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A Randomized Controlled Trial of Repeated Ketamine Administration for Chronic Posttraumatic Stress Disorder.

Adriana Feder, Sara Costi, Sarah B. Rutter, A. Collins, Usha Govindarajulu, Manish K. Jha, Sarah R. Horn, Marin Kautz, Morgan Corniquel, Katherine A. Collins, L. Bevilacqua, Andrew M. Glasgow, Jess W. Brallier, Robert H Pietrzak, James W. Murrough, Dennis S. Charney

American Journal of Psychiatry January 5, 2021 DOI: 10.1176/appi.ajp.2020.20050596 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Randomized controlled trial Peer reviewed
Sample size 30
Population Individuals with chronic PTSD
Interventions Ketamine Midazolam
Dose 0.5 mg/kg
Duration 2-week infusion period, with follow-up to assess loss of response
Topics Esketamine Ketamine PTSD
Citations 239
Key findings Repeated ketamine infusions significantly reduced PTSD symptom severity compared to midazolam, with a large effect size and a 67% responder rate at two weeks.

Abstract

Objective: Posttraumatic stress disorder (PTSD) is a chronic and disabling disorder, for which available pharmacotherapies have limited efficacy. The authors' previous proof-of-concept randomized controlled trial of single-dose intravenous ketamine infusion in individuals with PTSD showed significant and rapid PTSD symptom reduction 24 hours postinfusion. The present study is the first randomized controlled trial to test the efficacy and safety of repeated intravenous ketamine infusions for the treatment of chronic PTSD.

Methods: Individuals with chronic PTSD (N=30) were randomly assigned (1:1) to receive six infusions of ketamine (0.5 mg/kg) or midazolam (0.045 mg/kg) (psychoactive placebo control) over 2 consecutive weeks. Clinician-rated and self-report assessments were administered 24 hours after the first infusion and at weekly visits. The primary outcome measure was change in PTSD symptom severity, as assessed with the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5), from baseline to 2 weeks (after completion of all infusions). Secondary outcome measures included the Impact of Event Scale-Revised, the Montgomery-Åsberg Depression Rating Scale (MADRS), and side effect measures.

Results: The ketamine group showed a significantly greater improvement in CAPS-5 and MADRS total scores than the midazolam group from baseline to week 2. At week 2, the mean CAPS-5 total score was 11.88 points (SE=3.96) lower in the ketamine group than in the midazolam group (d=1.13, 95% CI=0.36, 1.91). Sixty-seven percent of participants in the ketamine group were treatment responders, compared with 20% in the midazolam group. Among ketamine responders, the median time to loss of response was 27.5 days following the 2-week course of infusions. Ketamine infusions were well tolerated overall, without serious adverse events.

Conclusions: This randomized controlled trial provides the first evidence of efficacy of repeated ketamine infusions in reducing symptom severity in individuals with chronic PTSD. Further studies are warranted to understand ketamine's full potential as a treatment for chronic PTSD.

In the evidence

This study is part of the evidence base for 2 syntheses in the library. Here is how each one recorded it.

  • Six ketamine infusions over two weeks produced significantly greater improvement in PTSD and depression scores than midazolam, with a large effect size and a 67% responder rate.

    Synthesized

  • Repeated ketamine infusions significantly reduced PTSD symptom severity compared to midazolam, with a large effect size and a 67% responder rate at two weeks.

    Synthesized

Comparable studies

Other randomized controlled trials on ketamine for PTSD, most cited first.

Study Year Design Participants
Efficacy of Intravenous Ketamine for Treatment of Chronic Posttraumatic Stress Disorder Patients with chronic PTSD related to a range of trauma exposures 2014 Randomized controlled trial n = 41
Long term structural and functional neural changes following a single infusion of Ketamine in PTSD Individuals diagnosed with PTSD 2023 Randomized controlled pilot trial n = 27
d-Serine is a potential biomarker for clinical response in treatment of post-traumatic stress disorder using (R,S)-ketamine infusion and TIMBER psychotherapy: A pilot study. Patients with post-traumatic stress disorder (PTSD) 2018 Pilot randomized placebo-controlled study n = 20
Ketamine-enhanced prolonged exposure therapy in veterans with PTSD: A randomized controlled trial protocol. Veterans with PTSD 2024 Randomized controlled trial n = 100
Combining DNA methylation features and clinical characteristics predicts ketamine treatment response for PTSD. Participants in the CAP-ketamine trial with PTSD 2026 Randomized controlled trial

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