To Test the Potential Efficacy of Repeated Intranasal Administration of Ketamine as a Treatment for PTSD

The objective of the present research protocol, a parallel-arm, double-blind, randomized controlled clinical trial, is to test the efficacy of repeated intranasal administration of the glutamatergic NMDA receptor antagonist ketamine in providing (1) rapid relief of and (2) sustained improvement in core PTSD symptoms and co-morbid depressive symptoms in patients with chronic PTSD. The effects of ketamine will be compared with those of repeated intranasal administration of the benzodiazepine anesthetic midazolam, which mimics some of the acute subjective effects of ketamine but is expected to have lesser or less sustained anxiolytic effect, and no sustained antidepressant effect.