Commonly known as laughing gas, nitrous oxide could become a powerful new weapon in the fight against severe depression, according to a significant new study.
Researchers from the University of Birmingham and University of Oxford have found that the colourless gas, typically used as a painkiller, offers fast-acting symptom relief for adults battling major depressive disorder and treatment-resistant depression.
A Rapid-Acting Antidepressant Breakthrough
The study, published in the journal eBioMedicine, analysed seven clinical trials and four protocol papers from investigators worldwide. Each study examined nitrous oxide's effects on various depressive disorders, including major depressive disorder, treatment-resistant depression and bipolar depression.
Kiranpreet Gill, a PhD researcher funded by the Medical Research Council at the University of Birmingham and the study's first author, emphasised the importance of this finding. "Depression is a debilitating illness, made even more so by the fact that antidepressants make no meaningful difference for almost half of all patients diagnosed with it," she stated.
"Our analyses show that nitrous oxide could form part of a new generation of rapid-acting treatments for depression."
How the Treatment Works and Lasts
Researchers discovered that a single treatment using inhaled clinical nitrous oxide at 50% concentration produced rapid and significant reductions in depressive symptoms within 24 hours. However, these positive effects typically faded within a week.
When the treatment was administered repeatedly over several weeks, patients experienced longer-lasting antidepressant effects. The gas is believed to work by targeting glutamate receptors in the brain, which are crucial for learning and memory, in a similar manner to ketamine - another rapid-acting antidepressant.
Professor David Nutt, a neuropsychopharmacology expert at Imperial College London, explained to The Independent: "It's called laughing gas because it removes the natural tension and anxiety we all have in our brains, so it allows people to become relaxed and happy instantly."
"It changes the brain blood flow and so probably disrupts the brain circuits of depression."
Safety Considerations and Future Research
The research team carefully examined the safety profile of nitrous oxide treatment. While some patients experienced temporary side effects including nausea, dizziness and headaches, these typically resolved quickly without medical intervention.
Although higher concentrations increased the likelihood of these side effects, researchers reported no immediate safety concerns. They stressed, however, that longer-term safety must be assessed through future studies.
Professor Steven Marwaha, from the University of Birmingham and senior author of the study, called the findings a "significant milestone".
"This is a significant milestone in understanding the potential of nitrous oxide as an added treatment option for patients with depression who have been failed by current treatments," he said. "This population has often lost hope of recovery, making the results of this study particularly exciting."
The research offers new hope for the approximately 48% of depression patients who don't respond to first-line antidepressant medications, potentially opening the door to more effective treatment options for those most in need.
