ELEctroconvulsive therapy (ECT) vs. Ketamine in patients with Treatment-resistant Depression: The ELEKT-D study protocol

Treatment-resistant depression: molecular mechanisms and management

Due to the heterogeneous nature of depression, the underlying etiological mechanisms greatly differ among individuals, and there are no known subtype-specific biomarkers to serve as precise targets for therapeutic efficacy. The extensive research efforts over the past decades have not yielded much success, and the currently used first-line conventional antidepressants are still ineffective for close to 66% of patients. Most clinicians use trial-and-error treatment approaches, which seem beneficial to only a fraction of patients, with some eventually developing treatment resistance. Here, we review evidence from both preclinical and clinical studies on the pathogenesis of depression and antidepressant treatment response. We also discuss the efficacy of the currently used pharmacological and non-pharmacological approaches, as well as the novel emerging therapies. The review reveals that the underlying mechanisms in the pathogenesis of depression and antidepressant response, are not specific, but rather involve an interplay between various neurotransmitter systems, inflammatory mediators, stress, HPA axis dysregulation, genetics, and other psycho-neurophysiological factors. None of the current depression hypotheses sufficiently accounts for the interactional mechanisms involved in both its etiology and treatment response, which could partly explain the limited success in discovering efficacious antidepressant treatment. Effective management of treatment-resistant depression (TRD) requires targeting several interactional mechanisms, using subtype-specific and/or personalized therapeutic modalities, which could, for example, include multi-target pharmacotherapies in augmentation with psychotherapy and/or other non-pharmacological approaches. Future research guided by interaction mechanisms hypotheses could provide more insights into potential etiologies of TRD, precision biomarker targets, and efficacious therapeutic modalities.

Ketamine vs Electroconvulsive Therapy for Treatment-Resistant Depression: A Secondary Analysis of a Randomized Clinical Trial

Importance

The ELEKT-D: Electroconvulsive Therapy (ECT) vs Ketamine in Patients With Treatment Resistant Depression (TRD) (ELEKT-D) trial demonstrated noninferiority of intravenous ketamine vs ECT for nonpsychotic TRD. Clinical features that can guide selection of ketamine vs ECT may inform shared decision-making for patients with TRD.

Objective

To evaluate whether selected clinical features were associated with differential improvement with ketamine vs ECT.

Design, Setting, and Participants

This secondary analysis of an open-label noninferiority randomized clinical trial was a multicenter study conducted at 5 US academic medical centers from April 7, 2017, to November 11, 2022. Analyses for this study, which were not prespecified in the trial protocol, were conducted from May 10 to Oct 31, 2023. The study cohort included patients with TRD, aged 21 to 75 years, who were in a current nonpsychotic depressive episode of at least moderate severity and were referred for ECT by their clinicians.

Exposures

Eligible participants were randomized 1:1 to receive either 6 infusions of ketamine or 9 treatments with ECT over 3 weeks.

Main Outcomes and Measures

Association between baseline factors (including 16-item Quick Inventory of Depressive Symptomatology Self-Report [QIDS-SR16], Montgomery-Asberg Depression Rating Scale [MADRS], premorbid intelligence, cognitive function, history of attempted suicide, and inpatient vs outpatient status) and treatment response were assessed with repeated measures mixed-effects model analyses.

Results

Among the 365 participants included in this study (mean [SD] age, 46.0 [14.5] years; 191 [52.3%] female), 195 were randomized to the ketamine group and 170 to the ECT group. In repeated measures mixed-effects models using depression levels over 3 weeks and after false discovery rate adjustment, participants with a baseline QIDS-SR16 score of 20 or less (-7.7 vs -5.6 points) and those starting treatment as outpatients (-8.4 vs -6.2 points) reported greater reduction in the QIDS-SR16 with ketamine vs ECT. Conversely, those with a baseline QIDS-SR16 score of more than 20 (ie, very severe depression) and starting treatment as inpatients reported greater reduction in the QIDS-SR16 earlier in course of treatment (-8.4 vs -6.7 points) with ECT, but scores were similar in both groups at the end-of-treatment visit (-9.0 vs -9.9 points). In the ECT group only, participants with higher scores on measures of premorbid intelligence (-14.0 vs -11.2 points) and with a comorbid posttraumatic stress disorder diagnosis (-16.6 vs -12.0 points) reported greater reduction in the MADRS score. Those with impaired memory recall had greater reduction in MADRS during the second week of treatment (-13.4 vs -9.6 points), but the levels of MADRS were similar to those with unimpaired recall at the end-of-treatment visit (-14.3 vs -12.2 points). Other results were not significant after false discovery rate adjustment.

Conclusions and Relevance

In this secondary analysis of the ELEKT-D randomized clinical trial of ECT vs ketamine, greater improvement in depression was observed with intravenous ketamine among outpatients with nonpsychotic TRD who had moderately severe or severe depression, suggesting that these patients may consider ketamine over ECT for TRD.

[Ketamine and suicidal behavior: Contribution of animal models of aggression-impulsivity to understanding its mechanism of action]

More than two-thirds of suicides occur during a major depressive episode. Acting out prevention measures and therapeutic options to manage the suicidal crisis are limited. The impulsive-aggressive dimensions are vulnerability factors associated with suicide in patients suffering from a characterized depressive episode: this can be a dimension involved in animals. Impulsive and aggressive rodent models can help analyze, at least in part, the neurobiology of suicide and the beneficial effects of treatments. Ketamine, a glutamatergic antagonist, by rapidly improving the symptoms of depressive episodes, would help reduce suicidal thoughts in the short term. Animal models share with humans impulsive and aggressive endophenotypes modulated by the serotonergic system (5-HTB receptor, MAO-A enzyme), neuroinflammation or the hypothalamic-pituitary-adrenal axis and stress. Significant effects of ketamine on these endophenotypes remain to be demonstrated.

Ketamine or ECT? What Have We Learned From the KetECT and ELEKT-D Trials?

1. Two recent clinical trials, KetECT and ELEKT-D, compared the effectiveness of ketamine and electroconvulsive therapy (ECT) for major depressive disorder. Notably, these trials reported marked differences in ECT's clinical outcomes of, with remission rates of 63% for KetECT and a strikingly lower rate of 22% for ELEKT-D, while the remission rates for ketamine were 46% and 38%, respectively. Considering that the primary objective of both trials was to compare the standard treatment (ECT) with an experimental intervention (ketamine), it is crucial to highlight the pronounced disparities in ECT's clinical outcomes. This article offers a comprehensive comparison of these trials while also exploring how patient characteristics, treatment protocols, and study designs may contribute to such pronounced outcome discrepancies. These differences highlight the heterogeneous nature of depression and underscore the need for personalized treatments. These studies also provide valuable insights into identifying the most suitable candidates for ketamine and ECT.

Looking through the lens of stigma: Understanding and anticipating concerns about the responsible development and use of psychiatric electroceutical interventions (PEIs)

Psychiatric electroceutical interventions (PEIs) show promise for treating depression, but few studies have examined stakeholders' views on them. Using interview data and survey data that analyzed the views of psychiatrists, patients, caregivers, and the general public, a conceptual map was created to represent stakeholders' views on four PEIs: electroconvulsive therapy (ECT), repetitive transcranial magnetic stimulation (TMS), deep brain stimulation (DBS), and adaptive brain implants (ABIs). Stigma emerged as a key theme connecting diverse views, revealing that it is a significant factor in the acceptance and usage of PEIs. Stigma not only discourages seeking mental health services for depression but also inhibits the acceptance of PEIs. Addressing the pervasive and complex effects of stigma highlights the need to change societal attitudes toward mental illnesses and their treatments and to provide support to patients who may benefit from these interventions. The map also demonstrates the value of conceptual mapping for anticipating and mitigating ethical considerations in the development and use of PEIs.

The Montreal model: an integrative biomedical-psychedelic approach to ketamine for severe treatment-resistant depression

Background

Subanesthetic ketamine has accumulated meta-analytic evidence for rapid antidepressant effects in treatment-resistant depression (TRD), resulting in both excitement and debate. Many unanswered questions surround ketamine's mechanisms of action and its integration into real-world psychiatric care, resulting in diverse utilizations that variously resemble electroconvulsive therapy, conventional antidepressants, or serotonergic psychedelics. There is thus an unmet need for clinical approaches to ketamine that are tailored to its unique therapeutic properties.

Methods

This article presents the Montreal model, a comprehensive biopsychosocial approach to ketamine for severe TRD refined over 6 years in public healthcare settings. To contextualize its development, we review the evidence for ketamine as a biomedical and as a psychedelic treatment of depression, emphasizing each perspectives' strengths, weaknesses, and distinct methods of utilization. We then describe the key clinical experiences and research findings that shaped the model's various components, which are presented in detail.

Results

The Montreal model, as implemented in a recent randomized clinical trial, aims to synergistically pair ketamine infusions with conventional and psychedelic biopsychosocial care. Ketamine is broadly conceptualized as a brief intervention that can produce windows of opportunity for enhanced psychiatric care, as well as powerful occasions for psychological growth. The model combines structured psychiatric care and concomitant psychotherapy with six ketamine infusions, administered with psychedelic-inspired nonpharmacological adjuncts including rolling preparative and integrative psychological support.

Discussion

Our integrative model aims to bridge the biomedical-psychedelic divide to offer a feasible, flexible, and standardized approach to ketamine for TRD. Our learnings from developing and implementing this psychedelic-inspired model for severe, real-world patients in two academic hospitals may offer valuable insights for the ongoing roll-out of a range of psychedelic therapies. Further research is needed to assess the Montreal model's effectiveness and hypothesized psychological mechanisms.

The Role of Psychotherapy in the Management of Treatment-Resistant Depression

This article reviews the role of psychotherapy in management of treatment-resistant depression (TRD). Meta-analyses of randomized trials show that psychotherapy has a positive therapeutic benefit in TRD. There is less evidence that one type of psychotherapy approach is superior to another. However, more trials have examined cognitive-based therapies than other forms of psychotherapy. Also reviewed is the potential combination of psychotherapy modalities and medication/somatic therapies as an approach to TRD. There is significant interest in ways that psychotherapy modalities could be combined with medication/somatic therapies to harness a state of enhanced neural plasticity and improve longer-term outcomes in mood disorders.

Pharmacological Mechanism of Ketamine in Suicidal Behavior Based on Animal Models of Aggressiveness and Impulsivity: A Narrative Review

Around 700,000 people die from suicide each year in the world. Approximately 90% of suicides have a history of mental illness, and more than two-thirds occur during a major depressive episode. Specific therapeutic options to manage the suicidal crisis are limited and measures to prevent acting out also remain limited. Drugs shown to reduce the risk of suicide (antidepressants, lithium, or clozapine) necessitate a long delay of onset. To date, no treatment is indicated for the treatment of suicidality. Ketamine, a glutamate NMDA receptor antagonist, is a fast-acting antidepressant with significant effects on suicidal ideation in the short term, while its effects on suicidal acts still need to be demonstrated. In the present article, we reviewed the literature on preclinical studies in order to identify the potential anti-suicidal pharmacological targets of ketamine. Impulsive-aggressive traits are one of the vulnerability factors common to suicide in patients with unipolar and bipolar depression. Preclinical studies in rodent models with impulsivity, aggressiveness, and anhedonia may help to analyze, at least in part, suicide neurobiology, as well as the beneficial effects of ketamine/esketamine on reducing suicidal ideations and preventing suicidal acts. The present review focuses on disruptions in the serotonergic system (5-HT_B receptor, MAO-A enzyme), neuroinflammation, and/or the HPA axis in rodent models with an impulsive/aggressive phenotype, because these traits are critical risk factors for suicide in humans. Ketamine can modulate these endophenotypes of suicide in human as well as in animal models. The main pharmacological properties of ketamine are then summarized. Finally, numerous questions arose regarding the mechanisms by which ketamine may prevent an impulsive-aggressive phenotype in rodents and suicidal ideations in humans. Animal models of anxiety/depression are important tools to better understand the pathophysiology of depressed patients, and in helping develop novel and fast antidepressant drugs with anti-suicidal properties and clinical utility.

Efficacy and Safety of Ketamine vs Electroconvulsive Therapy Among Patients With Major Depressive Episode: A Systematic Review and Meta-analysis

Importance

Whether ketamine is as effective as electroconvulsive therapy (ECT) among patients with major depressive episode remains unknown.

Objective

To systematically review and meta-analyze data about clinical efficacy and safety for ketamine and ECT in patients with major depressive episode.

Data Sources

PubMed, MEDLINE, Cochrane Library, and Embase were systematically searched using Medical Subject Headings (MeSH) terms and text keywords from database inception through April 19, 2022, with no language limits. Two authors also manually and independently searched all relevant studies in US and European clinical trial registries and Google Scholar.

Study Selection

Included were studies that involved (1) a diagnosis of depression using standardized diagnostic criteria, (2) intervention/comparator groups consisting of ECT and ketamine, and (3) depressive symptoms as an efficacy outcome using standardized measures.

Data Extraction and Synthesis

Data extraction was completed independently by 2 extractors and cross-checked for errors. Hedges g standardized mean differences (SMDs) were used for improvement in depressive symptoms. SMDs with corresponding 95% CIs were estimated using fixed- or random-effects models. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was followed.

Main Outcomes and Measures

Efficacy outcomes included depression severity, cognition, and memory performance. Safety outcomes included serious adverse events (eg, suicide attempts and deaths) and other adverse events.

Results

Six clinical trials comprising 340 patients (n = 162 for ECT and n = 178 for ketamine) were included in the review. Six of 6 studies enrolled patients who were eligible to receive ECT, 6 studies were conducted in inpatient settings, and 5 studies were randomized clinical trials. The overall pooled SMD for depression symptoms for ECT when compared with ketamine was -0.69 (95% CI, -0.89 to -0.48; Cochran Q, P = .15; I2 = 39%), suggesting an efficacy advantage for ECT compared with ketamine for depression severity. Significant differences were not observed between groups for studies that assessed cognition/memory or serious adverse events. Both ketamine and ECT had unique adverse effect profiles (ie, ketamine: lower risks for headache and muscle pain; ECT: lower risks for blurred vision, vertigo, diplopia/nystagmus, and transient dissociative/depersonalization symptoms). Limitations included low to moderate methodological quality and underpowered study designs.

Conclusions and Relevance

Findings from this systematic review and meta-analysis suggest that ECT may be superior to ketamine for improving depression severity in the acute phase, but treatment options should be individualized and patient-centered.

Assessment of Objective and Subjective Cognitive Function in Patients With Treatment-Resistant Depression Undergoing Repeated Ketamine Infusions

BACKGROUND

Subanesthetic ketamine infusions can elicit rapid and sustained antidepressant effects, yet the potential cognitive impact of ketamine has not been thoroughly examined. This study measured changes in objective and subjective cognitive function following repeated ketamine treatment.

METHODS

Thirty-eight patients with treatment-resistant depression were administered cognitive assessments before and after undergoing 7 i.v. ketamine infusions (0.5 mg/kg over 40 minutes) within a clinical trial examining the efficacy of single and repeated administrations. Depression severity and perceived concentration were evaluated with the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Quick Inventory of Depressive Symptoms Self-Report.

RESULTS

Twenty-three participants (60.5%) responded after repeated infusions (≥50% decrease in MADRS total scores). We measured significant improvements in several cognitive domains, including attention, working memory, verbal, and visuospatial memory (effect sizes ranging from Cohen d = 0.37-0.79). Cognitive changes were attributed to reduction in depressive symptoms except for improvement in verbal memory, which remained significant after adjustment for change in MADRS total score (P = .029, η p2 = 0.13). Only responders reported improvement in subjective cognitive function with repeated ketamine administration (MADRS item 6, P < .001, d = 2.00; Quick Inventory of Depressive Symptoms Self-Report item 10, P < .001, d = 1.36).

CONCLUSION

A short course of repeated ketamine infusions did not impair neurocognitive function in patients with treatment-resistant depression. Further research is required to understand the potential mediating role of response and remission on improved cognitive function accompanying ketamine treatment as well as to examine longer-term safety outcomes. ClinicalTrials.gov identifier NCT01945047.

Uso da cetamina na depressão resistente ao tratamento: uma revisão sistemática

RESUMO Objetivo A cetamina apresenta-se como uma alternativa promissora contra a depressão resistente ao tratamento (DRT), no entanto o conhecimento de sua aplicação como antidepressivo ainda é restrito. Diante disso, objetivou-se investigar sua eficácia em pacientes com DRT. Métodos A busca da literatura foi efetuada na base de dados MedLine. Os critérios de inclusão foram: estudos clínicos controlados e randomizados dos últimos cinco anos e em inglês. Excluímos os artigos que não responderam à pergunta PICO e aqueles com tamanho de amostra e metodologia de estudo destoantes, quando comparados aos ensaios que basearam esta revisão. Resultados Considerando uma amostra final de seis artigos, observou-se uma melhor resposta à cetamina (principalmente em ganho de humor), quando comparada ao tratamento convencional contra a DRT. Já com sua primeira infusão, na dose de 0,5 mg/kg, foi possível perceber seus efeitos antidepressivos. A manutenção desses efeitos parece ser obtida com a administração de 0,5 mg/kg do medicamento, três vezes por semana. Por outro lado, a redução de tal dosagem pode diminuir ou anular os efeitos. Conclusões O uso da cetamina apresentou resultados efetivos na melhora do quadro de DRT, com efeitos adversos de pequena gravidade e de fácil controle. Entretanto, outros estudos, com amostras maiores e métodos diferentes, são necessários, para uma conclusão de maior consistência.

Key considerations for the use of ketamine and esketamine for the treatment of depression: focusing on administration, safety, and tolerability

INTRODUCTION

Racemic ketamine, a derivative of phencyclidine, has been used as a dissociative anesthetic since 1970. In 2000, the first randomized controlled trial showed a rapid relief of depressive symptoms. Since then, intravenous ketamine and intranasal S-ketamine have been validated for the treatment of depression and suicidal ideation following dose-response and double-blind placebo-controlled clinical trials. In clinical practice, after dose titration and with repeated treatments, patients may experience approximately 2-3 weeks of symptomatic relief from depression.

AREAS COVERED

Areas covered in this narrative review include mechanism of action, dosing, safety, and tolerability. Some attention is paid to the possibility of R-ketamine as a future antidepressant.

EXPERT OPINION

We recommend further investigation into treatment dosing and frequency strategies as well as approaches that prolong the therapeutic effects. The current fixed dosing of esketamine for obese individuals may be insufficient. Additional investigation into co-administration with somatic and neuromodulation treatments needs investigation. Finally, continuing to monitor research subjects and patients long-term for the emergence of adverse effects on cognition or other organ systems is critical.

The Therapeutic Effects of Ketamine in Mental Health Disorders: A Narrative Review

Ketamine, a non-competitive N-methyl-d-aspartate receptor antagonist, is commonly used as an anesthetic and analgesic but has recently shown promising research in treating certain psychiatric conditions such as depression, post-traumatic stress disorder (PTSD), suicidal ideation, and substance use disorder. Due to its euphoric, dissociative, and hallucinogenic properties, ketamine has been abused as a recreational drug, which has led to rigid regulation of medication. The COVID-19 pandemic has been an unprecedented challenge for the American population which was reflected in increased reports of problems regarding their mental health. Mood disorders have dramatically increased in the past two years. Approximately one in ten people stated that they had started or increased substance use because of the COVID-19 pandemic. Furthermore, rates of suicidal ideation have significantly increased when compared to pre-pandemic levels, with more than twice the number of adults surveyed in 2018 indicating suicidal thoughts “within the last 30 days” at the time they were surveyed. Moreover, many responders indicated they had symptoms of PTSD. The PubMed database was searched using the keyword “ketamine,” in conjunction with “depression,” “suicidal ideation,” “substance use disorder,” and “post-traumatic stress disorder.” The inclusion criteria encompassed articles from 2017 to 2022 published in the English language that addressed the relationship between ketamine and mental health disorders. With this sharp increase in the prevalence of psychiatric disorders and an increased public interest in mental health combined with the promise of the therapeutic value of ketamine for certain mental health conditions, including suicidal ideation, this narrative review sought to identify recently published studies that describe the therapeutic uses of ketamine for mental health. Results of this review indicate that ketamine’s therapeutic effects offer a potential alternative treatment for depression, suicidal ideation, substance use disorders, and PTSD.

A comparison of the safety, feasibility, and tolerability of ECT and ketamine for treatment-resistant depression

INTRODUCTION

Treatment-resistant depression (TRD) is a problematic and prevalent public health and societal concern. Although electroconvulsive therapy (ECT) is the gold standard TRD intervention, the treatment evokes apprehension due to public perceptions, feasibility, and tolerability. Despite significant medical advancements, few medications have been approved by the U.S. Food and Drug Administration for TRD. In 2019, intranasal esketamine, the S-isomer of racemic ketamine, was approved for TRD, garnering significant excitement about the potential for the drug to act as an alternative treatment to ECT.

AREAS COVERED

The goal of this narrative review is to compare the safety, efficacy, and tolerability of ketamine and ECT; clarify whether ketamine is a reasonable alternative to ECT; and to facilitate improved treatment assignment for TRD. Empirical quantitative and qualitative studies and national and international guidelines these treatments are reviewed.

EXPERT OPINION

: The field awaits the results of two ongoing large comparative effectiveness trials of ECT and IV ketamine for TRD, which should help guide clinicians and patients as to the relative risk and benefit of these interventions. Over the next five years we anticipate further innovations in neuromodulation and in drug development which broadly aim to develop more tolerable versions of ECT and ketamine, respectively.

Patterns of use, clinical efficacy, safety and tolerability of Ketamine and Esketamine in treatment-resistant depression: Towards registry-based surveillance systems

More data on the long-term effects of Racemic Ketamine and Esketamine in TDR patients is needed. The implementation of centralized registries of their use for treatment of depression could be a tool of major importance for assessing their efficacy and safety in real-world clinical practice. This paper seeks to outline the rise and rationale behind these registry-based surveillance systems.

A systematic review of therapeutic ketamine use in children and adolescents with treatment-resistant mood disorders

Suicide is the second leading cause of death in the United States among individuals aged 10-24, and severe youth depression is often refractory to the current standards of care. Many studies have demonstrated the efficacy of ketamine in reducing depressive symptoms in adults with treatment-resistant mood disorders, though few studies utilizing ketamine in youth populations exist. This systematic review examines the current state of evidence for ketamine use in children with treatment-resistant mood disorders. We conducted a search utilizing two electronic databases for English-language studies investigating the therapeutic effects and side effect profile of ketamine in youth ≤ 19 years of age with a diagnosis of a treatment-resistant mood disorder. Analysis included subjects with treatment-resistant depression with and without psychotic features and with bipolar disorder. Primary outcome measures included the following scales: Montgomery-Asberg Depression Rating Scale, Children's Depression Rating Scale, Children's Depression Rating Scale Revised, Child Bipolar Questionnaire, Overt Aggression Scale, Yale-Brown Obsessive-Compulsive Scale, and Scale for Suicidal Ideation. Four published studies were identified that investigated therapeutic ketamine use in youth for the primary purpose of treating a treatment-resistant psychiatric disorder. Three additional studies that did not meet eligibility criteria were identified and discussed. Ketamine was shown in youth to generally improve depressive symptoms, decrease acute suicidality, and reduce mood lability, though a number of subjects remained resistant to its treatment. These findings substantiate the need for further longitudinal studies investigating ketamine's long-term safety, its efficacy, and abuse potential in the youth.

Therapeutic Horticulture as a Therapeutic Intervention in Patients Receiving Electroconvulsive Therapy (ECT) Treatment for Major Depressive Disorder

This study explored the effect of a structured therapeutic horticulture (TH) program on depression symptoms and quality of life indicators for individuals receiving inpatient electroconvulsive therapy (ECT) for major depressive disorders (MDD). Self-reported measures of depressive symptomatology (PHQ9, BDI-II) and quality of life (SF-36) were employed to compare intervention (n = 25) and control groups (n = 27), with the intervention group attending TH sessions for one-hour periods, twice per week, in addition to standard inpatient care associated with ECT received by both groups. All patients were assessed at admission, and after two weeks’ time or prior to discharge, during which the intervention group participated in a minimum of four TH sessions. Sessions were led by a horticultural therapist in an accessible on-campus greenhouse. Both groups improved significantly between assessment times one and two on both measures of depression, with a statistically significant difference in change scores for the BDI-II only, favoring the control over the intervention group (16.5, s.d. 12.78 versus 9.6, s.d. 10.15; p = 0.36). Both groups improved significantly on four of eight SF-36 subscales during the same period. A statistically significant difference in change scores was found for the Role Limitations-Physical Health (RLPH) subscale, where the intervention group improved between assessment periods, whereas the control group worsened (16.0, s.d.48.8 versus -9.3, s.d. 33.4; p = .033). Although quantifying group changes or improvement for individuals receiving intensive treatment for major depressive disorders (ECT) by the addition of an adjunct therapy is difficult, this study provides a basic premise for the consideration of various therapeutic horticulture settings to achieve therapeutic benefits through TH.

Molecular Biomarkers of Electroconvulsive Therapy Effects and Clinical Response: Understanding the Present to Shape the Future

Electroconvulsive therapy (ECT) represents an effective intervention for treatment-resistant depression (TRD). One priority of this research field is the clarification of ECT response mechanisms and the identification of biomarkers predicting its outcomes. We propose an overview of the molecular studies on ECT, concerning its course and outcome prediction, including also animal studies on electroconvulsive seizures (ECS), an experimental analogue of ECT. Most of these investigations underlie biological systems related to major depressive disorder (MDD), such as the neurotrophic and inflammatory/immune ones, indicating effects of ECT on these processes. Studies about neurotrophins, like the brain-derived neurotrophic factor (BDNF) and the vascular endothelial growth factor (VEGF), have shown evidence concerning ECT neurotrophic effects. The inflammatory/immune system has also been studied, suggesting an acute stress reaction following an ECT session. However, at the end of the treatment, ECT produces a reduction in inflammatory-associated biomarkers such as cortisol, TNF-alpha and interleukin 6. Other biological systems, including the monoaminergic and the endocrine, have been sparsely investigated. Despite some promising results, limitations exist. Most of the studies are concentrated on one or few markers and many studies are relatively old, with small sample sizes and methodological biases. Expression studies on gene transcripts and microRNAs are rare and genetic studies are sparse. To date, no conclusive evidence regarding ECT molecular markers has been reached; however, the future may be just around the corner.

Synthesizing the Evidence for Ketamine and Esketamine in Treatment-Resistant Depression: An International Expert Opinion on the Available Evidence and Implementation

Replicated international studies have underscored the human and societal costs associated with major depressive disorder. Despite the proven efficacy of monoamine-based antidepressants in major depression, the majority of treated individuals fail to achieve full syndromal and functional recovery with the index and subsequent pharmacological treatments. Ketamine and esketamine represent pharmacologically novel treatment avenues for adults with treatment-resistant depression. In addition to providing hope to affected persons, these agents represent the first non-monoaminergic agents with proven rapid-onset efficacy in major depressive disorder. Nevertheless, concerns remain about the safety and tolerability of ketamine and esketamine in mood disorders. Moreover, there is uncertainty about the appropriate position of these agents in treatment algorithms, their comparative effectiveness, and the appropriate setting, infrastructure, and personnel required for their competent and safe implementation. In this article, an international group of mood disorder experts provides a synthesis of the literature with respect to the efficacy, safety, and tolerability of ketamine and esketamine in adults with treatment-resistant depression. The authors also provide guidance for the implementation of these agents in clinical practice, with particular attention to practice parameters at point of care. Areas of consensus and future research vistas are discussed.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

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.

Neurocognitive performance of repeated versus single intravenous subanesthetic ketamine in treatment resistant depression

BACKGROUND

Ketamine demonstrated rapid antidepressant effects in treatment-resistant depression (TRD). However, evaluation of ketamine's neurocognitive effect in TRD is unclear. We aim to (1) characterize baseline neurocognitive performance as a predictor of the change in severity of depressive symptoms over time, and (2) investigate the association of six versus single intravenous (IV) ketamine and neurocognitive changes from baseline to the end of treatment.

METHODS

Subjects with TRD were randomized to receive either five IV midazolam followed by a single IV ketamine or six IV ketamine during a 12-day period. Depression symptom assessments occurred prior and 24 h after infusion days using the Montgomery-Åsberg Depression Rating Scale. Neurocognitive tasks were designed to test attention, memory, speed of processing, and set shifting using the CogState battery at baseline and at the end of treatment.

RESULTS

Better complex working memory at baseline predicted improvement in MADRS scores of ketamine (vs midazolam) after 5 infusions. Most, but not all, neurocognitive functions remained stable or improved after repeated or single ketamine. There was a greater differential effect of treatment on speed of processing, set shifting, and spatial working memory that favors subjects in the six ketamine group. These cognitive improvements from baseline to the end of treatment were robust when controlling for age and changes in depression severity.

CONCLUSION

The study suggests that six IV ketamine compared to single IV ketamine has a mood independent procognitive effect among TRD patients. Large scale studies are needed to confirm whether ketamine enhances cognitive function in TRD.

Medico-legal and bioethical perspectives following the constitutional legitimacy of assisted suicide in Italy

Assisted suicide is the subject of much debate throughout the world. In Italy, on 24 September 2019, the Italian Constitutional Court legitimised assisted suicide under certain conditions: self-determination capacity, irreversible illness and intense physical/psychological suffering of the patient. This historic judgement surely paved the way for an evolution of the Italian legal framework on the matter but also raised some challenging medico-legal and bioethical questions. This study aims at analysing two of the most controversial among them: the inclusion of psychiatric patients among eligible patients for assisted suicide and the position of physicians related to their right to conscientious objection.

A randomized, crossover comparison of ketamine and electroconvulsive therapy for treatment of major depressive episodes: a Canadian biomarker integration network in depression (CAN-BIND) study protocol

BACKGROUND

Recent evidence underscores the utility of rapid-acting antidepressant interventions, such as ketamine, in alleviating symptoms of major depressive episodes (MDE). However, to date, there have been limited head-to-head comparisons of intravenous (IV) ketamine infusions with other antidepressant treatment strategies in large randomized trials. This study protocol describes an ongoing multi-centre, prospective, randomized, crossover, non-inferiority trial comparing acute treatment of individuals meeting diagnostic criteria for a major depressive episode (MDE) with ketamine and electroconvulsive therapy (ECT) on efficacy, speed of therapeutic effects, side effects, and health care resource utilization. A secondary aim is to compare a 6-month maintenance strategy for ketamine responders to standard of care ECT maintenance. Finally, through the measurement of clinical, cognitive, neuroimaging, and molecular markers we aim to establish predictors and moderators of treatment response as well as treatment-elicited effects on these outcomes.

METHODS

Across four participating Canadian institutions, 240 patients with major depressive disorder or bipolar disorder experiencing a MDE are randomized (1:1) to a course of ECT or racemic IV ketamine (0.5 mg/kg) administered 3 times/week for 3 or 4 weeks. Non-responders (< 50% improvement in Montgomery-Åsberg Depression Rating Scale [MADRS] scores) crossover to receive the alternate treatment. Responders during the randomization or crossover phases then enter the 6-month maintenance phase during which time they receive clinical assessments at identical intervals regardless of treatment arm. ECT maintenance follows standard of care while ketamine maintenance involves: weekly infusions for 1 month, then bi-weekly infusions for 2 months, and finally monthly infusions for 3 months (returning to bi-weekly in case of relapse). The primary outcome measure is change in MADRS scores after randomized treatment as assessed by raters blind to treatment modality.

DISCUSSION

This multi-centre study will help identify molecular, imaging, and clinical characteristics of patients with treatment-resistant and/or severe MDEs who would benefit most from either type of therapeutic strategy. In addition to informing clinical practice and influencing health care delivery, this trial will add to the robust platform and database of CAN-BIND studies for future research and biomarker discovery.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT03674671. Registered September 17, 2018.

Ketamine plus propofol-electroconvulsive therapy (ECT) transiently improves the antidepressant effects and the associated brain functional alterations in patients with propofol-ECT-resistant depression

New methods for using ketamine in patients with propofol-electroconvulsive therapy-resistant depression (ECT-RD) are needed in the clinic. This study aimed to investigate the therapeutic efficacy of ketamine plus ECT in ECT-RD patients, along with the treatment-induced brain alterations. A total of 28 ECT-RD patients were intravenously injected with ketamine six times and treated with propofol-ECT six times alternately within two weeks. The Hamilton Depression Scale was used to assess the treatment effect. Global functional connectivity density (gFCD) and functional connectivity strength (FCS) were used to evaluate functional brain alterations. As compared with the propofol-ECT treatment group, the addition of ketamine could improve the therapeutic outcomes in patients with ECT-RD. The treatment increased gFCD in the left temporal and subgenual anterior cingulated cortex. Simultaneously, the treatment decreased FCS within the default mode network. Although increased functional connectivity could be sustained for 10 days, the clinical effect was only sustained 7 days, indicating that the clinical effect and functional brain alterations were disjointed. Ketamine plus propofol-ECT can obviously improve the effects of propofol-ECT in ECT-RD patients. However, the effect is limited in 7 days, suggesting the benefit is short-term.

The Impact of Childhood Maltreatment on Intravenous Ketamine Outcomes for Adult Patients with Treatment-Resistant Depression

Childhood maltreatment is associated with a poor treatment response to conventional antidepressants and increased risk for treatment-resistant depression (TRD). The N-methyl-D-aspartate receptor (NDMAR) antagonist ketamine has been shown to rapidly improve symptoms of depression in patients with TRD. It is unknown if childhood maltreatment could influence ketamine’s treatment response. We examined the relationship between childhood maltreatment using the Childhood Trauma Questionnaire (CTQ) and treatment response using the Quick Inventory of Depressive Symptoms–Self Report (QIDS-SR) in TRD patients receiving intravenous ketamine at a community outpatient clinic. We evaluated treatment response after a single infusion (n = 115) and a course of repeated infusions (n = 63). Repeated measures general linear models and Bayes factor (BF) showed significant decreases in QIDS-SR after the first and second infusions, which plateaued after the third infusion. Clinically significant childhood sexual abuse, physical abuse, and cumulative clinically significant maltreatment on multiple domains (maltreatment load) were associated with better treatment response to a single and repeated infusions. After repeated infusions, higher load was also associated with a higher remission rate. In contrast to conventional antidepressants, ketamine could be more effective in TRD patients with more childhood trauma burden, perhaps due to ketamine’s proposed ability to block trauma-associated behavioral sensitization.