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Ketamine

Modulation of the functional connectome in major depressive disorder by ketamine therapy

January 7, 2022 / Depressive Disorders, Ketamine, Neuroscience, Papers / Leave a Comment / By / , , , , , , , , , ,

Abstract

Background: Subanesthetic ketamine infusion therapy can produce fast-acting antidepressant effects in patients with major depression. How single and repeated ketamine treatment modulates the whole-brain functional connectome to affect clinical outcomes remains uncharacterized.

Methods: Data-driven whole brain functional connectivity (FC) analysis was used to identify the functional connections modified by ketamine treatment in patients with major depressive disorder (MDD). MDD patients (N = 61, mean age = 38, 19 women) completed baseline resting-state (RS) functional magnetic resonance imaging and depression symptom scales. Of these patients, n = 48 and n = 51, completed the same assessments 24 h after receiving one and four 0.5 mg/kg intravenous ketamine infusions. Healthy controls (HC) (n = 40, 24 women) completed baseline assessments with no intervention. Analysis of RS FC addressed effects of diagnosis, time, and remitter status.

Results: Significant differences (p < 0.05, corrected) in RS FC were observed between HC and MDD at baseline in the somatomotor network and between association and default mode networks. These disruptions in FC in MDD patients trended toward control patterns with ketamine treatment. Furthermore, following serial ketamine infusions, significant decreases in FC were observed between the cerebellum and salience network (SN) (p < 0.05, corrected). Patient remitters showed increased FC between the cerebellum and the striatum prior to treatment that decreased following treatment, whereas non-remitters showed the opposite pattern.

Conclusion: Results support that ketamine treatment leads to neurofunctional plasticity between distinct neural networks that are shown as disrupted in MDD patients. Cortico-striatal-cerebellar loops that encompass the SN could be a potential biomarker for ketamine treatment.

Sahib, A. K., Loureiro, J. R., Vasavada, M., Anderson, C., Kubicki, A., Wade, B., Joshi, S. H., Woods, R. P., Congdon, E., Espinoza, R., & Narr, K. L. (2020). Modulation of the functional connectome in major depressive disorder by ketamine therapy. Psychological medicine, 1–10. Advance online publication. https://doi.org/10.1017/S0033291720004560

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Does body mass index predict response to intravenous ketamine treatment in adults with major depressive and bipolar disorder? Results from the Canadian Rapid Treatment Center of Excellence

January 7, 2022 / Depressive Disorders, Ketamine, Papers, Psychiatry & Medicine / Leave a Comment / By / , , , , , , , , ,

Abstract

Background: Higher body mass index (BMI) has been found to predict greater antidepressant response to intravenous (IV) ketamine treatment. We evaluated the association between BMI and response to repeat-dose IV ketamine in patients with treatment-resistant depression (TRD).

Methods: Adults (N = 230) with TRD received four infusions of IV ketamine at a community-based clinic. Changes in symptoms of depression (ie, Quick Inventory for Depressive Symptomatology-Self-Report 16; QIDS-SR16), suicidal ideation (SI; ie, QIDS-SR16 SI item), anxiety (ie, Generalized Anxiety Disorder-7 Scale), anhedonic severity (ie, Snaith-Hamilton Pleasure Scale), and functioning (ie, Sheehan Disability Scale) following infusions were evaluated. Participants were stratified by BMI as normal (18.0-24.9 kg/m2; n = 72), overweight (25-29.9 kg/m2; n = 76), obese I (30-34.9 kg/m2; n = 47), or obese II (≥35.0 kg/m2; n = 35).

Results: Similar antidepressant effects with repeat-dose ketamine were reported between BMI groups (P = .261). In addition, categorical partial response (P = .149), response (P = .526), and remission (P = .232) rates were similar between the four BMI groups.

Conclusions: The findings are limited by the observational, open-label design of this retrospective analysis. Pretreatment BMI did not predict response to IV ketamine, which was effective regardless of BMI.

Lipsitz, O., McIntyre, R. S., Rodrigues, N. B., Lee, Y., Gill, H., Subramaniapillai, M., Kratiuk, K., Nasri, F., Mansur, R. B., & Rosenblat, J. D. (2020). Does body mass index predict response to intravenous ketamine treatment in adults with major depressive and bipolar disorder? Results from the Canadian Rapid Treatment Center of Excellence. CNS spectrums, 1–9. Advance online publication. https://doi.org/10.1017/S1092852920002102

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Post-Marketing Safety Concerns with Esketamine: A Disproportionality Analysis of Spontaneous Reports Submitted to the FDA Adverse Event Reporting System

December 1, 2020 / Ketamine, Papers, Psychiatry & Medicine, Publications / By / , , , ,

Abstract

Introduction: Esketamine nasal spray received approval for treatment-resistant depression in March 2019.

Objective: Using the FDA Adverse Event Reporting System (FAERS) database (March 2019-March 2020), we analysed esketamine-related adverse events (AEs) to detect and characterize relevant safety signals.

Methods: We used the consolidated case/non-case approach to estimate the reporting odds ratio (ROR) and information component (IC) with relevant confidence intervals (95% CI) for esketamine-related AEs with ≥4 counts. Comparisons between serious and non-serious AEs were performed using non-parametric tests.

Results: The FAERS database contained 962 cases of esketamine-related AEs, with signals detected for several AEs, such as dissociation (ROR = 1,612.64, 95% CI = 1,354.63, 1,919.79; IC = 8.19, 95% CI = 7.96, 8.35), sedation (ROR = 238.46, 95% CI = 202.98, 280.15; IC = 7, 95% CI = 6.75, 7.18), feeling drunk (ROR = 96.17, 95% CI = 61.42, 150.57; IC = 4.84, 95% CI = 4.09, 5.36), suicidal ideation (ROR = 24.03, 95% CI = 18.72, 30.84; IC = 4.31, 95% CI = 3.9, 4.61), and completed suicide (ROR = 5.75, 95% CI = 3.18, 10.41; IC = 2.25, 95% CI = 1.23, 2.94). Signals for suicidal and self-injurious ideation, but not suicide attempt and completed suicide, remained when comparing esketamine to venlafaxine. Females and patients receiving antidepressant polypharmacy, co-medication with mood stabilizers, antipsychotics, benzodiazepines, or somatic medications were more likely to suffer from serious versus non-serious AEs (χ2 = 125.29, p < 0.001, χ2 = 9.08, p = 0.003, χ2 = 8.14, p = 0.004, χ2 = 19.48, p < 0.001, χ2 = 25.62, p < 0.001, and χ2 = 16.79, p < 0.001, respectively).

Conclusions: Esketamine may carry a clear potential for serious AEs, which deserves urgent clarification by means of further prospective studies.

Gastaldon, C., Raschi, E., Kane, J. M., Barbui, C., & Schoretsanitis, G. (2021). Post-marketing safety concerns with esketamine: a disproportionality analysis of spontaneous reports submitted to the FDA adverse event reporting system. Psychotherapy and psychosomatics, 90(1), 41-48; 10.1159/000510703
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Hallucinogens in Mental Health: Preclinical and Clinical Studies on LSD, Psilocybin, MDMA, and Ketamine

January 7, 2022 / Ketamine, LSD, MDMA, Mushrooms / Psilocybin, Papers / Leave a Comment / By / , , , , , ,

Abstract

A revamped interest in the study of hallucinogens has recently emerged, especially with regard to their potential application in the treatment of psychiatric disorders. In the last decade, a plethora of preclinical and clinical studies have confirmed the efficacy of ketamine in the treatment of depression. More recently, emerging evidence has pointed out the potential therapeutic properties of psilocybin and LSD, as well as their ability to modulate functional brain connectivity. Moreover, MDMA, a compound belonging to the family of entactogens, has been demonstrated to be useful to treat post-traumatic stress disorders. In this review, the pharmacology of hallucinogenic compounds is summarized by underscoring the differences between psychedelic and nonpsychedelic hallucinogens as well as entactogens, and their behavioral effects in both animals and humans are described. Together, these data substantiate the potentials of these compounds in treating mental diseases.

De Gregorio, D., Aguilar-Valles, A., Preller, K. H., Heifets, B. D., Hibicke, M., Mitchell, J., & Gobbi, G. (2021). Hallucinogens in Mental Health: Preclinical and Clinical Studies on LSD, Psilocybin, MDMA, and Ketamine. The Journal of neuroscience : the official journal of the Society for Neuroscience, 41(5), 891–900. https://doi.org/10.1523/JNEUROSCI.1659-20.2020

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Combining Ketamine, Brain Stimulation (rTMS) and Mindfulness Therapy (TIMBER) for Opioid Addiction

February 6, 2022 / Anxiety Disorders / PTSD, Ketamine, Papers, Substance Use Disorder / Leave a Comment / By / ,

Abstract

Opioid addiction in the United States currently presents a national crisis despite availability of different treatments. Prior findings suggest that both repetitive transcranial magnetic stimulation (rTMS) and subanesthetic dose of ketamine are efficacious in patients with opioid use disorders (OUD) when administered in isolation. However, their therapeutic value may be undermined by varying clinical responses that tend to dissipate with treatment cessation. There has been no study to date that has used a combination of both for OUD, and there are still many unanswered questions with respect to both. TIMBER (Trauma Interventions using Mindfulness Based Extinction and Reconsolidation of memories) therapy attempts to alter the expression of emotionally charged memories such as traumatic memories, and has been successfully tried in chronic post-traumatic stress disorder (PTSD) and in combination with memory-altering pharmacotherapy like ketamine infusion. By a combination of extinction and reconsolidation of memory approaches, TIMBER works to not over-flood and/or retraumatize as is seen in other treatment approaches. TIMBER involves a balanced combination of both the memory extinction and memory reconsolidation approaches (rather than extinction-only approaches) which explains its superior efficacy in PTSD and benefit in substance use disorders.

Pradhan, B., & Rossi, G. (2020). Combining Ketamine, Brain Stimulation (rTMS) and Mindfulness Therapy (TIMBER) for Opioid Addiction. Cureus, 12(11), e11798. https://doi.org/10.7759/cureus.11798

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Is ketamine an appropriate alternative to ECT for patients with treatment resistant depression? A systematic review

January 21, 2022 / Depressive Disorders, Ketamine, Papers / Leave a Comment / By / , , , ,

Abstract

Objective: Ketamine has repeatedly shown to have rapid and robust antidepressant effects in patients with treatment resistant depression (TRD). An important question is whether ketamine is as effective and safe as the current gold standard electroconvulsive therapy (ECT).

Methods: The literature was searched for trials comparing ketamine treatment with ECT for depression in the Pubmed/MEDLINE database and Cochrane Trials Library.

Results: A total of 137 manuscripts were identified, 6 articles were included in this review. Overall quality of the included studies was diverse with relevant risk of bias for some of the studies. Results suggest that ketamine treatment might give faster but perhaps less durable antidepressant effects. Side effects differed from ECT, in particular less cognitive impairment was apparent in ketamine treatment.

Limitations: The included studies have limited sample sizes, use different treatment protocols and in most trials, longer term follow up is lacking. Furthermore, allocation bias appears likely in the non-randomized trials.

Conclusions: Current available literature does not yet provide convincing evidence to consider ketamine as an equally effective treatment alternative to ECT in patients with TRD. There are indications for a more favourable short term cognitive side effect profile after ketamine treatment. Methodologically well-designed studies with larger sample sizes and longer follow up duration are warranted.

Veraart, J., Smith-Apeldoorn, S. Y., Spaans, H. P., Kamphuis, J., & Schoevers, R. A. (2021). Is ketamine an appropriate alternative to ECT for patients with treatment resistant depression? A systematic review. Journal of affective disorders, 281, 82–89. https://doi.org/10.1016/j.jad.2020.11.123

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Corticosterone as a Potential Confounding Factor in Delineating Mechanisms Underlying Ketamine’s Rapid Antidepressant Actions

January 27, 2022 / Depressive Disorders, Ketamine, Neuroscience, Papers / Leave a Comment / By / , , , , , ,

Abstract

Recent research into the rapid antidepressant effect of subanesthetic doses of ketamine have identified a series of relevant protein cascades activated within hours of administration. Prior to, or concurrent with, these activation cascades, ketamine treatment generates dissociative and psychotomimetic side effects along with an increase in circulating glucocorticoids. In rats, we observed an over 3-fold increase in corticosterone levels in both serum and brain tissue, within an hour of administration of low dose ketamine (10 mg/kg), but not with (2R, 6R)-hydroxynorketamine (HNK) (10 mg/kg), a ketamine metabolite shown to produce antidepressant-like action in rodents without inducing immediate side-effects. Hippocampal tissue from ketamine, but not HNK, injected animals displayed a significant increase in the expression of sgk1, a downstream effector of glucocorticoid receptor signaling. To examine the role conscious sensation of ketamine’s side effects plays in the release of corticosterone, we assessed serum corticosterone levels after ketamine administration while under isoflurane anesthesia. Under anesthesia, ketamine failed to increase circulating corticosterone levels relative to saline controls. Concurrent with its antidepressant effects, ketamine generates a release of glucocorticoids potentially linked to disturbing cognitive side effects and the activation of distinct molecular pathways which should be considered when attempting to delineate the molecular mechanisms of its antidepressant function.

Wegman-Points, L., Pope, B., Zobel-Mask, A., Winter, L., Wauson, E., Duric, V., & Yuan, L. L. (2020). Corticosterone as a Potential Confounding Factor in Delineating Mechanisms Underlying Ketamine’s Rapid Antidepressant Actions. Frontiers in pharmacology, 11, 590221. https://doi.org/10.3389/fphar.2020.590221

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Increased signal diversity/complexity of spontaneous EEG, but not evoked EEG responses, in ketamine-induced psychedelic state in humans

January 6, 2022 / Ketamine, Neuroscience, Papers / Leave a Comment / By / , , , ,

Abstract

How and to what extent electrical brain activity reflects pharmacologically altered states and contents of consciousness, is not well understood. Therefore, we investigated whether measures of evoked and spontaneous electroencephalographic (EEG) signal diversity are altered by sub-anaesthetic levels of ketamine compared to normal wakefulness, and how these measures relate to subjective experience. High-density 62-channel EEG was used to record spontaneous brain activity and responses evoked by transcranial magnetic stimulation (TMS) in 10 healthy volunteers before and during administration of sub-anaesthetic doses of ketamine in an open-label within-subject design. Evoked signal diversity was assessed using the perturbational complexity index (PCI), calculated from EEG responses to TMS perturbations. Signal diversity of spontaneous EEG, with eyes open and eyes closed, was assessed by Lempel Ziv complexity (LZc), amplitude coalition entropy (ACE), and synchrony coalition entropy (SCE). Although no significant difference was found in TMS-evoked complexity (PCI) between the sub-anaesthetic ketamine condition and normal wakefulness, all measures of spontaneous EEG signal diversity (LZc, ACE, SCE) showed significantly increased values in the sub-anaesthetic ketamine condition. This increase in signal diversity correlated with subjective assessment of altered states of consciousness. Moreover, spontaneous signal diversity was significantly higher when participants had eyes open compared to eyes closed, both during normal wakefulness and during influence of sub-anaesthetic ketamine. The results suggest that PCI and spontaneous signal diversity may reflect distinct, complementary aspects of changes in brain properties related to altered states of consciousness: the brain’s capacity for information integration, assessed by PCI, might be indicative of the brain’s ability to sustain consciousness, while spontaneous complexity, as measured by EEG signal diversity, may be indicative of the complexity of conscious content. Thus, sub-anaesthetic ketamine may increase the complexity of the conscious content and the brain activity underlying it, while the level or general capacity for consciousness remains largely unaffected.

Farnes, N., Juel, B. E., Nilsen, A. S., Romundstad, L. G., & Storm, J. F. (2020). Increased signal diversity/complexity of spontaneous EEG, but not evoked EEG responses, in ketamine-induced psychedelic state in humans. PloS one, 15(11), e0242056. https://doi.org/10.1371/journal.pone.0242056

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The Effects of Ketamine on Cognition in Treatment-Resistant Depression: A Systematic Review and Priority Avenues for Future Research

January 6, 2022 / Depressive Disorders, Ketamine, Papers / Leave a Comment / By / , , , , , , , , ,

Abstract

Replicated evidence has documented cognitive deficits in populations with treatment-resistant depression (TRD). Approximately 40 % of patients with MDD present with impairment of one or more cognitive domains. As such, there is an unmet need to discover treatments that have pro-cognitive effects in TRD patients. Ketamine has demonstrated efficacy as a rapid-onset intervention for the treatment of depression. The objective of the current review was to assess the effects of ketamine on cognition in TRD patients. We systematically searched PubMed, Google Scholar and PsycINFO between database inception to March 24th, 2020. We identified five studies that evaluated cognition in TRD populations following ketamine treatment. All studies included a 0.5 mg/kg subanesthetic intravenous (IV) administration of ketamine. One study found significant improvements in complex (p = .008) and simple (p = .027) working memory and one study found improvements in visual learning memory following IV ketamine infusions (p = .014). Improvements in speed of processing and verbal learning memory were observed in anxious TRD participants only. Importantly, a subanesthetic dose of IV ketamine does not worsen cognitive function.

Gill, H., Gill, B., Rodrigues, N. B., Lipsitz, O., Rosenblat, J. D., El-Halabi, S., Nasri, F., Mansur, R. B., Lee, Y., & McIntyre, R. S. (2021). The Effects of Ketamine on Cognition in Treatment-Resistant Depression: A Systematic Review and Priority Avenues for Future Research. Neuroscience and biobehavioral reviews, 120, 78–85. https://doi.org/10.1016/j.neubiorev.2020.11.020

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The time course of psychotic symptom side effects of ketamine in the treatment of depressive disorders: a systematic review and meta-analysis

January 3, 2022 / Depressive Disorders, Ketamine, Papers / Leave a Comment / By / , , , ,

Abstract

Objective: Ketamine is a potential rapid-acting treatment for depression. Studies have suggested that the side effects are minimal and temporary, but the psychotic symptom side effects have yet to be fully examined. This study investigated whether ketamine infusion in the treatment of mood disorders is associated with increases in positive symptoms and whether these symptom effects endure over time.

Methods: A systematic review and meta-analysis of studies of ketamine in the treatment of depression. Embase and Medline databases were searched for studies including (a) participants with major affective disorders, (b) 0.4 or 0.5 mg intravenously administered ketamine, (c) measurement of positive symptoms using BPRS+, and (d) a within-subject repeated-measures design with participants serving as their own baseline.

Results: Seventeen studies met the inclusion criteria, comprising 458 participants. The meta-analyses examined symptom change occurring within the first 4 h, after 1 day, and after 3 days. Results showed significant BPRS+ increases within the first 30-60 min in 72% of studies, followed by a return to baseline levels.

Conclusion: Peak symptom change occurred within the first hour post infusion. There are limited data to determine if ketamine is safe in the longer term, but there were no indications that psychotic symptoms re-occurred after the first hour and in the days following administration.

Tashakkori, M., Ford, A., Dragovic, M., Gabriel, L., & Waters, F. (2021). The time course of psychotic symptom side effects of ketamine in the treatment of depressive disorders: a systematic review and meta-analysis. Australasian psychiatry : bulletin of Royal Australian and New Zealand College of Psychiatrists, 29(1), 80–87. https://doi.org/10.1177/1039856220961642

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