Comments to pharmacological and behavioral divergence of ketamine enantiomers by Jordi Bonaventura et al.

Summary

An open-label study of (R)-ketamine for depression cannot establish efficacy due to expectancy biases and large placebo effects, even in treatment-resistant patients. One patient showed clinically meaningful dissociation. The antidepressant efficacy and optimal dose of (R)-ketamine must be determined in randomized controlled trials. A study in healthy volunteers found that (R)-ketamine and (S)-ketamine produced similar frequency and character of dissociative and other central nervous system adverse effects when compared at doses equipotent for NMDAR antagonism.

Study at a glance

Abstract

antidepressant ef fi cacy without dissociative effects ” . Open-label study results cannot be used to establish ef fi cacy, partly because they increase the expectancy biases of both the rater and the patient, and even patients with treatment-resistant depression have shown large placebo effect sizes in trials involving various treatment modalities [17]. Thus, as indicated by Bonaventura et al., the antidepressant ef fi cacy and optimal dose of (R)-ketamine will need to be established in RCTs. Regarding dissociation, one of these patients manifested clinically meaningful dissociation, as indicated by a Clinician-Administered Dissociative States Scale score of 5. As a study in healthy volunteers that (R)-ketamine and (S)-ketamine dissociative and other CNS adverse effects that were similar in frequency, and character when compared at doses selected to be equipotent for NMDAR antagonism