Clinical factors predicting treatment resistant depression: affirmative results from the European multicenter study

Risk Phenotypes, Comorbidities, Pharmacotherapy, and Electroconvulsive Therapy (ECT) in a Cohort with Difficult-to-Treat Depression in Comparison to an Unmedicated Control Group

BACKGROUND

Approximately 15-25% of depressed patients suffer from difficult-to-treat depression (DTD). Patients with DTD require a thorough examination to avoid the oversight of treatable (psychiatric/somatic) comorbidities or (pseudo-)resistance to antidepressant drugs (ADs). Polymorphisms of the cytochrome P450 (CYP) enzymes 2D6 and 2C19, which play a major role in the metabolism of ADs, may contribute to resistance to ADs. Patients with DTD might benefit from electroconvulsive therapy (ECT).

METHODS

We enrolled 109 patients with DTD and 29 untreated depressed controls (UDC). We assessed risk phenotypes, comorbidities, and treatment, including ECT. We also performed pharmacokinetic analyses of CYP2D6 and CYP2C19.

RESULTS

DTD patients significantly more often suffered from comorbid psychiatric diseases, especially ICD-10: F40-F48 (DTD:40.4%, UDC:17.2%, OR 11.87, p=0.011) than UDC patients. DTD patients receiving ECT were more likely to achieve remission (37.7% vs. 11.8%, OR=3.96, p=0.023). Treatment with ADs did not differ between remitters and non-remitters. No significant differences were observed in the distribution of CYP2D6 and CYP2C19 variants between both groups.

CONCLUSION

Patients with DTD appear to experience comorbid neurotic stress and somatoform disorders (ICD-10: F40 - F48) more frequently. Therefore, a comprehensive differential diagnosis is crucial when patients do not respond sufficiently to antidepressant medication. Genotyping CYP2D6 and CYP2C19 should be considered.

Association of clinical characteristics, depression remission and suicide risk with discrepancies between self- and clinician-rated suicidal ideation: Two large naturalistic cohorts of outpatients with depression

Clinician- and self-rating of suicidal ideation (SI) are often discrepant. The aim of this study was to determine: 1) Association between discrepant self- and clinician-rated SI with clinical characteristics, depression remission and SA (SA) risk; 2) which SI assessment (self or clinician) predicted depression remission and risk of SA. LUEUR and GENESE are two large, prospective, naturalistic cohorts of French adult outpatients with unipolar depression treated and followed for 6 weeks. SI presence was assessed and defined with a score to the suicidal item of the Montgomery-Åsberg Depression Rating Scale ≥3. Discordant SI was defined as SI detection by only one of the two evaluators (patient or clinician). In both cohorts, 49.3 % (GENESE) and 34 % (LUEUR) patients had discordant SI. Clinical characteristics were more severe, and risk of SA was higher in patients with current SI (concordant and discordant) than in patients without SI and in the concordant than in the discordant group. Prediction of the risk of SA and of depression non-remission was comparable by the two ratings. Patients with SI (concordant and discordant) have more severe clinical characteristics and patients with concordant SI are the most at risk of SA during the follow-up. It is crucial to assess SI and to improve how it is evaluated.

Association between inflammatory joint disease and severe or treatment-resistant depression: population-based cohort and case-control studies in Sweden

OBJECTIVE

To investigate whether the association between depression and inflammatory joint disease (IJD; rheumatoid arthritis [RA], psoriatic arthritis [PsA], ankylosing spondylitis/spondyloarthropathies [AS], and juvenile idiopathic arthritis [JIA]) is affected by the severity or treatment-resistance of depression.

METHOD

Parallel cohort studies and case-control studies among 600,404 patients with a depressive episode identified in Swedish nationwide administrative registers. Prospective and retrospective risk for IJD in patients with depression was compared to matched population comparators, and the same associations were investigated in severe or treatment-resistant depression. Analyses were adjusted for comorbidities and sociodemographic covariates.

RESULTS

Patients with depression had an increased risk for later IJD compared to population comparators (adjusted hazard ratio (aHR) for any IJD 1.34 [95% CI 1.30-1.39]; for RA 1.27 [1.15-1.41]; PsA 1.45 [1.29-1.63]; AS 1.32 [1.15-1.52]). In case-control studies, patients with depression more frequently had a history of IJD compared to population controls (adjusted odds ratio (aOR) for any IJD 1.43 [1.37-1.50]; RA 1.39 [1.29-1.49]; PsA 1.59 [1.46-1.73]; AS 1.49 [1.36-1.64]; JIA 1.52 [1.35-1.71]). These associations were not significantly different for severe depression or TRD.

CONCLUSION

IJD and depression are bidirectionally associated, but this association does not seem to be influenced by the severity or treatment resistance of depression.

Structural Brain Connectivity and Treatment Improvement in Mood Disorder

Background: The treatment of depressive episodes is well established, with clearly demonstrated effectiveness of antidepressants and psychotherapies. However, more than one-third of depressed patients do not respond to treatment. Identifying the brain structural basis of treatment-resistant depression could prevent useless pharmacological prescriptions, adverse events, and lost therapeutic opportunities. Methods: Using diffusion magnetic resonance imaging, we performed structural connectivity analyses on a cohort of 154 patients with mood disorder (MD) and 77 sex- and age-matched healthy control (HC) participants. To assess illness improvement, the patients with MD went through two clinical interviews at baseline and at 6-month follow-up and were classified based on the Clinical Global Impression-Improvement score into improved or not-improved (NI). First, the threshold-free network-based statistics (NBS) was conducted to measure the differences in regional network architecture. Second, nonparametric permutations tests were performed on topological metrics based on graph theory to examine differences in connectome organization. Results: The threshold-free NBS revealed impaired connections involving regions of the basal ganglia in patients with MD compared with HC. Significant increase of local efficiency and clustering coefficient was found in the lingual gyrus, insula, and amygdala in the MD group. Compared with the NI, the improved displayed significantly reduced network integration and segregation, predominately in the default-mode regions, including the precuneus, middle temporal lobe, and rostral anterior cingulate. Conclusions: This study highlights the involvement of regions belonging to the basal ganglia, the fronto-limbic network, and the default mode network, leading to a better understanding of MD disease and its unfavorable outcome.

Perspectives in treatment-resistant depression: esketamine and electroconvulsive therapy

Modern electroconvulsive therapy (ECT) and the approval of nasal esketamine for clinical use have significantly improved the approach to treatment-resistant depression (TRD), which is defined as non-response to at least two different courses of antidepressants with verified adherence to treatment, adequate dosage, and duration of treatment. The goal of this literature review is to present the newest evidence regarding efficacy and safety. Furthermore, we aim to provide an overview of future perspectives in this field of research, for example, regarding structural and molecular effects. Both treatment methods will be critically evaluated for their individual advantages, disadvantages, and response rates. Firstly, we will discuss the well-established method of ECT and its different treatment modalities. Secondly, we will discuss the properties of ketamine, the discovery of its antidepressive effects and the route to clinical approval of the esketamine nasal spray. We will comment on research settings which have evaluated intravenous ketamine against ECT. The decision-making process between esketamine nasal spray or ECT should include the assessment of contraindications, age, severity of disease, presence of psychotic symptoms, patient preference and treatment accessibility. We conclude that both treatment options are highly effective in TRD. If both are indicated, pragmatically esketamine will be chosen before ECT; however, ECT studies in ketamine non-responders are missing.

Evidence versus expectancy: the development of psilocybin therapy

SUMMARY

Although the development of psilocybin therapy has come as a surprise to many, modern research with the drug has been ongoing for 25 years. Psilocybin therapy is composed of psilocybin dosing sessions embedded within a wider process of psychoeducation, psychological support and integration. Early phase clinical trial evidence is promising, particularly for treatment-resistant depression. However, masking probably fails and expectancy effects may be a part of the mechanism of change. Disambiguating between drug and expectancy effects is a necessary part of the development process, yet this is difficult if masking fails. Hitherto, masking and expectancy have not been routinely measured in psilocybin or other medication trials. Doing so represents an opportunity for research and may influence psychiatry more widely. In this opinion piece I summarise the clinical development process of psilocybin therapy thus far, discussing the hope, the hype, the challenges and the opportunities along the way.

Explainable multimodal prediction of treatment-resistance in patients with depression leveraging brain morphometry and natural language processing

Although 20 % of patients with depression receiving treatment do not achieve remission, predicting treatment-resistant depression (TRD) remains challenging. In this study, we aimed to develop an explainable multimodal prediction model for TRD using structured electronic medical record data, brain morphometry, and natural language processing. In total, 247 patients with a new depressive episode were included. TRD-predictive models were developed based on the combination of following parameters: selected tabular dataset features, independent components-map weightings from brain T1-weighted magnetic resonance imaging (MRI), and topic probabilities from clinical notes. All models applied the extreme gradient boosting (XGBoost) algorithm via five-fold cross-validation. The model using all data sources showed the highest area under the receiver operating characteristic of 0.794, followed by models that used combined brain MRI and structured data, brain MRI and clinical notes, clinical notes and structured data, brain MRI only, structured data only, and clinical notes only (0.770, 0.762, 0.728, 0.703, 0.684, and 0.569, respectively). Classifications of TRD were driven by several predictors, such as previous exposure to antidepressants and antihypertensive medications, sensorimotor network, default mode network, and somatic symptoms. Our findings suggest that a combination of clinical data with neuroimaging and natural language processing variables improves the prediction of TRD.

French Society for Biological Psychiatry and Neuropsychopharmacology (AFPBN) guidelines for the management of patients with partially responsive depression and treatment-resistant depression: Update 2024

INTRODUCTION

The purpose of this update is to add newly approved nomenclatures and treatments as well as treatments yet to be approved in major depressive disorder, thus expanding the discussions on the integration of resistance factors into the clinical approach.

METHODS

Unlike the first consensus guidelines based on the RAND/UCLA Appropriateness Method, the French Association for Biological Psychiatry and Neuropsychopharmacology (AFPBN) developed an update of these guidelines for the management of partially responsive depression (PRD) and treatment-resistant depression (TRD). The expert guidelines combine scientific evidence and expert clinicians' opinions to produce recommendations for PRD and TRD.

RESULTS

The recommendations addressed three areas judged as essential for updating the previous 2019 AFPBN guidelines for the management of patients with TRD: (1) the identification of risk factors associated with TRD, (2) the therapeutic management of patients with PRD and TRD, and (3) the indications, the modalities of use and the monitoring of recent glutamate receptor modulating agents (esketamine and ketamine).

CONCLUSION

These consensus-based guidelines make it possible to build bridges between the available empirical literature and clinical practice, with a highlight on the 'real world' of the clinical practice, supported by a pragmatic approach centred on the experience of specialised prescribers in TRD.

Indirect effect of impulsivity on suicide risk through self-esteem and depressive symptoms in a population with treatment-resistant depression: A FACE-DR study

INTRODUCTION

Suicide is a major health issue. Its prevalence is particularly high in subjects presenting major depression disorder (MDD), making this a key suicide-related risk factor. Suicide attempts in severe forms of MDD were assumed to be linked to impulsivity and loss of control. Nevertheless, we failed to find data specifically investigating the link between impulsivity and suicide risk in treatment-resistant depression (TRD). This study seeks to review this relationship.

METHOD

Patients were recruited for a prospective cohort. Suicide risk and impulsivity were assessed using the International Neuropsychiatric Interview and Barratt Impulsiveness Scale, Version 10, respectively, while the severity of depressive symptoms was assessed using the Montgomery-Asberg Depression Rating Scale, anxiety with the State-Trait Anxiety Inventory and childhood maltreatment using the Childhood Trauma Questionnaire.

RESULTS

220 TRD patients were enrolled in the study. The impulsivity score was correlated with self-esteem, marital status, professional status and anxiety. There was no direct link to suicide risk. However, impulsivity was associated with self-esteem (coefficient: -0.24; p value 0.043) and depressive symptom severity (coefficient: 0.; p value 0.045). The suicide risk was significantly correlated with depressive symptom severity (coefficient = 0.38, p < 0.001) and self-esteem (coefficient = -0.34, p = 0.01). Considering these correlations, we postulated that the effect of impulsivity on suicide risk could be mediated by self-esteem in terms of depressive symptom severity and we finally found a relevant mediation model within impulsivity having an indirect effect on suicide risk by impacting self-esteem and depressive symptoms with anxiety also playing a significant role as a covariable.

CONCLUSION

We found that impulsivity could play an indirect role with the involvement of self-esteem and depressive symptoms and the contributing role of anxiety.

Intestinal metabolites predict treatment resistance of patients with depression and anxiety

BACKGROUND

The impact of the gut microbiota on neuropsychiatric disorders has gained much attention in recent years; however, comprehensive data on the relationship between the gut microbiome and its metabolites and resistance to treatment for depression and anxiety is lacking. Here, we investigated intestinal metabolites in patients with depression and anxiety disorders, and their possible roles in treatment resistance.

RESULTS

We analyzed fecal metabolites and microbiomes in 34 participants with depression and anxiety disorders. Fecal samples were obtained three times for each participant during the treatment. Propensity score matching led us to analyze data from nine treatment responders and nine non-responders, and the results were validated in the residual sample sets. Using elastic net regression analysis, we identified several metabolites, including N-ε-acetyllysine; baseline levels of the former were low in responders (AUC = 0.86; 95% confidence interval, 0.69-1). In addition, fecal levels of N-ε-acetyllysine were negatively associated with the abundance of Odoribacter. N-ε-acetyllysine levels increased as symptoms improved with treatment.

CONCLUSION

Fecal N-ε-acetyllysine levels before treatment may be a predictive biomarker of treatment-refractory depression and anxiety. Odoribacter may play a role in the homeostasis of intestinal L-lysine levels. More attention should be paid to the importance of L-lysine metabolism in those with depression and anxiety.

Evaluating the use of electroconvulsive therapy in low-middle income countries: A narrative review

BACKGROUND

Electroconvulsive therapy (ECT) is a well-accepted intervention for treatment-resistant, serious mental illnesses. Its acceptability, efficacy, and tolerability are well documented in high-income settings, but less so in lower- and middle-income countries (LMICs). This report is a narrative review of ECT practice in the latter setting.

METHODS

A literature search was conducted using Medline and PubMed. Initial results yielded 81 publications in English. Following the screening, 19 papers were included to evaluate the information on ECT practice and perceptions.

RESULTS

Reports from LMICs on efficacy, tolerability, and perceptions of ECT were relatively sparse. In general, they confirm its use mostly for treatment-resistant major mental illnesses (i.e., depression, schizophrenia, bipolar disorder). Both modified and unmodified forms of ECT are used and considered equally effective, although the former is better tolerated. Use of unmodified ECT remains significant in LMICs due to its low cost and limited resource requirements. In general, there is satisfaction with ECT and its outcomes. The education of patients and families, content process, and research have been noted as areas to improve.

CONCLUSIONS

ECT is perceived as an effective intervention in LMICs, but use of unmodified ECT remains controversial. There is a need for the development and use of global guidelines to improve clinician training, knowledge sharing with patients and their families, and outcome research.

Preclinical models of treatment-resistant depression: challenges and perspectives

Treatment-resistant depression (TRD) is a subgroup of major depressive disorder in which the use of classical antidepressant treatments fails to achieve satisfactory treatment results. Although there are various definitions and grading models for TRD, common criteria for assessing TRD have still not been established. However, a common feature of any TRD model is the lack of response to at least two attempts at antidepressant pharmacotherapy. The causes of TRD are not known; nevertheless, it is estimated that even 60% of TRD patients are so-called pseudo-TRD patients, in which multiple biological factors, e.g., gender, age, and hormonal disturbances are concomitant with depression and involved in antidepressant drug resistance. Whereas the phenomenon of TRD is a complex disorder difficult to diagnose and successfully treat, the search for new treatment strategies is a significant challenge of modern pharmacology. It seems that despite the complexity of the TRD phenomenon, some useful animal models of TRD meet the construct, the face, and the predictive validity criteria. Based on the literature and our own experiences, we will discuss the utility of animals exposed to the stress paradigm (chronic mild stress, CMS), and the Wistar Kyoto rat strain representing an endogenous model of TRD. In this review, we will focus on reviewing research on existing and novel therapies for TRD, including ketamine, deep brain stimulation (DBS), and psychedelic drugs in the context of preclinical studies in representative animal models of TRD.

Putative role of glial cells in treatment resistance depression: An updated critical literation review and evaluation of single-nuclei transcriptomics data

AIMS

Major depressive disorder (MDD) is a prevalent global mental illness with diverse underlying causes. Despite the availability of first-line antidepressants, approximately 10-30 % of MDD patients do not respond to these medications, falling into the category of treatment-resistant depression (TRD). Our study aimed to elucidate the precise molecular mechanisms through which glial cells contribute to depression-like episodes in TRD.

MATERIALS AND METHODS

We conducted a comprehensive literature search using the PubMed and Scopus electronic databases with search terms carefully selected to be specific to our topic. We strictly followed inclusion and exclusion criteria during the article selection process, adhering to PRISMA guidelines. Additionally, we carried out an in-depth analysis of postmortem brain tissue obtained from patients with TRD using single-nucleus transcriptomics (sn-RNAseq).

KEY FINDINGS

Our data confirmed the involvement of multiple glia-specific markers (25 genes) associated with TRD. These differentially expressed genes (DEGs) primarily regulate cytokine signaling, and they are enriched in important pathways such as NFκB and TNF-α. Notably, DEGs showed significant interactions with the transcription factor CREB1. sn-RNAseq analysis confirmed dysregulation of nearly all designated DEGs; however, only Cx30/43, AQP4, S100β, and TNF-αR1 were significantly downregulated in oligodendrocytes (OLGs) of TRD patients. With further exploration, we identified the GLT-1 in OLGs as a hub gene involved in TRD.

SIGNIFICANCE

Our findings suggest that glial dysregulation may hinder the effectiveness of existing therapies for TRD. By targeting specific glial-based genes, we could develop novel interventions with minimal adverse side effects, providing new hope for TRD patients who currently experience limited benefits from invasive treatments.

Antidepressant effects of prolonged intermittent theta-burst stimulation monotherapy at the bilateral dorsomedial prefrontal cortex for medication and standard transcranial magnetic stimulation-resistant major depression: a three arm, randomized, double blind, sham-controlled pilot study

The dorsomedial prefrontal cortex (DMPFC) plays a pivotal role in depression and anxiosomatic symptom modulation. However, DMPFC stimulation using a double-cone coil has demonstrated inconsistent results for antidepressant efficacy. No study thus far has investigated the antidepressant and anti-anxiosomatic effects of prolonged intermittent theta-burst stimulation (piTBS) bilaterally over DMPFC. Furthermore, head-to-head comparisons of antidepressant effects between standard iTBS and piTBS warrant investigation. This double-blind, randomized, sham-controlled trial recruited 34 patients with highly treatment-resistant depression (TRD) unresponsive to antidepressants and standard repetitive transcranial magnetic stimulation (rTMS)/piTBS. These patients were randomly assigned to one of three monotherapy groups (standard iTBS, piTBS, or sham), with treatment administered bilaterally over the DMPFC twice per day for 3 weeks. The primary outcome was the overall changes of 17-item Hamilton Depression Rating Scale (HDRS-17) over 3-weeks intervention. The changes in Depression and Somatic Symptoms Scale (DSSS) as the secondary outcome and the anxiosomatic cluster symptoms as rated by HDRS-17 as the post-hoc outcome were measured. Multivariable generalized estimating equation analysis was performed. Although no differences in overall HDRS-17 changes between three groups were found, the antidepressant efficacy based on DSSS was higher in piTBS than in iTBS and sham at week 3 (group effect,p = 0.003, post-hoc: piTBS > iTBS, p = 0.002; piTBS > sham, p = 0.038). In post-hoc analyses, piTBS had more alleviation in anxiosomatic symptoms than iTBS (group effect, p = 0.002; post-hoc, p = 0.001). This first randomized sham-controlled study directly compared piTBS and iTBS targeting the DMPFC using a figure-of-8 coil and found piTBS may fail to demonstrate a significant antidepressant effect on overall depressive symptoms, but piTBS seems superior in alleviating anxiosomatic symptoms, even in depressed patients with high treatment resistance. This Trial registration (Registration number: NCT04037592). URL: https://clinicaltrials.gov/ct2/show/NCT04037592 .

Treatment-resistant depression: definition, prevalence, detection, management, and investigational interventions

Treatment-resistant depression (TRD) is common and associated with multiple serious public health implications. A consensus definition of TRD with demonstrated predictive utility in terms of clinical decision-making and health outcomes does not currently exist. Instead, a plethora of definitions have been proposed, which vary significantly in their conceptual framework. The absence of a consensus definition hampers precise estimates of the prevalence of TRD, and also belies efforts to identify risk factors, prevention opportunities, and effective interventions. In addition, it results in heterogeneity in clinical practice decision-making, adversely affecting quality of care. The US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have adopted the most used definition of TRD (i.e., inadequate response to a minimum of two antidepressants despite adequacy of the treatment trial and adherence to treatment). It is currently estimated that at least 30% of persons with depression meet this definition. A significant percentage of persons with TRD are actually pseudo-resistant (e.g., due to inadequacy of treatment trials or non-adherence to treatment). Although multiple sociodemographic, clinical, treatment and contextual factors are known to negatively moderate response in persons with depression, very few factors are regarded as predictive of non-response across multiple modalities of treatment. Intravenous ketamine and intranasal esketamine (co-administered with an antidepressant) are established as efficacious in the management of TRD. Some second-generation antipsychotics (e.g., aripiprazole, brexpiprazole, cariprazine, quetiapine XR) are proven effective as adjunctive treatments to antidepressants in partial responders, but only the olanzapine-fluoxetine combination has been studied in FDA-defined TRD. Repetitive transcranial magnetic stimulation (TMS) is established as effective and FDA-approved for individuals with TRD, with accelerated theta-burst TMS also recently showing efficacy. Electroconvulsive therapy is regarded as an effective acute and maintenance intervention in TRD, with preliminary evidence suggesting non-inferiority to acute intravenous ketamine. Evidence for extending antidepressant trial, medication switching and combining antidepressants is mixed. Manual-based psychotherapies are not established as efficacious on their own in TRD, but offer significant symptomatic relief when added to conventional antidepressants. Digital therapeutics are under study and represent a potential future clinical vista in this population.

Irremediability in psychiatric euthanasia: examining the objective standard

BACKGROUND

Irremediability is a key requirement for euthanasia and assisted suicide for psychiatric disorders (psychiatric EAS). Countries like the Netherlands and Belgium ask clinicians to assess irremediability in light of the patient's diagnosis and prognosis and 'according to current medical understanding'. Clarifying the relevance of a default objective standard for irremediability when applied to psychiatric EAS is crucial for solid policymaking. Yet so far, a thorough examination of this standard is lacking.

METHODS

Using treatment-resistant depression (TRD) as a test case, through a scoping review in PubMed, we analyzed the state-of-the-art evidence for whether clinicians can accurately predict individual long-term outcome and single out irremediable cases, by examining the following questions: (1) What is the definition of TRD; (2) What are group-level long-term outcomes of TRD; and (3) Can clinicians make accurate individual outcome predictions in TRD?

RESULTS

A uniform definition of TRD is lacking, with over 150 existing definitions, mostly focused on psychopharmacological research. Available yet limited studies about long-term outcomes indicate that a majority of patients with long-term TRD show significant improvement over time. Finally, evidence about individual predictions in TRD using precision medicine is growing, but methodological shortcomings and varying predictive accuracies pose important challenges for its implementation in clinical practice.

CONCLUSION

Our findings support the claim that, as per available evidence, clinicians cannot accurately predict long-term chances of recovery in a particular patient with TRD. This means that the objective standard for irremediability cannot be met, with implications for policy and practice of psychiatric EAS.

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.

Selective aryl hydrocarbon receptor modulators can act as antidepressants in obese female mice

BACKGROUND

Obese females are more likely to suffer from depression and are also more likely to be resistant to current medications. This study examined the potential antidepressant-like effects of 1,4-dihydroxy-2-napthoic acid (DHNA), a selective aryl hydrocarbon receptor modulator (SAhRM), in obese female mice.

METHODS

Obesity was established by feeding C57BL/6N female mice a high fat diet (HFD) for 9-10 weeks. Subsequently, mice were subjected to unpredictable chronic mild stress (UCMS) or remained unstressed. Daily administration of vehicle or 20 mg/kg DHNA began three weeks prior or on the third week of UCMS. Mice were examined for depression-like behaviors (sucrose preference, forced swim test (FST), splash and tape groom tests), anxiety (open-field test, light/dark test, novelty-induced hypophagia), and cognition (object location recognition, novel object recognition, Morris water maze).

RESULTS

UCMS did not alter, and DHNA slightly increased, weight gain in HFD-fed females. HFD decreased sucrose preference, increased FST immobility time, but did not alter splash and tape tests' grooming time. UCMS did not have additional effects on sucrose preference. UCMS further increased FST immobility time and decreased splash and tape tests' grooming time; these effects were prevented and reversed by DHNA treatment. HFD did not affect behaviors in the cognitive tests. UCMS impaired spatial learning; this effect was not prevented nor reversed by DHNA.

CONCLUSIONS

DHNA protected against UCMS-induced depression-like behaviors in HFD-fed female mice. DHNA neither improved nor worsened UCMS-induced impairment of spatial learning. Our findings indicate that DHNA has high potential to act as an antidepressant in obese females.

Effect of Ketamine on Sleep in Treatment-Resistant Depression: A Systematic Review

BACKGROUND

Depression is a debilitating disease with a high socioeconomic burden. Regular antidepressants usually require several weeks to ameliorate symptoms; however, numerous patients do not achieve remission. What is more, sleep disturbances are one of the most common residual symptoms. Ketamine is a novel antidepressant with rapid onset of action with a proven antisuicidal effect. Little is known about its impact on sleep-wake and circadian rhythm alterations. The aim of this systematic review is to research the impact ketamine has on sleep disturbances in depression.

METHODS

PubMed, Web of Science, and APA PsycINFO were searched for relevant studies on ketamine's impact on sleep disturbances in depression. Preferred Reporting Items for Systematic Reviews and Meta-Analyses PRISMA2020 methodology was applied. The systematic review protocol was registered in the PROSPERO Registry (CRD42023387897).

RESULTS

Five studies were included in this review. Two studies reported significant improvement in sleep measured by MADRS (Montgomery-Åsberg Depression Rating Scale) and QIDS-SR16 (Quick Inventory of Depressive Symptomatology Self-Report (16-item)) scales after intravenous ketamine and intranasal esketamine administration. One case report showed mitigation of symptoms in PSQI (Pittsburgh Sleep Quality Index) and ISI (Insomnia Severity Index) during 3-month treatment with esketamine. In two studies, sleep was objectively measured by nocturnal EEG (electroencephalography) and showed a decrease in nocturnal wakefulness accompanied by an increase in slow wave (SWS) and rapid eye movement (REM) sleep.

CONCLUSION

Ketamine reduces the severity of sleep insomnia in depression. Robust data are lacking. More research is needed.

Arketamine as adjunctive therapy for treatment-resistant depression: A placebo-controlled pilot study

BACKGROUND

Racemic ketamine is a mixture of (R)-ketamine (arketamine) and (S)-ketamine (esketamine), with the latter regarded as the main isomer for antidepressant effects. However, preclinical data and one open-label human trial suggest arketamine might exert a more potent and longer-lasting antidepressant effect with fewer side effects. We aimed to explore the feasibility of a randomized controlled trial of arketamine for treatment-resistant depression (TRD) and to assess its efficacy and safety compared to placebo.

METHODS

This is a, randomized, double-blind, crossover, pilot trial (n = 10). All participants received saline and arketamine (0.5 mg/kg) with a one-week interval. Treatment effects were analyzed with a linear mixed effects (LME) model.

RESULTS

Our analysis suggested the presence of a carryover effect, so the main efficacy analysis was limited to the first week, which demonstrated a main effect of time (p = 0.038) but not for treatment (p = 0.40) or their interaction (p = 0.95). This indicates that depression improved over time, but without significant difference between arketamine and placebo. Analyzing the two weeks together, findings were the same. Dissociation and other adverse events were minimal.

LIMITATIONS

This was a pilot study with a small sample and underpowered.

CONCLUSIONS

Arketamine was not superior to placebo for TRD but demonstrated to be extremely safe. Our findings reinforce the importance of continuing studies with this drug, with better powered clinical trials, perhaps considering a parallel design with higher or flexible doses and repeated administrations.

Association between impaired glucose metabolism and long-term prognosis at the time of diagnosis of depression: Impaired glucose metabolism as a promising biomarker proposed through a machine-learning approach

BACKGROUND

Predicting the course of depression is necessary for personalized treatment. Impaired glucose metabolism (IGM) was introduced as a promising depression biomarker, but no consensus was made. This study aimed to predict IGM at the time of depression diagnosis and examine the relationship between long-term prognosis and predicted results.

METHODS

Clinical data were extracted from four electronic health records in South Korea. The study population included patients with depression, and the outcome was IGM within 1 year. One database was used to develop the model using three algorithms. External validation was performed using the best algorithm across the three databases. The area under the curve (AUC) was calculated to determine the model's performance. Kaplan-Meier and Cox survival analyses of the risk of hospitalization for depression as the long-term outcome were performed. A meta-analysis of the long-term outcome was performed across the four databases.

RESULTS

A prediction model was developed using the data of 3,668 people, with an AUC of 0.781 with least absolute shrinkage and selection operator (LASSO) logistic regression. In the external validation, the AUCs were 0.643, 0.610, and 0.515. Through the predicted results, survival analysis and meta-analysis were performed; the hazard ratios of risk of hospitalization for depression in patients predicted to have IGM was 1.20 (95% confidence interval [CI] 1.02-1.41, p = 0.027) at a 3-year follow-up.

CONCLUSIONS

We developed prediction models for IGM occurrence within a year. The predicted results were related to the long-term prognosis of depression, presenting as a promising IGM biomarker related to the prognosis of depression.

Association of Treatment-Resistant Depression With Patient Outcomes and Health Care Resource Utilization in a Population-Wide Study

Importance

The totality of the societal and individual impact of treatment-resistant depression (TRD) is unknown, as is the potential to prognosticate TRD. The generalizability of many observational studies on TRD is limited.

Objective

To estimate the burden of TRD in a large population-wide cohort in an area with universal health care by including data from both health care types (psychiatric and nonpsychiatric) and, further, to develop a prognostic model for clinical use.

Design, Setting, and Participants

This cohort study, a population-based observational study, assessed data from the Stockholm MDD Cohort for episodes of major depressive disorder (MDD) between 2010 and 2017 that fulfilled predefined criteria for TRD (≥3 consecutive antidepressant treatments). Data analysis was performed from August 2020 to May 2022.

Main Outcomes and Measures

Outcomes were psychiatric and nonpsychiatric comorbid conditions, antidepressant treatments, health care resource utilization, lost workdays, all-cause mortality, and intentional self-harm and, in the prognostic model, TRD.

Results

A total of 158 169 unipolar MDD episodes (in 145 577 patients) were identified between January 1, 2012, and December 31, 2017 (64.7% women; median [IQR] age, 42 years [30-56]). Of these, 12 793 episodes (11%) fulfilled criteria for TRD. The median (IQR) time from the start of MDD episode to TRD was 552 days (294-932). Selective serotonin reuptake inhibitor was the most common class of antidepressant treatment in all treatment steps, and 5907 patients (46.2%) received psychotherapy at some point before initiation of the third pharmacological antidepressant treatment. Compared with matched non-TRD episodes, TRD episodes had more inpatient bed-days (mean, 3.9 days; 95% CI, 3.6-4.1, vs 1.3 days; 95% CI, 1.2-1.4) and more lost workdays (mean, 132.3 days; 95% CI, 129.5-135.1, vs 58.7 days; 95% CI, 56.8-60.6) 12 months after the index date. Anxiety, stress, sleep disorder, and substance use disorder were all more common comorbid conditions in TRD episodes. Intentional self-harm was more than 4 times more common in TRD episodes. The all-cause mortality rate for patients with MDD with TRD episodes was 10.7/1000 person-years at risk, compared with 8.7/1000 person-years at risk for patients with MDD without TRD episodes (hazard ratio, 1.23; 95% CI, 1.07-1.41). Median time from start of the first antidepressant treatment to start of the second, and from start of the second antidepressant treatment to start of the third, was 165 and 197 days, respectively. The severity of MDD, defined using the self-rating Montgomery-Åsberg Depression Rating Scale (MADRS-S) at time of MDD diagnosis, was found to be the most important prognostic factor for TRD (C index = 0.69).

Conclusions and Relevance

In this cohort study, TRD was a common variant of MDD when including patients from both health care types, which is associated with a high disease burden for both patients and society. The median time between initiation of new antidepressant treatments was longer than recommended in current treatment guidelines, suggesting room for more structured and timely depression care.

Comparison on the clinical features in patients with or without treatment-resistant depression: A National Survey on Symptomatology of Depression report

Patients with treatment-resistant depression (TRD) have fewer treatment options and worse prognoses than those without TRD. Although the etiology or pathophysiology of TRD remains unclear, certain clinical variables have been found to be related to its severity and prognosis. Therefore, 1151 patients with recurrent depression were recruited from the National Survey on Symptomatology of Depression (NSSD) and their depressive symptoms were assessed by using the doctor-rating assessment questionnaire. Then, the differences between patients with or without TRD were compared by parametric or nonparametric tests and the risk factors for TRD were explored by logistic regression. The results showed there were differences in clinical variables between patients with and without TRD. Additionally, we found depression with more somatic symptoms had a higher risk for TRD. Further analysis by stepwise logistic regression showed that age, gender, religious belief, drinking habit, the total course of depression, the number of hospitalizations, characteristics of seasonal episode remission, depressed mood, hypersexuality, emotionally incoherent psychotic symptoms, psychomotor agitation, respiratory system symptoms and history of suicide attempts were strongly associated with TRD. So, it is crucial for clinicians to identify these clinical features and adjust treatments timely.

Comparative efficacy of high-frequency repetitive transcranial magnetic stimulation to left dorsolateral prefrontal cortex as an augmentation strategy versus pharmacological augmentation in non-psychotic, unipolar, treatment-resistant depression: A randomized controlled trial

Background

Depression causes significant morbidity, disability and mortality, along with socioeconomic losses. Patients with depression who don't remit even with the second trial of anti-depressants need optimization, combination or augmentation strategies. Pharmacological strategies sometimes have unacceptable adverse effects.

Aim

The aim of this study is to compare the efficacy of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) to left dorsolateral prefrontal cortex (DLPFC) with that of pharmacological augmentation strategies in unipolar non-psychotic treatment-resistant depression.

Method

This is a randomized controlled trial.

Subjects

Cases of unipolar, non-psychotic, treatment-resistant depression between ages 20 and 60 years were taken.

Period of Study

The study period was from November 2016 to May 2018.

Randomization

Cases diagnosed as per ICD-10 criteria by a qualified psychiatrist. Cases of treatment-resistant depression (100) were divided into two arms by using a random number generator: rTMS arm and treatment as usual (TAU) arm.

Intervention

HF-rTMS to left DLPFC (rTMS group) and pharmacological augmentation with lithium, serotonin-dopamine antagonist, buspirone or thyroxine.

Results

In the rTMS arm, 44 patients and in TAU arm 41 completed the study. After 4 weeks of treatment augmentation, rTMS and TAU groups showed response rates of 52% and 46%, respectively. The difference between the two groups in terms of number of responders at the end of 4 weeks is not statistically significant. Additionally, factors associated with good response to rTMS were absence of a family history of psychiatric illness, no concomitant psychoactive substance use, being first episode of depression and mild-moderate severity of illness.

Conclusion

The study did not find rTMS augmentation to be significantly better than standard pharmacological augmentation therapies.

Beneficial effects of Silexan on co-occurring depressive symptoms in patients with subthreshold anxiety and anxiety disorders: randomized, placebo-controlled trials revisited

Silexan is a proprietary active substance produced from Lavandula angustifolia, with proven anxiolytic efficacy in subthreshold and generalized anxiety disorder as well as in mixed anxiety and depressive disorder with beneficial impact on anxiety-related sleep disturbances. The pharmacological profile and clinical observations suggest that Silexan may also have an antidepressant effect. To investigate the effect of Silexan on co-occurring depressive symptoms, we present a meta-analysis of the five placebo-controlled clinical trials hitherto performed with Silexan in subthreshold anxiety (n = 3) and anxiety disorders (n = 2). Patients of all trials received Silexan 1 × 80 mg/day or placebo for 10 weeks according to random assignment. Assessment of the antidepressant effect was based on item 'depressed mood' from the Hamilton Anxiety Rating Scale (HAMA) administered in all trials and on the total scores of the Montgomery Åsberg Depression Rating Scale (MADRS) or the Hamilton Depression Rating Scale (HAMD) used in three trials. After 10-week treatment, patients receiving Silexan showed significantly more pronounced score reduction for HAMA item 'depressed mood' than those in the placebo group (p = 0.01). Significant superiority of Silexan over placebo could also be shown for mean MADRS or HAMD total score reduction (three studies; p < 0.01). Silexan-treated patients with more severe depressive symptoms at baseline showed more pronounced improvements than those with milder symptoms. Our meta-analysis clearly shows that Silexan has a beneficial effect on co-occurring depressive symptoms in patients with subthreshold anxiety and anxiety disorders and may, hence, lead to important therapeutic implications for depressive disorders.

Treatment patterns and healthcare utilization of patients with treatment-resistant depression estimated using health insurance database: A population-based study from Taiwan

BACKGROUND

Determining the proportion of patients with treatment-resistant depression (TRD) among patients with unipolar depression receiving adequate pharmacological treatment (pharmaceutically treated depression [PTD]) is clinically important and may affect health care utilization. In Taiwan, these issues can be assessed by analyzing population-based data.

METHODS

The present study included data from the Taiwan National Health Insurance Research Database from 2010 to 2017. Among patients with depression, PTD was defined by the receipt of at least one adequate antidepressant treatment, and TRD was defined as receiving a third adequate antidepressant treatment after failure to respond to two prior treatments. Time of progression from PTD to TRD was estimated via the Kaplan-Meier function. A propensity-matched case-comparison cohort approach was used to compare resource utilization between patients with non-TRD PTD and TRD.

RESULTS

TRD was defined in 11.2 % of patients with unipolar depression and 37.1 % of PTD patients. The time of progression from PTD to TRD was approximately 1 year. Most TRD patients were women, middle-aged, and treated in general practice clinics. Antidepressant monotherapy, followed by antidepressant with augmentation, was the most common treatment strategy applied to TRD patients. Medical utilization was significantly higher in patients with TRD than those with non-TRD PTD across most aspects.

LIMITATIONS

TRD was defined based on pharmacological treatment patterns, as the reasons for changes in antidepressant regimens were not available.

CONCLUSION

Approximately one-third of patients with PTD developed TRD, often soon after receiving adequate pharmacological treatment. Patients with TRD used more medical resources than patients with non-TRD PTD.

Sex-dependent differences in the stress mitigating and antidepressant effects of selective aryl hydrocarbon receptor modulators

BACKGROUND

Our recent study demonstrated that selective aryl hydrocarbon receptor modulators (SAhRMs), such as 1,4-dihydroxy-2-napthoic acid (DHNA) act as antidepressants in female mice. Given that some effects of certain SAhRMs are known to also be mediated via estrogen receptor signaling, this study examined whether the effects of SAhRMs on mood, emotional state, and cognition are sex-dependent.

METHODS

C57BL/6N mice were fed with vehicle or 20 mg/kg DHNA for three weeks prior to four weeks of unpredictable chronic mild stress (UCMS). Mice were examined for depression-like behaviors (sucrose preference, forced swim test (FST), splash test, tape groom test), emotional state (open-field test, light/dark test, marble burying, novelty-induced hypophagia, elevated-plus maze), and cognition (object location recognition, novel object recognition, Morris water maze).

RESULTS

In females, UCMS decreased sucrose preference and increased FST immobility time; both effects were prevented by DHNA. In males, UCMS increased FST immobility time, and increased the latency to groom in the splash test. These effects were not mitigated by DHNA. However, in males, UCMS induced an increase in novelty-induced locomotion, an increase in the time spent in the light compartment in the L/D test, and an increase in the time spent with an object in a novel location. These effects were prevented by DHNA.

CONCLUSIONS

Our findings indicate that DHNA has high potential to act as antidepressants in females. However, given classical interpretation, DHNA did not appear to act as an antidepressant in males. Nonetheless, our findings indicate that DHNA can mitigate stress effects and reactivity in males.

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.

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

Treatment-resistant depression is a pleomorphic phenomenon occurring in 30% of patients with depression. The chance to achieve remission decreases with every subsequent episode. It constitutes a significant part of the global disease burden, causes increased morbidity and mortality, and is associated with poor quality of life. It involves multiple difficult-to-treat episodes, with increasing resistance over time. The concept of staging captures the process of changes causing increasing treatment resistance and global worsening of functioning in all areas of life. Ketamine is a novel rapid-acting antidepressant with neuroplastic potential. Here, we argue that ketamine use as an add-on treatment of resistant major depressive disorder, based on its unique pharmacological properties, can reverse this process, give hope to patients, and prevent therapeutic nihilism.

Venlafaxine XR treatment for older patients with major depressive disorder: decision trees for when to change treatment

BACKGROUND

Predictors of antidepressant response in older patients with major depressive disorder (MDD) need to be confirmed before they can guide treatment.

OBJECTIVE

To create decision trees for early identification of older patients with MDD who are unlikely to respond to 12 weeks of antidepressant treatment, we analysed data from 454 older participants treated with venlafaxine XR (150-300 mg/day) for up to 12 weeks in the Incomplete Response in Late-Life Depression: Getting to Remission study.

METHODS

We selected the earliest decision point when we could detect participants who had not yet responded (defined as >50% symptom improvement) but would do so after 12 weeks of treatment. Using receiver operating characteristic models, we created two decision trees to minimise either false identification of future responders (false positives) or false identification of future non-responders (false negatives). These decision trees integrated baseline characteristics and treatment response at the early decision point as predictors.

FINDING

We selected week 4 as the optimal early decision point. Both decision trees shared minimal symptom reduction at week 4, longer episode duration and not having responded to an antidepressant previously as predictors of non-response. Test negative predictive values of the leftmost terminal node of the two trees were 77.4% and 76.6%, respectively.

CONCLUSION

Our decision trees have the potential to guide treatment in older patients with MDD but they require to be validated in other larger samples.

CLINICAL IMPLICATIONS

Once confirmed, our findings may be used to guide changes in antidepressant treatment in older patients with poor early response.

Characteristics of the treatments for each severity of major depressive disorder: A real-world multi-site study

PURPOSE

In the treatment guidelines for major depressive disorder (MDD), the recommended treatment differs based on the severity. However, the type of treatment provided based on the severity of MDD in real-world clinical practice has not been investigated. In this study, we clarified the actual situation of MDD treatment in clinical practice and compared the treatment based on the severity of MDD.

METHODS

We used data from 1484 patients with MDD at discharge from October 2016 to March 2020.

RESULTS

The number of psychotropic prescriptions tended to be lower in those diagnosed with MDD in the severe group compared to in the non-severe group. There were significant differences among the three groups (mild, moderate/severe, and psychotic) in the percentage of patients who were not prescribed antipsychotics (p = 1.9 ×10^-6), a combination of antipsychotics and antidepressants (p = 5.0 ×10^-4), and the implementation rate of modified electroconvulsive therapy (m-ECT) (p = 3.4 ×10^-9). The percentage of patients with a severe diagnosis who underwent m-ECT was higher, which corresponded to the severity.

CONCLUSION

Our findings showed that the use of psychotropics decreased when the severity of MDD was diagnosed, and the rate of a combination of antipsychotics and antidepressants and the implementation rate of m-ECT increased with the severity. However, this study suggests that there is still an evidence-practice gap in the treatment of MDD in Japan, and guidelines are only partially adhered to in the treatment of depression.

3,3'-Diindolylmethane and 1,4-dihydroxy-2-naphthoic acid prevent chronic mild stress induced depressive-like behaviors in female mice

BACKGROUND

Current pharmaceutical treatments for depression are sometimes ineffective and may have unwanted side effects that interfere with patient compliance. This study examined the potential antidepressant-like effects of dietary- and microbial-derived aryl hydrocarbon receptor (AhR) ligands, 3,3'-diindolylmethane (DIM) and 1,4-dihydroxy-2-naphthoic acid (1,4-DHNA).

METHODS

Female C57BL/6 mice were subjected to unpredictable chronic mild stress (UCMS) or were unstressed. For three weeks prior to UCMS mice were fed daily with vehicle or 20 mg/kg DIM, 1,4-DHNA or AhR-inactive isomer 3,7-DHNA; another group was subjected to two weeks UCMS before ligand administration began. Mice were examined for anhedonia-like behavior as measured by the sucrose preference test. Additionally, anxiety levels of the mice were examined before UCMS and ligand administration began and at the end in the open field, light/dark, elevated plus maze, novelty-induced hypophagia, and marble burying tests. At the end of the experiment they were also examined in the Morris water maze (MWM) task.

RESULTS

Both DIM and 1,4-DHNA, but not 3,7-DHNA, successfully prevented and reversed UCMS-induced anhedonia-like behavior. Furthermore, both DIM and DHNA had little to no effect on anxiety levels and did not induce spatial learning deficits.

LIMITATIONS

Additional studies are required to determine to what degree the antidepressant-like effects of DIM and 1,4-DHNA can be attributed to their activities as AhR ligands.

CONCLUSIONS

Our findings indicate that dietary and microbial-derived AhR ligands may have clinical applications as potential antidepressants. Future studies are necessary to elucidate the role of AhR in depression-like states and the underlying mechanisms of action.

Courses of treatment and risk factors for treatment-resistant depression in Finnish primary and special healthcare: A nationwide cohort study

OBJECTIVE

Investigate incidence, risk factors and courses of treatment for treatment-resistant depression (TRD) in primary and special healthcare.

METHODS

All patients identified from nationwide registers, aged 16-65 years, diagnosed with depression in Finland during 2004-2016 were included. New antidepressant users were identified with six-month washout period and followed-up for two years to observe for presence of TRD, which was defined as initiation of a third trial after having failed two pharmacological treatment trials with adequate duration.

RESULTS

During follow-up, 177,144 persons had their first registered antidepressant treated depression (mean age: 39.5, 62.5% women). Of them, 10.9% (N = 19,322) met TRD criteria. Among the TRD patients, most common first and second antidepressants trials were: SSRIs (44.6%), mirtazapine (19.0%) and SNRIs (16.5%). As the third treatment line, antidepressant monotherapy (44.2% of TRD patients) was most common, followed by a combination of ≥2 antidepressants (32.1%), antipsychotic or mood stabilizer augmentation and an antidepressant (15.8%), both combination of antidepressants and an augmentation with a mood stabilizer or antipsychotic (4.9%), antipsychotic or mood stabilizer monotherapy (2.7%) and ECT (0.3%). Of TRD patients, 16.5% (N = 3188) progressed to the fifth treatment line, in which the most common treatments were antidepressant monotherapy (33.4%), antidepressant combinations (27.5%) and augmentation (24.2%). Factors associated with higher risk of TRD included male gender, younger age, higher initial disease severity and hospitalization at initial onset of depression.

CONCLUSIONS

Antidepressant monotherapies were still the most common fifth line of depression treatment. Severe depression, hospitalization due to depression, young age and male gender may predispose to TRD.

Resting-state functional connectivity correlates of anxiety co-morbidity in major depressive disorder

Major depressive disorder (MDD) is frequently co-morbid with anxiety disorders. The co-morbid state has poorer functional outcomes and greater resistance to first line treatments, highlighting the need for novel treatment targets. This systematic review examined differences in resting-state brain connectivity associated with anxiety comorbidity in young- and middle-aged adults with MDD, with the aim of identifying novel targets for neuromodulation treatments, as these treatments are thought to work partly by altering dysfunctional connectivity pathways. Twenty-one studies met inclusion criteria, including a total of 1292 people with MDD. Only two studies included people with MDD and formally diagnosed co-morbid anxiety disorders; the remainder included people with MDD with dimensional anxiety measurement. The quality of most studies was judged as fair. Results were heterogeneous, partly due to a focus on a small set of connectivity relationships within individual studies. There was evidence for dysconnectivity between the amygdala and other brain networks in co-morbid anxiety, and an indication that abnormalities of default mode network connectivity may play an underappreciated role in this condition.

Suicidal ideation and ECT, ECT and suicidal ideation: A register study

OBJECTIVE

Although electroconvulsive therapy (ECT) is anti-suicidal, it is not known whether the presence of suicidal ideation (SI) at baseline predicts response and remission after ECT. The aim of the study was to analyze the impact of baseline SI on response and remission following ECT treatment in a large sample of patients with depression and to assess SI before and after ECT.

METHODS

This population-based register study used data from the Swedish National Quality Register for ECT and the Swedish Patient Register. Patients aged 18 years or older who had received ECT for a unipolar or bipolar depressive episode between 2011 and 2018 were included in the study. SI was defined as a score of ≥4 on the last item of the Montgomery-Åsberg Depression Rating Scale - Self Assessment (MADRS-S). Using a logistic regression model, SI at baseline was used to predict response and remission following ECT, while controlling for depression severity, psychotic symptoms, presence of a comorbid personality disorder, age, sex, electrode position, unipolar or bipolar disorder, and number of previous suicide attempts at baseline.

RESULTS

In patients who exhibited SI at baseline, 53.7% (N = 632) of cases showed a response to ECT, whereas 68.4% (N = 690) of patients without SI showed a response. In addition, 27.2% (N = 320) of cases with SI achieved remission, whereas 48.5% (N = 489) of cases without SI achieved remission. The odds of achieving response and remission for patients with SI were 0.75 and 0.58 times, respectively, those for patients without SI. Of the 1178 patients with pre-treatment SI, 75.64% (N = 891) exhibited no SI at the end of treatment. Moreover, in this subgroup, the presence of a personality disorder, higher MADRS-S-score, and younger age were associated with persistent SI.

CONCLUSION

The presence of SI was associated with lower ECT response and remission rates. Nevertheless, depressive symptoms and SI were reduced in a large proportion of patients across both patient groups. Clinicians should be aware of the lower likelihood of achieving a successful outcome following ECT in younger patients who present with a non-psychotic depressive episode, SI, and (suspected) personality disorders. More research is warranted regarding if these patients can achieve similar or better results with other treatments.

The efficacy and safety of adjunctive intranasal esketamine treatment in major depressive disorder: a systematic review and meta-analysis

INTRODUCTION

Intranasal (IN) esketamine represents an innovative treatment for individuals with treatment resistant depression and depression with suicidal ideation and behavior. Herein, we synthesize extant long-term studies (≥ 4 weeks) regarding this treatment.

RESEARCH DESIGN AND METHODS

The interventional studies of IN esketamine in patients with depression having a study period of at least four weeks were included for our synthesis. A meta-analysis was undertaken for the efficacy and safety parameters of adjunctive IN esketamine vs IN placebo with an oral antidepressant. The data excluded from meta-analysis were synthesized narratively.

RESULTS

After pooling data from seven randomized controlled trials, treatment with adjunctive IN esketamine vs IN placebo was safe overall, and more effective at decreasing depressive symptoms (d = -0.239; 95%CI = -0.335,-0.142;p < 0.0001), with higher response (RR = 1.221; 95% CI = 1.055,1.428; p = 0.017) and remission (RR = 1.366; 95% CI = 1.182,1.578; p < 0.0001) rates. The year-long trials showed that treatment with adjunctive IN esketamine led to lower relapse rates with no considerable long-term side effects.

CONCLUSION

Intranasal esketamine was demonstrated to be safe, well tolerated, and rapidly effective in individuals with treatment resistant depression, suicidal ideation, and suicidal behavior.

Initiating Antidepressant Medication: What is the Most Important Factor?

Treatment initiation is arguably the most important step in the management of depression. It is important at this stage of treatment to establish a therapeutic partnership between physician and patient, to facilitate shared decision-making. With specific regard to pharmacotherapy, negative attitudes and beliefs about antidepressant medications are common among the general public, and these can impact on how physicians who prescribe antidepressant medication are viewed. Some of these beliefs are that antidepressants are addictive, and that they change an individual's personality. Before initiating treatment, it is important for physicians to understand the patient's attitudes towards treatment, as well as their goals for treatment, especially since the patient's goals may not be the same as the physician's. Physicians can also identify patients who may be at risk of treatment resistance-those with more severe symptoms, at risk of suicide, with higher number of lifetime depressive episodes and comorbid anxiety disorder-and to differentiate treatment resistance from overlapping comorbidities. Patients need to understand that depression results from an interaction between biological and environmental factors; the use of analogies with other diseases, such as hypertension and/or a broken leg, can help in this regard. Finally, patients can be reassured that antidepressant medication is effective, and the range of agents currently available today target multiple pathways. While monotherapy is the goal, some patients will require additional treatments to manage comorbid psychiatric conditions (e.g. anxiety) or to achieve complete remission of depression. Only through complete remission of symptoms do patients achieve a level of psychosocial functioning that is equivalent to the non-depressed population. By explaining these factors to the patient, and listening to the patient's beliefs, fears and goals, physicians can forge an effective therapeutic partnership for shared decision-making and maximise the chances of success from the time of treatment initiation.

Clinical and Biological Factors Are Associated with Treatment-Resistant Depression

Background: Treatment-resistant depression (TRD) is a debilitating condition associated with unmet clinical needs. Few studies have explored clinical characteristics and serum biomarkers associated with TRD. Aims: We investigated whether there were differences in clinical and biochemical variables between patients affected by TRD than those without. Methods: We recruited 343 patients (165 males and 178 females) consecutively hospitalized for MDD to the inpatient clinics affiliated to the Fondazione IRCCS Policlinico, Milan, Italy (n = 234), and ASST Monza, Italy (n = 109). Data were obtained through a screening of the clinical charts and blood analyses conducted during the hospitalization. Results: TRD versus non-TRD patients resulted to be older (p = 0.001), to have a longer duration of illness (p < 0.001), to be more currently treated with a psychiatric poly-therapy (p < 0.001), to have currently more severe depressive symptoms as showed by the Hamilton Depression Rating Scale (HAM-D) scores (p = 0.016), to have lower bilirubin plasma levels (p < 0.001). In addition, more lifetime suicide attempts (p = 0.035), more antidepressant treatments before the current episode (p < 0.001), and a lower neutrophil to lymphocyte ratio at borderline statistically significant level (p = 0.060) were all associated with the TRD group. Conclusion: We identified candidate biomarkers associated with TRD such as bilirubin plasma levels and NLR, to be confirmed by further studies. Moreover, TRD seems to be associated with unfavorable clinical factors such as a predisposition to suicidal behaviors. Future research should replicate these results to provide robust data in support of the identification of new targets of treatment and implementation of prevention strategies for TRD.

Treatment-Resistant Depression in Portugal: Perspective From Psychiatry Experts

Guidance about treatment-resistant depression (TRD) in Portugal is very limited, even though depression prevalence is among the highest in European countries. A questionnaire was conducted, followed by two advisory boards with seven Portuguese psychiatry experts, to characterize and discuss MDD and TRD epidemiology, diagnosis, patient journey, treatment options, and unmet clinical needs. Consensus was reached on the main issues. In daily practice, TRD can be defined as moderate to severe MDD episodes with insufficient clinical improvement after two antidepressant treatments, taken in adequate doses and duration. TRD diagnosis and treatment are mostly decided by psychiatrists at public hospitals. Treatment type and duration must be adjusted to characteristics of the patient and the depressive episode, including symptoms, number of previous episodes, comorbidities, and previous treatment response and side effects. The most relevant objectives of TRD treatment are reaching response and remission, prevention of suicide, and improvement of quality of life, functionality, and wellbeing. Regarding pharmacotherapy, antidepressant switch occurs more frequently with non-response, while optimization, combination, and augmentation are considered for patients with partial response. Psychotherapy should be considered in parallel to pharmacological treatment. Brain stimulation techniques are underused. Lifelong treatment is required for recurrent or more chronic TRD episodes, but patient adherence is also poorer in these cases. In Portugal, TRD management is limited by lack of access to specialist care and to many treatment options. These aspects highlight that conventional pharmacotherapy does not lead to remission in many patients and that optimization strategies are frequently necessary to achieve satisfactory treatment outcomes.

Pregabalin augmentation of antidepressants in major depression - results from a European multicenter study

BACKGROUND

We aimed to investigate the prescription pattern of pregabalin augmentation of antidepressants in major depressive disorder (MDD) and to explore variables associated with add-on pregabalin treatment.

METHODS

1410 MDD patients participated in this naturalistic European multicenter study with retrospective assessment of treatment response. Analyses of covariance, chi-squared tests, and binary logistic regressions were accomplished to determine differences in socio-demographic and clinical characteristics between MDD patients with and without pregabalin augmentation.

RESULTS

Add-on pregabalin was established in 102 (7.23%) MDD patients. Compared to those without receiving pregabalin, pregabalin-treated patients were characterized by a significantly higher likelihood for older age (mean: 54.74 ± 13.08 vs 49.93 ± 14.13 years), unemployment (78.43% vs 51.23%), melancholic features (83.33% vs 58.94%), inpatient treatment (72.55% vs 31.65%), previous psychiatric hospitalizations (13.52 ± 24.82 vs 4.96 ± 19.93 weeks), any somatic comorbidity (68.63% vs 44.57%), comorbid hypertension (37.25% vs 17.51%), more severe depressive symptom severity at the onset of the current episode (mean MADRS: 37.55 ± 9.00 vs 33.79 ± 7.52), receiving augmentation/combination treatment strategies in general (mean number of psychotropic drugs: 3.64 ± 0.92 vs 2.07 ± 1.17), and with antidepressants (50.00% vs 27.91%) and antipsychotics (46.08% vs 24.08%) in particular.

LIMITATIONS

Due to its observational cross-sectional study design, our patient sample might not be fully representative for MDD patients in primary care settings.

CONCLUSIONS

Our findings suggest that add-on pregabalin is particularly administered in more severe/difficult-to-treat MDD conditions, whereas no association between the prescription of adjunctive pregabalin and comorbid anxiety symptoms could be determined.

Novel drug developmental strategies for treatment-resistant depression

Major depressive disorder is a leading cause of disability worldwide. Because conventional therapies are ineffective in many patients, novel strategies are needed to overcome treatment‐resistant depression (TRD). Limiting factors of successful drug development in the last decades were the lack of (1) knowledge of pathophysiology, (2) translational animal models and (3) objective diagnostic biomarkers. Here, we review novel drug targets and drug candidates currently investigated in Phase I–III clinical trials. The most promising approaches are inhibition of glutamatergic neurotransmission by NMDA and mGlu₅ receptor antagonists, modulation of the opioidergic system by κ receptor antagonists, and hallucinogenic tryptamine derivates. The only registered drug for TRD is the NMDA receptor antagonist, S‐ketamine, but add‐on therapies with second‐generation antipsychotics, certain nutritive, anti‐inflammatory and neuroprotective agents seem to be effective. Currently, there is an intense research focus on large‐scale, high‐throughput omics and neuroimaging studies. These results might provide new insights into molecular mechanisms and potential novel therapeutic strategies.

Characterising the severity of treatment resistance in unipolar and bipolar depression

Background

Treatment-resistant depression (TRD) is classically defined according to the number of suboptimal antidepressant responses experienced, but multidimensional assessments of TRD are emerging and may confer some advantages. Patient characteristics have been identified as risk factors for TRD but may also be associated with TRD severity. The identification of individuals at risk of severe TRD would support appropriate prioritisation of intensive and specialist treatments.

Aims

To determine whether TRD risk factors are associated with TRD severity when assessed multidimensionally using the Maudsley Staging Method (MSM), and univariately as the number of antidepressant non-responses, across three cohorts of individuals with depression.

Method

Three cohorts of individuals without significant TRD, with established TRD and with severe TRD, were assessed (n = 528). Preselected characteristics were included in linear regressions to determine their association with each outcome.

Results

Participants with more severe TRD according to the MSM had a lower age at onset, fewer depressive episodes and more physical comorbidities. These associations were not consistent across cohorts. The number of episodes was associated with the number of antidepressant treatment failures, but the direction of association varied across the cohorts studied.

Conclusions

Several risk factors for TRD were associated with the severity of resistance according to the MSM. Fewer were associated with the raw number of inadequate antidepressant responses. Multidimensional definitions may be more useful for identifying patients at risk of severe TRD. The inconsistency of associations across cohorts has potential implications for the characterisation of TRD.

CYP2C19 polymorphisms are associated with severity of depression at initial evaluation and after the treatment independently of the prescribed medications: 4 weeks prospective study

BACKGROUND

The cytochrome P-450 2C19 (CYP2C19) enzyme is involved in the metabolism of numerous antidepressants. It also metabolises some endogenous substrates, which could also confer to vulnerability. We aimed to establish whether the severity of depression and treatment response are associated with the genetically predicted CYP2C19 phenotype.

METHODS

We assessed the CYP2C19 genotype-predicted metabolic phenotypes (normal, intermediate or ultrarapid, there were no poor metabolisers) in patients with moderate or severe depression. We used the self-rated Beck Depression Inventory-II (BDI-II) scale and the clinician-rated Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline, after 2 and 4 weeks of an empirical treatment trial. Patients and clinicians were blind to the genetic testing results.

RESULTS

Seventy-six patients participated in the present study. At baseline, impaired CYP2C19 metabolisers, compared to normal metabolisers, had higher BDI-II (P = 0.046; ηp2 = 0.08) but not MADRS score. Intermediate metabolisers more often had a diagnosis of severe depression than normal metabolisers (P = 0.003). After 4 weeks of empirical treatment, intermediate metabolisers had significantly higher MADRS and BDI-II scores than normal metabolisers (P = 0.006; ηp2  = 0.131 and P = 0.030; ηp2 = 0.091). These differences were independent of the use of CYP2C19-metabolised medications in the treatment trial, as well as the treatment discrepancy status.

CONCLUSIONS

Intermediate CYP2C19 polymorphism-predicted activity was associated with more severe depression after an empirical treatment trial. The lack of association between the prescription of CYP2C19-metabolised drugs and treatment response calls for a further look into the role of endogenous substrates of CYP2C19.

Association between the expression of lncRNA BASP-AS1 and volume of right hippocampal tail moderated by episode duration in major depressive disorder: a CAN-BIND 1 report

The pathophysiology of major depressive disorder (MDD) encompasses an array of changes at molecular and neurobiological levels. As chronic stress promotes neurotoxicity there are alterations in the expression of genes and gene-regulatory molecules. The hippocampus is particularly sensitive to the effects of stress and its posterior volumes can deliver clinically valuable information about the outcomes of antidepressant treatment. In the present work, we analyzed individuals with MDD (N = 201) and healthy controls (HC = 104), as part of the CAN-BIND-1 study. We used magnetic resonance imaging (MRI) to measure hippocampal volumes, evaluated gene expression with RNA sequencing, and assessed DNA methylation with the (Infinium MethylationEpic Beadchip), in order to investigate the association between hippocampal volume and both RNA expression and DNA methylation. We identified 60 RNAs which were differentially expressed between groups. Of these, 21 displayed differential methylation, and seven displayed a correlation between methylation and expression. We found a negative association between expression of Brain Abundant Membrane Attached Signal Protein 1 antisense 1 RNA (BASP1-AS1) and right hippocampal tail volume in the MDD group (β = -0.218, p = 0.021). There was a moderating effect of the duration of the current episode on the association between the expression of BASP1-AS1 and right hippocampal tail volume in the MDD group (β = -0.48, 95% C.I. [-0.80, -0.16]. t = -2.95 p = 0.004). In conclusion, we found that overexpression of BASP1-AS1 was correlated with DNA methylation, and was negatively associated with right tail hippocampal volume in MDD.

Risk Factors for Suicide and Suicide Attempts Among Patients With Treatment-Resistant Depression: Nested Case-Control Study

The risk of suicide is elevated among patients with treatment-resistant depression (TRD). Risk factors for suicide and suicide attempts among cases and controls with TRD were investigated using data from nationwide Swedish registers. Among 119,407 antidepressant initiators with a diagnosis of depression, 15,631 patients who started a third sequential treatment trial during the same depressive episode were classified with TRD. A nested case-control study compared cases with suicide and suicide attempts with up to three closely matched controls. Sociodemographic and clinical risk factors were assessed using conditional logistic regression analyses. In all, 178 patients died by suicide and 1,242 experienced a suicide attempt during follow-up. History of suicide attempts, especially if <1 year after the attempt, was a significant independent risk factor for suicide (adjusted odds ratio [aOR], 8.9; 95% confidence interval [CI], 5.1-15.7) as were 10 to 12 years of education compared to lower education (aOR, 1.69; 95% CI, 1.02-2.81). For attempted suicide, the strongest independent risk factors were history of suicide attempts (<1 year aOR, 5.1; 95% CI, 4.0-6.5), substance abuse (aOR, 2.6; 95% CI, 2.2-3.1), personality disorders (aOR, 1.9; 95% CI, 1.5-2.3), and somatic comorbidity (aOR, 2.0; 95% CI, 1.04-3.9). Suicide attempts, especially if recent, are strong risk factors for completed suicide among patients with TRD. Established risk factors for suicide attempts were confirmed for patients with TRD.