A retrospective analysis of ketamine intravenous therapy for post-traumatic stress disorder in real-world care settings.

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.