2019 · RCT
Phillips et al. 2019 - repeat dosing
Single and repeated ketamine infusions for reduction of treatment-resistant depression
Medically reviewed by: Pending medical review(draft)Last updated: June 4, 2026Evidence: Phillips JL et al.. American Journal of Psychiatry, 2019.
Population
41 patients with TRD
Intervention
Single vs repeated (6) IV ketamine infusions
Comparator
Within-subject comparison
Primary outcome
MADRS response and remission
Key findings
- Repeated dosing produced higher response rates than single dose
- Median time to relapse was modest without maintenance
- Supports a course-based protocol approach
Limitations
- Modest sample
- Open-label maintenance phase
Educational use only. The content on this page is provided for general educational purposes and does not constitute medical advice, diagnosis, or treatment. Ketamine and related therapies carry risks and are appropriate only under qualified medical supervision. Always consult a licensed healthcare professional about your individual situation. Information may change as research evolves.