High-dose ketamine infusion for the treatment of posttraumatic stress disorder in combat veterans

Ann Clin Psychiatry. 2019 Nov;31(4):271-279.


Introduction: Combat veterans are at high risk for the development of posttraumatic stress disorder (PTSD) and substance use disorders. Ketamine has been shown to be an effective treatment for numerous mental health disorders, although research on its efficacy in combat-related PTSD in veterans is very limited.

Methods: The study population consisted of 30 US military veterans with combat-related PTSD. Participants underwent a standard induction series of six 1-hour ketamine infusions with the goal of obtaining a transpersonal dissociative experience. Participants were given a series of self-report questionnaires to assess for changes in symptoms of depression, PTSD, and substance use prior to the first and sixth infusions.

Results: Symptoms of depression as measured by change in score on the Patient Health Questionnaire decreased significantly from an average of 18.9 to 9.5 (P < .001). Similarly, symptoms of PTSD as measured by change in score on the PSTD Checklist for DSM-5 dropped significantly from an average of 56.2 to 31.3 (P < .001). Self-reported levels of substance use did not significantly decrease during the study period, although the level of use trended down.

Conclusions: This observational study suggests that high-dose ketamine infusion therapy, which induced a transpersonal dissociative experience, could be a valuable tool in the treatment of combat-related PTSD. Further study is needed to better elucidate ketamine's mechanism of action with regards to the treatment of PTSD.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Dissociative Disorders / psychology
  • Female
  • Humans
  • Infusions, Intravenous*
  • Ketamine / therapeutic use*
  • Male
  • Middle Aged
  • Psychiatric Status Rating Scales / statistics & numerical data
  • Self Report
  • Stress Disorders, Post-Traumatic / drug therapy*
  • Stress Disorders, Post-Traumatic / epidemiology
  • Surveys and Questionnaires
  • Treatment Outcome
  • Veterans / psychology
  • Veterans / statistics & numerical data*


  • Ketamine