Previous research suggests that a single-dose of intravenous ketamine infusion results in significant and rapid reduction of posttraumatic stress disorder (PTSD) symptoms . Building on these findings, in a recent randomized controlled trial (RCT), repeated administration of ketamine infusions was tested for the efficacy and safety of treating chronic PTSD. Patients with chronic PTSD (n=30) were randomly assigned to receive six infusions of ketamine (0.5 mg/kg), or midazolam (0.045mg/kg) (the psychoactive placebo control) over 2 consecutive weeks. Assessments were made at 24 hours after the first infusion and at weekly visits. The primary outcome measure was change in PTSD symptom severity, assessed by the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5), from baseline to 2 weeks (after completion of all infusions). Secondary outcome measures were comprised of the Impact of Event-Scale-Revised, the Montgomery-Asberg Depression Rating Scale (MADRS), and side effects measures. The patients in the ketamine group demonstrated significantly greater improvement in CAPS-5 and MADRS total scores from baseline to week 2, compared to the midazolam group. This RCT offers the first evidence of efficacy of repeated ketamine infusions in reducing symptom severity in patients with PTSD. Future studies are needed.
References: Feder et al. The American Journal of Psychiatry 2021; Epub ahead of print. Abstract