A new pilot study gives an early glimpse into how veterans who are struggling with post-traumatic stress disorder (PTSD) may benefit from one simple, inexpensive treatment involving nitrous oxide, commonly known as laughing gas.

For military veterans with PTSD, symptoms such as anxiety, anger and depression can have a devastating effect on their health, daily routine, relationships and overall quality of life.

The study, which involved three military veterans struggling with PTSD, could lead to improved treatments for the debilitating psychiatric disorder that has affected thousands of current and former members of the U.S. military.

The findings are published in the Journal of Clinical Psychiatry.

“Effective treatments for PTSD are limited,” said anesthesiologist Peter Nagele, M.D., chair of the Department of Anesthesia & Critical Care at the University of Chicago Medicine and co-author of the paper. “While small in scale, this study shows the early promise of using nitrous oxide to quickly relieve symptoms of PTSD.”

Nagele is a pioneer in the field of using nitrous oxide to treat depression. Most commonly known for its use by dentists, nitrous oxide is a low-cost, easy-to-use medication. Although some patients may experience side effects like nausea or vomiting, the reactions are typically temporary.

For the new study, three veterans with PTSD were asked to inhale a single one-hour dose of 50% nitrous oxide and 50% oxygen through a face mask. Within hours after breathing nitrous oxide, two of the patients reported a marked improvement in their PTSD symptoms.

This improvement lasted one week for one of the patients, while the other patient’s symptoms gradually returned over the week. The third patient reported an improvement two hours after his treatment but went back to experiencing symptoms the next day.

“Like many other treatments, nitrous oxide appears to be effective for some patients but not for others,” explained Nagele, who is himself a veteran of the Austrian Army and grateful to have identified an opportunity to help other veterans. “Often drugs work only on a subset of patients, while others do not respond. It’s our role to determine who may benefit from this treatment, and who won’t.”

Exactly how and why nitrous oxide relieves symptoms of depression in some people and not others is still unclear. Most traditional antidepressants work through the brain chemical serotonin. Similar to ketamine, an anesthetic that recently received FDA approval in a nasal spray to treat those whose major depression has not responded to other drugs, nitrous oxide works through a different mechanism, by blocking N-methyl-D-aspartate (NMDA) receptors.

In a 2015 landmark study, Nagele discovered that two-thirds of patients with treatment-resistant depression experienced an improvement in symptoms after receiving nitrous oxide.

Moving into the future, Nagele is researching the ideal dose of nitrous oxide to treat intractable depression. Study participants with treatment-resistant depression were given different doses of nitrous oxide so that Nagele and his team could compare each dose’s effectiveness and side effects. The study is being funded by the Brain & Behavior Research Foundation.

The study was funded by the VA Office of Research and Development Clinical Science Research & Development Service. It involved a Stanford University School of Medicine team from the VA Palo Alto Health Care System, including principal investigators Drs. Carolyn Rodriguez and David Clark.

Source: University of Chicago Medical Center