Long-term safety of ketamine and esketamine in treatment of depression

At-home, telehealth-supported ketamine treatment for depression: Findings from longitudinal, machine learning and symptom network analysis of real-world data

BACKGROUND

Improving safe and effective access to ketamine therapy is of high priority given the growing burden of mental illness. Telehealth-supported administration of sublingual ketamine is being explored toward this goal.

METHODS

In this longitudinal study, moderately-to-severely depressed patients received four doses of ketamine at home over four weeks within a supportive digital health context. Treatment was structured to resemble methods of therapeutic psychedelic trials. Patients receiving a second course of treatment were also examined. Symptoms were assessed using the Patient Health Questionnaire (PHQ-9) for depression. We conducted preregistered machine learning and symptom network analyses to investigate outcomes (osf.io/v2rpx).

RESULTS

A sample of 11,441 patients was analyzed, demonstrating a modal antidepressant response from both non-severe (n = 6384, 55.8 %) and severe (n = 2070, 18.1 %) baseline depression levels. Adverse events were detected in 3.0-4.8 % of participants and predominantly neurologic or psychiatric in nature. A second course of treatment helped extend improvements in patients who responded favorably to initial treatment. Improvement was most strongly predicted by lower depression scores and age at baseline. Symptoms of Depressed mood and Anhedonia sustained depression despite ongoing treatment.

LIMITATIONS

This study was limited by the absence of comparison or control groups and lack of a fixed-dose procedure for ketamine administration.

CONCLUSIONS

At-home, telehealth-supported ketamine administration was largely safe, well-tolerated, and associated with improvement in patients with depression. Strategies for combining psychedelic-oriented therapies with rigorous telehealth models, as explored here, may uniquely address barriers to mental health treatment.

Esketamine in depression: putative biomarkers from clinical research

The discovery of racemic (R, S)-ketamine as a rapid-acting antidepressant and the subsequent FDA approval of its (S)-enantiomer, esketamine, for treatment-resistant depression (TRD) are significant advances in the development of novel neuropsychiatric therapeutics. Esketamine is now recognized as a powerful tool for addressing persistent symptoms of TRD compared to traditional oral antidepressants. However, research on biomarkers associated with antidepressant response to esketamine has remained sparse and, to date, has been largely extrapolated from racemic ketamine studies. Genetic, proteomic, and metabolomic profiles suggest that inflammation and mitochondrial function may play a role in esketamine's antidepressant effects, though these preliminary results require verification. In addition, neuroimaging research has consistently implicated the prefrontal cortex, striatum, and anterior cingulate cortex in esketamine's effects. Esketamine also shows promise in perioperative settings for reducing depression and anxiety, and these effects appear to correlate with increased peripheral biomarkers such as brain-derived neurotrophic factor and serotonin. Further indications are likely to be identified with the continued repurposing of racemic ketamine, providing further opportunity for biomarker study and mechanistic understanding of therapeutic effects. Novel methodologies and well-designed biomarker-focused clinical research trials are needed to more clearly elucidate esketamine's therapeutic actions as well as biologically identify those most likely to benefit from this agent, allowing for the improved personalization of antidepressant treatment.

Comparing the adverse effects of ketamine and esketamine between genders using FAERS data

Background

Ketamine was developed as an anesthetic. Esketamine is the isolated S-enantiomer of racemic ketamine. They provide new avenues for the treatment of depression, especially treatment-resistant depression. Considering differences in the pharmacokinetics and hormonal status of ketamine in patients of different genders, sex-based differences in esketamine adverse drug events (ADE) may also be observed. This study presents data mining and safety analysis of adverse events of ketamine and esketamine between genders, promoting the individualization of clinical practice.

Methods

Adverse drug reactions to ketamine and esketamine reported between the first quarter of 2004 and the second quarter of 2023 in the U.S. Food and Drug Administration on Adverse Event Reporting System (FAERS) were extracted. Thereafter, the reporting odds ratio (ROR) with 95% confidence interval (CI) was calculated.

Results

A total of 2907 female reports and 1634 male reports on esketamine were included in the analysis. ROR mining showed that completed suicide, decreased therapeutic product effects, urinary retention, and hypertension were common in men. Additionally, 552 female and 653 male ketamine reports were recorded. ROR mining revealed that toxicity to various agents, bradycardia, cystitis and agitation, were more likely to occur in men, whereas women were more likely to develop suicidal ideation, increased transaminase levels, sclerosing cholangitis, and sterile pyuria.

Conclusion

The adverse events of esketamine and ketamine differ across genders, which should be considered in clinical practice to provide individualized treatment.

Major challenges in youth psychopathology: treatment-resistant depression. A narrative review

Major depressive disorder (MDD) represents a major health issue in adolescents and young adults, leading to high levels of disability and profoundly impacting overall functioning. The clinical presentation of MDD in this vulnerable age group may slightly differ from what can be observed in adult populations, and psychopharmacological strategies do not always lead to optimal response. Resistance to antidepressant treatment has a prevalence estimated around 40% in youths suffering from MDD and is associated with higher comorbidity rates and suicidality. Several factors, encompassing biological, environmental, and clinical features, may contribute to the emergence of treatment-resistant depression (TRD) in adolescents and young adults. Furthermore, TRD may underpin the presence of an unrecognized bipolar diathesis, increasing the overall complexity of the clinical picture and posing major differential diagnosis challenges in the clinical practice. After summarizing current evidence on epidemiological and clinical correlates of TRD in adolescents and young adults, the present review also provides an overview of possible treatment strategies, including novel fast-acting antidepressants. Despite these pharmacological agents are promising in this population, their usage is expected to rely on risk-benefit ratio and to be considered in the context of integrated models of care.

The effect and mechanism of low-dose esketamine in neuropathic pain-related depression-like behavior in rats

BACKGROUND

Clinical evidence suggests that Esketamine (ESK) is an effective treatment for depression. However, the effects of Esketamine in treating depression-like behavior induced by neuropathic pain is unclear. The underlying molecular mechanisms require further investigation to provide new therapeutic targets for the treatment of clinical neuropathic pain-related depression.

METHODS

A neuropathic pain-related depression model was established in rats with spared nerve injury (SNI). Male Sprague-Dawley rats were randomly divided into four groups: Sham Group, SNI group, SNI + Normal Saline (NS) Group and SNI + ESK5mg/kg Group. Mechanical pain thresholds were measured to assess pain sensitivity in SNI rats. On the 14th day after surgery a forced swim test and sucrose preference test were used to evaluate the depressive-like behavior of rats in each group. Further, a proteomic analysis was used to quantify differentially expressed proteins. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed to explore the main protein targets of SNI in the medial prefrontal cortex. The expression of proteins was detected by Western blotting.

RESULTS

A neuropathic pain-related depression model was established. Compared with the Sham group, the mechanical pain threshold was decreased significantly (13.2 ± 1.0 vs. 0.7 ± 0.01 g n = 8), while immobility on the forced swim test was also decreased (93.1 ± 7.4 vs. 169.5 ± 9.6 s n = 8), and sucrose preference rate was significantly increased (98.8 ± 0.3 vs. 73.1 ± 1.4n = 7) in SNI group rats. Compared with the SNI + NS group, the mechanical pain threshold was not statistically significant, while immobility on the forced swim test was clearly decreased (161.1 ± 11.6 vs. 77.9 ± 5.0 s n = 8), and sucrose preference rate was significantly increased (53.1 ± 8.9 vs. 96.1 ± 1.4n = 7) in SNI + ESK5mg/kg group rats. To further investigate the underlying mechanism, we employed proteomics to identify proteins exhibiting more than a 1.2-fold difference (P < 0.05) in expression levels within each group for subsequent analysis. Relative to the Sham group, 88 downregulated and 104 up-regulated proteins were identified in the SNI group, while 120 and 84 proteins were up- and down-regulated in the Esketamine treatment group compared with the SNI + NS group. Compared with Sham group, the expressions of mGluR5 and Homer1a were up-regulated in the medial prefrontal cortex (mPFC) in SNI group (mGluR5:0.97 ± 0.05 vs 1.47 ± 0.15, Homer1a:1.03 ± 0.06 vs 1.46 ± 0.16n = 6), and down-regulated after intervention with Esketamine (mGluR5:1.54 ± 0.11 vs 1.06 ± 0.07, Homer1a:1.51 ± 0.13 vs 1.12 ± 0.34n = 6).

CONCLUSIONS

Low-dose Esketamine appeared to relieve depression-like behavior induced by neuropathic pain. The Homer1a-mGluR5 signaling pathway might be the mechanism of antidepressant effect of Esketamine.

Efficacy and safety of peri-partum Esketamine for prevention of post-partum depression in women undergoing caesarian section: A meta-analysis and systematic review of randomized controlled trials

Postpartum depression (PPD) is a psychiatric condition affecting women post-childbirth. Medication combined with psychotherapy, is the current protocol for its treatment. A meta-analysis was conducted using RevMan 5.4 to explore the efficacy and safety of peri-partum administration of esketamine for preventing PPD. After searching several databases to retrieve the relevant RCTs, seven were included in this analysis, with dichotomous data presented as risk ratio and continuous data as mean difference. The study found a lower incidence of PPD in the esketamine group compared to the control group (RR= 0.37), with significant difference in EPDS scores between the two groups (MD= -1.23) in the first week postpartum. The esketamine group reported a lower prevalence of PPD 4-6 weeks postpartum (RR= 0.48), and no significant difference in EPDS scores after 4 weeks postpartum (MD = -0.10). The esketamine group had a significantly higher incidence of hallucination (RR= 13.85). Other adverse effects, such as dizziness (RR= 4.09), nausea (RR= 0.88), vomiting (RR=0.74), headache (RR=1.52), nightmares (RR=1.22), pruritus (RR=0.29), and drowsiness (RR=1.57) did not show significant differences between the two groups. The study found that esketamine, with manageable side effects, reduces the prevalence of post-partum depression (PPD) after one week as well as after four to six weeks. However, the findings are limited by the limited number of available RCTs, and future research should determine the ideal dosage, the most effective method of administration and the long-term safety profile of esketamine so that it may be considered as an adjunct therapy or a potential sole treatment option.

Comparison of propofol-esketamine versus propofol-sufentanil for deep sedation and analgesia in children with autism: A randomized double-blind clinical trial

Propofol sedation, routinely used for endoscopic procedures, is safe and acceptable for children. Adjuvants, such as esketamine or sufentanil, are commonly added to improve the efficacy and safety of propofol sedation. This study aimed to compare the clinical efficacy and safety of propofol-esketamine (PE) versus propofol-sufentanil (PS) for deep sedation and analgesia in children with autism undergoing colonoscopy procedure. One hundred and twenty-four children with autism undergoing colonoscopy procedure were included in the study. Patients were randomly assigned to receive one of the two adjuvants: esketamine (0.3 mg/kg) or sufentanil (0.2 μg/kg), subsequently administered propofol 2.0 mg/kg to induce anesthesia. Additional doses of propofol (0.5-1.0 mg/kg) were administered as needed to ensure patient tolerance for the remaining duration of the procedure. Movement during the procedure, hemodynamic variables, the total dose of propofol, recovery time, and adverse events were recorded. The PE group exhibited a significantly lower incidence of severe movement during the procedure compared with the PS group (14.52% vs. 32.26%, p = 0.020). The PE group showed significantly lower incidence of respiratory depression, hypotension, and severe injection pain of propofol than the PS group during the procedure (all p < 0.05). The mean arterial pressure (MAP) decreased significantly after anesthesia induction in the PS group and remained lower than baseline (all p < 0.05). Compared with the combination of low-dose sufentanil (0.2 μg/mg) with propofol, the low-dose esketamine (0.3 mg/kg) combined with propofol provided more stable hemodynamics, higher quality of sedation, and fewer adverse events in children with autism undergoing colonoscopy procedure.

Number needed to treat (NNT) for ketamine and esketamine in adults with treatment-resistant depression: A systematic review and meta-analysis

BACKGROUND

Ketamine has been established as efficacious in adults living with Treatment-resistant Depression (TRD). Toward providing a quantifiable estimate of the clinical meaningfulness of the therapeutic benefit of ketamine, herein, we conduct a systematic review that aims to report the Number Needed to Treat (NNT) and the Number Needed to Harm (NNH).

METHODS

This systematic review searched Embase, Medline/Pubmed, PsycINFO and ClinicalTrials.gov from inception up to October 15th 2023, for placebo-controlled, Randomized Controlled Trials (RCTs) assessing racemic ketamine or esketamine therapy for unipolar TRD. We calculated NNT and NNH for ketamine treatments over various time points.

RESULTS

A total of 21 studies with 2042 participants were included. Racemic ketamine treatments had pooled NNTs for response of 7 at 4 h, 3 from one day to one week and 9 for studies at four weeks. Esketamine treatment was found to have a similar efficacy with an NNT of 2 at one day and 11 at four weeks. NNH values indicated low risk for ketamine treatments.

LIMITATIONS

Limitations in the data used include the possibility of functional unblinding and selective reporting bias. Moreover, the meta-analysis may have been limited in its precision by including low threshold definitions of treatment resistance (≥ 1 failed antidepressant) and low-dose ketamine treatments.

CONCLUSION

Herein, we determined that the NNT for ketamine treatment in adults living with TRD across different intervals of observation was <10. We conclude that the NNTs observed herein are highly clinically meaningful in this difficult to treat disorder.

Synergistic use of deep TMS therapy with IV ketamine infusions for major depressive disorder: a pilot study

OBJECTIVE

Major Depressive Disorder (MDD) is a pervasive psychiatric condition effecting approximately 21 million adults in the U.S. (8.4%). An estimated 30-60% of patients are resistant to traditional treatment approaches (medications and talk-therapy), alluding to the need for additional options. Two promising treatment modalities include transcranial magnetic stimulation (TMS) and ketamine infusions; both have shown efficacy in standalone studies but have scarcely been investigated synergistically in the same group of participants.

METHOD

In the current study, 169 participants with treatment-resistant MDD received 36 treatments of Deep TMS-only (H1 + H7 protocols), while 66 received 36 treatments of Deep TMS (H1 + H7 protocols) and 6 IV infusions of ketamine over the course of 9 weeks. Depressive symptoms were compared pre- and -post treatment in both conditions using the PHQ-9.

RESULTS

In both treatment groups, depressive symptoms were significantly reduced from pre-to-post and there were no significant differences in response between the TMS + ketamine condition and the TMS-only condition. The TMS + ketamine condition had an 80.30% response rate (53 out of 66) and 43.42% remission rate (28 out of 66) compared to a 76.92% response (130 out of 169) and 39.64% remission (67 out of 16) in the TMS-only condition.

CONCLUSION

These results support the notion that TMS treatments yield high response rates in treatment-resistant cases; however, in this investigation there was no added benefit for including 6 sessions of IV ketamine in conjunction with TMS. Future investigations using randomized-control designs and robust outcome measures are warranted.

Efficacy and safety of eight enhanced therapies for treatment-resistant depression: A systematic review and network meta-analysis of RCTs

BACKGROUND

Treatment-Resistant Depression (TRD) challenges psychiatric treatment, with existing guidelines covering only a subset of augmentation strategies.

METHODS

A network meta-analysis following PRISMA guidelines examined the efficacy and safety of TRD treatments, analyzing 72 randomized controlled trials from eight databases, assessing response and remission rates, tolerability, and safety through the Cochrane Risk of Bias Tool and CINeMA framework.

FINDINGS

Including 12,105 participants, the analysis highlighted ECT, Ketamine, Esketamine, and Psilocybin as superior first-line treatments due to their optimal balance between effectiveness and tolerability. Brexpiprazole and Quetiapine showed no significant efficacy over placebo in response rates, while Esketamine and Psilocybin exhibited lower tolerability.

INTERPRETATION

The results advocate for ECT, Ketamine, Esketamine, and Psilocybin as preferred treatments for TRD, guiding clinical practice with evidence-based recommendations for enhancing treatment outcomes. This study underscores the importance of considering both efficacy and safety in selecting augmentation strategies for TRD.

Protocol for a randomised controlled trial of ketamine versus ketamine and behavioural activation therapy for adults with treatment-resistant depression in the community

INTRODUCTION

Although short-term benefits follow parenteral ketamine for treatment-resistant major depressive disorder (TR-MDD), there are challenges that prevent routine use of ketamine by clinicians. These include acute dissociative effects of parenteral ketamine, high relapse rates following ketamine dosing and the uncertain role of psychotherapy. This randomised controlled trial (RCT) seeks to establish the feasibility of evaluating repeated oral doses of ketamine and behavioural activation therapy (BAT), compared with ketamine treatment alone, for TR-MDD. We also aim to compare relapse rates between treatment arms to determine the effect size of adding BAT to oral ketamine.

METHODS AND ANALYSIS

This is a prospectively registered, two-centre, single-blind RCT. We aim to recruit 60 participants with TR-MDD aged between 18 and 65 years. Participants will be randomised to 8 weeks of oral ketamine and BAT, or 8 weeks of oral ketamine alone. Feasibility will be assessed by tracking attendance for ketamine and BAT, acceptability of treatment measures and retention to the study follow-up protocol. The primary efficacy outcome measure is the Montgomery-Asberg Depression Rating Scale (MADRS) measured weekly during treatment and fortnightly during 12 weeks of follow-up. Other outcome measures will assess the tolerability of ketamine and BAT, cognition and activity (using actigraphy). Participants will be categorised as non-responders, responders, remitters and relapsed during follow-up. MADRS scores will be analysed using a linear mixed model. For a definitive follow-up RCT study to be recommended, the recruitment expectations will be met and efficacy outcomes consistent with a >20% reduction in relapse rates favouring the BAT and ketamine arm will be achieved.

ETHICS AND DISSEMINATION

Ethics approval was granted by the New Zealand Central Health and Disability Ethics Committee (reference: 2023 FULL18176). Study findings will be reported to participants, stakeholder groups, conferences and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

UTN: U1111-1294-9310, ACTRN12623000817640p.

Esketamine enhances memory reconsolidation in the novel object recognition task

Esketamine, the right-handed optical isomer of racemic ketamine, is a rapidly acting antidepressant approved by the FDA for treatment-resistant depression in 2019. However, few studies have investigated esketamine's role in learning and memory, particularly in the context of memory reconsolidation. Herein, we evaluated esketamine's role in memory reconsolidation in 7-week-old male Institute of Cancer Research mice subjected to the novel object recognition (NOR) memory task. The NOR reconsolidation procedure comprised three phases: sampling, reactivation, and testing. Esketamine-enhanced NOR memory performance when injected into mice 0 h after reactivation rather than following a 6 h delay. Conversely, administering esketamine 24 h after sampling without reactivation did not enhance NOR memory performance. Notably, esketamine exhibited no discernible effects on nonspecific responses, such as locomotor activity and exploratory behavior. Furthermore, the α-amino-3‑hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type receptor antagonist NBQX effectively blocked the esketamine-induced enhancement of memory reconsolidation. In conclusion, esketamine treatment markedly improves memory reconsolidation in NOR tasks, and this effect is linked to AMPA receptor activity.

The effect of scutellaria baicalensis and its active ingredients on major depressive disorder: a systematic review and meta-analysis of literature in pre-clinical research

Background: Scutellaria baicalensis, the dry root of scutellaria baicalensis georgi, is a traditional Chinese medicine with long. In clinic, scutellaria baicalensis is commonly used in prescription for the treatment of depression. Additionally, numerous pre-clinical studies have shown that Scutellaria baicalensis and its active constituents are effective for depression. In this study, we aims to systematically review the roles of scutellaria baicalensis in depression and summarize the possible mechanism. Methods: A systematic review and meta-analysis were conducted to analyze the existing studies on the effects of scutellaria baicalensis on depression in animal models. Briefly, we searched electronic databases including Pubmed and Embase for preclinical trial studies from inception to September 2023. The items in each study were evaluated by two independent reviewers, and meta-analyses were performed on scutellaria baicalensis-induced behavioral changes in the study. Finally, random effects model is used to collect data. Results: A total of 49 studies were identified, and 13 studies were included in the final analysis. They all reported the different antidepressant effects of scutellaria baicalensis and the underlying biological mechanisms. Among the included 13 studies, the results of eight articles SPT[SMD = -2.80, 95%CI(-4.03, -1.57), p < 0.01], the results of the nine articles OFT[SMD = -2.38, 95%CI(-3.53, -1.23), p < 0.01], and the results of two articles NSFT[SMD = -2.98, 95%CI(-3.94, -2.02), p < 0.01] were significantly different from the control group. The risk of bias was moderate in all studies, however, there was a significant heterogeneity among studies. Conclusion: These results preliminarily suggest that scutellaria baicalensis can alleviate depressive behaviors and modulate underlying mechanisms, which is expected to be a promising antidepressant.

Efficacy and acceptability of psilocybin for primary or secondary depression: A systematic review and meta-analysis of randomized controlled trials

Introduction

Psilocybin is a classic psychedelics, which has been shown to have antidepressant effects by many studies in recent years. In this study, we aim to evaluate the efficacy, acceptability and tolerability of psilocybin in the treatment of primary (major depressive disorder) or secondary (experiencing distress related to life-threatening diagnoses and terminal illness) depression.

Methods

We searched PubMed, EMBASE, Web of Science, Cochrane Library and ClinicalTrials.gov for clinical trials of psilocybin for depression (updated to 4 October, 2023). Effect size Hedges' g was used as an indicator of efficacy, and other outcomes included response rate, drop-out rate, and adverse events.

Results

A total of 10 studies were finally included in systematic review. 8 studies were included in the meta-analysis, involving a total of 524 adult patients, and produced a large effect size in favor of psilocybin (Hedge's g =-0.89, 95% CI -1.25~-0.53, I² = 70.19%, P<0.01). The therapeutic effects of psilocybin increase with increasing doses. Adverse events caused by psilocybin are generally transient and reversible, but serious adverse events also may occur.

Discussion

Our study shows that psilocybin has both short-term and long-term antidepressant effects and holds promise as a potential complementary or alternative therapy for depression, probably. Further research may reveal more about its therapeutic potential.

Esketamine pretreatment during cesarean section reduced the incidence of postpartum depression: a randomized controlled trail

BACKGROUND

Postpartum depression (PPD) is a common mental disease in postpartum women, which has received more and more attention in society. Ketamine has been confirmed for its rapid antidepressant effect in women with PPD. We speculate that esketamine, an enantiomer of ketamine, pretreatment during cesarean can also reduce the incidence of PPD.

METHODS

All the parturients enrolled in the study were randomly assigned to two groups: the esktamine group (0.2 mg/kg esketamine) and the control group (a same volume of saline). All the drugs were pumped for 40 min started from the beginning of the surgery. The Amsterdam Anxiety and Information Scale (APAIS) scores before the surgery, the Edinburgh postnatal depression scale (EPDS) scores at 4 d and 42 d after surgery, the Pain Numerical Rating Scale (NRS) scores at 6 h, 12 h, 24 h and 48 h post-operation were evaluated, as well as the adverse reactions were recorded.

RESULTS

A total of 319 parturients were analyzed in the study. The incidence of PPD (EPDS score > 9) in the esketamine group was lower than the control group at 4 days after surgery (13.8% vs 23.1%, P = 0.0430) but not 42 days after surgery (P = 0.0987). Esketamine 0.2 mg/kg could reduce the NRS score at 6 h,12 h and 24 h after surgery, as well as the use of vasoactive drugs during surgery (P < 0.05). The incidences of maternal dizziness (17.0%), blurred vision (5%), illusion (3.8%) and drowsiness (3.8%) in the esketamine group were higher than those of control group (P < 0.05).

CONCLUSIONS

Intraoperative injection of esketamine (0.2 mg/kg) prevented the occurrence of depression (EPDS score > 9) at 4 days after delivery but not 42 days. Esketamine reduced the NRS scores at 6 h, 12 h and 24 h after surgery, but the occurrence of maternal side effects such as dizziness, blurred vision, drowsiness and hallucination were increased.

TRIAL REGISTRATION

Registered in the Chinese Clinical Trial Registry (ChiCTR2100053422) on 20/11/2021.

Use of ketamine for treatment resistant depression: updated review of literature and practical applications to a community ketamine program in Edmonton, Alberta, Canada

Background

Though intravenous (IV) ketamine and intranasal (IN) esketamine are noted to be efficacious for treatment-resistant depression (TRD), access to each of these treatments within healthcare systems is limited due to cost, availability, and/or monitoring requirements. IV ketamine has been offered at two public hospital sites in Edmonton, Canada since 2015. Since then, demand for maintenance ketamine treatments has grown. This has required creative solutions for safe, accessible, evidence-based patient care.

Objectives

Aims of this paper are twofold. First, we will provide a synthesis of current knowledge with regards to the clinical use of ketamine for TRD. Consideration will be given regarding; off-label racemic ketamine uses versus FDA-approved intranasal esketamine, populations treated, inclusion/exclusion criteria, dosing, assessing clinical response, concomitant medications, and tolerability/safety. Second, this paper will describe our experience as a community case study in applying evidence-based treatment. We will describe application of the literature review to our clinical programming, and in particular focus on cost-effective maintenance treatments, long-term safety concerns, routes of ketamine administration other than via intravenous, and cautious prescribing of ketamine outside of clinically monitored settings.

Methodology

We conducted a literature review of the on the use of ketamine for TRD up to June 30, 2023. Key findings are reviewed, and we describe their application to our ketamine program.

Conclusion

Evidence for the use of ketamine in resistant depression has grown in recent years, with evolving data to support and direct its clinical use. There is an increasing body of evidence to guide judicious use of ketamine in various clinical circumstances, for a population of patients with a high burden of suffering and morbidity. While large-scale, randomized controlled trials, comparative studies, and longer-term treatment outcomes is lacking, this community case study illustrates that currently available evidence can be applied to real-world clinical settings with complex patients. As cost is often a significant barrier to accessing initial and/or maintenance IV or esketamine treatments, public ketamine programs may incorporate SL or IN ketamine to support a sustainable and accessible treatment model. Three of such models are described.

Apoptotic mechanism of development inhibition in zebrafish induced by esketamine

Esketamine, a widely used intravenous general anesthetic, is also employed for obstetric and pediatric anesthesia, and depression treatment. However, concerns regarding esketamine abuse have emerged. Moreover, the potential in vivo toxicity of esketamine on growth and development remains unclear. To address these concerns, we investigated the effects of esketamine exposure on developmental parameters, cell apoptosis, and gene expression in zebrafish. Esketamine exposure concentration-dependently decreased the heart rate and body length of zebrafish embryos/larvae while increasing the hatching rate and spontaneous movement frequency. Developmental retardation of zebrafish larvae, including shallow pigmentation, small eyes, and delayed yolk sac absorption, was also observed following esketamine treatment. Esketamine exposure altered the expression of apoptosis-related genes in zebrafish heads, primarily downregulating bax, caspase9, caspase3, caspase6, and caspase7. Intriguingly, BTSA1, a Bax agonist, reversed the anti-apoptotic and decelerated body growth effects of esketamine in zebrafish. Collectively, our findings suggest that esketamine may hinder embryonic development by inhibiting embryonic apoptosis via the Bax/Caspase9/Caspase3 pathway. To the best of our knowledge, this is the first study to report the lethal toxicity of esketamine in zebrafish. We have elucidated the developmental toxic effects of esketamine on zebrafish larvae and its potential apoptotic mechanisms. Further studies are warranted to evaluate the safety of esketamine in animals and humans.

Ketamine and rapid antidepressant action: new treatments and novel synaptic signaling mechanisms

Ketamine is an open channel blocker of ionotropic glutamatergic N-Methyl-D-Aspartate (NMDA) receptors. The discovery of its rapid antidepressant effects in patients with depression and treatment-resistant depression fostered novel effective treatments for mood disorders. This discovery not only provided new insight into the neurobiology of mood disorders but also uncovered fundamental synaptic plasticity mechanisms that underlie its treatment. In this review, we discuss key clinical aspects of ketamine's effect as a rapidly acting antidepressant, synaptic and circuit mechanisms underlying its action, as well as how these novel perspectives in clinical practice and synapse biology form a road map for future studies aimed at more effective treatments for neuropsychiatric disorders.

[Targeting NMDAR/AMPAR: a promising pharmacotherapeutic approach for depressive disorders]

Depression is a leading cause of disability and reduced work capacity worldwide. The monoamine theory of the pathogenesis of depression has remained dominant for many decades, however, drugs developed on its basis have limited efficacy. Exploring alternative mechanisms underlying this pathology could illuminate new avenues for pharmacological intervention. Targeting glutamatergic pathways in the CNS, particularly through modulation of NMDA and AMPA receptors, demonstrates promising results. This review presents some existing drugs with glutamatergic activity and novel developments based on it to enhance the efficacy of pharmacotherapy for depressive disorders.

Single and Multitarget Systems for Drug Delivery and Detection: Up-to-Date Strategies for Brain Disorders

This review summarizes the recent findings on the development of different types of single and multitarget nanoparticles for disease detection and drug delivery to the brain, focusing on promising active principles encapsulated and nanoparticle surface modification and functionalization. Functionalized nanoparticles have emerged as promising tools for the diagnosis and treatment of brain disorders, offering a novel approach to addressing complex neurological challenges. They can act as drug delivery vehicles, transporting one or multiple therapeutic agents across the blood-brain barrier and precisely releasing them at the site of action. In diagnostics, functionalized nanoparticles can serve as highly sensitive contrast agents for imaging techniques such as magnetic resonance imaging and computed tomography scans. By attaching targeting ligands to the nanoparticles, they can selectively accumulate in the affected areas of the brain, enhancing the accuracy of disease detection. This enables early diagnosis and monitoring of conditions like Alzheimer's or Parkinson's diseases. While the field is still evolving, functionalized nanoparticles represent a promising path for advancing our ability to diagnose and treat brain disorders with greater precision, reduced invasiveness, and improved therapeutic outcomes.

The possible place for psychedelics in pharmacotherapy of mental disorders

Since its emergence in the 1960s, the serotonergic theory of depression bore fruit in the discovery of a plethora of antidepressant drugs affecting the lives of millions of patients. While crucial in the history of drug development, recent studies undermine the effectiveness of currently used antidepressant drugs in comparison to placebo, emphasizing the long time it takes to initiate the therapeutic response and numerous adverse effects. Thus, the scope of contemporary pharmacological research shifts from drugs affecting the serotonin system to rapid-acting antidepressant drugs. The prototypical representative of the aforementioned class is ketamine, an NMDA receptor antagonist capable of alleviating the symptoms of depression shortly after the drug administration. This discovery led to a paradigm shift, focusing on amino-acidic neurotransmitters and growth factors. Alas, the drug is not perfect, as its therapeutic effect diminishes circa 2 weeks after administration. Furthermore, it is not devoid of some severe side effects. However, there seems to be another, more efficient, and safer way to target the glutamatergic system. Hallucinogenic agonists of the 5-HT2A receptor, commonly known as psychedelics, are nowadays being reconsidered in clinical practice, shedding their infamous 1970s stigma. More and more clinical studies prove their clinical efficacy and rapid onset after a single administration while bearing fewer side effects. This review focuses on the current state-of-the-art literature and most recent clinical studies concerning the use of psychedelic drugs in the treatment of mental disorders. Specifically, the antidepressant potential of LSD, psilocybin, DMT, and 5-MeO-DMT will be discussed, together with a brief summary of other possible applications.

Promising new pharmacological targets for depression: The search for efficacy

Pharmacological treatment of major depressive disorder (MDD) still relies on the use of serotonergic drugs, despite their limited efficacy. A few mechanistically new drugs have been developed in recent years, but many fail in clinical trials. Several hypotheses have been proposed to explain MDD pathophysiology, indicating that physiological processes such as neuroplasticity, circadian rhythms, and metabolism are potential targets. Here, we review the current state of pharmacological treatments for MDD, as well as the preclinical and clinical evidence for an antidepressant effect of molecules that target non-serotonergic systems. We offer some insights into the challenges facing the development of new antidepressant drugs, and the prospect of finding more effectiveness for each target discussed.

A synopsis of multitarget therapeutic effects of anesthetics on depression

Depression is a profound mental disorder that dampens the mood and undermines volition, which exhibited an increased incidence over the years. Although drug-based interventions remain the primary approach for depression treatment, the available medications still can't satisfy the patients. In recent years, the newly discovered therapeutic targets such as N-methyl-D-aspartate (NMDA) receptor, α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor, and tyrosine kinase B (TrkB) have brought new breakthroughs in the development of antidepressant drugs. Moreover, it has come to light that certain anesthetics possess pharmacological mechanisms intricately linked to the aforementioned therapeutic targets for depression. At present, numerous preclinical and clinical studies have explored the therapeutic effects of anesthetic drugs such as ketamine, isoflurane, N2O, and propofol, on depression. These investigations suggested that these drugs can swiftly ameliorate patients' depression symptoms and engender long-term effects. In this paper, we provide a comprehensive review of the research progress and potential molecular mechanisms of various anesthetic drugs for depression treatment. By shedding light on this subject, we aim to facilitate the development and clinical implementation of new antidepressant drugs based on anesthetic medications.

Multidisciplinary development of guidelines for ketamine treatment for treatment-resistant major depression disorder for use by adult specialist mental health services in New Zealand

BACKGROUND

The evidence base for racemic ketamine treatment for treatment-resistant major depressive disorder (TRD) continues to expand, but there are major challenges translating this evidence base into routine clinical care.

AIM

To prepare guidelines for ketamine treatment of TRD that are suitable for routine use by publicly funded specialist mental health services.

METHOD

We consulted with senior leadership, clinical pharmacy, psychiatrists, nursing, service users and Māori mental health workers on issues relating to ketamine treatment. We prepared treatment guidelines taking the evidence base for ketamine treatment and the consultation into account.

RESULTS

Ketamine treatment guidance is reported. This offers two treatment pathways, including a test of ketamine responsiveness with intramuscular ketamine and the dominant use of oral ketamine for a 3-month course to maximise the opportunity for the short-term benefits of ketamine to accumulate.

CONCLUSIONS

We have responded to the challenges of translating the evidence base for ketamine treatment into a form suitable for routine care.

Esketamine Nasal Spray versus Quetiapine for Treatment-Resistant Depression

BACKGROUND

In treatment-resistant depression, commonly defined as a lack of response to two or more consecutive treatments during the current depressive episode, the percentage of patients with remission is low and the percentage with relapse is high. The efficacy and safety of esketamine nasal spray as compared with extended-release quetiapine augmentation therapy, both in combination with ongoing treatment with a selective serotonin reuptake inhibitor (SSRI) or a serotonin-norepinephrine reuptake inhibitor (SNRI), in patients with treatment-resistant depression are unknown.

METHODS

In an open-label, single-blind (with raters unaware of group assignments), multicenter, phase 3b, randomized, active-controlled trial, we assigned patients, in a 1:1 ratio, to receive flexible doses (according to the summary of product characteristics) of esketamine nasal spray (esketamine group) or extended-release quetiapine (quetiapine group), both in combination with an SSRI or SNRI. The primary end point was remission, defined as a score of 10 or less on the Montgomery-Åsberg Depression Rating Scale (MADRS), at week 8 (scores range from 0 to 60, with higher scores indicating more severe depression). The key secondary end point was no relapse through week 32 after remission at week 8. All patients were included in the analysis; patients who discontinued the trial treatment were considered as having had an unfavorable outcome (i.e., they were grouped with patients who did not have remission or who had a relapse). Analyses of the primary and key secondary end points were adjusted for age and number of treatment failures.

RESULTS

Overall, 336 patients were assigned to the esketamine group and 340 to the quetiapine group. More patients in the esketamine group than in the quetiapine group had remission at week 8 (91 of 336 patients [27.1%] vs. 60 of 340 patients [17.6%]; P = 0.003) and had no relapse through week 32 after remission at week 8 (73 of 336 patients [21.7%] vs. 48 of 340 patients [14.1%]). Over 32 weeks of follow-up, the percentage of patients with remission, the percentage of patients with a treatment response, and the change in the MADRS score from baseline favored esketamine nasal spray. The adverse events were consistent with the established safety profiles of the trial treatments.

CONCLUSIONS

In patients with treatment-resistant depression, esketamine nasal spray plus an SSRI or SNRI was superior to extended-release quetiapine plus an SSRI or SNRI with respect to remission at week 8. (Funded by Janssen EMEA; ESCAPE-TRD ClinicalTrials.gov number, NCT04338321.).

Ketamine for Chronic Pain and Mental Health: Regulations, Legalities, and the Growth of Infusion Clinics

PURPOSE OF REVIEW

In this article, we will review evidence for ketamine's role in chronic pain and mental health conditions, its current legal status and abuse potential, and the regulations related to its administration in stand-alone infusion clinics, as well as future considerations.

RECENT FINDINGS

In the management of chronic pain, ketamine has shown potential to manage neuropathic pain and complex regional pain syndrome and has been used as a treatment for chronic pain management by clinics across the USA. Analogous to the historic rise of lidocaine clinics, ketamine clinics are demonstrating a similar pattern of unregulated growth. Ketamine is an anesthetic and analgesic agent commonly used in the perioperative setting and emergency department for sedation and pain management (Mo et al in West J Emerg Med 21(2):272-281, 2020). It was approved for use by the Federal Drug Administration in the USA in the 1970s as the sole anesthetic agent for short diagnostic and surgical procedures (Coppel et al. in Anaesthesia 28(3):293-296, 1973; Schwenk et al. in Reg Anesth Pain Med 43(5):456-466, 2018). Regarding its rising popularity as a treatment option in mental health, ketamine holds promise as a rapidly acting treatment for suicidal ideation and refractory depression.

Baseline cognitive function predicts full remission of suicidal symptoms among patients with treatment-resistant depression and strong suicidal ideation after low-dose ketamine infusion

BACKGROUND

Whether pretreatment working memory and response inhibition function are associated with the rapid and sustained antisuicidal effect of low-dose ketamine among patients with treatment-resistant depression (TRD) and strong suicidal ideation is unclear.

METHODS

We enrolled 65 patients with TRD, comprising 33 who received a single infusion of 0.5 mg/kg ketamine and 32 who received a placebo infusion. The participants performed working memory and go/no-go tasks prior to infusion. We assessed suicidal symptoms at baseline and on postinfusion Days 2, 3, 5, and 7.

RESULTS

The full remission of suicidal symptoms persisted for 3 days after a single ketamine infusion and the ketamine-related antisuicidal effect persisted for 1 week. Lower cognitive impairment at baseline (indicated by a higher rate of correct responses on a working memory task) was associated with the rapid and sustained antisuicidal effect of low-dose ketamine in patients with TRD and strong suicidal ideation.

DISCUSSION

Patients with TRD and strong suicidal ideation but low cognitive impairment may benefit the most from the antisuicidal effect of low-dose ketamine.

Comparison of remifentanil and esketamine in combination with propofol for patient sedation during fiberoptic bronchoscopy

BACKGROUND

Ideal sedation and analgesia strategies for fiberoptic bronchoscopy have not been found. At present, propofol based sedation strategy still has some defects, such as respiratory depression and blood pressure drop. It is difficult to meet the requirements of safety and effectiveness at the same time. The aim of this study was to compare the clinical efficacy of propofol/remifentanil with propofol/esketamine for patient sedation during fiberoptic bronchoscopy.

METHOD

Patients undergoing fiberoptic bronchoscopy were randomly assigned to propofol/ remifentanil (PR group; n = 42) or propofol/esketamine (PK group; n = 42) for sedation and analgesia. The primary outcome was the rate of transient hypoxia (oxygen saturation (SpO₂) < 95%). The secondary outcomes are the intraoperative hemodynamics, including the changes in blood pressure, heart rate, the incidence of adverse reactions, the total amount of propofol usage were recorded, and the satisfaction level of patients and bronchoscopists.

RESULTS

After sedation, the arterial pressure and heart rate of patients in the PK group were stable without significant decrease. Decreases in diastolic blood pressure, mean arterial pressure, and heart rate were observed in patients in the PR group (P < 0.05), although it was not of clinical relevance. The dosage of propofol in the PR group was significantly higher than that in the PK group (144 ± 38 mg vs. 125 ± 35 mg, P = 0.012). Patients in the PR group showed more transient hypoxia (SpO₂ < 95%) during surgery (7 vs. 0, 0% versus 16.6%, P = 0.018), more intraoperative choking (28 vs. 7, P < 0.01), postoperative vomiting (22 vs. 13, P = 0.076) and vertigo (15 vs. 13, P = 0.003). Bronchoscopists in the PK group showed more satisfaction.

CONCLUSION

Compared with remifentanil, the combination of esketamine with propofol in fiberoptic bronchoscopy leaded to more stable intraoperative hemodynamics, lower dosage of propofol, lower transient hypoxia rate, fewer incidence of adverse events, and greater bronchoscopists satisfaction.

Safety and tolerability of intramuscular and sublingual ketamine for psychiatric treatment in the Roots To Thrive ketamine-assisted therapy program: a retrospective chart review

Background

In the last few years, ketamine is becoming increasingly common in the treatment of mental health conditions, but there is a lack of safety data informing intramuscular and sublingual dosing in a community-focused group psychotherapy setting. The Roots To Thrive ketamine-assisted therapy (RTT-KaT) program is a unique 12-week RTT-KaT program with 12 community of practice (a form of group therapy) sessions and three ketamine medicine sessions.

Objectives

This study reports on adverse effects of intramuscular and sublingual ketamine dosing in a community group psychotherapy setting among 128 participants across four cohorts.

Design

Retrospective chart review.

Methods

A chart review of the RTT-KaT Program was performed retrospectively on four cohorts (n = 128) that participated in 448 sessions running between September 2020 and December 2021. Baseline characteristics and adverse events were captured including medication administration before, during, and after RTT-KaT sessions. Analyses by session and by individual were conducted. Chi-square test with Yates' continuity correction was used to assess side effects in subgroups from ketamine administration.

Results

RTT-KaT was well tolerated with none of the 128 participants dropping out of the program. Primarily, of the 448 sessions, 49.16% had elevated blood pressures post-KaT session by session. In terms of other adverse effects, 12.05% of participant-sessions experienced nausea, 2.52% had an episode of vomiting, 3.35% had a headache, and seven participant-sessions experienced dizziness. Analysis by individual revealed congruent findings.

Conclusion

These findings suggest good safety and tolerability for RTT-KaT among individuals seeking treatment for mental health issues. The majority of participants did not experience adverse reactions and the adverse events that were recorded involved transient symptoms that were resolved with rest and/or medications. The group therapy model described provides a comprehensive approach and presents a promising model for operating a KaT program in a community setting.

The effects of ketamine on symptoms of depression and anxiety in real-world care settings: A retrospective controlled analysis

INTRODUCTION

Ketamine intravenous therapy (KIT) appears effective for treating depression in controlled trials testing a short series of infusions. A rapidly proliferating number of clinics offer KIT for depression and anxiety, using protocols without a strong evidence basis. Controlled comparison of mood and anxiety from real-world KIT clinics, and the stability of outcomes, is lacking.

METHODS

We performed a retrospective controlled analysis on patients treated with KIT in ten community clinics across the US, between 08/2017-03/2020. Depression and anxiety symptoms were evaluated using the Quick Inventory of Depressive Symptomatology-Self Report 16-item (QIDS) and the Generalized Anxiety Disorder 7-item (GAD-7) scales, respectively. Comparison data sets from patients who did not undergo KIT were obtained from previously published real-world studies.

RESULTS

Of 2758 patients treated, 714 and 836 met criteria for analysis of KIT induction and maintenance outcomes, respectively. Patients exhibited significant and concordant reduction in both anxiety and depression symptoms after induction (Cohen's d = 1.14 and d = 0.9, respectively). Compared to two external datasets of KIT-naive depressed patients or patients starting standard antidepressant therapy, KIT patients experienced a significantly greater reduction in depression symptoms at eight weeks (Cohen's d = -1.03 and d = -0.62 respectively). Furthermore, we identified a subpopulation of late-responders. During maintenance, up to a year post-induction, increases in symptoms were minimal.

LIMITATIONS

Due to the retrospective nature of the analyses, interpreting this dataset is limited by incomplete patient information and sample attrition.

CONCLUSIONS

KIT treatment elicited robust symptomatic relief that remained stable up to one year of follow-up.

4-F-PCP, a Novel PCP Analog Ameliorates the Depressive-Like Behavior of Chronic Social Defeat Stress Mice via NMDA Receptor Antagonism

Major depressive disorder is a leading cause of disability in more than 280 million people worldwide. Monoamine-based antidepressants are currently used to treat depression, but delays in treatment effects and lack of responses are major reasons for the need to develop faster and more efficient antidepressants. Studies show that ketamine (KET), a PCP analog, produces antidepressant effects within a few hours of administration that lasts up to a week. However, the use of KET has raised concerns about side effects, as well as the risk of abuse. 4 -F-PCP analog is a novel PCP analog that is also an NMDA receptor antagonist, structurally similar to KET, and might potentially elicit similar antidepressant effects, however, there has been no study on this subject yet. Herein, we investigate whether 4-F-PCP displays antidepressant effects and explored their potential therapeutic mechanisms. 4-F-PCP at 3 and 10 mg/kg doses showed antidepressant-like effects and repeated treatments maintained its effects. Furthermore, treatment with 4-F-PCP rescued the decreased expression of proteins most likely involved in depression and synaptic plasticity. Changes in the excitatory amino acid transporters (EAAT2, EAAT3, EAAT4) were also seen following drug treatment. Lastly, we assessed the possible side effects of 4-F-PCP after long-term treatment (up to 21 days). Results show that 4-F-PCP at 3 mg/kg dose did not alter the cognitive function of mice. Overall, current findings provide significant implications for future research not only with PCP analogs but also on the next generation of different types of antidepressants.

Cytokine- and Vascular Endothelial Growth Factor-Related Gene-Based Genome-Wide Association Study of Low-Dose Ketamine Infusion in Patients with Treatment-Resistant Depression

BACKGROUND AND OBJECTIVE

Ketamine may work as an anti-inflammatory agent, and it increases the levels of vascular endothelial growth factor (VEGF) in patients with treatment-resistant depression. However, whether genes related to pro-inflammatory and anti-inflammatory cytokines and VEGF may predict the treatment response to ketamine remains unknown.Therefore the aim of this study was to analyze whether specific genes related to inflammatory processes and VEGF were associated with treatment response to low-dose ketamine in patients with treatment-resistant depression.

METHODS

Based on the genome data from our clinical trial, this study was a secondary analysis of candidate genes correlated with different timepoints of depressive symptoms. In total, 65 patients with treatment-resistant depression (n = 21 for ketamine 0.5 mg/kg, 20 for ketamine 0.2 mg/kg, and 24 for normal saline) were genotyped for 684,616 single nucleotide polymorphisms. Genes associated with 80 cytokines (i.e., interleukin [IL]-1, IL-6, tumor necrosis factor-α, and adiponectin) and VEGF (i.e., VEGF and VEGF receptors) were selected for the gene-based genome-wide association study on the antidepressant effect of a ketamine infusion.

RESULTS

Specific single nucleotide polymorphisms, including rs2540315 and rs75746675 in IL1R1 and rs79568085 in VEGFC, were related to the rapid (within 240 min) antidepressant effect of a ketamine infusion; specific single nucleotide polymorphisms, such as Affx-20131665 in PIGF and rs8179353, rs8179353, and rs8179353 in TNFRSF8, were associated with the sustained (up to 2 weeks) antidepressant effect of low-dose (combined 0.5 mg/kg and 0.2 mg/kg) ketamine.

CONCLUSIONS

Our findings further revealed that genes related to both anti-inflammatory and pro-inflammatory cytokines (i.e., IL-1, IL-2, IL-6, tumor necrosis factor-α, C-reactive protein, and adiponectin) and VEGF-FLK signaling predicted the treatment response to a ketamine infusion in patients with treatment-resistant depression. The synergic modulation of inflammatory and VEGF systems may contribute to the antidepressant effect of ketamine.

CLINICAL TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) number: UMIN000016985.

The molecular pathophysiology of depression and the new therapeutics

Major depressive disorder (MDD) is a highly prevalent and disabling disorder. Despite the many hypotheses proposed to understand the molecular pathophysiology of depression, it is still unclear. Current treatments for depression are inadequate for many individuals, because of limited effectiveness, delayed efficacy (usually two weeks), and side effects. Consequently, novel drugs with increased speed of action and effectiveness are required. Ketamine has shown to have rapid, reliable, and long-lasting antidepressant effects in treatment-resistant MDD patients and represent a breakthrough therapy for patients with MDD; however, concerns regarding its efficacy, potential misuse, and side effects remain. In this review, we aimed to summarize molecular mechanisms and pharmacological treatments for depression. We focused on the fast antidepressant treatment and clarified the safety, tolerability, and efficacy of ketamine and its metabolites for the MDD treatment, along with a review of the potential pharmacological mechanisms, research challenges, and future clinical prospects.