Laugh it off: Study shows laughing gas could treat depression
A team of researchers from the University of Chicago found that depression symptoms reduced for up to two weeks when people inhaled a low dose of laughing gas.
According to a new study, laughing gas – or nitrous oxide – could potentially help people suffering from depression.
Laughing gas and depression
In what is seen as a breakthrough for those patients who are struggling to find adequate help, a small study found that when people inhaled a low dose of laughing gas, their depression improved over the next two weeks.
News Scientist reports it is known that nitrous oxide can improve one’s mood as well as relieve pain – hence its original name of laughing gas – but the effect is thought to wear off quickly. It is often used as a sedative as it helps patients relax by inducing pleasurable feelings and is one of the most common anesthetics used by hospitals, dental surgeries and paramedics, as well as being available illegally in small capsules for recreational use.
How does laughing gas work?
The gas seems to chiefly affect the brain by blocking molecules on nerve cells called N-methyl-D-aspartate (NMDA) receptors. This is the same thing targeted by the stronger anaesthetic ketamine, which also relieves depression; a similar chemical to ketamine has recently been approved as a new intranasal spray treatment.
It isn’t known how NMDA receptors change one’s mood, but as the antidepressant effects of ketamine started to emerge, Peter Nagele, then an anaesthetist at Washington University School of Medicine in St Louis, Missouri, wondered if nitrous oxide had similar potential.
Back in 2014, Nagele and his colleagues found that one hour’s inhalation of nitrous oxide reduced symptoms for up to a day in people with depression who hadn’t improved after trying standard antidepressant medicines, but the study didn’t record whether the effect lasted any longer.
“We wondered if our past concentration had been too high,” says Nagele, who is now at the University of Chicago in Illinois. “Maybe by lowering the dose, we could find the ‘Goldilocks spot’ that would maximize clinical benefit and minimize negative side effects.”
The benefit of improving your mood
And so, in the latest study, Nagele’s team looked at 24 people with treatment-resistant depression and gave them half-dose nitrous oxide, a full dose or a placebo mixture of air and oxygen. They were given one treatment a month for three months as prolonged nitrous oxide use can lead to nausea and headaches.
“As with ketamine, nitrous oxide has the benefit of improving mood quickly,” says Nagele. “Something happens in the brain – it’s like flipping a switch. But how this works, no one knows.”
After two weeks, depression symptoms for those with the half-dose treatment had reduced by an average of five points on a commonly used depression rating scale, compared with those who had the placebo, which is a significant benefit. After the full-dose treatment, depression symptoms reduced a little more, although the difference was so small that it could have arisen by chance. The half-dose group also had a much lower incidence of side effects, such as nausea, headaches and light-headedness.
“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,” says Nagele. “This has never been shown before. It’s a very cool finding.”
Futurity reports that despite its “laughing gas” reputation, patients who receive such a low dosage actually fall asleep. “They’re not getting high or euphoric, they get sedated,” Nagele says.
The researchers now hope that these results, and other similar studies, will open the minds of reluctant physicians toward the unique properties of these drugs.
“These have just been pilot studies,” says Nagele. “But we need acceptance by the larger medical community for this to become a treatment that’s actually available to patients in the real world. Most psychiatrists are not familiar with nitrous oxide or how to administer it, so we’ll have to show the community how to deliver this treatment safely and effectively. I think there will be a lot of interest in getting this into clinical practice.
“There is a huge unmet need,” he says further. “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.”