Biomarkers of ketamine's antidepressant effect: An umbrella review

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.

Heart Rate Variability as a Potential Predictor of Response to Intranasal Esketamine in Patients with Treatment-Resistant Depression: A Preliminary Report

Background: Esketamine has received approval as a nasal spray (ESK-NS) for treatment-resistant depression (TRD) and evidence from real-world investigations has confirmed the effectiveness of ESK-NS, albeit with interindividual differences in response. Heart rate variability (HRV), defined as the fluctuation in time interval between consecutive heartbeats, can be used to measure autonomic dysfunction in psychiatric disorders and its role has been investigated in diagnosis and prognosis of depression. Methods: This preliminary report aims to evaluate HRV parameters and their association with treatment outcome in 18 patients (55.6% males, 55.6 ± 9.39 years old) with TRD treated with a target dose of ESK-NS for one month (mean dose: 80.9 ± 9.05 mg). The Beck Depression Inventory (BDI) and a 3 min resting electrocardiogram were used to assess changes in depressive symptoms and HRV measurements before and after treatment. Results: Responders (n = 8, 44.5%; based on ≥30% BDI scores reduction) displayed lower HRV values than non-responders at baseline (p = 0.019), which increased at one month (p = 0.038). Receiver-Operating Characteristic (ROC) curves obtained from a logistic regression displayed a discriminative potential for baseline HRV in our sample (AUC = 0.844). Conclusions: These preliminary observations suggest a mutual interaction between esketamine and HRV, especially in relation to treatment response. Further studies are required to investigate electrophysiological profiles among predictors of response to ESK-NS and allow for personalized intervention strategies in TRD that still represent a public health concern.

National trends and correlates of treatment resistance in major depressive episode and associated suicidal ideation and behaviors among adults in the United States

OBJECTIVE

To examine recent 12-year trends in prevalence of suicidal ideation and behaviors (SIBs) among US adults experiencing a past-year treatment-resistant depression (TRD).

METHODS

Using data from the National Survey of Drug Use and Health, we estimated the annual percentage of individuals aged ≥18 with TRD who reported past-year SIBs, and estimated linear trends adjusting for potentially confounding factors from 2009 to 2020.

RESULTS

Of estimated 237.5 million US adults, 7.1 % met diagnostic criteria for a past-year major depressive episode (MDE) between 2009 and 2020. Of these, 9.7 % met criteria for TRD. The proportion reporting past-year suicidal ideation in TRD ranged from 39.5 % (95 % confidence interval [CI], 32.1-47.3 %) in 2009-2010 to 43.4 % (95 % CI, 36.7-503 %) in 2019-2020, with an average annual percent change (AAPC) of 1.3 % (95 % CI, -0.7 % to 3.3 %). The prevalence of past-year suicide attempts in TRD was 7.3 % across the study period (AAPC, 0.1 %; 95 % CI, -4.3 % to 4.7 %). Past-year SIBs were significantly associated with an increased likelihood of meeting criteria for TRD among adults with MDE (adjusted odds ratio [AOR], 1.53; 95 % CI, 1.35-1.75 for suicidal ideation; AOR, 2.17; 95 % CI, 1.79-2.62 for suicide attempts). No significant differences were observed between 2019 and 2020, reflecting the COVID-19 pandemic.

CONCLUSION

Among individuals with TRD, proportions of SIBs are high. These findings underscore an urgent need for suicide prevention efforts in this high-risk population, including preventive services across diverse settings and accessibility to evidence-based pharmacological and non-pharmacological interventions.

The association between ketamine and esketamine and suicidality: reports to the Food And Drug Administration Adverse Event Reporting System (FAERS)

INTRODUCTION

Replicated evidence indicates that ketamine and esketamine reduce measures of suicidality in persons with treatment-resistant depression (TRD). It remains uncertain whether individuals experience worsening of preexisting suicidality with either agent.

RESEARCH DESIGN AND METHODS

The Food and Drug Administration Adverse Event Reporting System (FAERS) database was searched from 1970 and 2019 to 30 September 2023 for reports of suicidal ideation, depression suicidal, suicidal behavior, suicidal attempt, and completed suicide in association with ketamine and esketamine exposure, respectively. We present reporting odds ratios (ROR) significance was determined when the lower limit of the 95% confidence interval (CI) exceeded 1.0. Lithium was used as the control agent.

RESULTS

Observed a higher ROR for suicidal ideation (ROR 7.58, 95% CI 6.34-9.07) and depression suicidal (ROR 14.19, 95% CI 1.80-112.07) with esketamine. Significantly lower RORs were observed for suicide attempt with ketamine (ROR 0.15, 95% CI 0.11-0.21) and esketamine (ROR 0.57, 95% CI 0.48-0.67).

CONCLUSIONS

Mixed RORs across aspects of suicidality were observed with ketamine and esketamine. Limitations of the FAERS database prevent any determination of causal effects new onset suicidality to either agent. The lower RORs for suicide attempt with ketamine and esketamine is noted but cannot be interpreted as a direct therapeutic effect.

A retrospective analysis of iv ketamine outcome on hospitalisations in an unselected psychiatric sample

OBJECTIVE

This study aims to explore the outcome with iv ketamine treatment in a real-world clinical setting, primarily measured as posttreatment days hospitalised.

METHODS

The psychiatric medical records of 46 patients having received iv ketamine on a psychiatric treatment indication between 2015 and 2018 were retrospectively examined. Analysis comparing the number and duration of hospital admissions before and after ketamine treatment as well as logistic regression analysis to investigate clinical predictors of effectiveness, were performed. To assess patients' severity of depressed symptoms records were screened for MADRS-S scores.

RESULTS

No significant difference between pre- and posttreatment hospital days (p = 0.170), or number of hospitalisations (p = 0.740) were found. The response rate was 31% and remission rate 21%. None of the predictors showed statistical significance in the logistic model.

CONCLUSION

Iv ketamine treatment showed effectiveness in reducing depressive symptoms even with complex patients in a real-world clinical setting. However, this did not translate to a reduction in hospitalisation. Highlighting the multifaceted challenges posed when implementing iv ketamine treatment in clinical practice.

Clinical pharmacological innovation in the treatment of depression

INTRODUCTION

Deficiencies in standard of care antidepressants are driving novel drug discovery. A new age of antidepressant medications has emerged with the introduction of rapid-acting antidepressants with efficacy in treatment-resistant patients.

AREAS COVERED

The newly approved medicines and those in clinical development for major depressive disorder (MDD) are documented in this scoping review of newly approved and emerging antidepressants. Compounds are evaluated for clinical efficacy, tolerability, and safety and compared to those of standard of care medicines.

EXPERT OPINION

A new age of antidepressant discovery relies heavily on glutamatergic mechanisms. New medicines based upon the model of ketamine have been delivered and are in clinical development. Rapid onset and the ability to impact treatment-resistant depression, raises the question of the best first-line medicines for patients. Drugs with improvements in tolerability are being investigated (e.g. mGlu_2/3 receptor antagonists, AMPA receptor potentiators, and novel NMDA receptor modulators). Multiple companies are working toward the identification of novel psychedelic drugs where the requirement for psychedelic activity is not fully known. Gaps still exist - methods for matching patients with specific medicines are needed, and medicines for the prevention of MDD and its disease progression need research attention.

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.