Repeated ketamine infusions for antidepressant-resistant PTSD: Methods of a multicenter, randomized, placebo-controlled clinical trial

Posttraumatic stress disorder (PTSD) is a debilitating disorder with limited medication treatment options. Recent reports have described the dearth of research on new drug development as a crisis in the pharmacotherapy of PTSD. There are only two PTSD medications approved by the U.S. Food and Drug Administration, and both are serotonergic antidepressants. Therefore, there is a tremendous need to identify more effective and more rapidly acting pharmacotherapies for PTSD that work through novel neural mechanisms. Pilot evidence and case reports provided preliminary evidence supporting the safety and utility of investigating the therapeutic effects of ketamine in PTSD. However, the efficacy of this drug for PTSD has not yet been tested in active duty military or veteran populations. Here, we report the design and methods of a study funded under the Consortium to Alleviate PTSD. The study is a multisite, placebo-controlled, double–blind, randomized clinical trial to examine the dose-related efficacy of ketamine, as compared to placebo, in producing a rapid and sustained reduction in PTSD symptomatology in veterans and active duty military populations with antidepressant-resistant PTSD. Approximately 198 eligible participants who meet criteria for PTSD will be randomized to the study drug (i.e., ketamine 0.5 mg/kg, ketamine 0.2 mg/kg, or placebo). The study drug will be administered intravenously twice per week for 4 weeks, followed by a 4-week follow-up period. This ongoing study is the only trial of therapeutic effects of ketamine for PTSD and the first placebo-controlled trial to determine the dose-related effects of repeated ketamine on PTSD.