Insomnia and anxiety frequently co-occur with treatment-resistant depression (TRD). This study examined short-term changes in depression, anxiety, and insomnia symptoms post-ketamine in TRD and their inter-relationships. Seventy-one patients with TRD were assessed at baseline and 24 h after intravenous ketamine (0.5 mg/kg). Depression, anxiety, and insomnia were measured using the...
Treatment-resistant depression (TRD) remains a major clinical challenge, with highly variable responses to ketamine. Immune activation characterizes a subset of patients with TRD. The kynurenine pathway (KP), which integrates immunometabolic signals with glutamatergic neurotransmission, may provide candidate biomarkers to inform personalized treatment. We investigated whether KP metabolites and...
Ketamine exerts rapid antidepressant effects. However, currently available ketamine-based treatments are associated with dissociative and cardiovascular adverse effects. To evaluate the antidepressant efficacy and tolerability of KET01, a novel, oral, prolonged-release racemic ketamine tablet formulation. KET01-03 was an active-comparator, double-blind, double-dummy, crossover phase 1...
Introduction: This is the first randomized controlled trial to use both qualitative and quantitative methods to evaluate the effects of a combined sensory intervention that included mindfulness, music, and a light-occluding eye mask during antidepressant-dose ketamine treatment for depression. Methods: Forty-three participants with unipolar depressive disorder enrolled in the study; 22...
Abnormalities during rapid eye movement (REM) sleep contribute to the pathophysiology of major depressive disorder (MDD), but few studies have explored the relationship between REM sleep and treatment-resistant depression (TRD). In MDD, REM sleep abnormalities often manifest as alterations in total night REM Density (RD), RD in the first REM period (RD1), and REM Latency (RL). Among these, RD1...
Ketamine's antidepressant effects have been linked to its modulation of glutamatergic neurotransmission and synaptic plasticity. However, the precise roles of both glutamate (Glu) levels and brain-derived neurotrophic factor (BDNF) in this process remain incompletely understood. This study examined the relationship between ketamine-induced changes in Glu levels and peripheral BDNF levels using...
Ketamine is a dissociative anesthetic that induces a shift in global consciousness states and related brain dynamics. Portable low-density EEG systems could be used to monitor these effects. However, previous evidence is almost null and lacks adequate methods to address global dynamics with a small number of electrodes. This study delves into brain high-order interactions (HOI) to explore the...
Music and ketamine are both known to affect therapeutic outcomes, but few studies have investigated their co-administration. This scoping review describes the existing literature on the joint use of music and ketamine-or esketamine (the S(+) enantiomer of ketamine)-in humans. The review considers that extant studies have explored the intersection of ketamine/esketamine and music in healthy...
The NMDA antagonist S-ketamine is gaining increasing use as a rapid-acting antidepressant, although its exact mechanisms of action are still unknown. In this study, we investigated ketamine in respect to its properties toward central noradrenergic mechanisms and how they influence alertness behavior. We investigated the influence of S-ketamine on the locus coeruleus (LC) brain network in a...
Subanesthetic doses of ketamine induce an antidepressant effect within hours in individuals with treatment-resistant depression while it furthermore induces immediate but transient psychotomimetic effects. Among these psychotomimetic effects, an altered sense of self has specifically been associated with the antidepressant response to ketamine as well as psychedelics. However, there is plenty...
In a double-blinded cross-over design, 30 adults (mean age = 25.57, SD = 3.74; all male) were administered racemic ketamine and compared against saline infusion as a control. Both task-driven (auditory oddball paradigm) and resting-state EEG were recorded. HOI were computed using advanced multivariate information theory tools, allowing us to quantify nonlinear statistical dependencies between...
Ketamine is a rapid-acting antidepressant that also influences neural reactivity to affective stimuli. However, the effect of ketamine on behavioral affective reactivity is yet to be elucidated. The affect-modulated startle reflex paradigm (AMSR) allows examining the valence-specific aspects of behavioral affective reactivity. We hypothesized that ketamine alters the modulation of the startle...
Abstract Ketamine shows rapid antidepressant effects peaking 24 h after administration. The antidepressant effects may occur through changes in glutamatergic metabolite levels and resting-state functional connectivity (rsFC) within the default mode network (DMN). A multistage drug effect of ketamine has been suggested, inducing acute effects on dysfunctional network configuration and delayed...
Background: More than 2% of the general population experience suicidal ideas each year and a large number of them will attempt suicide. Evidence-based therapeutic options to manage suicidal crisis are currently limited. Objectives: The aim of this study was to overview the findings on the use of ketamine and esketamine for the treatment of suicidal ideas and acts. Design: Systematic review....
Any macrosystem consists of many microparticles. According to statistical physics, the macroproperties of a system are realized as the statistical average of the corresponding microproperties. In our study, a model based on ensemble theory from statistical physics is proposed. Specifically, the functional connectivity (FC) patterns confirmed by Leading Eigenvector Dynamics Analysis (LEiDA) are...
Ketamine is a drug that reduces depressive and elicits schizophrenia-like symptoms in humans. However, it is largely unexplored whether women and men differ with respect to ketamine-action and whether age contributes to drug-effects. In this study we assessed dissociative symptoms via the Clinician Administered Dissociative States Scale (CADSS) in a total of 69 healthy subjects aged between 18...
Ketamine acts as a rapid-acting antidepressant by restoring glutamatergic deficits and activating synaptic plasticity processes, with peak activity 24 h after infusion. Microtubule dynamics are known to play a key role in modulation of cytoskeleton and synaptic plasticity, as well as in signalling events in peripheral blood cells. Here, we correlated ketamine-induced change in...
Recently, ketamine has been investigated as a potential antidepressant option for treatment resistant depression. Unlike traditional drugs, it yields immediate effects, most likely via increased glutamatergic transmission and synaptic plasticity. However, ketamine administration in humans is systemic and its long-term impact on blood parameters has not yet been described in clinical studies....
Ketamine is receiving increasing attention as a rapid-onset antidepressant in patients suffering from major depressive disorder (MDD) with treatment resistance or severe suicidal ideation. Ketamine modulates several neurotransmitter systems, including norepinephrine via the norepinephrine transporter (NET), both peripherally and centrally. The locus coeruleus (LC), which has high NET...
Distraction and rumination are distinct response styles that determine how an individual deals with negative thoughts and feelings. Rumination is accompanied by an elevated self-focus, which is associated with increased resting state functional connectivity and decreased reactivity within the default mode network. Interestingly, the NMDA receptor antagonist ketamine reduces functional...
Increased amygdala reactivity might lead to negative bias during emotional processing that can be reversed by antidepressant drug treatment. However, little is known on how N-methyl-d-aspartate (NMDA) receptor antagonism with ketamine as a novel antidepressant drug target might modulate amygdala reactivity to emotional stimulation. Using functional magnetic resonance imaging (fMRI) and...
The topic of investigating how mindfulness meditation training can have antidepressant effects via plastic changes in both resting state and meditation state brain activity is important in the rapidly emerging field of neuroplasticity. In the present study, we used a longitudinal design investigating resting state fMRI both before and after 40 days of meditation training in 13 novices. After...
Increasing preclinical and clinical evidence underscores the strong and rapid antidepressant properties of the glutamate-modulating NMDA receptor antagonist ketamine. Targeting the glutamatergic system might thus provide a novel molecular strategy for antidepressant treatment. Since glutamate is the most abundant and major excitatory neurotransmitter in the brain, pathophysiological changes in...
Ketamine is a potent glutamatergic NMDA receptor antagonist with rapid antidepressant properties, thus providing a valuable research tool for the investigation of the neurobiology of major depressive disorder (MDD). Increasing evidence underscores the role of glutamate dependent neuroplasticity and glutamatergic neurotransmission and metabolism in the pathophysiology of MDD. This multimodal...
Background: Ketamine is a potent NMDA receptor antagonist with rapid antidepressant properties at subanaesthetic doses. This multimodal imaging study reveals the effects of a subanaesthetic ketamine infusion on fMRI-BOLD responses during an emotional processing task and their relationship to glutamatergic metabolite concentrations in the pregenual anterior cingulate cortex (PACC) assessed by...