Researchers are celebrating a new option for people with severe depression

A Christchurch psychiatrist has sole approval outside clinical trials - to prescribe magic mushroom medication, for treatment-resistant depression.

Psilocybin remains unapproved, but that expert can now prescribe it for severe cases.

Auckland University Professor Suresh Muthukumaraswamy says research has shown some promising therapy results from the drug.

He says it's been found to increase neuroplasticity, possibly enabling the brain to make new connections it's lost.