Depression is one of the most common mental health disorders; researchers estimate over 264 million people worldwide have the disease. And, between 10-30 percent of people diagnosed with clinical depression are unable to find relief even after multiple rounds of treatment with antidepressants. 

To find a therapy for people diagnosed with treatment-resistant depression, researchers have been testing some unconventional drugs. These include the clinical anesthetic ketamine, as well as the active ingredient in magic mushrooms, psilocybin. Now, we can add laughing gas to the list.

A paper recently published in Science Translational Medicine reports results from a small, early-stage clinical trial conducted by researchers at the University of Chicago and Washington University School of Medicine. They found that inhaling a mixture of oxygen and nitrous oxide, the active chemical in laughing gas, significantly improved depression symptoms compared to inhaling oxygen alone in people diagnosed with treatment-resistant depression.

Larger studies will be necessary to validate these results. Nonetheless, early indications are that laughing gas may offer new hope for people diagnosed with treatment-resistant depression.