The Downstaging Concept in Treatment-Resistant Depression: Spotlight on Ketamine

Intravenous ketamine infusions in patients with depression and Epilepsy: Case series

BACKGROUND

Mood disorders affect approximately one-third of individuals with epilepsy, posing an increased risk of suicide. There is an unquestionable need for more effective antidepressant treatment in this group of patients. This study explores the safety and tolerability of low-dose intravenous ketamine in six patients with comorbid depression and epilepsy. This report is limited to the post-hoc observation of six patients only. Thus, no causative conclusions are warranted, and prospective, large sample studies are needed to demonstrate the effect of ketamine on seizures, depression, and side effect profile along with the systematic outcome measures assessment.

METHODS

Six patients diagnosed with major depressive disorder (MDD) or bipolar disorder I (BP-I) and concurrent epilepsy received a series of eight intravenous ketamine infusions alongside their standard antidepressant, mood stabilizer, and antiseizure medications.

RESULTS

The observed side effects were mild and transient, with no exacerbation of epilepsy noted. No serious adverse events occurred. Four patients experienced a significant reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) scores, two achieving full remission. Three patients reported a subjective decrease in seizure activity during the twelve-month follow-up.

CONCLUSIONS

Short-term intravenous ketamine treatment demonstrated favorable safety and tolerability profile with clinical efficacy in six patients with depression and epilepsy.

Neural correlates of treatment response to ketamine for treatment-resistant depression: A systematic review of MRI-based studies

Treatment-resistant depression (TRD) is defined as patients diagnosed with depression having a history of failure with different antidepressants with an adequate dosage and treatment duration. The NMDA receptor antagonist ketamine rapidly reduces depressive symptoms in TRD. We examined neural correlates of treatment response to ketamine in TRD through a systematic review of brain magnetic resonance imaging (MRI) studies. A comprehensive search in PubMed was performed using "ketamine AND depression AND magnetic resonance." The time span for the database queries was "Start date: 2018/01/01; End date: 2024/05/31." Total 41 original articles comprising 1,396 TRD and 587 healthy controls (HC) were included. Diagnosis of depression was made using the Structured Clinical Interview for DSM Disorders (SCID), the Mini-International Neuropsychiatric Interview (MINI), and/or the clinical assessment by psychiatrists. Patients with affective psychotic disorders were excluded. Most studies applied ketamine [0.5mg/kg racemic ketamine and/or 0.25mg/kg S-ketamine] diluted in 60cc of normal saline via intravenous infusion over 40 min one time, four times, or six times spaced 2-3 days apart over 2 weeks. Clinical outcome was defined as either remission, response, and/or percentage changes of depressive symptoms. Brain MRI of the T2*-weighted imaging (resting-state or task performance), arterial spin labeling, diffusion weighted imaging, and T1-weighted imaging were acquired at baseline and mainly 1-3days after the ketamine administration. Only the study results replicated by ≥ 2 studies and were included in the default-mode, salience, fronto-parietal, subcortical, and limbic networks were regarded as meaningful. Putative brain-based markers of treatment response to ketamine in TRD were found in the structural/functional features of limbic (subgenual ACC, hippocampus, cingulum bundle-hippocampal portion; anhedonia/suicidal ideation), salience (dorsal ACC, insula, cingulum bundle-cingulate gyrus portion; thought rumination/suicidal ideation), fronto-parietal (dorsolateral prefrontal cortex, superior longitudinal fasciculus; anhedonia/suicidal ideation), default-mode (posterior cingulate cortex; thought rumination), and subcortical (striatum; anhedonia/thought rumination) networks. Brain features of limbic, salience, and fronto-parietal networks could be useful in predicting the TRD with better response to ketamine in relief of anhedonia, thought rumination, and suicidal ideation.

Low-carbohydrate diet as a nutritional intervention in a major depression disorder: focus on relapse prevention

OBJECTIVES

Mood disorders are trending to be among the leading causes of years lived with disability. Despite multiple treatment options, around 30% patients with major depressive disorder (MDD) develop treatment resistant depression (TRD) and fail to respond to current pharmacological therapies. This study aimed to explore the potential benefits of nutritional treatment strategies, along with their molecular mechanisms of action, focusing especially on low-carbohydrate diet (LCHD), ketogenic diet (KD) and other strategies based on carbohydrates intake reduction.

METHODS

A comprehensive literature review was conducted to determine the impact of LCHD on alleviating depressive symptoms in patients with MDD, along with an explanation of its mode of action.

RESULTS

The study revealed significant impact of nutritional interventions based on restriction in carbohydrate intake such as LCHD, KD or sugar-sweetened beverages (SSB) exclusion on anxiety or depression symptoms reduction, mood improvement and lower risk of cognitive impairment or depression. The efficacy of these approaches is further substantiated by their underlying molecular mechanisms, mainly brain-derived neurotrophic factor (BDNF) which is a potential key target of sugar restriction diets in terms of neuroplasticity.

DISCUSSION

Healthcare professionals may consider implementing LCHD strategies for MDD and TRD patients to modify the disease process, maintain euthymia, and prevent depressive episode relapses. Ranging from the exclusion of SSB to the adherence to rigorous LCHD regimens, these nutritional approaches are safe, straightforward to implement, and may confer benefits for well-being and relapse prevention in this specific patient population.

Treatment-emergent symptoms during short-term ketamine administration in treatment-resistant bipolar depression: A retrospective cross-sectional descriptive study

Symptoms that emerge during pharmacological treatment of bipolar depression are frequently observed, underscoring the necessity for comprehensive treatment monitoring. This observational study sought to observe the correlation of eight intravenous ketamine infusions with treatment-emergent depressive symptoms in treatment-resistant bipolar depression patients who maintained their baseline psychotropic and chronic somatic treatments. Depressive symptoms were evaluated using the Inventory of Depressive Symptomatology Self-Report 30 (IDS-SR30). Treatment-emergent symptoms TES were defined as symptoms absent at baseline but present at the conclusion of the study. The most common TES included decreased appetite, increased weight, hypersomnia, and diurnal mood variation. Conversely, feelings of sadness, altered perceptions of the future, decreased interest in sex, and physical discomfort were absent in all patients. Notably, 13.6 % of patients reported thoughts of death or suicide. Larger-scale studies, integrating clinician-rated and patient-reported outcome measures, are essential to deepen our understanding of treatment-emergent symptoms. Establishing regulatory or professional definitions for treatment-emergent symptoms is warranted to improve the robustness of future research endeavors.

Single arketamine in treatment resistant depression: Presentation of 3 cases with regard to sick-leave duration

BACKGROUND

Ketamine is the prototypal rapid-acting antidepressant (RAAD) for TRD with approved indication for esketamine-nasal spray (ESK-NS). Distinctly, arketamine (R-KET) demonstrates enhanced antidepressant effects and neuroplasticity changes compared to esketamine, with fewer dissociative side effects and abuse potential. This study focuses on R-ketamine's therapeutic implications, safety, and tolerability in TRD treatment.

METHODS

We report on a year-long follow-up of three TRD patients post-single IV R-KET administration. The study, conducted under the clinical trial PCN-101 (NCT05414422), observed these subjects for healthcare resource utilization and social support system impact. Participants, adults diagnosed with recurrent major depressive disorder without psychotic features, were observed in a year-long follow-up period for safety.

RESULTS

Case analyses revealed significant symptom reduction and improved social and vocational functioning, with reduced sick leaves and hospitalizations post-treatment. However, one case developed a substance use disorder, underscoring the need for vigilant monitoring. The study highlights R-KET's transformative potential in managing depression, indicating a shift in TRD treatment strategies towards early, aggressive interventions.

CONCLUSIONS

Despite promising findings, the study faces limitations due to its small sample size, lack of randomization, and potential observational design biases. The results, while aligning with existing ketamine research, require cautious interpretation and warrant further investigation with larger, more robust studies. This exploration of R-KET's role in home-based TRD treatment opens avenues for future research, particularly focusing on its long-term effectiveness and safety in diverse patient populations. This study is registered in clinicaltrials.gov: NCT06232291.

Short-term ketamine use in bipolar depression: a review of the evidence for short-term treatment management

Bipolar depression constitutes a major problem in psychiatry. It correlates with high suicidality, treatment resistance, chronicity, and poor quality of life. Registered treatment for bipolar depression is limited and insufficient. There is an urgent need for implementing new therapeutic strategies. Intranasal ketamine's enantiomer-esketamine is a novel rapid-acting antidepressant with proven efficacy in treatment-resistant depression. Research on bipolar depression, although not as comprehensive, indicates that it may be a viable and safe substitute with minimal risk for mood polarity changes. Reports suggest that ketamine treatment in bipolar depression may reduce suicidal tendencies, decrease anhedonia, and alleviate anxiety. Ketamine's mood-stabilizing properties are also hypothesized. In this narrative review, we focus on ketamine use as an add-on to standard medication for the acute treatment of bipolar depression.

Esketamine in treatment-resistant depression patients comorbid with substance-use disorder: A viewpoint on its safety and effectiveness in a subsample of patients from the REAL-ESK study

Esketamine, the S-enantiomer of ketamine, has recently emerged as a therapy for treatment-resistant depression (TRD), showing both rapid antidepressant action and good efficacy and high safety. It is also indicated for the acute short-term treatment of psychiatric emergency due to major depressive disorder (MDD) and for depressive symptoms in adults with MDD with acute suicidal thoughts/behavior. We here provide preliminary insights on esketamine nasal spray (ESK-NS) effectiveness and safety among patients with a substance use disorder (SUD) within the sample of patients with TRD collected for the observational, retrospective, multicentre REAL-ESK study. Twenty-six subjects were retrospectively selected according to the presence of a SUD in comorbidity. Subjects enrolled completed the three different follow-up phases (T0/baseline, T1/after one month, and T2/after three months) and there were no dropouts. A decrease in Montgomery-Asberg depression rating scale (MADRS) scores was recorded, thus highlighting the antidepressant efficacy of ESK-NS (MADRS decreased from T0 to T1, t = 6.533, df=23, p<0.001, and from T1 to T2, t = 2.029, df=20, p = 0.056). Considering tolerability and safety issues, one or more side effects were reported by 19/26 subjects (73%) after treatment administration. All reported side effects were time-dependent and did not cause significant sequelae; among them, dissociative symptoms (38%) and sedation (26%) were the most frequently reported. Finally, no cases of abuse or misuse of ESK-NS were reported. Despite study limitations related to the inherent nature of the study, a limited number of patients, and a short follow-up period, ESK-NS showed to be effective and safe in patients diagnosed with TRD comorbid with a SUD.

Exploring the Relationship between Mood Disorders and Coexisting Health Conditions: The Focus on Nutraceuticals

Major depressive disorder and bipolar disorder are the leading causes of global disability. Approximately 50% of patients fail to attain remission, prompting a pronounced focus on the significance of dietary patterns and specific nutrients within the pathophysiology of mood disorders. The connection between chronic diseases and mood disorders follows a bidirectional pattern: physical ailments are interrelated with affective disorders, and, concurrently, mood symptoms often precede chronic diseases and have the potential to worsen their prognosis. Nutraceuticals affect factors that could potentially impact the onset of mood disorders: monoamines and brain-derived neurotrophic factor (BDNF) concentrations, neuroinflammation, oxidative stress, and sleep quality. Furthermore, mood disorders rarely manifest in isolation. Typically, such patients concurrently experience other mental disorders or somatic comorbidities: obesity, hypertension, diabetes, polycystic ovary syndrome (PCOS), etc., where providing nutritional support is also pertinent. To optimize the therapeutic approach for individuals with mood disorders, incorporating nutritional support may not solely ameliorate symptoms stemming directly from the mental condition, but also indirectly through interventions targeting comorbidities.

Inflammation and Treatment-Resistant Depression from Clinical to Animal Study: A Possible Link?

The aim of this study was to investigate the relationship between treatment-resistant depression (TRD) and inflammation in humans and experimental models. For the human study, a retrospective cohort study was conducted with 206 participants; half were on antidepressants for major depressive disorder. The patients were divided into healthy and depressed groups. Inflammation was assessed based on the values of the main inflammatory biomarkers (CRP, WBC and ESR). For the animal experiments, 35 adult male Wistar rats were assigned to stressed and non-stressed groups. Inflammation and stress were induced using lipopolysaccharide and chronic unpredictable mild stress. A 10 mg/kg intraperitoneal injection of fluoxetine (FLX), a known antidepressant, was simultaneously administered daily for 4 weeks. Behavioral tests were performed. The plasma levels of inflammatory and stress biomarkers were measured and were significantly higher in the stressed and non-responsive groups in both studies. This study provides evidence of the link between inflammation and TRD. We further observed a possible link via the Phosphorylated Janus Kinase 2 and Phosphorylated Signal Transducer and Activator of Transcription 3 (P-JAK2/P-STAT3) signaling pathway and found that chronic stress and high inflammation hinder the antidepressant effects of FLX. Thus, non-response to antidepressants could be mitigated by treating inflammation to improve the antidepressant effect in patients with TRD.

Ketamine as Add-On Treatment in Psychotic Treatment-Resistant Depression

Psychotic treatment-resistant depression is a complex and challenging manifestation of mood disorders in the clinical setting. Psychotic depression is a subtype of major depressive disorder characterized by mood-consistent hallucinations and/or delusions. Psychotic depression is often underdiagnosed and undertreated. Ketamine appears to have rapid and potent antidepressant effects in clinical studies, and the Federal Drug Agency approved the use of ketamine enantiomer esketamine-nasal spray for treatment-resistant depression pharmacotherapy in 2019. This study aimed to assess the usage of ketamine for major depressive disorder with psychotic features as an add-on treatment to the standard of care. Here we present four inpatients suffering from treatment-resistant depression with psychotic features, including one with severe suicidal crisis, all treated with 0.5 mg/kg intravenous infusion of ketamine. Subsequent monitoring revealed no exacerbation of psychotic symptoms in short and long-term observation, while stable remission was observed in all cases with imminent antisuicidal effect. Results suggest ketamine may benefit individuals with treatment-resistant depression with psychotic features.