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.
Harvard Review of Psychiatry
March 1, 2022
Igor D. Bandeira, Daniel H. Lins-Silva, Vitor Breseghello Cavenaghi et al.
35 citations
Ketamine shows potential for fast onset of action and good tolerability in treating obsessive-compulsive disorder (OCD), but results have been erratic. The systematic review included nine articles: three randomized controlled trials, three case reports, two open-label trials, and one retrospective chart review. Most studies used only single-session racemic ketamine administered intravenously. No evidence demonstrates whether racemic ketamine, S-ketamine, or R-ketamine has the best efficacy, and only sparse evidence suggests combining ketamine with psychotherapy could benefit patients. Future randomized, double-blind, placebo-controlled trials with larger samples, multiple sessions, and appropriate washout periods are needed.
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.
Bipolar Disorder
January 1, 2025
Breno Souza-Marques, Ana Teresa Caliman-Fontes, Gustavo C. Leal et al.
Some people with bipolar disorder continue to have symptoms despite available treatments, leading researchers to explore repurposing drugs of abuse—such as stimulants, ketamine, and psychedelics—as novel therapies. While clinical trials show promising efficacy for some of these drugs, concerns about their risks have emerged. This chapter examines the potential benefits and, especially, the associated risks, including addiction, worsening of psychiatric symptoms, and adverse physical and cognitive effects. It offers a balanced risk–benefit analysis that weighs these factors against the severity of bipolar disorder, alternative treatments, and the possibility of individualized risk stratification, aiming to inform clinical decisions and guide future research.