The study, at Washington University School of Medicine in St Louis, is believed to be the first research in which patients with depression were given laughing gas.
In 20 patients who had treatment-resistant clinical depression, the researchers found that two-thirds experienced an improvement in symptoms after receiving nitrous oxide.
In comparison, one-third of the same patients reported improved symptoms after treatment with a placebo. The patients were evaluated on the day of and day after each treatment.
As many as one-third of patients with clinical depression do not respond to existing treatments, which points to the need to develop more effective therapies.
Laughing gas is attractive because its side effects are limited - the most common are nausea and vomiting - and it leaves the body very quickly after people stop breathing the gas.
They cite an anecdotal finding from the study that the improvements lasted for at least one week in some patients.
As part of the study, patients received two treatments, but neither the subjects nor the researchers knew the order in which those treatments were given.
In one session, patients were given a gas mixture that was half oxygen and half nitrous oxide - the same mixture dentists give to patients undergoing dental procedures.
In a second session, the patients received a placebo mixture of oxygen and nitrogen, the two main gases in the air we breathe.
One day after nitrous oxide treatment, seven patients reported mild improvement in their symptoms, while another seven reported significant improvement.
Three patients reported that their symptoms had disappeared almost completely. No patients said their symptoms worsened after treatment with nitrous oxide.
"When they received nitrous oxide, many of the patients reported a rapid and significant improvement," said co-investigator Charles R Conway, associate professor of psychiatry.
You’ve reached your limit of 5 free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Access to Exclusive Premium Stories
Over 30 subscriber-only stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app