More than 264 million individuals of all ages suffer from depression globally. While there are effective treatments for moderate and severe depression, scientists have been investigating non-traditional therapies as a viable option for the past decades since a significant proportion of people with depression (around 15 percent) don't respond to typical antidepressant medications.
Now, a new study from the University of Chicago Medicine and Washington University has discovered that a low dose of nitrous oxide, often called laughing gas, can ease symptoms of depression that are otherwise resistant to existing drugs.
Nitrous oxide is a common anesthetic used in dentistry and surgery to provide short-term pain relief. The study, published in the journal Science Translational Medicine, has found that a single inhalation session with 25 percent nitrous oxide gas was nearly as effective as 50 percent nitrous oxide at relieving symptoms of treatment-resistant depression. Moreover, it does so with fewer unpleasant side effects.
Researchers also discovered that the advantages persisted significantly longer than previously thought, with some subjects feeling improvements for up to two weeks.
The study explained
Inspired by research on ketamine (which is also an anesthetic) and depression, the researchers had previously examined the effects of a one-hour inhalation session with 50 percent nitrous oxide gas in 20 individuals. Compared to placebo, the session alleviated patients' depressive symptoms for at least 24 hours; however, many patients had adverse side effects such as nausea and headaches.
As a result, the researchers wondered if the concentration of 50 percent had been too high. According to Peter Nagele, MD, Chair of Anesthesia and Critical Care at UChicago Medicine, they wondered whether they could find "the 'Goldilocks spot' that would maximize clinical benefit and minimize negative side effects" by lowering the dose.
In the new trial, the researchers followed a similar protocol with 20 patients, but this time included an extra inhalation session with 25 percent nitrous oxide. Surprisingly, even with only half the nitrous oxide dosage, the therapy was nearly as effective as 50 percent nitrous oxide. Furthermore, only one-quarter of the unfavorable side effects were reported.
Following that, patients' clinical depression scores were assessed and additional evaluations were performed over a two-week period. The findings were extremely encouraging. "The reduction in side effects was unexpected and quite drastic, but even more excitingly, the effects after a single administration lasted for a whole two weeks," explained Nagele. "This has never been shown before. It's a very cool finding."
While it is true that non-traditional treatments for depression hardly gain acceptance in the mainstream, researchers hope that these findings will persuade skeptical clinicians of the drugs' unique qualities.
"There is a huge unmet need," he said. "There are millions of depressed patients who don't have good treatment options, especially those who are dealing with suicidality. If we develop effective, rapid treatments that can really help someone navigate their suicidal thinking and come out on the other side -- that's a very gratifying line of research."
If you are having thoughts of suicide, you can call the National Suicide Prevention Lifeline at 1-800-273-8255 (TALK). You can find a list of additional resources at Speaking of Suicide.