Copper and anti-anhedonic effect of ketamine in treatment-resistant depression

Non-response to short-term ketamine use for treatment-resistant depression

BACKGROUND

Ketamine is currently gaining attention as a rapid-acting antidepressant for treatment-resistant depression (TRD). However, many patients fail to respond, and limited data exist on predictors of non-response. This study aims to characterize the sociodemographic and clinical features associated with non-response to ketamine among TRD patients.

METHODS

This is a post-hoc analysis of a naturalistic observational study, which enrolled 40 inpatients with treatment-resistant major depressive disorder and analyzed sociodemographic and clinical features in responders and non-responders stratified per Montgomery-Åsberg Depression Rating Scale (MADRS) during short-term ketamine administration (intravenous dosage: 0,5 mg/kg and orally: 2.0 or 2.5 mg/kg) that comprise over 4 weeks.

RESULTS

In this study, 30 patients (75%) were classified as non-responders. No significant differences were detected among sociodemographic and clinical features beyond the history of substance use disorder (SUD) - only 53.3% of non-responders reported prior SUD (vs. 100%; p = 0.0075) and a lower number of psychiatric comorbidities (p = 0.0381).

CONCLUSION

This study highlights key characteristics of TRD non-responders to ketamine, including lower rates of SUD and fewer psychiatric comorbidities. These findings suggest that a higher burden of traditional TRD risk factors may not limit ketamine efficacy and could even enhance response compared to "pure" major depressive disorder. Identifying potential non-responders early can optimize treatment decisions, reduce ineffective exposure, and guide future research on improving TRD management.

Common Regulatory Mechanisms Mediated by Cuproptosis Genes in Inflammatory Bowel Disease and Major Depressive Disorder

BACKGROUND

The prevalence of major depressive disorder (MDD) among patients with inflammatory bowel disease (IBD) is significantly higher compared to the general population, suggesting a potential link between their pathogeneses. Cuproptosis, defined as cell death caused by intracellular copper accumulation, has not been thoroughly investigated in the context of IBD and MDD. This study aims to uncover the molecular mechanisms of cuproptosis-related genes (CRGs) in both conditions and to explore novel therapeutic strategies by the modulation of CRGs.

METHODS

In this study, we identified differentially expressed CRGs between normal and disease samples. We calculated the correlation among CRGs and between CRGs and immune cell infiltrations across various tissues. Four machine learning algorithms were employed to identify key CRGs associated with IBD and MDD. Additionally, drug sensitivity, molecular docking, and molecular dynamics simulations were conducted to predict therapeutic drugs for IBD and MDD.

RESULTS

We identified DLD, DLAT, DLST, PDHB, and DBT as common DE-CRGs, and DLD, LIAS, SLC31A1, SCO2, and CDKN2A as key CRGs associated with both IBD and MDD. Consequently, DLD was recognized as a shared biomarker in both diseases. A total of 37 potential therapeutic drugs were identified for IBD and MDD. Based on the molecular docking and molecular dynamics simulation analyses, barasertib and NTP-TAE684, which target DLAT, were predicted to be the most effective compounds.

CONCLUSIONS

These findings have substantially enhanced our understanding of the similarities and differences in the regulatory mechanisms of CRGs within brain-gut axis diseases. Key biomarkers have been identified, and potential therapeutic drugs have been predicted to effectively target IBD and MDD.

The quest for optimal ketamine dosing formula in treatment-resistant major depressive disorder

BACKGROUND

Emerging evidence indicates that intravenous ketamine is effective in managing treatment-resistant unipolar and bipolar depression. Clinical studies highlight its favorable efficacy, safety, and tolerability profile within a dosage range of 0.5-1.0 mg/kg based on actual body weight. However, data on alternative dosage calculation methods, particularly in relation to body mass index (BMI) and therapeutic outcomes, remain limited.

METHODS

This retrospective analysis of an open-label study aims to evaluate dose calculation strategies and their impact on treatment response among inpatients with treatment-resistant major depressive disorder (MDD) (n = 28). The study employed the Boer and Devine formulas to determine lean body mass (LBM) and ideal body weight (IBW), and the Mosteller formula to estimate body surface area (BSA). The calculated doses were then compared with the actual doses administered or converted to a dosage per square meter for both responders and non-responders.

RESULTS

Regardless of treatment response, defined as a reduction of 50% in the Montgomery-Åsberg Depression Rating Scale, the use of alternative ketamine dosing formulas resulted in underdosing compared to the standardized dose of 0.5 mg/kg. Only two participants received higher doses (102.7% and 113.0%) when the Devine formula was applied.

CONCLUSIONS

This study suggests that ketamine dosing formulas, alternative to the standardized 0.5 mg/kg based on body weight, may lead to underdosing and potentially impact outcome interpretation. To enhance dosing accuracy, future studies should consider incorporating body impedance analysis and waist-to-hip ratio measurements, as this study did not account for body composition.

Sleep alterations in treatment-resistant depression patients undergoing ketamine treatment

BACKGROUND

This study examines self-reported sleep alterations in treatment-resistant depression (TRD) inpatients following intravenous ketamine administration.

METHODS

This is a post-hoc analysis of a naturalistic observational study, which enrolled 28 inpatients with treatment-resistant major depressive disorder and analyzed self-reported sleep changes (items 1-4; 'insomnia', 'nighttime restlessness', 'early morning waking', 'hypersomnia') in Inventory of Depressive Symptomatology 30-item (IDS SR-30) in responders and non-responders stratified per Montgomery-Åsberg Depression Rating Scale (MADRS) during short-term ketamine treatment.

RESULTS

Responders, as well as non-responders, did not experience significant changes in IDS SR-30 sleep items ('insomnia', 'nighttime restlessness', 'early morning waking', 'hypersomnia') (p's > 0.05) at 7-day follow-up after eight intravenous ketamine infusions as compared to baseline.

CONCLUSION

Neither responders, nor non-responders reported any significant alterations in sleep patterns during ketamine infusions. These findings are not in line with current literature, as so far modest improvements in sleep during ketamine treatment have been reported. Results should be interpreted with caution, primarily due to the small sample size.

Subcallosal area 25: Its responsivity to the stress hormone cortisol and its opposing effects on appetitive motivation in marmosets

Aberrant activity in caudal subcallosal anterior cingulate cortex (scACC) is implicated in depression and anxiety symptomatology, with its normalisation a putative biomarker of successful treatment response. The function of scACC in emotion processing and mental health is not fully understood despite its known influence on stress-mediated processes through its rich expression of mineralocorticoid and glucocorticoid receptors. Here we examine the causal interaction between area 25 within scACC (scACC-25) and the stress hormone, cortisol, in the context of anhedonia and anxiety-like behaviour. In addition, the overall role of scACC-25 in hedonic capacity and motivation is investigated under transient pharmacological inactivation and overactivation. The results suggest that a local increase of cortisol in scACC-25 shows a rapid induction of anticipatory anhedonia and increased responsiveness to uncertain threat. Separate inactivation and overactivation of scACC-25 increased and decreased motivation and hedonic capacity, respectively, likely through different underlying mechanisms. Together, these data show that area scACC-25 has a causal role in consummatory and motivational behaviour and produces rapid responses to the stress hormone cortisol, that mediates anhedonia and anxiety-like behaviour.

Celiac disease and depressive disorders as nutritional implications related to common factors - A comprehensive review

Celiac disease (CD) is an immune-mediated disease affecting the small intestine. The only treatment strategy for CD is the gluten-free diet (GFD). One of the more common mental disorders in CD patients is major depressive disorder (MDD). The influence of GFD on the occurrence of MDD symptoms in patients with CD will be evaluated. This diet often reduces nutritional deficiencies in these patients and also helps to reduce depressive symptoms. Both disease entities are often dominated by the same deficiencies of nutrients such as iron, zinc, selenium, iodine, or B and D vitamins. Deficiencies of particular components in CD can favor MDD and vice versa. Gluten can adversely affect the mental state of patients without CD. Also, intestinal microbiota may play an important role in the described process. This work aims to comprehensively assess the common factors involved in the pathomechanisms of MDD and CD, with particular emphasis on nutrient imbalances. Given the complexity of both disease entities, and the many common links, more research related to improving mental health in these patients and the implementation of a GFD would need to be conducted, but it appears to be a viable pathway to improving the quality of life and health of people struggling with CD and MDD. Therefore, probiotics, micronutrients, macronutrients, and vitamin supplements are recommended to reduce the risk of MDD, given that they may alleviate the symptoms of both these disease entities. In turn, in patients with MDD, it is worth considering testing for CD.

Anhedonia and depression severity measures during ketamine administration in treatment-resistant depression

Background

Anhedonia is a core symptom of depression characterized by a diminished ability to experience pleasure. Currently available treatments for depression often fall short in adequately addressing anhedonia that often presents as a chronic and debilitating symptom. Ketamine is known to possess antianhedonic properties.

Methods

This post-hoc analysis of a naturalistic observational study of treatment-resistant depression inpatients (n=28) analyzed antianhedonic response patterns measured by Snaith-Hamilton Pleasure Scale and changes in Inventory of Depressive Symptomatology in responders (n=6) and non-responders (n=22) stratified per Montgomery-Åsberg Depression Rating Scale during short-term ketamine treatment.

Results

Results show that responders significantly improve in anhedonia over time (p=0.0084) and at the 7th infusion and follow-up (both p<0.05). Non-responders reported significant reduction in anhedonia over time (p=0.0011) and at the 5th, 7th infusion and at the follow-up (all p's<0.05). Non-responders were also observed to improve significantly in self-reported depression at the 7th infusion (p=0.0219) but not at the follow-up.

Discussion

There is no complete overlap between change in depressive symptoms and anhedonia. Therefore, it might be assumed ketamine alleviates anhedonia as an individual symptom domain regardless of formal treatment outcome.

Cuproptosis-related genes prediction feature and immune microenvironment in major depressive disorder

Background

Major depressive disorder (MDD) is a severe, unpredictable, ill-cured, relapsing neuropsychiatric disorder. A recently identified type of death called cuproptosis has been linked to a number of illnesses. However, the influence of cuproptosis-related genes in MDD has not been comprehensively assessed in prior study.

Aim

This investigation intends to shed light on the predictive value of cuproptosis-related genes for MDD and the immunological microenvironment.

Methods

GSE38206, GSE76826, GSE9653 databases were used to analyze cuproptosis regulators and immune characteristics. To find the genes that were differently expressed, weighted gene co-expression network analysis was employed. We calculated the effectiveness of the random forest model, generalized linear model, and limit gradient lifting to arrive at the best machine prediction model. Nomogram, calibration curve, and decision curve analysis were used to show the anticipated MDD's accuracy.

Results

This study found that there were activated immune responses and cuproptosis-related genes that were dysregulated in people with MDD compared to healthy controls. Considering the test performance of the learned model and validation on subsequent datasets, the RF model (including OSBPL8, VBP1, MTM1, ELK3, and SLC39A6) was considered to have the best discriminative performance. (AUC = 0.875).

Conclusion

Our study constructed a prediction model to predict MDD risk and clarified the potential connection between cuproptosis and MDD.

Associations of serum zinc, copper, and selenium with sleep disorders in the American adults: Data from NHANES 2011-2016

BACKGROUND

Even though various studies have been conducted to investigate the relationship between trace metals and sleep, few epidemiological studies have evaluated the relationship between trace metals and sleep disorders in American adults.

OBJECTIVE

This study intended to evaluate the associations of serum zinc (Zn), copper (Cu), selenium (Se), Zn/Cu, Zn/Se, and Cu/Se ratios with sleep disorders in American adults.

METHODS

We conducted a cross-sectional analysis of 3660 adults aged ≥18 years old who participated in the National Health and Nutrition Examination Survey (NHANES) 2011-2016. Binary logistic regression was employed to calculate the odds ratio (OR) and 95 % confidence interval (CI) of either serum trace metals or serum trace metals ratios with risks among sleep disorder phenotypes. The restricted cubic spline (RCS) model was additionally utilized to check the dose-response relationships between serum trace metals, serum trace metals ratios, and sleep disorders.

RESULTS

Logistic regression demonstrated that higher serum Zn (OR: 0.70, 95 % CI: 0.51-0.97, p = 0.035), Zn/Cu (OR: 0.62, 95 % CI: 0.45-0.87, p = 0.007), and Zn/Se (OR: 0.68, 95 % CI: 0.49-0.95, p = 0.025) were related to a decreased likelihood of self-reported sleep disorders, and dose-response relationships were detected by the RCS models, after adjustment for sociodemographic, behavioral, and health characteristics. No associations between serum Cu, Se, Cu/Se, and sleep disorders were observed. The findings in the sensitivity analyses were consistent with these results.

CONCLUSION

Our study revealed that serum Zn, Zn/Cu, and Zn/Se were inversely associated with the risk of self-reported sleep disorders in US adults.

Safety and Tolerability of the Acute Ketamine Treatment in Treatment-Resistant Depression: Focus on Comorbidities Interplay with Dissociation and Psychomimetic Symptoms

There is evidence for ketamine use in treatment-resistant depression (TRD). Several safety concerns arise regarding adverse drug reactions in specific subpopulations. The aim of this study was to investigate the safety of intravenous ketamine treatment in relation to dissociative and psychotic measures in TRD inpatients with Major Depressive Disorder (MDD) and Bipolar depression (BP) with comorbidities. In total, 49 inpatients with MDD or BP were treated with ketamine following the registered naturalistic observational protocol in a tertiary reference unit for mood disorders (NCT04226963). This dataset represents an intermittent analysis of an observational study performed for interim modeling of observational learning. The observations were applied to the inhomogeneous TRD population in a single site with no blinding and were limited to acute administration. The presence of epilepsy was significantly associated with an elevation in the BPRS over time (p = 0.008). Psychotic symptomatology with BPRS scores for comorbid conditions excluding epilepsy turned out to be insignificant (p = 0.198) regardless of the diagnosis. However, for a subgroup of patients with epilepsy (n = 6), a substantial fluctuation was seen across all administrations in the time course of the study. The study results contribute to the literature on the safety and tolerability profile of CNS adverse drug reactions in short-term treatment with intravenous ketamine as an add-on intervention to current standard-of-care psychotropic medication in TRD-MDD and TRD-BP inpatients with comorbidities. The careful consideration of comorbidities and concomitant medication is needed with ketamine administration along with close-clinical supervision at every visit.

BMI Modifies the Association Between Depression Symptoms and Serum Copper Levels

Depression is one of the most common mental disorders which dramatically threatens public health and wellness. Copper has been known to be involved in many biological processes that could help explaining the occurrence of depression. However, studies focusing on its effect have yielded mixed results. The present study aims to evaluate the association between serum copper levels and depression symptoms. It also investigates the effect of modification of BMI (body mass index) on depression symptoms. A total of 5419 US adults aged 20 years or older from the National Health and Nutrition Examination Survey (NHANES) 2011-2016 participated in the cross-sectional study. Logistic regression models were applied using depression levels as the outcome and serum cooper/selenium/zinc categories as the main predictor, with the adjustments of gender, age, marital status, race, education, family income level, alcohol drinking, cigarette smoking, diabetes, pressure, stroke, and BMI. The interaction terms for copper levels and other covariates were further incorporated into the model to assess their roles in predicting depression symptoms. The prevalence of depression symptoms was significantly higher in samples with a high copper level. Among the levels of serum copper, selenium, and zinc, only the association between depression symptoms and serum copper levels was observed to be significant in the unadjusted model (P = 0.002). Individuals with a high copper level (114-134 μg/dL) and a very high copper level (≥ 134 μg/dL) had 1.85 (95% CI 1.24, 2.77)- and 1.72 (95% CI 1.21, 2.44)-fold higher odds ratio of depression symptoms, respectively, compared to those with a normal serum copper level. Although the association was not significant in the adjusted models, in which confounders were added, the interaction of copper level, including high and very high copper levels, and obesity (BMI ≥ 30 kg/m²) exhibited significantly higher odds ratio (4.12 (95% CI 1.38, 12.27) and 4.53 (95% CI 1.87, 10.96)) of having depression symptoms. The concentration of serum copper was positively associated with the prevalence of depression symptoms. Obesity exacerbated the risk of having depression symptoms in people with high serum copper levels.

Abnormal habenula functional connectivity characterizes treatment-resistant depression

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Habenular hyper connectivity characterizes treatment-resistant depression.

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An interplay between reward and default mode networks is linked to suicidality.

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Abnormal habenula connectivity is a possible mechanism for anhedonia.

Background

A significant proportion of patients with major depressive disorder are resistant to antidepressant medication and psychological treatments. A core symptom of treatment-resistant depression (TRD) is anhedonia, or the inability to feel pleasure, which has been attributed to disrupted habenula function – a component of the reward network. This study aimed to map detailed neural circuitry architecture related to the habenula to identify neural mechanisms of TRD.

Methods

35 TRD patients, 35 patients with treatment-sensitive depression (TSD), and 38 healthy controls (HC) underwent resting-state functional magnetic resonance imaging. Functional connectivity analyses were performed using the left and right habenula as seed regions of interest, and the three groups were compared using whole-brain voxel-wise comparisons.

Results

The TRD group demonstrated hyperconnectivity of the left habenula to the left precuneus cortex and the right precentral gyrus, compared to the TSD group, and to the right precuneus cortex, compared to the TSD and HC groups. In contrast, TSD demonstrated hypoconnectivity than HC for both connectivity measures. These connectivity values were significantly higher in patients with a history of suicidal ideation.

Conclusions

This study provides evidence that, unlike TSD, TRD is characterized by hyperconnectivity of the left habenula particularly with regions of the default mode network. An increased interplay between reward and default mode networks is linked to suicidality and could be a possible mechanism for anhedonia in hard to treat depression.

Dissociative symptoms with intravenous ketamine in treatment-resistant depression exploratory observational study

There is evidence for ketamine use in treatment-resistant depression (TRD). Several safety and tolerability concerns arise regarding adverse drug reactions and specific subpopulations. This paper aims to investigate the relationship between dissociative and psychometric measures in course of intravenous ketamine treatment in TRD inpatients with major depressive disorder and bipolar disorder.This study result represents safety data in a population of 49 inpatients with major depressive disorder and bipolar disorder subjects receiving eight 0.5 mg/kg of ketamine intravenous infusions, with a duration of 40 min each, as an add-on treatment to standard-of-care pharmacotherapy, registered in the naturalistic observational protocol of the tertiary reference unit for mood disorders (NCT04226963). The safety psychometrics assessed dissociation and psychomimetic symptomatology with the Clinician-Administered Dissociative States Scale (CADSS) the Brief Psychiatric Rating Scale (BPRS).The significant differences in CADSS scores between measurements in course of the treatment were observed (P = .003). No significant differences between BPRS measurements were made after infusions. In each case, both BPRS and CADSS values dropped to the "absent" level within 1 hour from the infusion. Neither CADSS nor BPRS scores were associated with the treatment outcome.The study demonstrates a good safety profile of intravenous ketamine as an add-on intervention to current psychotropic medication in TRD. The abatement of dissociation was observed in time with no sequelae nor harm. The study provides no support for the association between dissociation and treatment outcome.This study may be underpowered due to the small sample size. The protocol was defined as a study on acute depressive symptomatology without blinding.

Somatic Comorbidities and Cardiovascular Safety in Ketamine Use for Treatment-Resistant Depression

Background and Objectives: There is evidence for ketamine efficacy in treatment-resistant depression (TRD). Several safety and tolerability concerns arise that some psychotropic agents may provide blood pressure or/and heart rate alterations. The aim of this study is to review blood pressure measurements in course of the treatment with ketamine on treatment refractory inpatients with somatic comorbidities in the course of MDD and BP. Materials and Methods: The study population of 49 patients comprised MDD and BP subjects treated with ketamine registered in the naturalistic observational protocol of treatment-resistant mood disorders (NCT04226963). Results: The conducted analysis showed that among people suffering from hypertension there is a higher increase in systolic blood pressure (RR) after infusion 2 (p = 0.004) than among people who do not suffer from hypertension. Patients with hypertension have a higher increase in diastolic RR compared to those not suffering from hypertension (p = 0,038). Among the subjects with diabetes mellitus, significant differences occurred for infusions 2 (p = 0.020), 7 (p = 0.020), and 8 (p = 0.035) for heart rate (HR), compared to subjects without diabetes mellitus. A higher increase in diastolic RR was noted in the group of subjects suffering from diabetes mellitus (p = 0.010) compared to those who did not. In the hyperlipidemic patients studied, a significantly greater decrease in HR after infusion 5 (p = 0.031) and systolic RR after infusion 4 (p = 0.036) was noted compared to nonpatients. People after a stroke had significantly higher increases in diastolic RR after infusions 4 (p = 0.021) and 6 (p = 0.001) than those who did not have a stroke. Patients suffering from epilepsy had a significantly greater decrease in systolic RR after the 8th infusion (p = 0.017) compared to those without epilepsy. Limitations: The study may be underpowered due to the small sample size. The observations apply to inhomogeneous TRD population in a single-site with no blinding and are limited to the acute administration. Conclusions: This study supports evidence for good safety and tolerability profile for short-term IV ketamine use in TRD treatment. However, risk mitigation measures are to be considered in patients with metabolic and cardiovascular comorbidities.

Central nervous system-related safety and tolerability of add-on ketamine to antidepressant medication in treatment-resistant depression: focus on the unique safety profile of bipolar depression

BACKGROUND

There is evidence supporting the use of ketamine in treatment-resistant depression (TRD). However, there are some safety and tolerability concerns associated with ketamine. This study aimed to investigate ketamine's safety and tolerability to the central nervous system and to assess the relationship between dissociative symptomology and psychometric outcomes during and after intravenous ketamine treatment concurrent with treatment by varying psychotropic medications in treatment-refractory inpatients with major depressive disorder (MDD) and bipolar disorder (BP).

METHODS

A total of 49 patients with MDD and BP were included in this study. The subjects were administered ketamine and were assessed for changes using an observational protocol.

RESULTS

No antidepressants were associated with psychomimetic symptomatology except for citalopram (p = 0.019). Patients treated with citalopram showed a higher intensity of psychomimetic symptomatology. The use of classic mood-stabilizers was significantly associated with an increase in psychomimetic symptomatology according to the Brief Psychiatric Rating Scale (BPRS; lamotrigine p = 0.009, valproate p = 0.048, lithium p = 0.012). No sequelae were observed.

CONCLUSIONS

Despite the limitations that this study may be underpowered due to the small sample size, the sample consisted of a heterogeneous TRD population in a single site, and there no blinding of who underwent only acute ketamine administration, our observations indicate ketamine use requires close safety and tolerability monitoring with regards to psychomimetic and dissociative symptoms in TRD-BP and careful management for MDD patients.ClinicalTrials.gov identifier: NCT04226963.

Intravenous Ketamine Infusions in Treatment-Resistant Bipolar Depression: An Open-Label Naturalistic Observational Study

PURPOSE

Bipolar disorder is a chronic and recurrent condition often associated with treatment resistance and suicidality. There is an unmet need for effective treatment in this group of patients. Ketamine has been demonstrated to have antidepressant and antisuicidal properties in unipolar depression. Most of the available studies concern unipolar depression. Here, we present the efficacy and safety of IV ketamine as an add-on treatment in patients with bipolar I and bipolar II depression.

PATIENTS AND METHODS

Thirteen patients with treatment-resistant bipolar depression (TRBD) received eight IV infusions of 0.5 mg/kg ketamine twice a week over four weeks. This is an open-label naturalistic observational study. Ketamine is an add-on treatment. Depressive symptoms were measured with the Montgomery-Asberg Depression Rating Scale (MADRS), and manic symptoms were measured with the Young Mania Rating Scale (YMRS). Psychomimetic symptoms were assessed with the Clinician-Administered Dissociative States Scale (CADSS) and the Brief Psychiatric Rating Scale (BPRS).

RESULTS

The rates of response and remission after the seventh infusion of ketamine were 61.5% and 46.2%, respectively. A significant antisuicidal effect was observed in responders at the 7th infusion. Suicidality was measured with item 10 on the MADRS scale. The average time to respond was between 21.1 and 23.2 days to remission. There was an increase in the CADSS scores during the treatment compared to baseline and follow-up, but no differences between responders and non-responders were observed. No affective switch was observed according to the YMRS scale scores. Ketamine treatment was associated with a transient increase in arterial blood pressure. No serious adverse events, however, were observed.

CONCLUSION

This report presents the preliminary results of IV ketamine effectiveness and safety in treatment-resistant bipolar depression. The findings suggest that it is a feasible, safe and well-tolerated treatment option in this group of patients. There is a definite need for more studies in this field.

Association of VEGF With Antianhedonic Effects of Repeated-Dose Intravenous Ketamine in Treatment-Refractory Depression

Objectives: To first explore the role of plasma vascular endothelial growth factor (VEGF) concentrations in ketamine's antianhedonic effects, focusing on Chinese patients with treatment-refractory depression (TRD). Methods: Seventy-eight patients with treatment-refractory major depressive disorder (MDD) or bipolar disorder (BD) were treated with six ketamine infusions (0.5 mg/kg). Levels of anhedonia were measured using the Montgomery-Åsberg Depression Rating Scale (MADRS) anhedonia item at baseline, day 13 and 26. Plasma VEGF concentrations were examined at the same time points as the MADRS. Results: Despite a significant reduction in anhedonia symptoms in individuals with treatment-refractory MDD (n = 59) or BD (n = 19) after they received repeated-dose ketamine infusions (p < 0.05), no significant changes in plasma VEGF concentrations were found at day 13 when compared to baseline (p > 0.05). The alteration of plasma VEGF concentrations did not differ between antianhedonic responders and non-responders at days 13 and 26 (all ps > 0.05). Additionally, no significant correlations were observed between the antianhedonic response to ketamine and plasma VEGF concentrations (all ps > 0.05). Conclusion: This preliminary study suggests that the antianhedonic effects of ketamine are not mediated by VEGF.

Antianhedonic Effect of Repeated Ketamine Infusions in Patients With Treatment Resistant Depression

Anhedonia constitutes one of the main symptoms of depressive episode. It correlates with suicidality and significantly effects the quality of patient's lives. Available treatments are not sufficient against this group of symptoms. Ketamine is a novel, rapid acting strategy for treatment resistant depression. Here we report the change in symptoms of anhedonia measured by Snaith-Hamilton Pleasure Scale as an effect of eight ketamine infusions as an add-on treatment in 42 patients with treatment resistant depression. We also determined the effect of this change on the severity of depressive symptoms measured by Inventory for Depression Symptomatology-Self Report 30-Item (IDS-SR 30). We have observed statistically significant decrease in the level of anhedonia during ketamine treatment. After adjusting for potential confounders we have found that significant reduction in Snaith-Hamilton Pleasure Scale (SHAPS) after each infusion and 1 week post treatment was observed only among patients who did not use benzodiazepines. The reduction in symptoms of anhedonia mediates the antidepressive effect of ketamine. The results need replication in a larger randomized placebo controlled trial.

Copper Concentrations in Ketamine Therapy for Treatment-Resistant Depression

Changes in serum copper concentration are observed in patients with depressive symptoms. Unmet needs in contemporary antidepressant treatment have increased interest in non-monoaminergic antidepressants, such as ketamine, an anaesthetic drug that has demonstrated a rapid antidepressant effect in patients with treatment-resistant depression (TRD). The purpose of this study was to examine whether serum copper concentrations change during ketamine treatment and whether there is an association between the copper concentrations and treatment response measured using psychometric scale scores. Moreover, the interlink between somatic comorbidities and copper concentration was studied. Patients with major depressive disorder or bipolar disorder were rated weekly by a clinician using the Montgomery-Asberg Depression Rating Scale (MADRS) and Young Mania Rating Scale (YMRS). Copper level assessments were carried out weekly before the start of ketamine treatment and then after every second infusion and one week after the last ketamine infusion. The serum concentration of copper before ketamine treatment was significantly higher than that after the fifth infusion (p = 0.016), and the serum concentration after the treatment was significantly higher than that after the fifth infusion (p = 0.048). No significant correlations between changes in the copper serum concentrations and MADRS or YMRS were found. The serum copper level was not associated with somatic comorbidities during the course of treatment. This study provides data on the role of copper in short-term intravenous ketamine treatment in TRD, although no clear evidence of a connection between the copper level and treatment response was found.