Nitrous oxide, also known as laughing gas, has long been known to temporarily improve mood and can even relieve pain. Therefore, it is a commonly used anesthetic in hospitals, dental offices and for paramedics. Now it has emerged as a potential therapeutic agentagainst depressionproven. In a small study, test participants inhaled a low dose. The depression improved after just two weeks.
How laughing gas works
Nitrous oxide appears to affect the brain. There it blocks the so-called N-methyl-D-aspartate (NMDA) receptors - molecules on nerve cells. It therefore has the same effect as the approved medicationKetamine, which is used for treatmentused by depression, but is stronger. So Peter Nagele, then an anesthesiologist at Washington University School of Medicine in St. Louis, Missouri, decided to see whether the gas could have a similar effect.
In a study, he and his colleagues examined the potential of nitrous oxide in people who suffered from depression and whose symptoms had not improved despite standard antidepressants. The team found that an hour-long inhalation reduced this by up to a day. However, this study did not determine whether this effect lasted longer. That's why the team recently conducted a new study:
The second study and its results
Twenty-four people who also did not respond to standard treatment measures took part in Nagele's new study. They were divided into three groups. All received one treatment per month for three months with either a half dose, a full dose of nitrous oxide or a placebo (a mixture of air and oxygen). The team also used a depression rating scale to assess the effect.
After just two weeks, depression symptoms had decreased by an average of five points using the half dose compared to the placebo group. In the group that received the full dose, the results were even slightly better. However, the difference was so small that it could well have been a coincidence. Side effects such as nausea, headaches and drowsiness, which are typical of laughing gas, also occurred less frequently in the half-dose group.
Like ketamine, nitrous oxide has the benefit of quickly improving mood, says Nagele, now at the University of Chicago in Illinois. “Something happens in the brain – it’s like you flip a switch. But no one knows how it works.”
You can find the study hereScience Translational Medicine.
