Background
TRD, acute suicidal ideation or behavior, illness, depressive disorder, depressive symptoms, MDD
Major depressive disorder (MDD) is a disabling illness with a lifetime prevalence globally of ~ 15% (> 300 million people worldwide) and 20.6% in US adults [TRD is associated with poor health-related quality of life (HRQoL) [Recently, the N-methyl-D-aspartate receptor antagonist esketamine (ESK; the S-enantiomer of ketamine racemate) nasal spray, in conjunction with an oral AD, was approved by the U.S. Food and Drug Administration for the treatment of TRD and depressive symptoms in patients with MDD who have acute suicidal ideation or behavior [