Effect of Ketamine vs. Active Placebo on Suicidal Ideation in Depressed Inpatients With Major Depressive Disorder or Bipolar Depression

This double-blind, randomized, parallel-group pilot study tests whether repeated IV ketamine plus treatment as usual reduces suicidal ideation more than an active placebo (midazolam) plus treatment as usual in inpatients with major depressive disorder or bipolar depression.

Participants receive six infusions (0.5 mg/kg ketamine or 0.045 mg/kg midazolam) infused over ~40 minutes across two weeks; primary outcomes include SSI and C-SSRS at days 14 and 42, with MADRS and safety monitoring as secondary measures.