This parallel-group, randomised, quadruple-blind, controlled trial (n=104 planned; 63 actual) compares up to eight IV ketamine infusions (0.05 mg/kg) versus midazolam (0.045 mg/kg) in inpatients with major depressive episodes.
Pragmatic, randomised, parallel-group superiority trial in patients admitted to St Patrick's University Hospital for a major depressive episode; participants randomised 1:1 to up to eight twice-weekly infusions of ketamine or midazolam over up to four weeks.
Primary outcome compares mood-rating change from before first infusion to 24 hours after final infusion; participants followed for 24 weeks to assess relapse. Blinding includes participants and assessors; clinical and safety monitoring performed throughout.
Up to eight twice-weekly sub-anaesthetic ketamine infusions over up to four weeks (inpatient), administered by anaesthetist.
Up to eight infusions over four weeks; administered by consultant anaesthetist.
Up to eight twice-weekly midazolam infusions over up to four weeks (inpatient), administered by anaesthetist.
Midazolam (Hypnovel) 0.045 mg/kg given as active comparator; recorded as active comparator in registry.