Chronic N-methyl-D-aspartate receptor (NMDAR) antagonist treatment can provide valuable neurochemical and neuroanatomical models of experimental psychosis. One such antagonist, ketamine, with its short half-time and well-documented psychotomimetic action, has cognitive effects resembling various aspects of schizophrenia-like symptoms. In order to obtain insights into possible relationships...
Available evidence indicates that a single, low-dose administration of ketamine is a robust, rapid-onset intervention capable of mitigating depressive symptoms in adults with treatment-resistant mood disorders. Additional evidence also suggests that ketamine may offer antisuicide effects. Herein, we propose that the antidepressant effects reported with ketamine administration are mediated, in...
Ketamine produces rapid and long-lasting antidepressant effects in patients. The involvement of ketamine metabolites in these actions has been proposed. The effects of ketamine and its metabolites norketamine and dehydronorketamine on ligand binding to 80 receptors, ion channels and transporters was investigated at a single concentration of 10 μM. The affinities of all three compounds were then...
This analysis examines the neuronal foundation of drug-induced psychomimetic symptoms by relating the severity of these symptoms to changes in functional connectivity for a range of different psychoactive compounds with varying degrees of psychomimetic effects. The repeated measures design included 323 resting-state functional magnetic resonance imaging time series and measures of subjective...
Objective Exposing to NMDAR receptor antagonists, such as ketamine, produces schizophrenia-like symptoms in humans and deteriorates symptoms in schizophrenia patients. Meanwhile, schizophrenia is associated with alterations of cytokines in the immune system. This study aims to examine the serum TNF-α, IL-6 and IL-18 levels in chronic human ketamine users as compared to healthy subjects. The...
BACKGROUND: The purpose of this study was to assess the efficacy and safety and to explore the dose response of esketamine intravenous (IV) infusion in patients with treatment-resistant depression (TRD). METHODS: This multicenter, randomized, placebo-controlled trial was conducted in 30 patients with TRD. Patients were randomly assigned 1:1:1 to receive an IV infusion of .20 mg/kg or .40 mg/kg...
To consolidate the evidence from the literature to evaluate the role of ketamine in the treatment of bipolar depression. Major databases, including MEDLINE, EMBASE, Cochrane, and Scopus, were searched through October 2014, for studies reporting the role of ketamine in the treatment of bipolar depression. Only randomized controlled trials were included in the meta-analysis. We calculated...
We aimed to evaluate the effect of anaesthesia with thiopental (4 mg kg(-1)), ketamine (1 mg kg(-1)) and ketamine-thiopental (1 mg kg(-1) and 4 mg kg(-1), respectively) combination during electroconvulsive therapy (ECT) on the Hamilton Depression Rating Scale (HDRS) and Hamilton Anxiety Rating Scale (HAM-A) and haemodynamic variables in patients with resistant major depression. Patients with...
Ketamine may represent an efficient alternative antidepressant with rapid therapeutic onset; however, the clinical use of ketamine is hampered by psychosis-like side-effects. Recent studies suggest that the nitric oxide (NO) donor sodium nitroprusside (SNP) prevents psychosis-like abnormalities triggered by ketamine or another NMDA receptor (NMDAR) antagonist, phencyclidine (PCP) in rats. SNP...
OBJECTIVE: The authors conducted a systematic review and meta-analysis of ketamine and other N-methyl-d-aspartate (NMDA) receptor antagonists in the treatment of major depression. METHOD: Searches of MEDLINE, PsycINFO, and other databases were conducted for placebo-controlled, double-blind, randomized clinical trials of NMDA antagonists in the treatment of depression. Primary outcomes were...
Major depressive disorder and bipolar depression are among the most prevalent and disabling mental disorders worldwide. Real-world effectiveness trials in major depressive disorder have underscored that most pharmacological options target monoamines, which are involved in a minority (15-20%) of synaptic contacts in the mammalian brain. Most synapses (∼50%) use the amino acid glutamate as their...
BACKGROUND: One of the shortcomings of the available treatments for major depressive disorder (MDD) is the time delay between starting the treatment and achieving an antidepressant response. OBJECTIVES: We aimed to determine the effect of Ketamine as a synergistic antidepressant and anesthetic agent on MDD in electroconvulsive therapy (ECT). PATIENTS AND METHODS: Twenty-two patients with MDD...
Frequent ketamine abuse in adulthood correlates with increased risk of psychosis, as well as cognitive deficits, including disruption of higher-order executive function and memory formation. Although the primary abusers of ketamine are adolescents and young adults, few studies have evaluated its effects on juvenile cognition. Therefore, the current study analyzes the effect of adolescent...
Ketamine is a NMDA receptor antagonist that produces rapid antidepressant responses in individuals with major depressive disorder. The antidepressant action of ketamine has been linked to blocking NMDA receptor activation at rest, which inhibits eukaryotic elongation factor2 kinase leading to desuppression of protein synthesis and synaptic potentiation in the CA1 region of the hippocampus....
Depression and suicide are known to be intricately entwined but the neurobiological basis underlying this association is yet to be understood. Ketamine is an N-methyl d-aspartate (NMDA) receptor antagonist used for induction and maintenance of general anaesthesia but paradoxically its euphoric effects lead to its classification under drugs of abuse. The serendipitous finding of rapid-onset...
The history of ketamine and phencyclidine from their development as potential clinical anaesthetics through drugs of abuse and animal models of schizophrenia to potential rapidly acting antidepressants is reviewed. The discovery in 1983 of the NMDA receptor antagonist property of ketamine and phencyclidine was a key step to understanding their pharmacology, including their psychotomimetic...
Although the efficacy of racemate ketamine, a rapid onset and sustained antidepressant, for patients with treatment-resistant depression was a serendipitous finding, clinical use of ketamine is limited, due to psychotomimetic side effects and abuse liability. Behavioral and side-effect evaluation tests were applied to compare the two stereoisomers of ketamine. To elucidate their potential...
In this paper, we found that subanesthetic doses of ketamine, similar to those used in antidepressant studies, increase anterior theta and gamma power but decrease posterior theta, delta, and alpha power, as revealed by magnetoencephalographic recordings. Dynamic causal modeling of frontoparietal connectivity changes with ketamine indicated a decrease in NMDA and AMPA-mediated...
BACKGROUND: Suicide is a devastating public health problem and very few biological treatments have been found to be effective for quickly reducing the intensity of suicidal ideation (SI). We have previously shown that a single dose of ketamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, is associated with a rapid reduction in depressive symptom severity and SI in patients with...
SUMMARY Major depressive disorder is among the most commonly diagnosed disabling mental diseases. Several non-pharmacological treatments of depression upregulate adenosine concentration and/or adenosine A1 receptors (A1R) in the brain. To test whether enhanced A1R signaling mediates antidepressant effects, we generated a transgenic mouse with enhanced doxycycline-regulated A1R expression,...