A Randomized, Double-blind, Placebo-controlled Phase Il Study to Evaluate the Efficacy, Safety, and Pharmacokinetic Characteristics of (R)-Ketamine Hydrochloride Nasal Spray in Patients With Depression and Acute Suicidal Ideation or Behavior
The purpose of this study is to learn about: * To evaluate the efficacy of PRT-042 nasal spray for the Rapid Reduction of the depressive symptoms in adults with major depressive disorder (MDD) with acute suicidal ideation or behavior * To evaluate the safety and pharmacokinetic (PK) characteristics after multiple dose of PRT-042 nasal spray in adults with major depressive disorder (MDD) with acute suicidal ideation or behavior