Abstract: Background: Approximately one third of individuals with major depressive disorder have treatment-resistant depression (TRD). Glutamatergic modulators such as the N-methyl-d-aspartate receptor antagonist ketamine have rapid and robust antidepressant effects, but their use has been limited by accessibility and route of administration. This open-label pilot study assessed the adjunctive...
-enantiomer, intranasal esketamine, for the treatment of major depressive disorder (MDD). Initial studies found that a single subanesthetic-dose IV ketamine infusion rapidly (within one day) improved depressive symptoms in individuals with MDD and bipolar depression, with antidepressant effects lasting three to seven days. In 2019, esketamine received FDA approval as an adjunctive treatment for...