A retrospective analysis of ketamine intravenous therapy for post-traumatic stress disorder in real-world care settings.
L. Mcinnes, Robert M. Berman, Matthew J Worley, E. Shih
Psychiatry Research August 20, 2025 DOI: 10.1016/j.psychres.2025.116689 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort study using electronic health record data Peer reviewed |
|---|---|
| Sample size | 8,136 |
| Population | Outpatient psychiatric patients diagnosed with PTSD, 87% with comorbid depression |
| Intervention | Ketamine Intravenous Therapy (KIT) |
| Dose | 0.6-0.8 mg/kg |
| Measures | PTSD Checklist for DSM-5 (PCL-5), Patient Health Questionnaire-9 (PHQ-9) |
| Topics | Esketamine Ketamine PTSD |
| Key findings | The number of ketamine intravenous therapy treatments was associated with significant reductions in PTSD and depression symptoms, with the largest improvements in the first three treatments. By the sixth treatment, model-estimated mean reductions were 22.4 points on the PCL-5 and 7.1 points on the PHQ-9, both exceeding thresholds for clinically meaningful change, though improvements diminished with additional treatments and higher later doses did not appear to meaningfully enhance symptom reduction. |
Abstract
Objective: The study evaluated the effectiveness of Ketamine Intravenous Therapy (KIT) in reducing post-traumatic stress disorder (PTSD) and depression symptoms, using electronic health record data from outpatient psychiatric patients with PTSD.
Method: We analyzed data from 8,136 patients diagnosed with PTSD, 87 % (N = 7,070) of whom also had comorbid depression. Symptom severity was measured using the PTSD Checklist for DSM-5 (PCL-5) and the Patient Health Questionnaire-9 (PHQ-9). Linear mixed effects models were used to estimate changes in symptoms over time, with number of treatments as the primary predictor. Linear, quadratic, and logarithmic terms for treatment number were tested to explore different possible patterns of symptom change over time.
Results: The number of KIT treatments was associated with significant reductions in PTSD and depression symptoms. The model using a logarithmic transformation of treatment number provided the best fit to the data, suggesting diminishing improvements with additional treatments. By the 6th treatment, model-estimated mean reductions reached 22.4 points on the PCL-5 and 7.1 points on the PHQ-9, both exceeding thresholds for clinically meaningful change. The largest improvements occurred within the first three treatments, at doses of 0.6-0.8 mg/kg. While higher doses were often used in later treatments, our findings suggest that this did not appear to meaningfully enhance symptom reduction.
Conclusions: KIT is associated with reduced PTSD and depression symptoms in a community sample, with the most substantial gains occurring early in treatment. These findings support KIT as a promising treatment option for PTSD patients.
Comparable studies
Other observational and cohort studies on ketamine for PTSD, most cited first.