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.
Schizophrenia research
September 1, 2024
Ana Teresa Caliman-Fontes, Flávia Vieira, Gustavo C Leal et al.
7 citations
Catatonia, a condition recognized since the 1800s, remains difficult to diagnose and treat. A systematic review of 20 studies involving 25 patients who received ketamine or esketamine for catatonia found that 80% of patients responded to treatment and 44% achieved remission, with no worsening of catatonic or psychotic symptoms. Only one patient stopped treatment due to intolerable dissociative effects. Most patients were female (61.9%), with an average age of 44.4 years, and had underlying mood disorders. The evidence suggests ketamine may be effective for catatonia, even in patients with psychotic disorders, where it has traditionally been considered contraindicated. The authors advocate reevaluating this contraindication, noting potentially greater benefits for those with mood disorders.
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 psychiatric research
August 1, 2023
Igor D Bandeira, Gustavo C Leal, Fernanda S Correia-Melo et al.
In a pilot trial of six people with bipolar I or II disorder who had been depressed for at least four weeks, two intravenous infusions of arketamine (0.5 mg/kg followed one week later by 1 mg/kg) rapidly reduced depression severity. Depression scores on the Montgomery-Åsberg Depression Rating Scale fell from a baseline mean of 36.66 to 27.83 one day after the first infusion and from 32.0 to 17.66 one day after the second infusion. The drug was well tolerated with almost no dissociation and no manic symptoms. The findings suggest arketamine has rapid-acting antidepressant properties for bipolar depression, consistent with earlier animal research on major depression.
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.