Medicine
September 1, 2018
Fernanda S. Correia-Melo, Gustavo C. Leal, Michelle S. Carvalho et al.
61 citations
A protocol describes a planned randomized, controlled, double-blind noninferiority trial comparing a single infusion of esketamine (0.25 mg/kg) with racemic ketamine (0.5 mg/kg) for treatment-resistant depression. The primary outcome is remission rates at 24 and 72 hours after infusion. Secondary outcomes include cognition, dissociation, and blood biomarkers. The authors state that no study has directly compared these two forms, and a head-to-head test is needed to see if esketamine is comparable in efficacy and safety.
Trends in Psychiatry and Psychotherapy
May 27, 2025
Mariana V. F. Echegaray, Rodrigo P. Mello, Guilherme M. Magnavita et al.
11 citations
Among people with treatment-resistant depression, the intensity of dissociation caused by a single infusion of ketamine or esketamine is linked to greater antidepressant effect one day later, but only when dissociative symptoms are mild to moderate. For every one-point increase on a dissociation scale up to 15 points, depression scores improved by an average of 0.5 points after 24 hours. This relationship was not observed at 72 hours or 7 days after infusion. The study was not originally designed to test this relationship, so confounding factors were not controlled, and the finding should be considered suggestive rather than definitive.
Psychiatry research
June 1, 2025
Flávia Vieira, Ana Teresa Caliman-Fontes, Breno Souza-Marques et al.
A systematic review of 46 studies on ketamine and its enantiomers for major depressive disorder identified 16 assessment tools used to measure suicidal behavior. Most were explicit, clinician-rated scales such as the Montgomery-Åsberg Depression Rating Scale (MADRS), Hamilton Depression Rating Scale (HAM-D), and Beck Scales for Suicide Ideation. Only the Suicide Ideation and Behavior Assessment Tool (SIBAT) was specifically developed for rapid-acting antidepressant trials. The variety of instruments used across studies makes comparisons difficult. The MADRS is suggested as a reasonable choice for assessing suicidal behavior in this context, though no single tool is universally preferable.
Journal of affective disorders
June 1, 2023
Gustavo C Leal, Breno Souza-Marques, Rodrigo P Mello et al.
In a small pilot trial, the antidepressant arketamine was compared with placebo for treatment-resistant depression. Ten participants received both arketamine (0.5 mg/kg) and saline one week apart in a randomized, double-blind, crossover design. Depression improved over time, but there was no significant difference between arketamine and placebo. Dissociation and other adverse events were minimal. The study was underpowered, and the authors conclude that arketamine was not superior to placebo but was extremely safe, recommending larger trials with different dosing strategies.