Adjunctive intranasal esketamine for major depressive disorder: A systematic review of randomized double-blind controlled-placebo studies

Ketamine and electroconvulsive therapy for severe depression: A network meta-analysis of efficacy and safety

BACKGROUND

Ketamine, electroconvulsive therapy (ECT), and their combination are effective for treating severe depression, but few large-scale studies have compared these.

METHODS

We searched databases for randomized controlled trials (RCTs) using ketamine, ECT, ketamine + ECT, or placebo for severe depression. Standardized measures were efficacy outcomes. Risk of bias was assessed. Stata and ADDIS were used for network meta-analysis (NMA) comparing efficacy and adverse reactions post-treatment. This study was registered on PROSPERO (CRD42023476740).

RESULTS

17 RCTs with 1370 patients were included. NMA showed ECT and ketamine improved Hamilton Depression Rating Scale (HDRS) versus placebo; other comparisons not significant. Rank probabilities showed highest probability for ECT, followed by ketamine + ECT, ketamine, placebo. No differences in Montgomery-Asberg Depression Rating Scale (MADRS); highest rank probability again for ECT, followed by ketamine + ECT, ketamine, placebo.

CONCLUSIONS

Analysis suggests ECT superior to ketamine and their combination for improving depressive severity, but individualized treatment selection warranted. Higher adverse reactions with ketamine + ECT need further study for optimized combined use.

Effects of ketamine and esketamine on preventing postpartum depression after cesarean delivery: A meta-analysis

BACKGROUND

Ketamine and esketamine has been suggested to have potential efficacy in preventing postpartum depression (PPD) recent years. The aim of this meta-analysis was to evaluate the effectiveness of ketamine and esketamine on PPD after cesarean delivery.

METHODS

We systematically searched PubMed, Embase, and the Cochrane Library for studies investigating the efficacy of ketamine and esketamine in preventing PPD. The primary outcomes of this study were risk ratios (RRs) and EPDS scores (Edinburgh Postnatal Depression Scale) in relation to PPD after ketamine and esketamine. The second outcomes were the postoperative adverse events.

RESULTS

Thirteen randomized controlled trials (RCTs) and one retrospective study including 2916 patients were analyzed, including six on the use of ketamine and eight on the use of esketamine. The risk ratios and EPDS scores of PPD were significantly decreased in the ketamine/esketamine group compared to those in the control group in one week and four weeks postoperative periods. Subgroup analyses showed that high dosage, administrated in patient controlled intravenous analgesia (PCIA) method and only esketamine exhibited a significant reduction in the incidence and EPDS scores of PPD in one week and four week postoperative. However, the incidences of postoperative adverse events, such as dizziness, diplopia, hallucination, and headache were significantly higher in the ketamine/esketamine group than that in the control group.

CONCLUSION

Ketamine and esketamine appear to be effective in preventing PPD in the one week and four week postoperative periods after cesarean delivery with moderate certainty of evidence. But they can also lead to some short-term complications too. Future high-quality studies are needed to confirm the efficacy of ketamine and esketamine in different countries.

Oral esketamine in patients with treatment-resistant depression: a double-blind, randomized, placebo-controlled trial with open-label extension

About one-third of patients with depression do not achieve adequate response to current treatment options. Although intravenous and intranasal administrations of (es)ketamine have shown antidepressant properties, their accessibility and scalability are limited. We investigated the efficacy, safety, and tolerability of generic oral esketamine in patients with treatment-resistant depression (TRD) in a randomized placebo-controlled trial with open-label extension. This study consisted of 1) a six-week fixed low-dose treatment phase during which 111 participants received oral esketamine 30 mg or placebo three times a day; 2) a four-week wash-out phase; and 3) an optional six-week open-label individually titrated treatment phase during which participants received 0.5 to 3.0 mg/kg oral esketamine two times a week. The primary outcome measure was change in depressive symptom severity, assessed with the Hamilton Depression Rating Scale (HDRS17), from baseline to 6 weeks. Fixed low-dose oral esketamine when compared to placebo had no benefit on the HDRS17 total score (p = 0.626). Except for dizziness and sleep hallucinations scores, which were higher in the esketamine arm, we found no significant difference in safety and tolerability aspects. During the open-label individually titrated treatment phase, the mean HDRS17 score decreased from 21.0 (SD 5.09) to 15.1 (SD 7.27) (mean difference -6.0, 95% CI -7.71 to -4.29, p < 0.001). Our results suggest that fixed low-dose esketamine is not effective in TRD. In contrast, individually titrated higher doses of oral esketamine might have antidepressant properties.

A mitochondrial nexus in major depressive disorder: Integration with the psycho-immune-neuroendocrine network

Nervous system processes, including cognition and affective state, fundamentally rely on mitochondria. Impaired mitochondrial function is evident in major depressive disorder (MDD), reflecting cumulative detrimental influences of both extrinsic and intrinsic stressors, genetic predisposition, and mutation. Glucocorticoid 'stress' pathways converge on mitochondria; oxidative and nitrosative stresses in MDD are largely mitochondrial in origin; both initiate cascades promoting mitochondrial DNA (mtDNA) damage with disruptions to mitochondrial biogenesis and tryptophan catabolism. Mitochondrial dysfunction facilitates proinflammatory dysbiosis while directly triggering immuno-inflammatory activation via released mtDNA, mitochondrial lipids and mitochondria associated membranes (MAMs), further disrupting mitochondrial function and mitochondrial quality control, promoting the accumulation of abnormal mitochondria (confirmed in autopsy studies). Established and putative mechanisms highlight a mitochondrial nexus within the psycho-immune neuroendocrine (PINE) network implicated in MDD. Whether lowering neuronal resilience and thresholds for disease, or linking mechanistic nodes within the MDD pathogenic network, impaired mitochondrial function emerges as an important risk, a functional biomarker, providing a therapeutic target in MDD. Several treatment modalities have been demonstrated to reset mitochondrial function, which could benefit those with MDD.

Efficacy and safety of ketamine and esketamine for unipolar and bipolar depression: an overview of systematic reviews with meta-analysis

Background

Unipolar and bipolar depression present treatment challenges, with patients sometimes showing limited or no response to standard medications. Ketamine and its enantiomer, esketamine, offer promising alternative treatments that can quickly relieve suicidal thoughts. This Overview of Reviews (OoR) analyzed and synthesized systematic reviews (SRs) with meta-analysis on randomized clinical trials (RCTs) involving ketamine in various formulations (intravenous, intramuscular, intranasal, subcutaneous) for patients with unipolar or bipolar depression. We evaluated the efficacy and safety of ketamine and esketamine in treating major depressive episodes across various forms, including unipolar, bipolar, treatment-resistant, and non-resistant depression, in patient populations with and without suicidal ideation, aiming to comprehensively assess their therapeutic potential and safety profile.

Methods

Following PRIOR guidelines, this OoR's protocol was registered on Implasy (ID:202150049). Searches in PubMed, Scopus, Cochrane Library, and Epistemonikos focused on English-language meta-analyses of RCTs of ketamine or esketamine, as monotherapy or add-on, evaluating outcomes like suicide risk, depressive symptoms, relapse, response rates, and side effects. We included studies involving both suicidal and non-suicidal patients; all routes and formulations of administration (intravenous, intramuscular, intranasal) were considered, as well as all available comparisons with control interventions. We excluded meta-analysis in which the intervention was used as anesthesia for electroconvulsive therapy or with a randomized ascending dose design. The selection, data extraction, and quality assessment of studies were carried out by pairs of reviewers in a blinded manner. Data on efficacy, acceptability, and tolerability were extracted.

Results

Our analysis included 26 SRs and 44 RCTs, with 3,316 subjects. The intervention is effective and well-tolerated, although the quality of the included SRs and original studies is poor, resulting in low certainty of evidence.

Limitations

This study is limited by poor-quality SRs and original studies, resulting in low certainty of the evidence. Additionally, insufficient available data prevents differentiation between the effects of ketamine and esketamine in unipolar and bipolar depression.

Conclusion

While ketamine and esketamine show promising therapeutic potential, the current evidence suffers from low study quality. Enhanced methodological rigor in future research will allow for a more informed application of these interventions within the treatment guidelines for unipolar and bipolar depression.

Systematic review registration

[https://inplasy.com/inplasy-2021-5-0049/], identifier (INPLASY202150049).

The correlation of Esketamine with specific adverse events: a deep dive into the FAERS database

Analyzing the vast data from FAERS database to evaluate the association between Esketamine and specific adverse events to guide clinical practice and regulatory decisions. Data related to Esketamine adverse events from 2019 Q1 to 2023 Q1 were collected from FAERS database. After data standardization, various signal quantification technologies, such as ROR, PRR, BCPNN, and MGPS, were employed to identify and evaluate adverse reaction signals closely related to the use of Esketamine comprehensively. A total of 5061 reports with Esketamine as the primary suspected drug were obtained, identifying 117 adverse reaction terms (PT) involving 27 system organ class (SOC) categories. Apart from the adverse events already mentioned in the drug's instructions, this study identified some new, clinically valuable potential AE signals, such as Flashback, Tachyphylaxis, and Autoscopy. In addition, high-ranking results included euphoric mood, feeling of relaxation, and feeling drunk. Notably, the occurrence frequencies of suicidal ideation and suicide attempt were relatively high, so clinicians should be particularly vigilant about these potential adverse reactions when using Esketamine. Moreover, since this drug is administered as a nasal spray, issues such as drug monitoring procedure incorrectly performed and nasal discomfort may arise. This study underscores the potential adverse reactions and risks of Esketamine in clinical applications, especially regarding long-term efficacy, addiction risks, and suicidal risks.

Latin American consensus recommendations for the management and treatment of patients with treatment-resistant depression (TRD)

Despite the abundance of literature on treatment-resistant depression (TRD), there is no universally accepted definition of TRD, and available treatment pathways for the management of TRD vary across the Latin American region, highlighting the need for a uniform definition and treatment principles to optimize the management of TRD in Latin America.

METHODS

Following a thematic literature review and pre-meeting survey, a Latin America expert panel comprising 14 psychiatrists with clinical experience in managing patients with TRD convened and utilized the RAND/UCLA appropriateness method to develop consensus-based recommendations on the appropriate definition of TRD and principles for its management.

RESULTS

The expert panel agreed that 'treatment-resistant depression' (TRD) is defined as 'failure of two drug treatments of adequate doses, for 4-8 weeks duration with adequate adherence, during a major depressive episode'. A stepwise treatment approach should be employed for the management of TRD - treatment strategies can include maximizing dose, switching to a different class, and augmenting or combining treatments. Nonpharmacological treatments, such as electroconvulsive therapy, are also appropriate options for patients with TRD.

CONCLUSION

These consensus recommendations on the operational definition of TRD and approved treatments for its management can be adapted to local contexts in the Latin American countries but should not replace clinical judgement. Individual circumstances and benefit-risk balance should be carefully considered while determining the most appropriate treatment option for patients with TRD.

Molecular mechanisms of rapid-acting antidepressants: New perspectives for developing antidepressants

Major depressive disorder (MDD) is a chronic relapsing psychiatric disorder. Conventional antidepressants usually require several weeks of continuous administration to exert clinically significant therapeutic effects, while about two-thirds of the patients are prone to relapse of symptoms or are completely ineffective in antidepressant treatment. The recent success of the N-methyl-D-aspartic acid (NMDA) receptor antagonist ketamine as a rapid-acting antidepressant has propelled extensive research on the action mechanism of antidepressants, especially in relation to its role in synaptic targets. Studies have revealed that the mechanism of antidepressant action of ketamine is not limited to antagonism of postsynaptic NMDA receptors or GABA interneurons. Ketamine produces powerful and rapid antidepressant effects by affecting α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors, adenosine A1 receptors, and the L-type calcium channels, among others in the synapse. More interestingly, the 5-HT2A receptor agonist psilocybin has demonstrated potential for rapid antidepressant effects in depressed mouse models and clinical studies. This article focuses on a review of new pharmacological target studies of emerging rapid-acting antidepressant drugs such as ketamine and hallucinogens (e.g., psilocybin) and briefly discusses the possible strategies for new targets of antidepressants, with a view to shed light on the direction of future antidepressant research.

A comparative analysis of antidepressant and anti-suicidal effects of repeated ketamine infusions in elderly and younger adults with depression

OBJECTIVES

This study aims to investigate the differences in safety and antidepressant effects of multi-infusion ketamine treatment between elderly and young adults with depression.

METHODS

The safety, antidepressant, and anti-suicidal effects of multi-infusion ketamine were compared between 19 elderly (≥50 years) and 116 younger (<50 years) adults with depression; all were treated with six ketamine infusions (0.5 mg/kg). Montgomery-Åsberg Depression Rating Scale (MADRS) was used to measure the depressive symptoms, and suicidal ideation was measured with Beck Scale for Suicide Ideation (SSI)-part 1, Hamilton Rating Scale for Depression (HAMD) item 3, and (MADRS) item 10. Dissociative and psychotomimetic symptoms were evaluated based on the Clinician-Administered Dissociative States Scale (CADSS) and the Brief Psychiatric Rating Scale (BPRS)-four items.

RESULTS

Multi-Ketamine infusions resulted in a lower (trend) antidepressant response (37.1 % versus 57.8 %) and antidepressant remission (15.8 % versus 47.4 %) in elderly patients with depression compared with younger patients with depression (all ps > 0.05). Interestingly, elderly patients with depression had a higher MADRS score after six ketamine infusions compared with younger patients (p = 0.04). No significant differences in SSI-part 1 scores, HAMD item 3 scores, MADRS item 10 scores, CADSS scores, and BPRS-four items scores were found between the two groups at any assessment point (all ps > 0.05).

CONCLUSION

Our study shows that repeated-dose infusions of ketamine may be a feasible treatment strategy in elderly Chinese patients with depression; however, elderly patients with depression may be less responsive to ketamine compared with younger adults with depression.

Reduction in Cognitive Symptoms Following Intranasal Esketamine Administration in Patients With Chronic Treatment-resistant Depression: A 12-Week Case Series

BACKGROUND

Cognitive symptoms are a core feature of depressive disorders, interfere with full functional recovery and are prominent in patients with treatment-resistant depression (TRD), particularly in severe chronic cases. Intranasal (IN) esketamine was recently approved for the treatment of TRD; however, its effects on cognitive symptoms are unclear. In this article, we describe cognitive changes in 8 patients with chronic TRD who were treated with IN administration of esketamine.

METHODS

Eight outpatients with chronic TRD received IN esketamine over 3 months and were assessed at baseline and after 4, 8, and 12 weeks of treatment using the Montgomery-Åsberg Depression Rating Scale (MADRS), the Digit Symbol Substitution Test (DSST), the Trail Making Test-B (TMT-B), the Patient Deficits Questionnaire for Depression 5-item (PDQ-D5), the Hamilton Anxiety Rating Scale (HARS), and the Clinical Global Impressions Scale (CGI).

FINDINGS

We observed reductions in cognitive symptoms according to DSST, TMT-B, and PDQ-D5 scores within the first 2 months of treatment with IN esketamine. These improvements were observed before patients achieved clinical response (≥50% decrease in baseline MADRS scores), and they also occurred earlier than reductions in HARS scores.

CONCLUSIONS

A clinical response to IN esketamine was detected in severely ill patients with chronic TRD after 3 months of treatment. Interestingly, improvements on measures of cognitive symptoms were observed before patients achieved antidepressant response. These preliminary observations suggest an additional value to the antidepressant properties of IN esketamine. Clinical studies specifically investigating cognition as a primary outcome measure of IN esketamine in TRD are warranted.

Current and Future Directions of Drug Delivery for the Treatment of Mental Illnesses

Mental illnesses including anxiety disorders, autism spectrum disorder, post-traumatic stress disorder, schizophrenia, depression, and others exact an immense toll on the healthcare system and society at large. Depression alone impacts 21 million adults and costs over $200 billion annually in the United States. However, pharmaceutical strategies to treat mental illnesses are lagging behind drug development in many other disease areas. Because many of the shortcomings of therapeutics for mental illness relate to delivery problems, drug delivery technologies have the potential to radically improve the effectiveness of therapeutics for these diseases. This review describes the current pharmacotherapeutic approaches to treating mental illnesses as well as drug delivery approaches that have improved existing therapies. Approaches to improve drug bioavailability, provide controlled release of therapeutics, and enable drug targeting to the central nervous system (CNS) will be highlighted. Moreover, next-generation delivery approaches such as environmentally-controlled release and interval/sequential drug release will be addressed. Based on the evolving landscape of the treatment of mental illnesses, the nascent field of drug delivery in mental health has tremendous potential for growth in terms of both economic and patient impact.

Intranasal (R, S)-ketamine delivery induces sustained antidepressant effects associated with changes in cortical balance of excitatory/inhibitory synaptic activity

In 2019, an intranasal (IN) spray of esketamine SPRAVATO® was approved as a fast-acting antidepressant by drug Agencies US FDA and European EMA. At sub-anesthetic doses, (±)-ketamine, a non-competitive glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, increases the overall excitability of the medial prefrontal cortex (mPFC), an effect being essential for its rapid antidepressant activity. We wondered if this effect of ketamine could come from changes in the balance between neuronal excitation and inhibition (E/I balance) in the mPFC. Here, we performed a preclinical approach to study neurochemical and behavioral responses to a single IN ketamine dose in BALB/cJ mice, a strain more sensitive to stress. By using in vivo microdialysis, we measured cortical E/I balance as the ratio between glutamate to GABA extracellular levels 24 h post-ketamine. We found, for the first time, that E/I balance was shifted in favor of excitation rather than inhibition in the mPFC but more robustly with IN KET than with a single intraperitoneal (IP) dose. Increases in plasma and brain ketamine, norketamine and HNKs levels suggest different metabolic profiles of IP and IN ketamine 30 min post-dose. A significantly larger proportion of ketamine and HNKs in the brain are derived from the IN route 30 min post-dose. It may be linked to the greater magnitude in E/I ratio following IN delivery relative to IP at t24 h. This study suggests that both IP and IN are effective brain delivery methods inducing similar sustained antidepressant efficacy of KET, but the way they induced neurotransmitter changes is slightly different.

Role of group II metabotropic glutamate receptors in ketamine's antidepressant actions

Major Depressive Disorder (MDD) is a serious neuropsychiatric disorder afflicting around 16-17 % of the global population and is accompanied by recurrent episodes of low mood, hopelessness and suicidal thoughts. Current pharmacological interventions take several weeks to even months for an improvement in depressive symptoms to emerge, with a significant percentage of individuals not responding to these medications at all, thus highlighting the need for rapid and effective next-generation treatments for MDD. Pre-clinical studies in animals have demonstrated that antagonists of the metabotropic glutamate receptor subtype 2/3 (mGlu_2/3 receptor) exert rapid antidepressant-like effects, comparable to the actions of ketamine. Therefore, it is possible that mGlu₂ or mGlu₃ receptors to have a regulatory role on the unique antidepressant properties of ketamine, or that convergent intracellular mechanisms exist between mGlu_2/3 receptor signaling and ketamine's effects. Here, we provide a comprehensive and critical evaluation of the literature on these convergent processes underlying the antidepressant action of mGlu_2/3 receptor inhibitors and ketamine. Importantly, combining sub-threshold doses of mGlu_2/3 receptor inhibitors with sub-antidepressant ketamine doses induce synergistic antidepressant-relevant behavioral effects. We review the evidence supporting these combinatorial effects since sub-effective dosages of mGlu_2/3 receptor antagonists and ketamine could reduce the risk for the emergence of significant adverse events compared with taking normal dosages. Overall, deconvolution of ketamine's pharmacological targets will give critical insights to influence the development of next-generation antidepressant treatments with rapid actions.

Ketamine, benzoate, and sarcosine for treating depression

Studies have demonstrated the beneficial therapeutic effects of sarcosine, benzoate, and ketamine (including esketamine and arketamine) on depression. These drugs mainly act by modulating N-methyl-d-aspartate glutamate receptors (NMDARs) and reducing inflammation in the brain. Although ketamine, benzoate, and sarcosine act differently as the antagonists or coagonists of NMDARs, they all have demonstrated efficacy in animal models or human trials. In vitro and in vivo studies have indicated that sarcosine, benzoate, and ketamine exert their anti-inflammatory effects by inhibiting microglial activity. This review summarizes and compares the efficacy of the possible therapeutic mechanisms of sarcosine, benzoate, ketamine, esketamine, and arketamine. These compounds act as both NMDAR modulators and anti-inflammatory drugs and thus can be effective in the treatment of depression.

Possible Use of Minocycline in Adjunction to Intranasal Esketamine for the Management of Difficult to Treat Depression following Extensive Pharmacogenomic Testing: Two Case Reports

The advent of intra-nasal esketamine (ESK), one of the first so called fast-acting antidepressant, promises to revolutionize the management of treatment resistant depression (TRD). This NMDA receptor antagonist has proven to be rapidly effective in the short- and medium-term course of the illness, revealing its potential in targeting response in TRD. Although many TRD ESK responders are able to achieve remission, a considerable portion of them undergo a metamorphosis of their depression into different clinical presentations, characterized by instable responses and high recurrence rates that can be considered closer to the concept of Difficult to Treat Depression (DTD) than to TRD. The management of these DTD patients usually requires a further complex multidisciplinary approach and can benefit from the valuable contribution of new personalized medicine tools such as therapeutic drug monitoring and pharmacogenetics. Despite this, these patients usually come with long and complex previous treatments history and, often, advanced and sophisticated ongoing pharmacological schemes that can make the finding of new alternative options to face the current recurrences extremely challenging. In this paper, we describe two DTD patients—already receiving intranasal ESK but showing an instable course—who were clinically stabilized by the association with minocycline, a semisynthetic second-generation tetracycline with known and promising antidepressant properties.

Early improvement as a predictor of final remission in patients with treatment-resistant depression receiving electroconvulsive therapy with ketofol anesthesia

OBJECTIVE

To examine whether early symptom improvement can predict eventual remission following electroconvulsive therapy (ECT) with ketamine plus propofol (ketofol) anesthesia in patients with treatment-resistant depression (TRD).

METHODS

Thirty Han Chinese subjects suffering from TRD were administered ketofol anesthesia during ECT. Remission was defined as a score of ≤7 on the 17-item Hamilton Depression Rating Scale (HAMD-17). Receiver operating characteristic (ROC) curves were applied to identify the number of ECT sessions (i.e., 1, 2, 3, or 4 ECT sessions) that had the best discriminative capacity for eventual remission. The best definition of early improvement to predict final remission was determined by using the Youden index.

RESULTS

Of the 30 patients with TRD, 16 (53.3%) and 30 (100%) were classified as remitters and responders, respectively. A 45% reduction in the HAMD-17 score after 3 ECT sessions was the optimum definition of early improvement in the prediction of eventual remission, with relatively good sensitivity (88%) and specificity (93%). Patients with than without early improvement had a greater possibility of achieving favorable ECT outcomes.

CONCLUSION

Final remission of TRD following ECT with ketofol anesthesia appeared to be predicted by early improvement, as indicated by a 45% reduction in HAMD-17 score after 3 ECT sessions.

Efficacy and safety of racemic ketamine and esketamine for depression: a systematic review and meta-analysis

BACKGROUND

Racemic ketamine and esketamine have demonstrated rapid antidepressant effects. We aimed to review the efficacy and safety of racemic and esketamine for depression.

RESEARCH DESIGN AND METHODS

We conducted a PRISMA-guided review for relevant randomized controlled trials of racemic or esketamine for unipolar or bipolar major depression from database inception through 2021. We conducted random-effects meta-analyses using pooled rate ratios (RRs) and Cohen's standardized mean differences (d) with their 95% confidence intervals (CI).

RESULTS

We found 36 studies (2903 participants, 57% female, 45.1 +/- 7.0 years). Nine trials used esketamine, while the rest used racemic ketamine. The overall study quality was high. Treatment with any form of ketamine was associated with improved response (RR=2.14; 95% CI, 1.72-2.66; I2=65%), remission (RR=1.64; 95% CI, 1.33-2.02; I2=39%), and depression severity (d=-0.63; 95% CI, -0.80 to -0.45; I2=78%) against placebo. Overall, there was no association between treatment with any form of ketamine and retention in treatment (RR=1.00; 95% CI, 0.99-1.01; I2<1%), dropouts due to adverse events (RR=1.56; 95% CI, 1.00-2.45; I2<1%), or the overall number of adverse events reported per participant (OR=2.14; 95% CI, 0.82-5.60; I2=62%) against placebo.

CONCLUSIONS

Ketamine and esketamine are effective, safe, and acceptable treatments for individuals living with depression.

Effects of intranasal (S)-ketamine on Veterans with co-morbid treatment-resistant depression and PTSD: A retrospective case series

BACKGROUND

(S)-ketamine is a glutamatergic drug with potent and rapid acting effects for the treatment of depression. Little is known about the effectiveness of intranasal (S)-ketamine for treating patients with comorbid depression and post-traumatic stress disorder (PTSD).

METHODS

We performed a retrospective case series analysis of clinical outcomes in 35 Veterans with co-morbid depression and PTSD who were treated with intranasal (S)-ketamine treatments at the VA San Diego Neuromodulation Clinic between Jan 2020 and March 2021. Veterans were not randomized or blinded to treatment. The primary outcome measured was a change in patient health questionnaire-9 (PHQ-9) and PTSD Checklist for DSM-5 (PCL-5) scores across the first 8 treatments (induction period) using a repeated measures analysis of variance (ANOVA). In a smaller sub-group (n = 19) of Veterans who received at least 8 additional treatments, we analyzed whether intranasal (S)-ketamine continued to show treatment effects. Finally, we performed a sub-group and correlation analyses to understand how changes in PHQ-9 and PCL-5 scores were related across treatments.

FINDINGS

During the induction phase of treatment there was an absolute reduction of 5.1 (SEM 0.7) on the patient health questionnaire-9 (PHQ-9) rating scale for depression, from 19.8 (SEM 0.7) at treatment 1 to 14.7 (SEM 0.8) at treatment 8 (week 4) (F(7238) = 8.3, p = 1e-6, partial η² = 0.2). Five Veterans (14%) showed a clinically meaningful response (50% reduction in PHQ-9 score) at treatment 8. There was an absolute reduction of 15.5 +/- 2.4 on the patient checklist 5 (PCL-5) rating scale for PTSD, from 54.8 (SEM 2) at treatment 1 down to 39.3 (SEM 2.5) at treatment 8 (F(7238) = 15.5, p = 2e-7, partial η² = 0.31). Sixteen Veterans (46%) showed a clinically meaningful response (reduction in PCL-5 of > 30%) in PTSD. Change in PHQ-9 correlated with change in PCL-5 at treatment 8 (r = 0.47, p = 0.005), but a decrease in PTSD symptoms were observable in some individuals with minimal anti-depressant response.

INTERPRETATIONS

While this is an open-label retrospective analysis, our results indicate that both depression and PTSD symptoms in Veterans with dual-diagnoses may improve with repeated intranasal (S)-ketamine treatment. The effects of (S)-ketamine on PTSD symptoms were temporally and individually distinct from those on depression, suggesting potentially different modes of action on the two disorders. This work may warrant formal randomized controlled studies on the effects of intranasal (S)-ketamine for individuals with co-morbid MDD and PTSD.

FUNDING

VA Center of Excellence in Stress and Mental Health, VA ORD (Career Development Award to DSR), Burroughs-Wellcome Fund Award (DSR), NIMH (EL).

The antidepressant effect and safety of non-intranasal esketamine: A systematic review

BACKGROUND

The introduction of esketamine into the field of psychiatry comes on the heels of excitement from studies on racemic ketamine. While the intranasal route has been the most studied to date, other modes of administration of esketamine may also be of interest in the management of depression.

AIMS

To systematically review the literature on non-intranasal esketamine for depression in terms of its antidepressant effect and safety.

METHODS

We searched PubMed, Embase, the Cochrane Library, and Google Scholar from inception up to February 2021. Search terms included a combination of Medical Subject Headings and text words indicative of esketamine and depression. We selected both controlled and uncontrolled studies examining non-intranasal esketamine for the treatment of depression.

RESULTS

We identified four randomized controlled trials (RCTs) on intravenous esketamine and 15 open-label studies on intravenous (n = 80), subcutaneous (n = 73), and oral (n = 5) esketamine. We found intravenous, subcutaneous, and possibly oral administration of esketamine to be effective in reducing depressive symptoms in most patients with major depressive disorder, bipolar depression, and (severe) treatment-resistant depression. Clinical response to repeated administration of esketamine persisted over the course of treatment. Esketamine was well tolerated by most patients, but open-label data indicate marked psychotomimetic symptoms in exceptional cases. The overall quality of the controlled studies was considered high, the overall quality of the uncontrolled studies low to moderate.

CONCLUSIONS

Intravenous, subcutaneous, and possibly oral esketamine may offer an effective and safe addition to the depression treatment armamentarium. However, as most included studies lacked a control group and had small sample sizes, the quality of our results is limited. Different types and formulations of ketamine remain to be compared directly.

Ketamine for suicidality: an umbrella review

The urgent need for appropriate treatment for suicide, the tenth leading cause of death, has led to numerous studies. This study aims to systematically identify and appraise systematic reviews with or without meta-analyses investigating ketamine in suicidal ideation and behaviors. The study protocol was published in PROSPERO (CRD42021285320). Scopus, ISI, Embase, PubMed, CINAHL, PsycINFO, Cochrane Library, Google Scholar, and two registries were searched on October 29 without any restrictions for systematic reviews investigating the efficacy of ketamine on suicidal ideation and behaviors. The primary outcome was the final inference of ketamine effectiveness. A formal narrative synthesis was conducted, and the AMSTAR-2 tool was used to evaluate the quality of the studies. No funding was received. Of 27 studies that addressed ketamine for suicidal ideation, only four reported mixed or negative results, and out of nine reviews, esketamine was significantly beneficial only in five. A transient rise in pulse rate and blood pressure, dissociation, confusion, blurred vision, nausea, and vertigo were of the most common adverse effects; however, most were mild. More than two-thirds of the included studies qualified as low or critically low quality. Preliminary evidence for the short-term efficacy of ketamine in suicidality was noted by the majority of reviews; however, long-term effects remained unknown. Due to the non-high quality of many studies and the limitations of core studies, further studies are required.

Neurological Adverse Events Associated With Esketamine: A Disproportionality Analysis for Signal Detection Leveraging the FDA Adverse Event Reporting System

Esketamine was approved for the treatment of treatment-resistant depression in 2019. After the approval of esketamine, numerous concerns have been raised regarding its long-term safety and tolerability. A previous systematic pharmacovigilance study on esketamine-related adverse events (AEs) was published in 2020; however, it has not been updated 2 years later. The primary aim of this study was to detect and characterize neurological safety signals of esketamine to partially update the knowledge in this field using the FDA pharmacovigilance database. Reporting odds ratio (ROR) was calculated for esketamine-related neurological AEs from 2019 to 2021 with a signal considered when the lower limit of the 95% confidence interval (CI) of ROR (ROR₀₂₅) exceeded one. Severe and non-severe cases were compared using an independent samples t-test or chi-squared (χ2) test, and a rating scale was used to prioritize the signals. The database contained 720 cases of esketamine-associated neurological AEs, with 21 signals detected, ranging from a ROR₀₂₅ of 1.05 (disturbance in attention) to 204.00 (sedation). 16 latest neurological AEs emerged in the second year of marketing approval of esketamine, with eight signals detected. The associations between esketamine and nervous system disorders persisted when stratifying by sex, age, and reporter type, whereas the spectrum of neurological AEs differed in stratification regimens. Esketamine dosage, antidepressant polypharmacy, or co-prescription with benzodiazepines affected AEs severity (t = 2.41, p = 0.017; χ2 = 6.75, p = 0.009; and χ2 = 4.10, p = 0.043; respectively), while age and sex did not (p = 0.053 and p = 0.397, respectively). Three signals were categorized as moderate clinical priority [i.e., sedation, dizziness, and dysgeusia (priority points 7, 5, and 5, respectively)], showing the same early failure type profiles. Notably, seven detected disproportionality signals were not previously detected in clinical trials. Although the majority of results were in line with those obtained in the previous study, there were discrepancies in the spectrum of neurological AEs and the effects of several risk factors on AEs severity among the two studies that should be recognized and managed early in clinical treatments.

Recent advances in the psychopharmacology of major depressive disorder

This review highlights some of the recent advances in the psychopharmacology of major depressive disorder (MDD). We synthesise evidence on emerging pharmacological therapies targeting the serotonergic system, before exploring several novel treatment targets: the glutamatergic system, the GABAergic system and inflammation. When describing new treatment avenues, we examine the evidence base and how far these new treatments are from routine practice.

A Review of Ocular Complications Associated with Medications Used for Anxiety, Depression, and Stress

This review of commonly prescribed psychotropic drugs aims to update the clinician on possible ophthalmic side effects that may include dry eye, diplopia, mydriasis, and cataracts. This review summarizes our current knowledge of known ocular side effects of psychotropic drugs based on reviews, case reports, case-control studies, a case series, and cross-sectional observational studies reported in the recent literature. The review covers disorders related to depression, anxiety, and stress which are commonly encountered within society and can have debilitating impacts on an individual's quality of life that may require chronic therapeutic management. The main medications used in the treatment and management of these conditions typically target receptors, metabolic enzymes, or transport pumps that alter the pre- and/or post-synaptic levels of neurotransmitters such as serotonin, norepinephrine, dopamine, gamma-aminobutyric acid, and opioids to improve mood and/or relieve pain and anxiety. Novel non-therapeutic options are undergoing clinical trials, and some patients may seek alternative therapies or have associated substance abuse issues to alleviate their symptoms. This review summarizes some of the clinical signs of depression and the main therapeutic options and their reported ocular side effects which may be pertinent today given the rise in use of psychotropic medications used to manage depression, anxiety, and stress.

Is (R)-ketamine a Potential Therapeutic Agent for Treatment-Resistant Depression with Less Detrimental Side Effects? A Review of Molecular Mechanisms Underlying Ketamine and its Enantiomers

Approximately one-third of individuals with major depressive disorder are resistant to conventional antidepressants (i.e., monoamine-based therapies), and, even among respondents, a proper therapeutic effect may require weeks of treatment. Ketamine, a racemic mixture of the two enantiomers, (R)-ketamine and (S)-ketamine, is an N-methyl-d-aspartate receptor (NMDAR) antagonist and has been shown to have rapid-acting antidepressant properties in patients with treatment-resistant depression (TRD). Although (R)-ketamine has a lower affinity for NMDAR, it presents greater potency and longer-lasting antidepressant properties, with no major side effects, than racemic ketamine or (S)-ketamine in preclinical findings. Thereby, ketamine and its enantiomers have not only an antagonistic effect on NMDAR but also a strong synaptogenic-modulatory effect, which is impaired in TRD pathophysiology. In this review, we summarize the current evidence regarding the modulation of neurotransmission, neuroplasticity, and neural network activity as putative mechanisms of these rapid-acting antidepressants, highlighting differences on intracellular signaling pathways of synaptic proteins such as mammalian target of rapamycin (mTOR), extracellular signal-regulated kinase (ERK) and brain-derived neurotrophic factor (BDNF). In addition, we discuss probable mechanisms involved in the side effects of ketamine and its enantiomers.

Non-parenteral Ketamine for Depression: A Practical Discussion on Addiction Potential and Recommendations for Judicious Prescribing

Intravenous (IV) ketamine is increasingly used off-label at subanesthetic doses for its rapid antidepressant effect, and intranasal (IN) esketamine has been recently approved in several countries for treating depression. The clinical utility of these treatments is limited by a paucity of publicly funded IV ketamine and IN esketamine programs and cost barriers to private treatment programs, as well as the drug cost for IN esketamine itself, which makes generic ketamine alternatives an attractive option. Though evidence is limited, use of non-parenteral racemic ketamine formulations (oral, sublingual, and IN) may offer more realistic access in less rigidly supervised settings, both for acute and maintenance treatment in select cases. However, the psychiatric literature has repeatedly cautioned on the addictive potential of ketamine and raised caution for both less supervised and longer-term use of ketamine. To date, these concerns have not been discussed in view of available evidence, nor have they been discussed within a broader clinical context. This paper examines the available relevant literature and suggests that ketamine misuse risks appear not dissimilar to those of other well-established and commonly prescribed agents with abuse potential, such as stimulants or benzodiazepines. As such, ketamine prescribing should be considered in a similar risk/benefit context to balance patient access and need for treatment with concern for potential substance misuse. Our consortium of mood disorder specialists with significant ketamine prescribing experience considers prescribing of non-parenteral ketamine a reasonable clinical treatment option in select cases of treatment-resistant depression. This paper outlines where this may be appropriate and makes practical recommendations for clinicians in judicious prescribing of non-parenteral ketamine.

Remission of functional motor symptoms following esketamine administration in a patient with treatment-resistant depression: a single-case report

Functional movement disorders (FMD) involve a broad range of abnormal involuntary movements not consistent with neurological diseases. These conditions often occur in combination with mood and anxiety disorders and are associated with poor clinical outcomes. We report the case of a 57-year-old woman diagnosed with treatment-resistant depression (TRD) and comorbid FMD treated with weekly intranasal administrations of esketamine over a six-month follow-up period. A comprehensive clinical and psychometric assessment was carried out at different time points. After 2 months of treatment, a complete remission of motor and axial functional disturbances (athetosis, trunk torsion and genuflections) was detectable, along with a progressive improvement in depressive symptoms during follow-up until full remission. According to novel lines of evidence, glutamatergic transmission might play a role in the pathophysiology of FMD through aberrant limbic-motor interactions. We report that treatment with esketamine, a noncompetitive N-methyl-d-aspartate glutamatergic receptor antagonist, was associated with remission of FMD symptoms in a patient with TRD. Pharmacological compounds modulating brain glutamatergic activity may be of potential benefit in the clinical management of FMD.

Ketamine for the treatment of mental health and substance use disorders: comprehensive systematic review

BACKGROUND

In the past two decades, subanaesthetic doses of ketamine have been demonstrated to have rapid and sustained antidepressant effects, and accumulating research has demonstrated ketamine's therapeutic effects for a range of psychiatric conditions.

AIMS

In light of these findings surrounding ketamine's psychotherapeutic potential, we systematically review the extant evidence on ketamine's effects in treating mental health disorders.

METHOD

The systematic review protocol was registered in PROSPERO (identifier CRD42019130636). Human studies investigating the therapeutic effects of ketamine in the treatment of mental health disorders were included. Because of the extensive research in depression, bipolar disorder and suicidal ideation, only systematic reviews and meta-analyses were included. We searched Medline and PsycINFO on 21 October 2020. Risk-of-bias analysis was assessed with the Cochrane Risk of Bias tools and A Measurement Tool to Assess Systematic Reviews (AMSTAR) Checklist.

RESULTS

We included 83 published reports in the final review: 33 systematic reviews, 29 randomised controlled trials, two randomised trials without placebo, three non-randomised trials with controls, six open-label trials and ten retrospective reviews. The results were presented via narrative synthesis.

CONCLUSIONS

Systematic reviews and meta-analyses provide support for robust, rapid and transient antidepressant and anti-suicidal effects of ketamine. Evidence for other indications is less robust, but suggests similarly positive and short-lived effects. The conclusions should be interpreted with caution because of the high risk of bias of included studies. Optimal dosing, modes of administration and the most effective forms of adjunctive psychotherapeutic support should be examined further.

Trends in Ketamine Use, Exposures, and Seizures in the United States up to 2019

Objectives. To determine whether there have been shifts in nonmedical ketamine use, poisonings ("exposures"), and seizures. Methods. We used generalized additive models to detect trends in past-year use (2006-2019), exposures (1991-2019), and seizures (2000-2019) involving ketamine in the United States. Results. There was a quarterly increase in self-reported past-year nonmedical ketamine use in 2006 to 2014 (Β = 0.21; P = .030) and an increase in 2015 to 2019 (Β = 0.29; P = .036), reaching a peak of 0.9% in late 2019. The rate of exposures increased from 1991 through 2019 (Β = 0.87; P = .006), and there was an increase to 1.1 exposures per 1 000 000 population in 2014, with rates remaining stable through 2019. The rate of ketamine seizures increased from 2000 through 2019 (Β = 2.27; P < .001), with seizures reaching a peak in 2019 at 3.2 per 1000 seizures. Conclusions. Indicators suggest that ketamine use and availability has increased, including before increased medical indications, but nonmedical use is still currently uncommon despite increased acceptance and media coverage. (Am J Public Health. 2021;111(11):2046-2049. https://doi.org/10.2105/AJPH.2021.306486).

Use of ketamine and esketamine for depression: an overview of systematic reviews with meta-analyses

PURPOSE

To summarize the evidence of efficacy and safety of the use of ketamine and esketamine for depression.

METHODS

A literature search was performed in Medline, the Cochrane Library, LILACS, and CRD until November 2020. We included systematic reviews with meta-analyses of randomized controlled trials on the use of ketamine and esketamine in adult patients with depression. Two authors independently performed the study selection and data extraction. The AMSTAR-2 tool was used to appraise the quality of included reviews.

RESULTS

A total of 118 records were identified, and 11 studies fully met the eligibility criteria. Compared to control, ketamine improved the clinical response at 40 min to 1 week and clinical remission at 80 min to 72 h, and esketamine improved both outcomes at 2 h to 4 weeks. Ketamine and esketamine also had a beneficial effect on the depression scales score and suicidality. For adverse events, oral ketamine did not show significant change compared to control, while intranasal esketamine showed difference for any events, such as dissociation, dizziness, hypoesthesia, and vertigo. Most reviews were classified as "critically low quality," and none of them declared the source of funding of the primary studies and assessed the potential impact of risk of bias in primary studies.

CONCLUSION

Ketamine and esketamine showed a significant antidepressant action within a few hours or days after administration; however, the long-term efficacy and safety are lacking. In addition, the methodological quality of the reviews was usually critically low, which may indicate the need for higher quality evidence in relation to the theme.

Ketamine and other glutamate receptor modulators for depression in adults with unipolar major depressive disorder

BACKGROUND

Many studies have recently been conducted to assess the antidepressant efficacy of glutamate modification in mood disorders. This is an update of a review first published in 2015 focusing on the use of glutamate receptor modulators in unipolar depression.

OBJECTIVES

To assess the effects - and review the acceptability and tolerability - of ketamine and other glutamate receptor modulators in alleviating the acute symptoms of depression in people with unipolar major depressive disorder.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Embase and PsycINFO all years to July 2020.  We did not apply any restrictions to date, language or publication status.

SELECTION CRITERIA

Double- or single-blinded randomised controlled trials (RCTs) comparing ketamine, memantine, esketamine or other glutamate receptor modulators with placebo (pill or saline infusion), other active psychotropic drugs, or electroconvulsive therapy (ECT) in adults with unipolar major depression.

DATA COLLECTION AND ANALYSIS

Three review authors independently identified studies, assessed trial quality and extracted data. The primary outcomes were response rate (50% reduction on a standardised rating scale) and adverse events. We decided a priori to measure the efficacy outcomes at different time points and run sensitivity/subgroup analyses. Risk of bias was assessed using the Cochrane tool, and certainty of the evidence was assessed using GRADE.

MAIN RESULTS

Thirty-one new studies were identified for inclusion in this updated review. Overall, we included 64 studies (5299 participants) on ketamine (31 trials), esketamine (9), memantine (5), lanicemine (4), D-cycloserine (2), Org26576 (2), riluzole (2), atomoxetine (1), basimglurant (1), citicoline (1), CP-101,606 (1), decoglurant (1), MK-0657 (1), N-acetylcysteine (1), rapastinel (1), and sarcosine (1). Forty-eight studies were placebo-controlled, and 48 were two-arm studies. The majority of trials defined an inclusion criterion for the severity of depressive symptoms at baseline: 29 at least moderate depression; 17 severe depression; and five mild-to-moderate depression. Nineteen studies recruited only patients with treatment-resistant depression, defined as inadequate response to at least two antidepressants. The majority of studies investigating ketamine administered as a single dose, whilst all of the included esketamine studies used a multiple dose regimen (most frequently twice a week for four weeks). Most studies looking at ketamine used intravenous administration, whilst the majority of esketamine trials used intranasal routes. The evidence suggests that ketamine may result in an increase in response and remission compared with placebo at 24 hours odds ratio (OR) 3.94, 95% confidence interval (CI) 1.54 to 10.10; n = 185, studies = 7, very low-certainty evidence). Ketamine may reduce depression rating scale scores over placebo at 24 hours, but the evidence is very uncertain (standardised mean difference (SMD) -0.87, 95% CI -1.26 to -0.48; n = 231, studies = 8, very low-certainty evidence). There was no difference in the number of participants assigned to ketamine or placebo who dropped out for any reason (OR 1.25, 95% CI 0.19 to 8.28; n = 201, studies = 6, very low-certainty evidence). When compared with midazolam, the evidence showed that ketamine increases remission rates at 24 hours (OR 2.21, 95% CI 0.67 to 7.32; n = 122,studies = 2, low-certainty evidence). The evidence is very uncertain about the response efficacy of ketamine at 24 hours in comparison with midazolam, and its ability to reduce depression rating scale scores at the same time point (OR 2.48, 95% CI 1.00 to 6.18; n = 296, studies = 4,very low-certainty evidence). There was no difference in the number of participants who dropped out of studies for any reason between ketamine and placebo (OR 0.33, 95% CI 0.05 to 2.09; n = 72, studies = 1, low-certainty evidence). Esketamine treatment likely results in a large increase in participants achieving remission at 24 hours compared with placebo (OR 2.74, 95% CI 1.71 to 4.40; n = 894, studies = 5, moderate-certainty evidence). Esketamine probably results in decreases in depression rating scale scores at 24 hours compared with placebo (SMD -0.31, 95% CI -0.45 to -0.17; n = 824, studies = 4, moderate-certainty evidence). Our findings show that esketamine increased response rates, although this evidence is uncertain (OR 2.11, 95% CI 1.20 to 3.68; n = 1071, studies = 5, low-certainty evidence). There was no evidence that participants assigned to esketamine treatment dropped out of trials more frequently than those assigned to placebo for any reason (OR 1.58, 95% CI 0.92 to 2.73; n = 773, studies = 4,moderate-certainty evidence). We found very little evidence for the remaining glutamate receptor modulators. We rated the risk of bias as low or unclear for most domains, though lack of detail regarding masking of treatment in the studies reduced our certainty in the effect for all outcomes.

AUTHORS' CONCLUSIONS

Our findings show that ketamine and esketamine may be more efficacious than placebo at 24 hours. How these findings translate into clinical practice, however, is not entirely clear. The evidence for use of the remaining glutamate receptor modulators is limited as very few trials were included in the meta-analyses for each comparison and the majority of comparisons included only one study. Long term non-inferiority RCTs comparing repeated ketamine and esketamine, and rigorous real-world monitoring are needed to establish comprehensive data on safety and efficacy.

Long-Term Efficacy of Intranasal Esketamine in Treatment-Resistant Major Depression: A Systematic Review

Esketamine (ESK) has been approved as a rapid-acting intranasal treatment for treatment-resistant depression (TRD). Although existing studies have investigated the efficacy of ESK in the 4-week induction phase, our knowledge about long-term ESK efficacy remains poor. The aim of this systematic review was to summarize the available data on long-term ESK efficacy for TRD. A systematic search was performed including articles in English, up to 31 March 2021. The search found 7 relevant studies, involving 1024 adult TRD patients. Continuing treatment with ESK after the 4-week induction phase may be associated with stable efficacy in relapse prevention among TRD patients. Conversely, the long-term antidepressant effectiveness upon discontinuation of ESK might be limited, although data from three studies had a moderate to high risk of bias. Overall, the results on the effectiveness of this compound in the long term are mixed. According to our findings, ESK treatment should be continued following the induction phase to reach a stable efficacy in relapse prevention, while the long-term antidepressant and anti-suicidal effects of ESK after discontinuation are inconsistent. Currently, the level of proof of ESK efficacy in long-term TRD treatment remains low and more RCTs with larger sample sizes and active comparators are needed.

Media coverage about medical benefits of MDMA and ketamine affects perceived likelihood of engaging in recreational use

Background

Research on the efficacy of ketamine in treating depression and 3,4-methylenedioxymethamphetamine (MDMA) in treating post-traumatic stress disorder have been widely covered by the media. Given recent widespread coverage of the efficacy of these drugs, it is important to determine whether such coverage influences prevalence of recreational use. While longitudinal studies would be most ideal for assessing this, to acquire preliminary data, we tested survey items assessing this potential phenomenon in a population known for high prevalence of use of these drugs.

Method

Adults entering randomly selected nightclubs in New York City (n = 209) were surveyed about drug use. Questions were included to assess their perceived likelihood of recent media coverage about medical benefits associated with use of ketamine and MDMA affecting their own use.

Results

Two-thirds (66.8%) of participants had ever used ecstasy/MDMA and 22.6% had ever used ketamine. The plurality of participants reported that media coverage about ketamine (46.1%) and MDMA (39.9%) did not affect their likelihood of using. 10.1% and 21.0% of participants reported increased likelihood of using ketamine and MDMA, respectively. 52.3% of those reporting past-month ketamine use and 6.1% of those reporting no lifetime use reported being more likely to use in response to media coverage about ketamine. 28.6% of those reporting past-month ecstasy use and 5.5% of those reporting no lifetime use reported being more likely to use in response to media coverage about MDMA.

Discussion

Media coverage about the medical benefits of ketamine and MDMA might influence specific subsets of people to use.

"Novel Psychopharmacology for Depressive Disorders"

Major depressive disorder carries a significant burden and a high risk for suicide. The need for more effective, safer, and faster-acting drugs is, therefore, compelling. The present chapter briefly assesses the most promising agents, focusing on non-monoamine-targeting compounds, namely, the glutamate antagonist ketamine and its enantiomer esketamine. A critical overview of the evidence and the pitfalls associated with current antidepressant drug development is likewise provided in the following text.

Intravenous arketamine for treatment-resistant depression: open-label pilot study

We aimed to analyze the efficacy and safety of arketamine, the R(-)-enantiomer of ketamine, for treatment-resistant depression (TRD) in humans. Open-label pilot trial, seven subjects with TRD received a single intravenous infusion of arketamine (0.5 mg/kg); primary outcome was change in Montgomery-Åsberg Depression Rating Scale (MADRS) 24 h after. Mean MADRS dropped from 30.7 before infusion to 10.4 after one day, a mean difference of 20.3 points [CI 95% 13.6-27.0; p < 0.001]; dissociation was nearly absent. Arketamine might produce fast-onset and sustained antidepressant effects in humans with favorable safety profile, like previously reported with animals; further controlled-trials are needed.

Corticotropin Releasing Hormone Signaling in the Bed Nuclei of the Stria Terminalis as a Link to Maladaptive Behaviors

The bed nuclei of the stria terminalis (BST) is a limbic region in the extended amygdala that is heavily implicated in anxiety processing and hypothalamic-adrenal-pituitary (HPA) axis activation. The BST is complex, with many nuclei expressing different neurotransmitters and receptors involved in a variety of signaling pathways. One neurotransmitter that helps link its functions is corticotropin releasing hormone (CRH). BST CRH neuron activation may cause both anxiogenic and anxiolytic effects in rodents, and CRH neurons interact with other neuron types to influence anxiety-like responses as well as alcohol and drug–seeking behavior. This review covers the link between BST CRH neurons and thirteen other neurotransmitters and receptors and analyzes their effect on rodent behavior. Additionally, it covers the translational potential of targeting CRH signaling pathways for the treatment of human mental health disorders. Given the massive impact of anxiety, mood, and substance use disorders on our society, further research into BST CRH signaling is critical to alleviate the social and economic burdens of those disorders.

Depression: Biological markers and treatment

Nowadays depression is considered as a systemic illness with different biological mechanisms involved in its etiology, including inflammatory response, hypothalamic-pituitary-adrenal (HPA) axis dysregulation and neurotransmitter and neurotrophic systems imbalance. Novel "omics" approaches, such as metabolomics and glycomics provide information about altered metabolic pathways and metabolites, as well as disturbances in glycosylation processes affected by or causing the development of depression. The clinical diagnosis of depression continues to be established based on the presence of the specific symptoms, but due to its heterogeneous underlying biological background, that differs according to the disease stage, there is an unmet need for treatment response biomarkers which would facilitate the process of appropriate treatment selection. This paper provides an overview of the role of major stress response system, the HPA axis, and its dysregulation in depression, possible involvement of neurotrophins, especially brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor and insulin-like growth factor-1, in the development of depression. Article discusses how activated inflammation processes and increased cytokine levels, as well as disturbed neurotransmitter systems can contribute to different stages of depression and could specific metabolomic and glycomic species be considered as potential biomarkers of depression. The second part of the paper includes the most recent findings about available medical treatment of depression. The described biological factors impose an optimistic conclusion that they could represent easy obtainable biomarkers potentially predicting more personalized treatment and diagnostic options.

Experimental Therapeutics in Treatment-Resistant Major Depressive Disorder

Treatment-Resistant Depression (TRD) patients remain a challenging sub-division of patients with Major Depressive Disorder (MDD) in day to day clinical practice. As with any diagnostic condition, comprehensive evaluation, exclusion of other psychiatric conditions, assessment of co-morbid medical and psychiatric illnesses and psychosocial stressors are the keys to appropriate diagnosis and subsequent management. There are various management options available for the treatment of MDD, however, about 30% of the patients fail to achieve full remission of symptoms despite multiple trials and belong to this sub-category of MDD. This article brings forth discussion of other non-conventional medication and non-medication treatment alternatives that merit exploration of their efficacy in TRD. Many of the proposed novel medications and other treatment modalities such as Deep Brain Stimulation, exercise, yoga are already used for other medical and psychiatric disorders and have some evidence suggesting their potential benefits in TRD in conjunction with conventional medications or even as monotherapy. Nevertheless, more research is needed in this direction to establish effectiveness.

A Preliminary Study of Adjunctive Nonconvulsive Electrotherapy for Treatment-Refractory Depression

Nonconvulsive electrotherapy (NET) defined as electrical brain stimulation administered like standard electroconvulsive therapy (ECT), but below seizure threshold, could be effective for patients with treatment-refractory depression (TRD) with fewer adverse neurocognitive outcomes. However, there is a lack of studies in Chinese patients with TRD. Thus, this study was conducted to examine the efficacy and safety of adjunctive NET for Chinese patients with TRD. Twenty TRD patients were enrolled and underwent six NET treatments. Depressive symptoms, response, and remission were assessed with the 17-item Hamilton Depression Rating Scale (HAMD-17) at baseline and after 1, 3, and 6 NET treatments. Neurocognitive function was assessed by the Wisconsin Card Sorting Test (WCST) at baseline and after the completion of six NET treatments. Mean HAMD-17 scores declined significantly from 26.2 to 10.4 (p < 0.001) after post-NET. The rates of response and remission were 60.0% (95% CI: 36.5-83.5) and 10.0% (95% CI: 0-24.4), respectively. Neurocognitive performance improved following a course of NET. No significant association was found between changes in depressive symptoms and baseline neurocognitive function. Adjunctive NET appeared to be effective for patients with TRD, without adverse neurocognitive effects. Randomized controlled studies were warranted to confirm these findings.

Major Depressive Disorder: Advances in Neuroscience Research and Translational Applications

Major depressive disorder (MDD), also referred to as depression, is one of the most common psychiatric disorders with a high economic burden. The etiology of depression is still not clear, but it is generally believed that MDD is a multifactorial disease caused by the interaction of social, psychological, and biological aspects. Therefore, there is no exact pathological theory that can independently explain its pathogenesis, involving genetics, neurobiology, and neuroimaging. At present, there are many treatment measures for patients with depression, including drug therapy, psychotherapy, and neuromodulation technology. In recent years, great progress has been made in the development of new antidepressants, some of which have been applied in the clinic. This article mainly reviews the research progress, pathogenesis, and treatment of MDD.

Comparative efficacy and side-effect profile of ketamine and esketamine in the treatment of unipolar and bipolar depression: protocol for a systematic review and network meta-analysis

INTRODUCTION

Despite a range of antidepressant drugs and therapies, approximately one-third of patients fail to achieve meaningful recovery, prompting the urgent need for more effective treatment for depression. Several open-label studies randomised controlled trials (RCTs) and meta-analyses have been conducted to confirm the therapeutic efficacy and side effects of ketamine and esketamine. Esketamine is (S)- enantiomer of ketamine; however, there is limited evidence comparing esketamine and ketamine in treating unipolar and bipolar depression have been published so far.

METHODS AND ANALYSIS

We will include all double-blind RCTs comparing efficacy and side-effect profile of ketamine and esketamine in the treatment of unipolar and bipolar depression. Our primary outcomes will be study-defined response at endpoint assessment; dropouts due to adverse events and other adverse drug reactions. Published studies will be retrieved through relevant database searches. Reference selection and data extraction will be independently completed by two investigators, resolving inconsistencies by consensus or a discussion with the third investigator. For each outcome, we will undertake a network meta-analysis to synthesise all evidence. Local and global methods will be used to evaluate consistency. We will assess the quality of evidence contributing to network estimates with the Confidence in Network Meta-Analysis web application.

ETHICS AND DISSEMINATION

This work does not require ethics approval as it will be based on published studies. This review will be published in peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

CRD42020201559.

Ketamine and the Future of Rapid-Acting Antidepressants

The therapeutic onset of traditional antidepressants is delayed by several weeks and many depressed patients fail to respond to treatment altogether. In contrast, subanesthetic ketamine can rapidly alleviate symptoms of depression within hours of a single administration, even in patients who are considered treatment-resistant. Ketamine is thought to exert these effects by restoring the integrity of neural circuits that are compromised in depression. This hypothesis stems in part from preclinical observations that ketamine can strengthen synaptic connections by increasing glutamate-mediated neurotransmission and promoting rapid neurotrophic factor release. An improved understanding of how ketamine, and other novel rapid-acting antidepressants, give rise to these processes will help foster future therapeutic innovation. Here, we review the history of antidepressant treatment advances that preceded the ketamine discovery, critically examine mechanistic hypotheses for how ketamine may exert its antidepressant effects, and discuss the impact this knowledge has had on ongoing drug discovery efforts.

The Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Recommendations for the Use of Racemic Ketamine in Adults with Major Depressive Disorder: Recommandations Du Groupe De Travail Du Réseau Canadien Pour Les Traitements De L'humeur Et De L'anxiété (Canmat) Concernant L'utilisation De La Kétamine Racémique Chez Les Adultes Souffrant De Trouble Dépressif Majeur

OBJECTIVE

Patients with major depressive disorder often have limited response to first-line and second-line medications; hence, novel pharmacological treatments are needed for treatment-resistant depression (TRD). Ketamine, an N-methyl-d-aspartate (NMDA) receptor antagonist, has demonstrated rapid antidepressant effects in patients with TRD. The Canadian Network for Mood and Anxiety Treatments (CANMAT) convened a task force to review the evidence for efficacy and safety of racemic ketamine and to provide recommendations for its use in clinical practice.

METHODS

A systematic review was conducted with computerized search of electronic databases up to January 31, 2020 using combinations of search terms, inspection of bibliographies, and review of other ketamine guidelines and consensus statements. The level of evidence and lines of treatment were assigned according to CANMAT criteria. Recommendations were given in question-answer format.

RESULTS

Intravenous (IV) racemic ketamine given as a single infusion has Level 1 evidence for efficacy in adults with TRD. The evidence for multiple infusions, given as an acute series or as ongoing maintenance treatment, is limited to Level 3. Adverse events associated with ketamine infusions include behavioral (e.g., dissociative symptoms) and physiological (e.g., hypertension) events. There is only Level 3 or 4 evidence for non-IV formulations of racemic ketamine. Consensus recommendations are given for clinical administration of IV ketamine including patient selection, facility and personnel issues, monitoring, and maintaining response.

CONCLUSIONS

Single-dose IV racemic ketamine is a third-line recommendation for adults with TRD. The need for repeated and maintenance ketamine infusions should be carefully assessed on a case-by-case basis with consideration of potential risks and benefits. Because of limited evidence for efficacy and risk for misuse and diversion, the use of oral and other formulations of racemic ketamine should be limited to specialists with ketamine-prescribing expertise and affiliations with tertiary or specialized centers.

[A review of the antidepressant properties of ketamine]

Major depression is a frequent and disabling disorder. Despite great developments in the field of psychopharmacology since the 1950's, delayed onset of action and treatment resistance to current pharmacological options, such as serotonin reuptake inhibitors, remain a therapeutic challenge. The recent discovery of the rapid antidepressant action of ketamine, an NMDA (N-methyl-D-aspartate) receptor antagonist, has brought a revolution to this field. This paper presents a comprehensive review of the clinical research on the antidepressant properties of ketamine as well as its presumed mechanisms of action.

The 2020 Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders

OBJECTIVES

To provide advice and guidance regarding the management of mood disorders, derived from scientific evidence and supplemented by expert clinical consensus to formulate s that maximise clinical utility.

METHODS

Articles and information sourced from search engines including PubMed, EMBASE, MEDLINE, PsycINFO and Google Scholar were supplemented by literature known to the mood disorders committee (e.g. books, book chapters and government reports) and from published depression and bipolar disorder guidelines. Relevant information was appraised and discussed in detail by members of the mood disorders committee, with a view to formulating and developing consensus-based recommendations and clinical guidance. The guidelines were subjected to rigorous consultation and external review involving: expert and clinical advisors, key stakeholders, professional bodies and specialist groups with interest in mood disorders.

RESULTS

The Royal Australian and New Zealand College of Psychiatrists mood disorders clinical practice guidelines 2020 (MDcpg²⁰²⁰) provide up-to-date guidance regarding the management of mood disorders that is informed by evidence and clinical experience. The guideline is intended for clinical use by psychiatrists, psychologists, primary care physicians and others with an interest in mental health care.

CONCLUSION

The MDcpg²⁰²⁰ builds on the previous 2015 guidelines and maintains its joint focus on both depressive and bipolar disorders. It provides up-to-date recommendations and guidance within an evidence-based framework, supplemented by expert clinical consensus.

MOOD DISORDERS COMMITTEE

Gin S Malhi (Chair), Erica Bell, Darryl Bassett, Philip Boyce, Richard Bryant, Philip Hazell, Malcolm Hopwood, Bill Lyndon, Roger Mulder, Richard Porter, Ajeet B Singh and Greg Murray.

Association of plasma VEGF levels and the antidepressant effects of ketamine in patients with depression

AIMS

Growing evidence suggests that vascular endothelial growth factor (VEGF) may be involved in the neuronal mechanisms underlying both depression aetiology and the response to ketamine treatments. The aim of this study was to examine whether changes in plasma VEGF levels are associated with the antidepressant effects of repeated ketamine infusions in patients with depression.

METHODS

Ninety-six patients with depression were enrolled and received six ketamine infusions during a 12-day period. Depressive symptom severity and plasma VEGF levels were measured by the Montgomery-Åsberg Depression Rating Scale (MADRS) and an enzyme-linked immunosorbent assay (ELISA) respectively, at baseline, 13 days and 26 days.

RESULTS

Despite a significant improvement in MADRS scores after patients received six ketamine infusions (p < 0.001), no changes in plasma VEGF levels were observed at 13 days when compared with baseline. Moreover, no significant difference in plasma VEGF levels at baseline and 13 days was found between ketamine responders and nonresponders. No association was found between the antidepressant effects of repeated ketamine treatments and plasma VEGF levels.

CONCLUSION

This study indicated that VEGF may not be a potential predictor of antidepressant response to repeated intravenous administration of ketamine in patients with depression.

Comparative effectiveness of esketamine in the treatment of anhedonia in bipolar and unipolar depression

BACKGROUND

Anhedonia is a symptom associated with poorer outcomes in depression treatment, including resistance to treatment, higher functional impact and suicidality. Few drugs are known to adequately treat anhedonia in both unipolar and bipolar depression. The NMDA antagonist ketamine has been demonstrated to be effective in rapidly ameliorating anhedonia in depressive episodes. The main aim of present study is to evaluate the anti-anhedonic effect of esketamine, the S-enantiomer of ketamine recently approved for treatment-resistant depression, in unipolar and bipolar depression.

METHODS

70 patients with unipolar or bipolar depression were treated with 6 weekly subcutaneous esketamine infusions (0.5-1mg/kg). Anhedonia was measured through MADRS item 8 before and 24h after each infusion.

RESULTS

A significant reduction in anhedonia severity was observed (p<0.0001) after 6 infusions. The effect was statistically significant 24h after the first infusion (p<0.001) in both unipolar and bipolar groups and increased with repeated infusions. Anti-anhedonic effect of esketamine did not differ between groups.

LIMITATIONS

This is an open-label, real-world study. Lack of blinding and of a placebo arm may limit the interpretation of findings.

CONCLUSION

Although preliminary, present findings suggest that repeated subcutaneous esketamine infusions are effective for the treatment of anhedonia in both unipolar and bipolar depressed patients. These results need to be confirmed through replication in larger double-blinded controlled trials.

Ketamine treatment for individuals with treatment-resistant depression: longitudinal qualitative interview study of patient experiences

BACKGROUND

Ketamine has recently received considerable attention regarding its antidepressant and anti-suicidal effects. Trials have generally focused on short-term effects of single intravenous infusions. Research on patient experiences is lacking.

AIMS

To investigate the experiences over time of individuals receiving ketamine treatment in a routine clinic, including impacts on mood and suicidality.

METHOD

Twelve fee-paying patients with treatment-resistant depression (6 females, 6 males, age 21-70 years; 11 reporting suicidality and 6 reporting self-harm) who were assessed as eligible for ketamine treatment participated in up to three semi-structured interviews: before treatment started, a few weeks into treatment and ≥2 months later. Data were analysed thematically.

RESULTS

Most participants hoped that ketamine would provide respite from their depression. Nearly all experienced improvement in mood following initial treatments, ranging from negligible to dramatic, and eight reported a reduction in suicidality. Improvements were transitory for most participants, although two experienced sustained consistent benefit and two had sustained but limited improvement. Some participants described hopelessness when treatment stopped working, paralleled by increased suicidal ideation for three participants. The transient nature and cost of treatment were problematic. Eleven participants experienced side-effects, which were significant for two participants. Suggestions for improving treatment included closer monitoring and adjunctive psychological therapy.

CONCLUSIONS

Ketamine treatment was generally experienced as effective in improving mood and reducing suicidal ideation in the short term, but the lack of longer-term benefit was challenging for participants, as was treatment cost. Informed consent procedures should refer to the possibilities of relapse and associated increased hopelessness and suicidality.