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.
European archives of psychiatry and clinical neuroscience
December 16, 2024
Gustavo C Leal, Isabel Lima-Araújo, David G Roiter et al.
7 citations
Arketamine, an enantiomer of ketamine, has been less studied than esketamine or racemic ketamine, but recent preclinical work suggests it may have prolonged antidepressant effects and a better safety profile. This scoping review of 20 studies involving 410 subjects found arketamine was primarily investigated for pain management and depression. Early evidence indicates it may reduce pain, though most studies were small and in non-clinical settings. In psychiatry, trials show potential antidepressant effects, but results are inconsistent and some studies unpublished. A consistent finding is arketamine's favorable safety profile, with fewer dissociative and psychotomimetic effects than esketamine or racemic ketamine. Larger, well-designed studies are needed to determine its therapeutic potential.
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.
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.