Ketamine also shows promise as a treatment for TRD and and PTSD together, and for PTSD alone. A randomized double-blind crossover trial published in 2014 evaluated the efficacy of ketamine infusions for PTSD versus midazolam — a benzodiazepine sold under the brand Versed1 . In 41 patients seen between 2005 and 2009 at the Icahn School of Medicine in New York, researchers found that, as a primary outcome measure, those randomly assigned ketamine showed greater reduction of PTSD symptoms than those who were administered midazolam.
A single-dose treatment of ketamine resulted in a rapid reduction of PTSD symptoms that were maintained beyond 24 hours by all participants. The treatment was generally well tolerated with dissociative symptoms typically abating within two hours. Common transient side effects included blurred vision, dry mouth, restlessness, fatigue, nausea, poor coordination, and headache.
In a 2018 open-label study2 , researchers investigated the efficacy of serial ketamine infusions (0.5 mg six times in 12 days) in 15 patients experiencing Treatment-Resistant Depression and PTSD comorbidly (simultaneously). The researchers found an 80 percent remission rate for PTSD and a 93 percent response rate for Treatment-Resistant Depression. The median relapse times for those in remission with PTSD and Treatment-Resistant Depression were 41 days and 20 days, respectively. These findings indicate ketamine’s effectiveness in causing a rapid reduction of treatment-resistant and comorbid mental health symptoms.
In a 2021 randomized clinical trial3 of individuals with chronic PTSD, 30 participants were randomly assigned to a test group that received intravenous ketamine or a control group that, like the above study, received an IV psychoactive placebo (midazolam). The ketamine group showed a significant and rapid reduction in PTSD symptoms compared to the control group, lasting more than two weeks post-treatment, with no major side effects.
