A Study to Assess the Efficacy and Safety of PRT-042 Nasal Spray for the Rapid Reduction of the Symptoms of Major Depressive Disorder, Including Suicidal Ideation, in Participants Who Are Assessed to be at Imminent Risk for Suicide
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
• Participant must meet Diagnostic and Statistical Manual of Mental Disorders (5th edition) (DSM-5) diagnostic criteria for Major Depressive Disorder (MDD), without psychotic features, based upon clinical assessment and confirmed by the Mini International Psychiatric Interview (MINI) .
• Participants must have current suicidal ideation with intent, confirmed by a Yes response to Question B3 \[Think (even momentarily) about harming or of hurting or of injuring yourself: with at least some intent or awareness that you might die as a result; or think about suicide (ie, about killing yourself)?\] and Question B10 \[Intend to act on thoughts of killing yourself?\] obtained from the MINI.
• Participant has a Montgomery Asberg Depression Rating Scale (MADRS) total score of greater than (≥) 28 and the score for item 10suicide ideation of greater than (≥) 3 predose on Day 1