Use of nitrous oxide in the treatment of major depressive disorder and treatment-resistant major depressive disorder: A systematic review and meta-analysis nitrous oxide in depressive disorders.

Major Depressive Disorder (MDD) has, as a conventional treatment, pharmacological therapy with selective monoamine reuptake inhibitors. However, the medication does not always have a rapid action for exacerbated cases, and moreover, it is estimated that 15 to 30% of patients do not respond effectively to conventional treatment, leading to 'treatment-resistant depressive mood disorder' (TRD). Thus, it is necessary to search for new therapeutic methods for exacerbated and resistant cases.