Could laughing gas be used to treat severe depression?

I, on the other hand, had a terrible anxiety reaction to laughing gas that kept me awake for two days......

http://goo.gl/cVG7nF

The team, from Washington University School of Medicine in St. Louis, MO, reports the findings of their proof-of-concept study into the effects of laughing gas on severe, treatment-resistantdepression in the journal Biological Psychiatry.

They believe it is the first study where patients with depression have been given nitrous oxide or laughing gas, a fact that lead researcher Peter Nagele, assistant professor of anesthesiology, remarks on:

"It's kind of surprising that no one ever thought about using a drug that makes people laugh as a treatment for patients whose main symptom is that they're so very sad."

The study involved 20 patients with severe depression whose illness was not responding to conventional treatment.