A single, one-hour treatment that involves breathing in a mixture of oxygen and nitrous oxide — otherwise known as laughing gas — significantly improved symptoms in people with treatment-resistant depression, according to new data from researchers at Washington University School of Medicine in St. Louis and the University of Chicago.
In a phase 2 clinical trial, the researchers demonstrated that symptoms of depression improve rapidly following treatment with inhaled nitrous oxide. Further, they reported the benefits can last for several weeks.
The findings are published June 9 in the journal Science Translational Medicine.
“A large percentage of patients don’t respond to standard antidepressant therapies — the patients in this study had failed an average of 4.5 antidepressant trials — and it’s very important to find therapies to help these patients,” said Charles R. Conway, MD, a professor of psychiatry at Washington University and one of the study’s senior investigators. “That we saw rapid improvements in many such patients in the study suggests nitrous oxide may help people with really severe, resistant depression.”
Conway, and the study’s other co-senior investigator, Peter Nagele, MD, professor and chair of the Department of Anesthesia & Critical Care at the University of Chicago, and who previously had an appointment in the Department of Anesthesiology at Washington University School of Medicine, have been studying the potential of nitrous oxide as an antidepressant for the past decade.
Standard antidepressant drugs affect norepinephrine and serotonin receptors in the brain, yet they often take weeks to improve a person’s symptoms. Nitrous oxide, however, interacts with different receptors on brain cells — NMDA glutamate receptors — and tends to improve symptoms within hours when effective.