Nitrous oxide—the gas dentists have used for decades—appears to lift depression symptoms within hours, not weeks. In a review of seven clinical trials involving 247 people with treatment-resistant depression, a single hour-long breathing session at 50% concentration produced noticeable improvement by the two-hour mark, with benefits still visible 24 hours later.
The catch: the relief faded within a week. But when researchers looked at studies where people received multiple sessions over several weeks, the improvements held.
How it works, and why it matters
Unlike antidepressants that take weeks to reshape your brain chemistry, nitrous oxide appears to work almost immediately. It blocks a specific receptor that regulates glutamate, a chemical messenger involved in mood regulation. At the same time, it increases blood flow to the brain and may quiet the brain's default mode network—the mental loop that keeps depressed people stuck in rumination and self-criticism.
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Start Your News DetoxFor people with severe depression who haven't responded to standard treatments, this speed matters. "Nitrous oxide is a promising rapid-acting treatment for depressive disorders," says Angharad de Cates from the University of Birmingham, who led the analysis. "It has the potential to form part of a new generation of rapid-acting treatments."
The research team, led by Kiranpreet Gill, reviewed studies published between 2015 and 2025, examining both major depressive disorder and bipolar depression. The pattern was consistent: single doses provided quick but temporary relief, while repeated sessions produced more durable improvements.
Compared to ketamine—another fast-acting antidepressant already being used in some clinics—nitrous oxide appears to cause fewer severe side effects and requires less intensive monitoring. That could make it more accessible, though it's still years away from routine clinical use.
The next phase is understanding the optimal dosing schedule: How many sessions? How far apart? Can the benefits be extended without needing indefinite treatment? The research is preliminary, but for people exhausted by depression that won't budge on conventional medication, the possibility of relief measured in hours rather than months is worth taking seriously.
