Systematic review · 2025
Review of seven trials of IV ketamine for PTSD finds mixed but promising results
- Original title
- Effects of Intravenous Ketamine on Posttraumatic Stress Disorder (PTSD): A Systematic Review.
- Authors
- Yin L, Lu A, Le GH, et al.
- Journal
- Acta psychiatrica Scandinavica, 2025
- Molecules
- Ketamine
- Conditions
- PTSD
- Participants
- 323
- Evidence grade
- Moderate
- Source
- Read the original paper
The question
Does ketamine given by intravenous drip help people with post-traumatic stress disorder (PTSD), and what might be happening in the brain when it does?
What they did
Researchers searched four medical research databases (PubMed, MEDLINE, Embase and PsychINFO) from their beginnings up to September 2025. They included only randomized controlled trials, in which people are assigned by chance to ketamine or to a comparison treatment, testing intravenous ketamine for PTSD. Seven studies with a combined 323 participants met the criteria. The review also looked at brain-imaging findings reported in those trials.
What they found
Two of the seven trials showed meaningful improvement in PTSD symptoms with ketamine compared with a control or placebo, measured on two standard rating scales: the Clinician-Administered PTSD Scale for DSM-5 and the Impact of Event Scale-Revised. Trials using several infusions appeared to do better than those using a single dose. Preliminary findings suggested repeated lower doses (0.2 mg/kg) sustained benefits better than the more commonly used dose (0.5 mg/kg). In people given ketamine, symptom improvement was linked to greater damping of the amygdala, a fear-processing brain region, by the ventromedial prefrontal cortex, an area involved in regulating emotion.
The fine print
Only two of seven trials found a clear benefit over placebo, so the evidence is far from consistent. The total of 323 participants across all studies is small, and the review does not report a pooled statistical estimate, follow-up lengths or side effects. The dose comparison is described as preliminary, and the brain-imaging link is an association, not proof of a mechanism. This summary is based on the abstract alone.
What it means
Intravenous ketamine may help some people with PTSD, particularly when given as a course of infusions rather than once, but the trial evidence so far is small and inconsistent.
Evidence grade: Moderate. A systematic review limited to randomized controlled trials, but it pools only seven small studies with inconsistent findings and reports no combined statistical analysis.
This summary is based on the study’s published abstract.