Randomised, triple-blind, parallel pilot trial (n=6) comparing once-weekly IV ketamine 0.5 mg/kg vs midazolam 0.045 mg/kg for up to four weeks to prevent relapse after successful ECT in adults with major depressive disorder.
This pilot trial recruited ECT responders with major depressive disorder and randomised consenting responders to once-weekly intravenous ketamine (0.5 mg/kg) or midazolam (0.045 mg/kg) infusions for up to four weeks, with six-month follow-up for relapse.
The primary aim was feasibility and process outcomes to inform a definitive trial; the clinical secondary outcome was relapse rate at six months measured by the HRSD-24. Safety, cognitive effects and dissociative/psychotomimetic symptoms were assessed during and after infusions.
Assessments included baseline and weekly HRSD-24 scores, CADSS and BPRS for dissociative and psychotomimetic effects, cognitive battery including ACE-R and K-AMI, and monitoring of adverse events throughout the study.
Intravenous ketamine infusions 0.5 mg/kg over 40 minutes, up to four once-weekly infusions.
Infusion over 40 minutes; course up to four once-weekly infusions.
Intravenous midazolam 0.045 mg/kg over 40 minutes, up to four once-weekly infusions (active comparator).
Midazolam 0.045 mg/kg (Roche Products Ireland Ltd) as active comparator; prepared as 50 ml saline infusion over 40 minutes.