Repeated subcutaneous esketamine for treatment-resistant depression: Impact of the degree of treatment resistance and anxiety comorbidity

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

BACKGROUND

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

Rapid and long-lasting effects of subcutaneous esketamine on suicidality: An open-label study in patients with treatment-resistant depression

Therapeutics for suicide management is limited, taking weeks to work. This open-label clinical trial with 18 treatment-resistant depressive patients tested subcutaneous esketamine (8 weekly sessions) for suicidality. We noted a rapid and enduring effect of subcutaneous esketamine, lasting from one week to six months post-treatment, assessed by the Beck Inventory for Suicidality (BSI). There was an immediate drop in suicidality, 24 h following the initial dose, which persisted for seven days throughout the eight-week dosing period. Additionally, this study is the first to examine a six-month follow-up after multiple administrations of subcutaneous esketamine, finding consistently lower levels of suicidality throughout this duration. Conversely, suicidality also was measured along the 8-weeks of treatment by a psychiatrist using the Montgomery-Asberg Depression Rating Scale (MADRS), which showed significant reduction only after two treatment sessions expanding until the last session. Moreover, notably, 61% of patients achieved remission on suicidality (MADRS). These results suggest that weekly subcutaneous esketamine injections offer a cost-effective approach that induces a rapid and sustained response to anti-suicide treatment. This sets the stage for further, more controlled studies to corroborate our initial observations regarding the effects of SC esketamine on suicidality. Registered trial at: https://ensaiosclinicos.gov.br/rg/RBR-1072m6nv.

Investigating the Effectiveness and Tolerability of Intranasal Esketamine Among Older Adults With Treatment-Resistant Depression (TRD): A Post-hoc Analysis from the REAL-ESK Study Group

INTRODUCTION

Treatment-resistant depression (TRD) is a serious and debilitating psychiatric disorder that frequently affects older patients. Esketamine nasal spray (ESK-NS) has recently been approved as a treatment for TRD, with multiple studies establishing its efficacy and tolerability. However, the real-world effectiveness, tolerability, and safety of this treatment in older adults is still unclear.

OBJECTIVES

To evaluate the efficacy and tolerability of ESK-NS in older subjects with TRD.

METHODS

This is a post-hoc analysis of the REAL-ESK study, a multicenter, retrospective, observational study. Participants here selected were 65 years or older at baseline. The Montgomery-Åsberg Depression Rating Scale (MADRS) and the Hamilton Anxiety Rating Scale (HAM-A) were used to assess depressive and anxiety symptoms, respectively. Data were collected at three-time points: baseline, 1 month after the start of treatment (T1), and 3 months after treatment (T2).

RESULTS

The sample included older adults with TRD (n = 30). MADRS and HAM-A values decreased significantly at T1 (T0 versus T1: pholm <0.001, Cohen's d = 0.840) and T2 follow-ups (T0 versus T2: pholm <0.001, Cohen's d = 1.419). At T2, 53.3% of subjects were responders (MADRS score reduced ≥50%), while 33.33% were in remission (MADRS<10). ESK-NS-related adverse effects were in order of frequency dizziness (50%), followed by dissociation (33.3%), sedation (30%), and hypertension (13.33%). Six out of 30 participants (20%) discontinued treatment.

CONCLUSIONS

Our findings provide preliminary evidence of ESK-NS effectiveness in older adults with TRD, a highly debilitating depressive presentation. Furthermore, we observe high levels of treatment-emergent adverse events, which, in the majority of instances, did not require treatment suspension.

Predicting outcome with Intranasal Esketamine treatment: A machine-learning, three-month study in Treatment-Resistant Depression (ESK-LEARNING)

Treatment-resistant depression (TRD) represents a severe clinical condition with high social and economic costs. Esketamine Nasal Spray (ESK-NS) has recently been approved for TRD by EMA and FDA, but data about predictors of response are still lacking. Thus, a tool that can predict the individual patients' probability of response to ESK-NS is needed. This study investigates sociodemographic and clinical features predicting responses to ESK-NS in TRD patients using machine learning techniques. In a retrospective, multicentric, real-world study involving 149 TRD subjects, psychometric data (Montgomery-Asberg-Depression-Rating-Scale/MADRS, Brief-Psychiatric-Rating-Scale/BPRS, Hamilton-Anxiety-Rating-Scale/HAM-A, Hamilton-Depression-Rating-Scale/HAMD-17) were collected at baseline and at one month/T1 and three months/T2 post-treatment initiation. We trained three different random forest classifiers, able to predict responses to ESK-NS with accuracies of 68.53% at T1 and 66.26% at T2 and remission at T2 with 68.60% of accuracy. Features like severe anhedonia, anxious distress, mixed symptoms as well as bipolarity were found to positively predict response and remission. At the same time, benzodiazepine usage and depression severity were linked to delayed responses. Despite some limitations (i.e., retrospective study, lack of biomarkers, lack of a correct interrater-reliability across the different centers), these findings suggest the potential of machine learning in personalized intervention for TRD.

Overview of treatment-resistant depression

Patients with major depressive disorder (MDD) often exhibit an inadequate treatment response or failure to achieve remission following treatment with antidepressant drugs. Treatment-resistant depression (TRD) is proposed to identify this clinical scenario. Compared to those without TRD, patients with TRD have significantly lower health-related quality of life in mental and physical dimensions, more functional impairment and productivity loss, and higher healthcare costs. TRD imposes a massive burden on the individual, family, and society. However, a lack of consensus on the TRD definition limits the comparison and interpretation of TRD treatment efficacy across trials. Furthermore, because of the various TRD definitions, there is scarce treatment guideline specifically for TRD, in contrast to the rich treatment guidelines for MDD. In this chapter, common issues related to TRD, such as proper definitions of an adequate antidepressant trial and TRD, were carefully reviewed. Prevalence of and clinical outcomes related to TRD were summarized. We also summarized the staging models ever proposed for the diagnosis of TRD. Furthermore, we highlighted variations in the definition regarding the lack of or an inadequate response in treatment guidelines for depression. Up-to-date treatment options for TRD, including pharmacological strategies, psychotherapeutic interventions, neurostimulation techniques, glutamatergic compounds, and even experimental agents were reviewed.

Rethinking ketamine and esketamine action: Are they antidepressants with mood-stabilizing properties?

Ketamine and esketamine, the S-enantiomer of the racemic mixture, have recently generated considerable interest as potential therapeutic agents for Treatment-Resistant Depression (TRD), a complex disorder that includes various psychopathological dimensions and distinct clinical profiles (e.g., comorbid personality disorder, bipolar spectrum, dysthymic disorder). This perspective article provides a comprehensive overview of the action of ketamine/esketamine from a dimensional point of view, taking into account the high prevalence of bipolarity in TRD and the evidence of the efficacy of these substances on mixed features, anxiety, dysphoric mood, and, generally, bipolar traits. Additionally, the article underscores the complexity of the pharmacodynamic mechanisms of action of ketamine/esketamine, which goes beyond the non-competitive antagonism of NMDA-R. The need for further research and evidence is highlighted, mainly to evaluate the efficacy of esketamine nasal spray in bipolar depression, the presence of bipolar elements as a predictor of response, and the potential role of these substances as mood stabilizers. The article implies that, in the future, ketamine/esketamine could be used with fewer limitations, not only as antidepressants for the most severe form of depression but also as valuable tools to stabilize subjects with mixed symptoms or bipolar spectrum.

Impact of Repeated Doses of Subcutaneous Esketamine on Acute Dissociative Symptoms in Treatment-Resistant Depression

BACKGROUND

Esketamine has been approved by the US Food and Drug Administration (FDA) as an adjunctive treatment for use in conjunction with an oral antidepressant for patients with treatment-resistant depression (TRD), but dissociative symptoms are common adverse effects.

METHODS

A retrospective analysis of 394 subcutaneous esketamine injections given to 70 patients with TRD that were administered once a week during a six-week trial in conjunction with oral antidepressant therapy. Doses between 0.5 to 1.0 mg/kg were administered according to the patient's response. Dissociative symptoms were assessed using the Clinician-Administered Dissociative States Scale (CADSS) 30 and 60 min after every weekly treatment (day 1, 8, 15, 22, 29 and 36).

RESULTS

Seventy patients received a total of 394 subcutaneous esketamine injections over six weeks. Over time, the evolution of CADSS scores demonstrated a significant mean difference of CADSS at 60 min post-injection (p = 0.010) throughout the six infusions. The mean CADSS scores at 60 min on day 22, 29 and 36 were similar. There were no differences between mean CADSS scores 30 min after the injections, no clinical correlation between response and dissociative symptoms, no correlation between time and demographic and clinical characteristics and no interactions between time and combined medication.

CONCLUSIONS

Our results suggest that repeated subcutaneous esketamine doses are safe and well-tolerated regarding their acute dissociative and psychotomimetic symptoms. Symptoms usually peak at 30 min and decrease at 60 min post-injection, returning to their pretreatment levels at 120 min. Dissociative symptoms do not correlate with antidepressant response.

Factors associated with antidepressant responses to repetitive transcranial magnetic stimulation in antidepressant-resistant depression

Background

A significant proportion of patients with major depressive disorder (MDD) failed to respond to antidepressant medications. Repetitive transcranial magnetic stimulation (rTMS) is an effective option for treating such treatment-resistant patients with MDD (TRD). Reliable clinical predictors for antidepressant responses to rTMS remain elusive.

Methods

In total, 212 patients with MDD who failed to respond to at least one adequate antidepressant trial and had a detailed evaluation before rTMS were recruited for chart review. Demographic data, clinical characteristics, psychiatric comorbidities, symptom ratings [e.g., objective and subjective depression, life stress, depression refractoriness by Maudsley Staging Method (MSM)], and antidepressant treatment responses were analyzed.

Results

MSM-subitem1 (duration of current depressive episode; Beta = 0.209, p = 0.004), MSM-subitem5 (a history of ECT treatment; Beta = –0.210, p = 0.004), and psychiatric admissions (Beta = 0.241, p = 0.001) predicted antidepressant response of rTMS treatment. ECT was underutilized (only 3.3%). Psychiatric admissions [Exp(B) = 1.382, p = 0.021], a comorbidity of OCD [0.047, 0.005], and life stress level [0.984, 0.029] predicted the history of ECT treatment.

Conclusion

Several clinical variables (e.g., number of psychiatric admissions, OCD as a comorbidity, and life stress level) were reliable clinical factors associated with antidepressant responses of rTMS treatment and may be utilized in combination with MSM subitems to evaluate levels of TRD.

Real-world effectiveness of ketamine in treatment-resistant depression: A systematic review & meta-analysis

Ketamine is a promising therapeutic option in treatment-resistant depression (TRD). The acute efficacy of ketamine in TRD has been demonstrated in replicated randomised-controlled trials (RCTs), but the generalizability of RCT data to real-world practice is limited. To this end, we conducted a systematic review (Search date: 25/12/2021; 1482 records identified) and meta-analysis of studies evaluating the real-world clinical effectiveness of ketamine in TRD patients. Four overlapping syntheses (Total n = 2665 patients; k = 79 studies) and 32 meta-regressions (Total n = 2050; k = 37) were conducted. All results suggest that the mean antidepressant effect is substantial (mean ± 95% CI, % responded = 45 ± 10%; p< 0.0001, % remitted = 30 ± 5.9%; p< 0.0001, Hedges g of symptomatological improvement = 1.44 ± 0.609; p < 0.0001), but the effect varies considerably among patients. The more treatment-resistant cases were found to remit less often (p < 0.01), but no such effect on response was evident (p > 0.05). Meta-regressions also confirmed that the therapeutic effect does not significantly decline with repeated treatments (p > 0.05). These results demonstrate that even the most treatment-resistant patients may benefit from ketamine, and that mid-to-long term treatment is effective in many patients.

Ketamine Treatment for Refractory Anxiety: A systematic review

There is a growing interest in the psychiatric properties of the dissociative anaesthetic ketamine, as single doses have been shown to have fast‐acting mood‐enhancing and anxiolytic effects, which persist for up to a week after the main psychoactive symptoms have diminished. Therefore, ketamine poses potential beneficial effects in patients with refractory anxiety disorders, where other conventional anxiolytics have been ineffective. Ketamine is a noncompetitive antagonist of the N‐methyl‐d‐aspartate (NMDA) glutamate receptor, which underlies its induction of pain relief and anaesthesia. However, the role of NMDA receptors in anxiety reduction is still relatively unknown. To fill this paucity in the literature, this systematic review assesses the evidence that ketamine significantly reduces refractory anxiety and discusses to what extent this may be mediated by NMDA receptor antagonism and other receptors. We highlight the temporary nature of the anxiolytic effects and discuss the high discrepancy among the study designs regarding many fundamental factors such as administration routes, complementary treatments and other treatments.

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 and esketamine for crisis management in patients with depression: Why, whom, and how?

Currently, only a limited number of interventions can rapidly relieve depressive symptomatology in patients with major depressive disorder or bipolar disorder experiencing extreme distress. Such crises, especially when suicide attempt or ideation is involved, are a major risk factor of suicide. Ketamine, a N-methyl-d-aspartate glutamate receptor antagonist, and its enantiomer esketamine rapidly reduce depressive symptoms in depressed patients with current suicidal ideation. Recently, esketamine has been approved for use in patients with depression at risk of suicide and for psychiatric emergency by major medical agencies in the United States and Europe, whereas ketamine is increasingly used off-label. However, there is currently limited guidance on why, when, and how to use these drugs in patients with depression to treat a crisis. In this review article, we provide a succinct overview of the cellular and molecular mechanisms of action of ketamine and esketamine, and of the functional brain changes following their administration. We also summarize the major clinical studies on ketamine and esketamine efficacy in patients experiencing a crisis (generally, suicidal ideation), and propose a profile of patients who can benefit most from such drugs, on the basis of neurobiological and clinical observations. Finally, we describe the administration mode, the efficacy and tolerability profiles, the side effect management, possible concomitant treatments and the issue of deprescribing.

Low-dose ketamine infusion in treatment-resistant double depression: Revisiting the adjunctive ketamine study of Taiwanese patients with treatment-resistant depression

BACKGROUND

Whether a single low-dose ketamine infusion may have rapid antidepressant and antisuicidal effects in patients with treatment-resistant double depression remains unclear.

METHODS

This study enrolled 35 patients with treatment-resistant double depression, 12 of whom received 0.5 mg/kg ketamine, 11 received 0.2 mg/kg ketamine, and 12 received normal saline as a placebo. The patients were assessed using the 17-item Hamilton Rating Scale for Depression (HDRS) prior to the initiation of infusions, at 40 and 240 min post-infusion, and sequentially on Days 2-7 and on Day 14 after ketamine or placebo infusions.

RESULTS

A single 0.5 mg/kg ketamine infusion had rapid antidepressant (p = 0.031, measured by the HDRS) and antisuicidal (p = 0.033, measured by the HDRS item 3 scores) effects in patients with treatment-resistant double depression. However, 0.2 mg/kg ketamine was insufficient to exert rapid antidepressant and antisuicidal effects in this patient population with severe and chronic illness.

DISCUSSION

In this patient population, the commonly used dose of 0.5 mg/kg was sufficient. Additional studies are required to investigate whether repeated infusions of low-dose ketamine may also maintain antidepressant and antisuicidal effects in patients with treatment-resistant double depression.

A Clinical Rationale for Assessing the Impact of Childhood Sexual Abuse on Adjunctive Subcutaneous Esketamine for Treatment-Resistant Depression

Background: A history of child sexual abuse (CSA) is related to higher suicide rates and poor treatment outcomes in depressed adult patients. Twenty years after the first study investigating the effects of ketamine/esketamine on depression and suicide, there is a lack of data on the CSA effects on this emerging treatment. Here, we assess the impact of CSA on adjunctive subcutaneous (SC) esketamine for treatment-resistant depression (TRD). Methods: A directed acyclic graphic (DAG) was designed to identify clinical confounders between CSA and esketamine predictors of response. The confounders were applied in a statistical model to predict depression symptom trajectory in a sample of 67 TRD outpatients. Results: The patient sample had a relatively high prevalence rate of CSA (35.82%). Positive family history of first-degree relatives with alcohol use disorder and sex were clinical mediators of the effects of esketamine in a CSA adult population. Overall, the presence of at least one CSA event was unrelated to esketamine symptom reduction. Conclusions: Unlike responses to conventional antidepressants and psychotherapy, CSA does not appear to predict poor response to esketamine.

Subcutaneous Ketamine in Depression: A Systematic Review

Background: Ketamine has been shown to produce a rapid and robust antidepressant effect. Though numerous routes of administration have been studied, subcutaneous (SC) has proven to be a convenient and cost-effective route making its use particularly relevant in developing countries. Here we provide a systematic review covering the use of SC racemic ketamine and esketamine in depression, including its efficacy, safety and tolerability. Methods: A systematic literature search was carried out, from inception through March, 2021, using PubMed/MEDLINE, EMBASE and Web of Science, with no limits of language. After identifying 159 potentially relevant articles, 12 articles were selected after applying our inclusion/exclusion criteria. These comprised two randomized clinical trials, five case-reports and five retrospective studies. Given the small number of studies found and their heterogeneous nature, a meta-analysis was not considered appropriate. Here we provide a synthesis of these data including participant characteristics, dose range, efficacy, safety/ tolerability. Risk of bias was accessed using the Cochrane risk of bias tool. Results: SC Ketamine was administered to unipolar and bipolar patients a single or multiple doses, weekly or twice-weekly, a dose-titration approach was made in major studies, dose ranged from 0.1 to 0.5 mg/Kg of racemic ketamine and 0.5-1 mg/Kg of esketamine. Across all studies, SC ketamine showed a rapid and robust antidepressant effect, with response/ remission rates from 50 to 100% following both single or multiple doses, with transitory side effects. Conclusion: SC racemic ketamine and esketamine in depression is a promising strategy showing beneficial efficacy and tolerability. Future studies exploring the SC route, its cost-effectiveness, and a direct comparison with IV and intranasal (IN) protocols are warranted. Systematic Review Registration: CRD42019137434.