Empirical evidence for the neurocognitive effect of nitrous oxide as an adjunctive therapy in patients with treatment resistant depression: A randomized controlled study.
Psychiatry research August 1, 2023 Jin Liu, Xiaotian Zhao, Xiyu Wei et al.
A double-blinded, placebo-controlled randomized trial tested whether nitrous oxide (N2O) improves cognitive function in 44 patients with treatment-resistant depression. Thirty-four patients completed cognitive tests before treatment and at 1 and 2 weeks after a one-hour inhalation of 50% N2O/50% oxygen or placebo (50% air/50% oxygen). Although N2O did not produce a significant antidepressant effect at 1 week, patients who received N2O showed better executive function at 1 week compared with placebo, and this improvement remained after controlling for changes in depressive symptoms. No significant differences were found in subjective cognitive function, processing speed, or attention over the 2-week follow-up. The results suggest N2O may have a pro-cognitive effect on executive function independent of mood improvement.