Importance: A single subanesthetic dose of ketamine produces an antidepressant response in patients with major depressive disorder (MDD) within hours, but the mechanism of antidepressant effect is uncertain. Objective: To evaluate whether ketamine dose and brain glutamate and glutamine (Glx) and γ-aminobutyric acid (GABA) level responses to ketamine are related to antidepressant benefit and...
There is an ongoing debate as to whether ketamine anesthesia suppresses neurophysiologic complexity at doses sufficient for surgical anesthesia, with previous human studies reporting surrogates of both suppressed and preserved levels of cortical complexity. However, these studies have not assessed cortical dynamics in higher gamma frequencies, which have previously been demonstrated to...
Major depressive disorder (MDD) is a common, serious, debilitating condition affecting 350 million people worldwide, which remains to be unsatisfactorily treated with 53% of patients still complaining of symptoms after completing their courses with the correct dosage. Ketamine, which was approved by the Food and Drug Administration in 2019, is a potential treatment option for those recalcitrant...
Subanesthetic ketamine is found to induce fast-acting and pronounced antidepressant effects, even in treatment resistant depression (TRD). However, it remains unclear how ketamine modulates neural function at the brain systems-level to regulate emotion and behavior. Here, we examined treatment-related changes in the inhibitory control network after single and repeated ketamine therapy in TRD....
Abstract To elucidate the genetic underpinnings of the antidepressant efficacy of S-ketamine (esketamine) nasal spray in major depressive disorder (MDD), we performed a genome-wide association study (GWAS) in cohorts of European ancestry (n = 527). This analysis was followed by a polygenic risk score approach to test for associations between genetic loading for psychiatric conditions, symptom...
OBJECTIVE: Ketamine's effects on different dimensions of depressive symptomatology, including typical/melancholic and atypical depression, remain largely unknown. This study examined the effects of a single intravenous dose of ketamine on general depressive symptoms (measured using the Montgomery-Asberg Depression Rating Scale (MADRS), typical/melancholic symptoms (measured using the MADRS5),...
The objective of this study was to investigate the safety of repeated parenteral ketamine for depression. An electronic survey inquiring about the frequency of adverse events was distributed to providers of parenteral ketamine for depression. In addition, the investigators conducted a search of published studies describing six or more repeated parenteral ketamine treatments administered to...
Augmentative treatment is considered the best second-option when a first-choice drug has partial limitations, particularly by allowing antidepressant dose reduction. Considering that ketamine has significant knock-on effects, this study investigated the effects of single coadministration with subthreshold doses of ketamine plus guanosine in a corticosterone (CORT)-induced animal model of...
Obsessive-Compulsive Disorder (OCD), characterized by intrusive thoughts (obsessions) and repetitive behaviors (compulsions), is associated with dysfunction in fronto-striatal circuits. There are currently no fastacting pharmacological treatments for OCD. However, recent clinical studies demonstrated that an intravenous infusion of ketamine rapidly reduces OCD symptoms. To probe mechanisms...
Ketamine, an anesthetic developed in the early 1960s, is also a popular abused drug among young people at dance parties and raves and among spiritual seekers, because it produces schizophrenia-like symptoms and dissociation (i.e., out-of-body experience). Regarding mood disorders, ketamine exerts robust antidepressant actions in treatment-resistant patients with depression. Ketamine is a...