Brain Reactivity to Nitrous Oxyde in Depression : an MRI and Ultrasound Study (PROTOBRAIN Pilote)
Status:
Completed
Trial end date:
2021-06-10
Target enrollment:
Participant gender:
Summary
Recent evidence suggest that Nitrous Oxyde (N2O) could exhibit antidepressant effect in
treatment-resistant depression (TRD). However, the pathophysiology of this effect remains
unclear and could include glutamatergic activity but also cerebrovascular effects and changes
in brain connectivity. The goal of our study is to characterize brain reactivity to N2O in
TRD patients, as assessed with Ultrasound Tissue Pulsatility Imaging (TPI) and Magnetic
Resonance Imaging (MRI) (including Arterial Spin Labeling - ASL - for brain perfusion and
Blood-Oxygen-Level Dependent - BOLD - for brain connectivity and pulsatility).
Ultrasound and MRI Neuroimaging will be measured before, during and after a single one-hour
exposure of a 50%N20/50%O2 mixture, in depressed individuals (n=20) and healthy volunteers
(n=10). We make the hypothesis that brain reactivity will be lower in depressed individuals
nonresponders to N2O compared to responders and healthy controls. This study would provide
further characterisation of the pathophysiology of the antidepressant response to N2O, as
well as providing potential biomakers (Ultrasound and MRI) for treatment response to N2O in
TRD.