects were still present in the mice one month later, meaning just one dose of the drug can have a lasting impact.

'It was a real surprise to see such enduring changes from just one dose of psilocybin,' Kwan said. 

'These new connections may be the structural changes the brain uses to store new experiences.'