Nitrous Oxide as a Putative Novel Dual-Mechanism Treatment for Bipolar Disorder
Status:
Terminated
Trial end date:
2020-06-07
Target enrollment:
Participant gender:
Summary
This study is a 7-day randomized, double-blind proof-of-concept pilot study of nitrous oxide
vs. midazolam in 40 adults (20-60 years) with bipolar disorder (BD) (type I or II). Ongoing
pharmacological and psychosocial treatments may continue, provided that they have not been
initiated or significantly modified in the preceding 2 weeks. Participants' current treatment
as prescribed by clinical psychiatrists will not be modified or interfered in this study. The
study involves 3 visits. During study visit 1, participants will complete screening to ensure
study eligibility. This will be done using interview measures. During study visit 2,
participants will complete anthropomorphic measurements, measurement of endothelial function,
screening blood work, ECGs, and an anaesthesia screener. During study visit 3, participants
will receive the treatment (nitrous oxide or midazolam), complete an MRI scan, and complete
interview measures and self-reports. There will be anthropomorphic measurements taken as
well. The participant will be required to complete phone interviews and self-reports over the
subsequent 7 days. There are 4 main predictions: 1. Nitrous oxide will significantly reduce
depression symptoms vs. midazolam. 2. Nitrous oxide will significantly increase frontal
cortical perfusion vs. midazolam. 3. Lower perfusion in frontal cortical regions at baseline
will be associated with greater improvement in depression symptoms following nitrous oxide
treatment. 4. Poorer endothelial function will be associated with greater improvement in
depression symptoms following nitrous oxide treatment.