Nitrous oxide, aka laughing gas, aka whippets, is a promising treatment for depression, according to researchers from University of Chicago anaesthetist Peter Nagele and colleagues at Washington University School of Medicine. Interestingly, the nitrous oxide affects the brain in a similar way as Ketamine, another dissociative psychedelic which is also now used to treat severe depression. How it works to relieve depression, Nagele says, remains a mystery. From New Scientist:
Prolonged nitrous oxide use can can lead to nausea and headaches. 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.
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.
"A phase 2 trial of inhaled nitrous oxide for treatment-resistant major depression" (Science Translational Medicine)