Ketamine Research: Clinical Studies and other Resources

1. Murrough, Perez, et al. “Rapid and Longer-Term Antidepressant Effects of Repeated Ketamine Infusions in Treatment-Resistant Major Depression”  Biological Psychiatry  2013 Aug 15; 74(4): 250–256. 


SUMMARY:  In this article, there were 24 patients treated with six IV infusions of ketamine (.5mg/kg) over 12 days.  The overall response rate was 71% as defined as a reduction in the MADRS scale by  greater than 50%.  The median time to relapse after the last ketamine infusion was 18 days.  25% were symptom free at 90 days, 75% of patients had symptoms free days between 11-27 days.  Side effects were reported to be a mild significant increase in dissociative symptoms.  One patient had to discontinue therapy due to an increase in blood pressure that did not respond to medications (highest BP 180/115).

2. Shiroma, Johns et al. “Augmentation of response and remission to serial intravenous subanesthetic ketamine in treatment resistant depression” Journal  of Affective Disorders. 2014 Feb;155:123-9.


SUMMARY:  In this article, there were 14 patients treated with six IV infusions during a 12 day period.  12 subjects finished all six infusions with 92% response rate and 66% went into remission.  5 out of 11 responders remained in “response status” during the next 28 days.  For the 6 out of 11 responders that relapsed, the mean time was 16 days.  Response was defined as ≥50% improvement in baseline MADRS score and remission was defined as MADRS score ≤9.  No subject experienced severe dissociative symptoms or hemodynamic changes that required stopping the infusions.

3. Sanacora, Frye, McDonald, et al.  “A Consensus Statement on the Use of Ketamine in the Treatment of Mood Disorders”  JAMA Psychiatry. April 2017;74(4):399-405.


SUMMARY:  This review and consensus statement provides a general overview of the data on the use of ketamine for the treatment of mood disorders and highlights the limitations of the existing knowledge.  The suggestions provided are intended to facilitate clinical decision making and encourage an evidence-based approach to using ketamine in the treatment of psychiatric disorders considering the limited information that is currently available. This article provides information on potentially important issues related to the off-label treatment approach that should be considered to help ensure patient safety.

4. Correll, Maleki et al.  “Subanesthetic ketamine infusion therapy: a retrospective analysis of a novel therapeutic approach to complex regional pain syndrome.”  Pain Medicine. 2004 Sep;5(3):263-75.


SUMMARY:  This article reviewed 33 cases of patients with CRPS that were treated with Ketamine infusion.  The patients received a prolonged low dose infusion of ketamine, on average 10-20mg/hr over 2-4 days.  76% of patients experienced complete pain relief after the first course of treatment.  Pain relief lasted at least three months for most patients.  Adding a second course of treatment allowed over 50% to be pain free for over a year.  One patient had to discontinue additional treatments after the first infusion after developing elevated liver enzymes.  These did normalize after treatment was stopped.

5. Patil SAnitescu M. “Efficacy of outpatient ketamine infusions in refractory chronic pain syndromes: a 5-year retrospective analysis. Pain Medicine. 2012 Feb;13(2):263-9.


SUMMARY:  This article reviewed 49 patients receiving outpatient ketamine infusions for various pain syndrome – 18 with CRPS.  For patients with CRPS, the average reduction in the pain score on a ten point scale was 7.2.  For the other pain conditions, the average reduction in the pain score was 5.1.  Average pain relief was at least three weeks.

6. Feder, Parides et al.  “Efficacy of intravenous ketamine for treatment of chronic posttraumatic stress disorder: a randomized clinical trial.”  JAMA Psychiatry. 2014 Jun;71(6):681-8.


SUMMARY:  In this double blind, placebo-controlled cross over study, a single dose of Ketamine (.5mg/kg over 40 minutes) was compared to midazolam.  Authors note a significant immediate reduction in the CAPS score and frequently this reduction was maintained for over 2 weeks.  The only side effects noted were transient dissociative symptoms, none of which required stopping the infusion.