Antidepressant Efficacy Of Ketamine Research Articles

Predicting Antidepressant Effects of Ketamine: the Role of the Pregenual Anterior Cingulate Cortex as a Multimodal Neuroimaging Biomarker.

Growing evidence underscores the utility of ketamine as an effective and rapid-acting treatment option for major depressive disorder (MDD). However, clinical outcomes vary between patients. Predicting successful response may enable personalized treatment decisions and increase clinical efficacy. We here explored the potential of pregenual anterior cingulate cortex (pgACC) activity to predict antidepressant effects of ketamine in relation to ketamine-induced changes in glutamatergic metabolism. Prior to a single i.v. infusion of ketamine, 24 patients with MDD underwent functional magnetic resonance imaging during an emotional picture-viewing task and magnetic resonance spectroscopy. Changes in depressive symptoms were evaluated using the Beck Depression Inventory measured 24 hours pre- and post-intervention. A subsample of 17 patients underwent a follow-up magnetic resonance spectroscopy scan. Antidepressant efficacy of ketamine was predicted by pgACC activity during emotional stimulation. In addition, pgACC activity was associated with glutamate increase 24 hours after the ketamine infusion, which was in turn related to better clinical outcome. Our results add to the growing literature implicating a key role of the pgACC in mediating antidepressant effects and highlighting its potential as a multimodal neuroimaging biomarker of early treatment response to ketamine.

The Neglected Role of Psychotherapy for Treatment-Resistant Depression.

The Neglected Role of Psychotherapy for Treatment-Resistant Depression.

Study protocol for SKIPMDD: subcutaneous ketamine infusion in palliative care patients with advanced life limiting illnesses for major depressive disorder (phase II pilot feasibility study)

IntroductionMajor depressive disorder (MDD) in people with advanced life-limiting illnesses can have significant impact on the quality-of-life of those affected. The management of MDD in the palliative care setting can...

Ketamine specifically reduces cognitive symptoms in depressed patients: An investigation of associated neural activation patterns

Major depressive disorder (MDD) is characterized by heterogeneous cognitive, affective and somatic symptoms. Hence, the investigation of differential treatment effects on these symptoms as well as the identification of symptom specific biomarkers might crucially contribute to the development of individualized treatment strategies.We here aimed to examine symptom specific responses to treatment with ketamine, which repeatedly demonstrated rapid antidepressant effects in severe MDD. Additionally, we investigated working memory (WM) related brain activity associated with changes in distinct symptoms in order to identify specific response predictors. In a sample of 47 MDD patients receiving a single sub-anesthetic dose of ketamine, we applied a three-factor solution of the Beck Depression Inventory (BDI) to detect symptom specific changes 24 h post-infusion. A subsample of 16 patients underwent additional fMRI scanning during an emotional working memory task prior to ketamine treatment. Since functional aberrations in the default mode network (DMN) as well as in the dorsolateral prefrontal cortex (DLPFC) have been associated with impaired cognitive and emotional processing in MDD, we investigated neural activity in these regions.Our results showed that ketamine differentially affects MDD symptoms, with the largest symptom reduction in the cognitive domain. WM related neuroimaging results indicated that a more pronounced effect of ketamine on cognitive symptoms is predicted by lower DMN deactivation and higher DLPFC activation. Findings thereby not only indicate that ketamine's antidepressant efficacy is driven by a pro-cognitive mechanism, but also suggest that this might be mediated by increased potential for adaptive adjustment in the circumscribed brain regions.

Anxiety during ketamine infusions is associated with negative treatment responses in major depressive disorder

About 20 to 30 percent of patients with Major Depressive Disorder (MDD) do not respond to standard treatment and are considered treatment-resistant. The N-methyl-d-aspartate (NMDA) glutamate receptor antagonist ketamine has demonstrated rapid antidepressant effects in treatment-resistant MDD, but it is unknown whether its acute psychological effects are related to the later antidepressant effect. Therefore, we investigated the association between antidepressant responses to ketamine and the quality of ketamine-induced psychological experiences in MDD. A total of 31 patients (M = 49.5 ± 11.2 years, 16 women) were treated with three ketamine infusions per week (0.5 mg/ kg over 40 min) administered for two consecutive weeks. Depression severity was assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline, after four and 24 h and at end of treatment. The 5-Dimensional Altered States of Consciousness Rating Scale (5D-ASC) was applied four hours after the first infusion to assess the subjective quality of acute psychological effects. Patients with a ≥ 50% MADRS reduction from baseline to end of treatment were considered as responders. After six infusions, 17 of 31 patients (55%) showed a response to ketamine treatment, while 14 patients (45%) had no response. Anxiety-related experiences induced by ketamine were significantly higher in non-responders. Percentage MADRS reduction after four hours and individual levels of ketamine-induced anxiety were predictive of a response at end of treatment. The study demonstrated the considerable impact of ketamine-induced anxiety on the antidepressant efficacy of ketamine. It underpins the importance of considering patients’ subjective experiences and underlines the possibility of a phenotypic response predictor.

Role of Actinobacteria and Coriobacteriia in the antidepressant effects of ketamine in an inflammation model of depression

Ketamine, an N-methyl-d-aspartic acid receptor (NMDAR) antagonist, elicits rapid-acting and sustained antidepressant effects in treatment-resistant depressed patients. Accumulating evidence suggests that gut microbiota via the gut-brain axis play a role in the pathogenesis of depression, thereby contributing to the antidepressant actions of certain compounds. Here we investigated the role of gut microbiota in the antidepressant effects of ketamine in lipopolysaccharide (LPS)-induced inflammation model of depression. Ketamine (10 mg/kg) significantly attenuated the increased immobility time in forced swimming test (FST), which was associated with the improvements in α-diversity, consisting of Shannon, Simpson and Chao 1 indices. In addition to α-diversity, β-diversity, such as principal coordinates analysis (PCoA), and linear discriminant analysis (LDA) coupled with effect size measurements (LEfSe), showed a differential profile after ketamine treatment. Furthermore, a total of 30 bacteria were significantly altered in the LPS + saline treated mice and LPS + ketamine treated mice. Interestingly, two bacteria, including the phylum Actinobacteria and the class Coriobacteriia were significantly correlated with the immobility time of FST. Importantly, the receiver operating characteristic (ROC) curves demonstrated that the phylum Actinobacteria and the class Coriobacteriia were potential biomarker for the antidepressant effects of ketamine in an inflammation model. These findings suggest that antidepressant effects of ketamine might be related to the regulation of abnormal composition of gut microbiota, and that the phylum Actinobacteria and the class Coriobacteriia might be potential biomarkers for ketamine's antidepressant efficacy.

VGF and its C-terminal peptide TLQP-62 in ventromedial prefrontal cortex regulate depression-related behaviors and the response to ketamine.

Patients with major depressive disorder (MDD) often have structural and functional deficits in the ventromedial prefrontal cortex (vmPFC), but the underlying molecular pathways are incompletely understood. The neuropeptide precursor VGF (non-acronymic) plays a critical role in depression and antidepressant efficacy in hippocampus and nucleus accumbens, however its function in vmPFC has not been investigated. Here, we show that VGF levels were reduced in Brodmann area 25 (a portion of human vmPFC) of MDD patients and in mouse vmPFC following chronic restraint stress (CRS), and were increased by ketamine in mouse vmPFC. VGF overexpression in vmPFC prevented behavioral deficits induced by CRS, and VGF knockdown in vmPFC increased susceptibility to subchronic variable stress (SCVS) and reduced ketamine's antidepressant efficacy. Acute intra-vmPFC TLQP-62 infusion induced behavioral phenotypes that mimic those produced by antidepressant drug treatment. These antidepressant-like effects were sustained for 7 days and were abolished by local Bdnf gene ablation, or pretreatment with xestospongin C, an inhibitor of IP3-mediated Ca2+ release, or SKF96365, an inhibitor of store-operated and TRPC channel-mediated Ca2+ entry. In conclusion, VGF in the vmPFC regulates susceptibility to stress and the antidepressant response to ketamine. TLQP-62 infusion produces sustained antidepressant responses that require BDNF expression and calcium mobilization in vmPFC.

Features of dissociation differentially predict antidepressant response to ketamine in treatment-resistant depression

BackgroundKetamine induces rapid and robust antidepressant effects, and many patients also describe dissociation, which is associated with antidepressant response. This follow-up study investigated whether antidepressant efficacy is uniquely related to dissociative symptom clusters. MethodsTreatment-resistant patients with major depressive disorder (MDD) or bipolar disorder (BD) (n = 126) drawn from three studies received a single subanesthetic (0.5 mg/kg) ketamine infusion. Dissociative effects were measured using the Clinician-Administered Dissociative States Scale (CADSS). Antidepressant response was measured using the 17-item Hamilton Depression Rating Scale (HAM-D). A confirmatory factor analysis established the validity of CADSS subscales (derealization, depersonalization, amnesia), and a general linear model with repeated measures was fitted to test whether subscale scores were associated with antidepressant response. ResultsFactor validity was supported, with a root mean square error of approximation of .06, a comparative fit index of .97, and a Tucker-Lewis index of .96. Across all studies and timepoints, the depersonalization subscale was positively related to HAM-D percent change. A significant effect of derealization on HAM-D percent change was observed at one timepoint (Day 7) in one study. The amnesia subscale was unrelated to HAM-D percent change. LimitationsPossible inadequate blinding; combined MDD/BD datasets might have underrepresented ketamine's antidepressant efficacy; the possibility of Type I errors in secondary analyses. ConclusionsFrom a psychometric perspective, researchers may elect to administer only the CADSS depersonalization subscale, given that it was most closely related to antidepressant response. From a neurobiological perspective, mechanistic similarities may exist between ketamine-induced depersonalization and antidepressant response, although off-target effects cannot be excluded.

Ketamine for Depression: An Update

A decade has now passed since research into the antidepressant effects of ketamine began in earnest, after the clinical trial reported by Zarate et al. in 2006 ( 1 Zarate Jr, C.A. Singh J.B. Carlson P.J. Brutsche N.E. Ameli R. Luckenbaugh D.A. et al. A randomized trial of an N-methyl-D-aspartate antagonist in treatment-resistant major depression. Arch Gen Psychiatry. 2006; 63: 856-864 Crossref PubMed Scopus (2608) Google Scholar ). In that proof-of-concept study, 18 medication-free patients with treatment-resistant major depressive disorder (TRD) showed a large reduction in core depressive symptoms within hours of receiving a single low-dose 0.5 mg/kg intravenous infusion of ketamine as measured by the 21-item Hamilton Depression Rating Scale compared with saline placebo. Perhaps most strikingly, the antidepressant effects persisted without additional dosing of ketamine for days or up to several weeks in some cases. While these unexpected findings have been met with justifiable skepticism, replication from independent research programs is now fostering a degree of consensus in the field that ketamine is in fact associated with a true rapid-onset and persistent antidepressant effect, even in patients with TRD ( 2 Murrough J.W. Iosifescu D.V. Chang L.C. Al Jurdi R.K. Green C.E. Perez A.M. et al. Antidepressant efficacy of ketamine in treatment-resistant major depression: A two-site randomized controlled trial. Am J Psychiatry. 2013; 170: 1134-1142 Crossref PubMed Scopus (808) Google Scholar , 3 Newport D.J. Carpenter L.L. McDonald W.M. Potash J.B. Tohen M. Nemeroff C.B. et al. Ketamine and other NMDA antagonists: Early clinical trials and possible mechanisms in depression. Am J Psychiatry. 2015; 172: 950-966 Crossref PubMed Scopus (401) Google Scholar ). If the observed effect is true, what are the implications and what are the critical research questions to now be asked? Sex Differences in Effects of Ketamine on Behavior, Spine Density, and Synaptic Proteins in Socially Isolated RatsBiological PsychiatryVol. 80Issue 6PreviewThe mechanistic underpinnings of sex differences in occurrence of depression and efficacy of antidepressant treatments are poorly understood. We examined the effects of isolation stress (IS) and the fast-acting antidepressant ketamine on anhedonia and depression-like behavior, spine density, and synaptic proteins in male and female rats. Full-Text PDF Bidirectional Homeostatic Regulation of a Depression-Related Brain State by Gamma-Aminobutyric Acidergic Deficits and Ketamine TreatmentBiological PsychiatryVol. 80Issue 6PreviewMajor depressive disorder is increasingly recognized to involve functional deficits in both gamma-aminobutyric acid (GABA)ergic and glutamatergic synaptic transmission. To elucidate the relationship between these phenotypes, we used GABAA receptor γ2 subunit heterozygous (γ2+/−) mice, which we previously characterized as a model animal with construct, face, and predictive validity for major depressive disorder. Full-Text PDF Open AccessIntravenous Esketamine in Adult Treatment-Resistant Depression: A Double-Blind, Double-Randomization, Placebo-Controlled StudyBiological PsychiatryVol. 80Issue 6PreviewThe 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). Full-Text PDF Open Access

Ketamine and Other NMDA Antagonists: Early Clinical Trials and Possible Mechanisms in Depression.

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. 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 rates of treatment response and transient remission of symptoms. Secondary outcomes included change in depression symptom severity and the frequency and severity of dissociative and psychotomimetic effects. Results for each NMDA antagonist were combined in meta-analyses, reporting odds ratios for dichotomous outcomes and standardized mean differences for continuous outcomes. Ketamine (seven trials encompassing 147 ketamine-treated participants) produced a rapid, yet transient, antidepressant effect, with odds ratios for response and transient remission of symptoms at 24 hours equaling 9.87 (4.37-22.29) and 14.47 (2.67-78.49), respectively, accompanied by brief psychotomimetic and dissociative effects. Ketamine augmentation of ECT (five trials encompassing 89 ketamine-treated participants) significantly reduced depressive symptoms following an initial treatment (Hedges' g=0.933) but not at the conclusion of the ECT course. Other NMDA antagonists failed to consistently demonstrate efficacy; however, two partial agonists at the NMDA coagonist site, d-cycloserine and rapastinel, significantly reduced depressive symptoms without psychotomimetic or dissociative effects. The antidepressant efficacy of ketamine, and perhaps D-cycloserine and rapastinel, holds promise for future glutamate-modulating strategies; however, the ineffectiveness of other NMDA antagonists suggests that any forthcoming advances will depend on improving our understanding of ketamine's mechanism of action. The fleeting nature of ketamine's therapeutic benefit, coupled with its potential for abuse and neurotoxicity, suggest that its use in the clinical setting warrants caution.

Ketamine for depression: evidence, challenges and promise.

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 primary neurotransmitter, and preclinical models of depression have implicated aberrant glutamatergic neurotransmission for 25 years (1). More recently, the N-methyl-D-aspartate (NMDA) glutamate receptor antagonist ketamine was shown to produce rapid and robust antidepressant effects in patients with treatment-resistant major depressive disorder and bipolar depression (2–7).

PC-FACS

PC-FACS

Ketamine for Treatment-Resistant Depression: Ready or Not for Clinical Use?

(Reprinted with permission from the American Journal of Psychiatry 2013; 170(10):1079–1081)

Antidepressant Efficacy of Ketamine in Treatment-Resistant Major Depression: A Two-Site Randomized Controlled Trial

Ketamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, has shown rapid antidepressant effects, but small study groups and inadequate control conditions in prior studies have precluded a definitive conclusion. The authors evaluated the rapid antidepressant efficacy of ketamine in a large group of patients with treatment-resistant major depression. This was a two-site, parallel-arm, randomized controlled trial of a single infusion of ketamine compared to an active placebo control condition, the anesthetic midazolam. Patients with treatment-resistant major depression experiencing a major depressive episode were randomly assigned under double-blind conditions to receive a single intravenous infusion of ketamine or midazolam in a 2:1 ratio (N=73). The primary outcome was change in depression severity 24 hours after drug administration, as assessed by the Montgomery-Åsberg Depression Rating Scale (MADRS). The ketamine group had greater improvement in the MADRS score than the midazolam group 24 hours after treatment. After adjustment for baseline scores and site, the MADRS score was lower in the ketamine group than in the midazolam group by 7.95 points (95% confidence interval [CI], 3.20 to 12.71). The likelihood of response at 24 hours was greater with ketamine than with midazolam (odds ratio, 2.18; 95% CI, 1.21 to 4.14), with response rates of 64% and 28%, respectively. Ketamine demonstrated rapid antidepressant effects in an optimized study design, further supporting NMDA receptor modulation as a novel mechanism for accelerated improvement in severe and chronic forms of depression. More information on response durability and safety is required before implementation in clinical practice.

P.2.f.028 Antidepressant efficacy of ketamine in treatment-resistant major depression: a two-site, randomised controlled trial

P.2.f.028 Antidepressant efficacy of ketamine in treatment-resistant major depression: a two-site, randomised controlled trial

Replication of Ketamine's Antidepressant Efficacy in Bipolar Depression: A Randomized Controlled Add-On Trial

Currently, no pharmacological treatments for bipolar depression exist that exert rapid (within hours) antidepressant or antisuicidal effects. We previously reported that intravenous administration of the N-methyl-D-aspartate antagonist ketamine produced rapid antidepressant effects in patients with treatment-resistant bipolar depression. The present study sought to replicate this finding in an independent sample. In this double-blind, randomized, crossover, placebo-controlled study, 15 subjects with DSM-IV bipolar I or II depression maintained on therapeutic levels of lithium or valproate received a single intravenous infusion of either ketamine hydrochloride (.5 mg/kg) or placebo on 2 test days 2 weeks apart. The primary outcome measure was the Montgomery-Asberg Depression Rating Scale, which was used to rate overall depressive symptoms at baseline; at 40, 80, 110, and 230 minutes postinfusion; and on days 1, 2, 3, 7, 10, and 14 postinfusion. Within 40 minutes, depressive symptoms, as well as suicidal ideation, significantly improved in subjects receiving ketamine compared with placebo (d = .89, 95% confidence interval = .61-1.16, and .98, 95% confidence interval = .64-1.33, respectively); this improvement remained significant through day 3. Seventy-nine percent of subjects responded to ketamine and 0% responded to placebo at some point during the trial. The most common side effect was dissociative symptoms, which occurred only at the 40-minute time point. This study replicated our previous finding that patients with bipolar depression who received a single ketamine infusion experienced a rapid and robust antidepressant response. In addition, we found that ketamine rapidly improved suicidal ideation in these patients.