Study of Nitrous Oxide Effects on Brain Circuits in Treatment-Resistant Major Depression and Healthy Adults Using MRI

What this Trial Is About

Researchers are investigating treatment-resistant major depression TRMD, a condition where about 15-20% of patients do not respond to standard depression treatments like medication and psychotherapy. This study evaluates the effects of nitrous oxide, a drug that blocks NMDA glutamate receptors, on brain function in both TRMD patients and healthy volunteers. The goal is to understand how nitrous oxide influences brain networks related to emotion and depression using advanced brain imaging techniques. Participants will undergo two inhalation sessions spaced at least one month apart, receiving either one hour of nitrous oxide mixed with oxygen or a placebo gas nitrogen and oxygen. Up to six functional connectivity MRI scans will be performed to compare brain activity before and after each inhalation session. This allows detailed study of the brains default mode, affective, and cognitive control networks, among others. During the study, participants will be screened for safety and eligibility, including assessments for MRI compatibility and psychiatric status. Researchers will measure changes in functional brain connectivity two hours after inhalation sessions. The study involves careful monitoring of brain scans, medical history, and clinical evaluations to ensure safety and gather data on nitrous oxides impact. Participation lasts through two inhalation sessions and multiple MRI scans, with intervals designed to prevent overlap of treatment effects.

NMDA Receptor Antagonist Nitrous Oxide Targets Affective Brain Circuits