Defining treatment-resistant depression

The role of KCNQ channel activators in management of major depressive disorder

Depression, a complex disorder with significant treatment challenges, necessitates innovative therapeutic approaches to address its multifaceted nature and enhance treatment outcomes. The modulation of KCNQ potassium (K+) channels, pivotal regulators of neuronal excitability and neurotransmitter release, is a promising innovative therapeutic target in psychiatry. Widely expressed across various tissues, including the nervous and cardiovascular systems, KCNQ channels play a crucial role in modulating membrane potential and regulating neuronal activity. Recent preclinical evidence suggests that KCNQ channels, particularly KCNQ3, contribute to the regulation of neuronal excitability within the reward circuitry, offering a potential target for alleviating depressive symptoms, notably anhedonia. Studies using animal models demonstrate that interventions targeting KCNQ channels can restore dopaminergic firing balance and mitigate depressive symptoms. Human studies investigating the effects of KCNQ channel activators, such as ezogabine, have shown promising results in alleviating depressive symptoms and anhedonia. The aforementioned observations underscore the therapeutic potential of KCNQ channel modulation in depression management and highlight the need and justification for phase 2 and phase 3 dose-finding studies as well as studies prespecifying symptomatic targets in depression including anhedonia.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The complexity of treatment-resistant depression: A data-driven approach

BACKGROUND

Recent systematic reviews highlight great variability in defining and assessing treatment-resistant depression (TRD). A key problem is that definitions are consensus rather than data-led. This study seeks to offer a comprehensive socio-demographic and clinical description of a relevant sample.

METHODS

As part of a pragmatic randomized controlled trial, patients (N = 129) were managed in primary care for persistent depression and diagnosed with TRD. Data included previous treatment attempts, characteristics of the depressive illness, functioning, quality of life, co-occurring problems including suicidality, psychiatric and personality disorders, physical health conditions, and adverse events.

RESULTS

Findings show a severe and chronic course of depression with a duration of illness of 25+ years. Overall, 82.9 % had at least one other psychiatric diagnosis and 82.2 % at least one personality disorder; 69.8 % had significant musculoskeletal, gastrointestinal, genitourinary, or cardiovascular and respiratory physical health problems. All but 14 had severe difficulties in social and occupational functioning and reported severely impaired quality of life. Suicidal ideation was high: 44.9 % had made at least one serious suicide attempt and several reported multiple attempts with 17.8 % reporting a suicide attempt during childhood or adolescence. Of the patients, 79.8 % reported at least one adverse childhood experience.

LIMITATIONS

Potential for recall bias, not examining possible interactions, and absence of a control group.

CONCLUSIONS

Our findings reveal a complex and multifaceted condition and call for an urgent reconceptualization of TRD, which encompasses many interdependent variables and experiences. Individuals with TRD may be at a serious disadvantage in terms of receiving adequate treatment.

Treatment resistant late-life depression: A narrative review of psychosocial risk factors, non-pharmacological interventions, and the role of clinical phenotyping

BACKGROUND

Treatment resistant depression (TRD) is a subset of major depressive disorder (MDD) in which symptoms do not respond to front line therapies. In older adults, the assessment and treatment of TRD is complicated by psychosocial risk factors unique to this population, as well as a relative paucity of research.

METHODS

Narrative review aimed at (1) defining TRLLD for clinical practice and research; (2) describing psychosocial risk factors; (3) reviewing psychological and non-pharmacological treatments; (4) discussing the role of clinical phenotyping for personalized treatment; and (5) outlining research priorities.

RESULTS

Our definition of TRLLD centers on response to medication and neuromodulation in primary depressive disorders. Psychosocial risk factors include trauma and early life adversity, chronic physical illness, social isolation, personality, and barriers to care. Promising non-pharmacological treatments include cognitive training, psychotherapy, and lifestyle interventions. The utility of clinical phenotyping is highlighted by studies examining the impact of comorbidities, symptom dimensions (e.g., apathy), and structural/functional brain changes.

LIMITATIONS

There is a relative paucity of TRLLD research. This limits the scope of empirical data from which to derive reliable patterns and complicates efforts to evaluate the literature quantitatively.

CONCLUSIONS

TRLLD is a complex disorder that demands further investigation given our aging population. While this review highlights the promising breadth of TRLLD research to date, more research is needed to help elucidate, for example, the optimal timing for implementing risk mitigation strategies, the value of collaborative care approaches, specific treatment components associated with more robust response, and phenotyping to help inform treatment decisions.

Sociodemographic predictors of the association between self-reported sleep duration and depression

A growing interest has been recently reported in exploring sleep duration within psychology context in particular to its relation to some mental chronic diseases such as depression. The aim of this study is to investigate the association between self-reported sleep hours as an outcome and self-perceived depression among Emirati adults, after adjusting for sociodemographic factors such as age, gender, marital status, and employment status. We performed a cross-sectional analysis using 11,455 participants baseline data of the UAE Healthy Future Study (UAEHFS). Univariate and multivariate logistic regression models were performed with self-reported sleep hours as an outcome. The predictors were the self-reported depression by measuring the PHQ-8 score, sociodemographic factors (age, gender, marital status, and employment status) Odds ratios with 95% confidence intervals (CI) were reported. In a sensitivity analysis, a multivariate imputation by chained equations (MICE) procedure was applied with classification and Regression Trees (CART) to impute missing values. Overall, 11,455 participants were included in the final analysis of this study. Participants' median age was 32.0 years (Interquartile-Range: 24.0, 39.0). There were 6,217 (54.3%) males included in this study. In total, 4,488 (63.6%) of the participants reported sleep duration of more than 7 hours. Statistically significant negative association was observed between the total PHQ-8 score as a measure for depression and binarized self-reported sleep, OR = 0.961 (95% CI: 0.948, 0.974). For one unit increase in age and BMI, the odds ratio of reporting shorter sleep was 0.979 (95% CI: 0.969, 0.990) and 0.987 (95% CI: 0.977, 0.998), respectively. The study findings indicate a correlation between self-reported depression and an increased probability of individuals reporting shorter self-perceived sleep durations especially when considering the sociodemographic factors as predictors. There was a variation in the effect of depression on sleep duration among different study groups. In particular, the association between reported sleep duration and reported depression, students and unemployed individuals have reported longer sleep hours as compared to employed participants. Also, married individuals reported a higher percentage of longer sleep duration as compared to single and unmarried ones when examined reported depression as a predictor to sleep duration. However, there was no gender differences in self-perceived sleep duration when associated with reported depression.

Psilocybin for dementia prevention? The potential role of psilocybin to alter mechanisms associated with major depression and neurodegenerative diseases

Major depression is an established risk factor for subsequent dementia, and depression in late life may also represent a prodromal state of dementia. Considering current challenges in the clinical development of disease modifying therapies for dementia, the focus of research is shifting towards prevention and modification of risk factors to alter the neurodegenerative disease trajectory. Understanding mechanistic commonalities underlying affective symptoms and cognitive decline may reveal biomarkers to aid early identification of those at risk of progressing to dementia during the preclinical phase of disease, thus allowing for timely intervention. Adult hippocampal neurogenesis (AHN) is a phenomenon that describes the birth of new neurons in the dentate gyrus throughout life and it is associated with spatial learning, memory and mood regulation. Microglia are innate immune system macrophages in the central nervous system that carefully regulate AHN via multiple mechanisms. Disruption in AHN is associated with both dementia and major depression and microgliosis is a hallmark of several neurodegenerative diseases. Emerging evidence suggests that psychedelics promote neuroplasticity, including neurogenesis, and may also be immunomodulatory. In this context, psilocybin, a serotonergic agonist with rapid-acting antidepressant properties has the potential to ameliorate intersecting pathophysiological processes relevant for both major depression and neurodegenerative diseases. In this narrative review, we focus on the evidence base for the effects of psilocybin on adult hippocampal neurogenesis and microglial form and function; which may suggest that psilocybin has the potential to modulate multiple mechanisms of action, and may have implications in altering the progression from major depression to dementia in those at risk.

Pain-Insomnia-Depression Syndrome: Triangular Relationships, Pathobiological Correlations, Current Treatment Modalities, and Future Direction

Pain-insomnia-depression syndrome (PIDS) is a complex triad of chronic pain, insomnia, and depression that has profound effects on an individual's quality of life and mental health. The pathobiological context of PIDS involves complex neurobiological and physiological mechanisms, including alterations in neurotransmitter systems and impaired pain processing pathways. The first-line therapeutic approaches for the treatment of chronic pain, depression, and insomnia are a combination of pharmacological and non-pharmacological therapies. In cases where patients do not respond adequately to these treatments, additional interventions such as deep brain stimulation (DBS) may be required. Despite advances in understanding and treatment, there are still gaps in knowledge that need to be addressed. To improve our understanding, future research should focus on conducting longitudinal studies to uncover temporal associations, identify biomarkers and genetic markers associated with PIDS, examine the influence of psychosocial factors on treatment responses, and develop innovative interventions that address the complex nature of PIDS. The aim of this study is to provide a comprehensive overview of these components and to discuss their underlying pathobiological relationships.

Dialectical Behavior Therapy as an intervention for Treatment Resistant Depression in adults: A protocol for systematic review and meta-analysis

BACKGROUND

Major Depressive Disorder is a long-term, recurring, and very common illness that is associated with a significant decline in functional ability. The gold-standard method of treating depression is pharmacotherapy, which involves the use of antidepressant medications either alone or in various combinations. However, approximately 30% of Major Depressive Disorder patients suffer from Treatment Resistant Depression, a more severe condition that has a profound impact on patients' lives. Our study aims to conduct the first comprehensive review and meta-analysis to assess the effectiveness and safety of adding Dialectical Behavior Therapy to antidepressant medications compared to groups using pharmacotherapy alone as an intervention for adults with Treatment Resistant Depression.

MATERIALS AND METHODS

We will search for publications in the following databases: Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Lilacs, Web of Science, and PsycINFO. We will manually review the reference lists of the included studies to identify potentially relevant studies. There will be no restrictions on the language or publication date. Quality assessment of the included studies will be performed independently according to the Cochrane Risk of Bias instrument. To assess the certainty of the findings' body of evidence, we will use the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. This study aims to determine the effectiveness and safety of Dialectical Behavior Therapy as an intervention for Treatment Resistant Depression in adults.

ETHICS AND DISSEMINATION

Ethical approval was not required as individual patient data was not obtained. Our intention is to publish the systematic review in a medical journal that offers open access upon completion of the process.

TRIAL REGISTRATION

PROSPERO registration number CRD42023406301. Registered on March 24, 2023.

Use of transcranial magnetic stimulation (TMS) for studying cognitive control in depressed patients: A systematic review

Major depressive disorder (MDD) is a debilitating mental disorder and the leading cause of disease burden. Major depressive disorder is associated with emotional impairment and cognitive deficit. Cognitive control, which is the ability to use perceptions, knowledge, and information about goals and motivations to shape the selection of goal-directed actions or thoughts, is a primary function of the prefrontal cortex (PFC). Psychotropic medications are one of the main treatments for MDD, but they are not effective for all patients. An alternative treatment is transcranial magnetic stimulation (TMS). Previous studies have provided mixed results on the cognitive-enhancing effects of TMS treatment in patients with MDD. Some studies have found significant improvement, while others have not. There is a lack of understanding of the specific effects of different TMS protocols and stimulation parameters on cognitive control in MDD. Thus, this review aims to synthesize the effectiveness of the TMS methods and a qualitative assessment of their potential benefits in improving cognitive functioning in patients with MDD. We reviewed 21 studies in which participants underwent a treatment of any transcranial magnetic stimulation protocol, such as repetitive TMS or theta-burst stimulation. One of the primary outcome measures was any change in the cognitive control process. Overall, the findings indicate that transcranial magnetic stimulation (TMS) may enhance cognitive function in patients with MDD. Most of the reviewed studies supported the notion of cognitive improvement following TMS treatment. Notably, improvements were predominantly observed in inhibition, attention, set shifting/flexibility, and memory domains. However, fewer significant improvements were detected in evaluations of visuospatial function and recognition, executive function, phonemic fluency, and speed of information processing. This review found evidence supporting the use of TMS as a treatment for cognitive deficits in patients with MDD. The results are promising, but further research is needed to clarify the specific TMS protocol and stimulation locations that are most effective.

Genome-Wide Association Study of Treatment-Resistant Depression: Shared Biology With Metabolic Traits

OBJECTIVE

Treatment-resistant depression (TRD) occurs in roughly one-third of all individuals with major depressive disorder (MDD). Although research has suggested a significant common variant genetic component of liability to TRD, with heritability estimated at 8% when compared with non-treatment-resistant MDD, no replicated genetic loci have been identified, and the genetic architecture of TRD remains unclear. A key barrier to this work has been the paucity of adequately powered cohorts for investigation, largely because of the challenge in prospectively investigating this phenotype. The objective of this study was to perform a well-powered genetic study of TRD.

METHODS

Using receipt of electroconvulsive therapy (ECT) as a surrogate for TRD, the authors applied standard machine learning methods to electronic health record data to derive predicted probabilities of receiving ECT. These probabilities were then applied as a quantitative trait in a genome-wide association study of 154,433 genotyped patients across four large biobanks.

RESULTS

Heritability estimates ranged from 2% to 4.2%, and significant genetic overlap was observed with cognition, attention deficit hyperactivity disorder, schizophrenia, alcohol and smoking traits, and body mass index. Two genome-wide significant loci were identified, both previously implicated in metabolic traits, suggesting shared biology and potential pharmacological implications.

CONCLUSIONS

This work provides support for the utility of estimation of disease probability for genomic investigation and provides insights into the genetic architecture and biology of TRD.

Inclusion of the severe and enduring anorexia nervosa phenotype in genetics research: a scoping review

BACKGROUND

Anorexia nervosa has one of the highest mortality rates of all mental illnesses. For those who survive, less than 70% fully recover, with many going on to develop a more severe and enduring phenotype. Research now suggests that genetics plays a role in the development and persistence of anorexia nervosa. Inclusion of participants with more severe and enduring illness in genetics studies of anorexia nervosa is critical.

OBJECTIVE

The primary goal of this review was to assess the inclusion of participants meeting the criteria for the severe enduring anorexia nervosa phenotype in genetics research by (1) identifying the most widely used defining criteria for severe enduring anorexia nervosa and (2) performing a review of the genetics literature to assess the inclusion of participants meeting the identified criteria.

METHODS

Searches of the genetics literature from 2012 to 2023 were performed in the PubMed, PsycINFO, and Web of Science databases. Publications were selected per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The criteria used to define the severe and enduring anorexia nervosa phenotype were derived by how often they were used in the literature since 2017. The publications identified through the literature search were then assessed for inclusion of participants meeting these criteria.

RESULTS

most prevalent criteria used to define severe enduring anorexia nervosa in the literature were an illness duration of ≥ 7 years, lack of positive response to at least two previous evidence-based treatments, a body mass index meeting the Diagnostic and Statistical Manual of Mental Disorders-5 for extreme anorexia nervosa, and an assessment of psychological and/or behavioral severity indicating a significant impact on quality of life. There was a lack of consistent identification and inclusion of those meeting the criteria for severe enduring anorexia nervosa in the genetics literature.

DISCUSSION

This lack of consistent identification and inclusion of patients with severe enduring anorexia nervosa in genetics research has the potential to hamper the isolation of risk loci and the development of new, more effective treatment options for patients with anorexia nervosa.

Comparative Efficacy of Dopamine Partial Agonists by Doses for Treatment-Resistant Depression: A Systematic Review and Dose-Response Model-Based Network Meta-analysis

BACKGROUND

The augmentative antidepressant effects of dopamine partial agonists (aripiprazole, brexpiprazole, and cariprazine) for treatment-resistant depression have been compared in a previous network meta-analysis. However, the comparative efficacy of the dose-responses of these drugs remains unclear. Therefore, we aimed to estimate the dose-response relationships and compare the effects of each dopamine partial agonist doses.

METHODS

We conducted a systematic review of the Cochrane Library, PubMed, CINHAL, and ClinicalTrials.gov databases until January 1, 2023. Double-blind, randomized, placebo-controlled trials evaluating aripiprazole, brexpiprazole, and cariprazine for treatment-resistant depression were included. A random-effect dose-response model-based network meta-analysis was conducted. This study was registered in PROSPERO (CRD42023393035).

RESULTS

The maximum effective doses were 5.5 mg for aripiprazole, 1.6 mg for brexpiprazole, and 1.5 mg for cariprazine, respectively. Although all doses of the 3 drugs were significantly more effective than placebo, aripiprazole ranging from 5.5 to 12.5 mg was significantly more effective than brexpiprazole 0.5 mg and cariprazine ranging from 0.5 to 1 mg. Moreover, aripiprazole ranging from 7.5 to 12.5 mg was significantly more effective than all doses of cariprazine. In addition, brexpiprazole ranging from 1 to 3 mg was significantly more effective than cariprazine 0.5 mg and brexpiprazole ranging from 1.6 to 2.5 mg was significantly superior to cariprazine 1 mg. There were no doses at which brexpiprazole overcame aripiprazole, and cariprazine overcame aripiprazole or brexpiprazole.

CONCLUSIONS

Aripiprazole, brexpiprazole, and cariprazine may be effective in treatment-resistant depression in that order, with the maximum effective doses at 5.5 mg, 1.6 mg, and 1.5 mg, respectively.

Recent Advances in the Treatment of Treatment-Resistant Depression: A Narrative Review of Literature Published from 2018 to 2023

PURPOSE OF REVIEW

We review recent advances in the treatment of treatment-resistant depression (TRD), a disorder with very limited treatment options until recently. We examine advances in psychotherapeutic, psychopharmacologic, and interventional psychiatry approaches to treatment of TRD. We also highlight various definitions of TRD in recent scientific literature.

RECENT FINDINGS

Recent evidence suggests some forms of psychotherapy can be effective as adjunctive treatments for TRD, but not as monotherapies alone. Little recent evidence supports the use of adjunctive non-antidepressant pharmacotherapies such as buprenorphine and antipsychotics for the treatment of TRD; side effects and increased medication discontinuation rates may outweigh the benefits of these adjunctive pharmacotherapies. Finally, a wealth of recent evidence supports the use of interventional approaches such as electroconvulsive therapy, ketamine/esketamine, and transcranial magnetic stimulation for TRD. Recent advances in our understanding of how to treat TRD have largely expanded our knowledge of best practices in, and efficacy of, interventional psychiatric approaches. Recent research has used a variety of TRD definitions for study inclusion criteria; research on TRD should adhere to inclusion criteria based on internationally defined guidelines for more meaningfully generalizable results.

Common pitfalls, and how to avoid them, in child and adolescent psychopharmacology: Part I

As Faculty of the British Association for Psychopharmacology course on child and adolescent psychopharmacology, we present here what we deem are the most common pitfalls, and how to avoid them, in child and adolescent psychopharmacology. In this paper, we specifically addressed common pitfalls in the pharmacological treatment of attention-deficit/hyperactivity disorder, anxiety, bipolar disorder, depression, obsessive-compulsive disorder and related disorders, and tic disorder. Pitfalls in the treatment of other disorders are addressed in a separate paper (part II).

How different definition criteria may predict clinical outcome in treatment resistant depression: Results from a prospective real-world study

Management of treatment-resistant depression (TRD) remains a major public health challenge, also due to the lack of a consensus around TRD definition. We investigated the impact of different definitions of TRD on identifying patients with distinct features in terms of baseline characteristics, treatment strategies, and clinical outcome. We conducted a prospective naturalistic study on 538 depressed inpatients. Patients were screened for treatment resistance by two TRD definitions: looser criteria (lTRD) and stricter criteria (sTRD). We compared baseline characteristics, treatment and clinical outcome between the TRD groups and their non-TRD counterparts. 52.97 % of patients were identified as lTRD, only 28.81 % met the criteria for sTRD. sTRD patients showed lower rates of remission and slower symptom reduction compared to non-TRD patients and received more challenging treatments. Surprisingly, patients identified as sTRD also exhibited lower rates of psychiatric comorbidities, including personality disorders, substance abuse, or alcohol misuse. Stricter TRD criteria identify patients with worse clinical outcomes. Looser criteria may lead to overdiagnosis and over treatment. Clinical features known to be possible risk factors for TRD, as psychiatric comorbidities, showed to be more suggestive of a "difficult to manage" depression rather than a proper TRD.

Deep brain stimulation for refractory major depressive disorder: a comprehensive review

Deep brain stimulation (DBS) has emerged as a promising treatment for select patients with refractory major depressive disorder (MDD). The clinical effectiveness of DBS for MDD has been demonstrated in meta-analyses, open-label studies, and a few controlled studies. However, randomized controlled trials have yielded mixed outcomes, highlighting challenges that must be addressed prior to widespread adoption of DBS for MDD. These challenges include tracking MDD symptoms objectively to evaluate the clinical effectiveness of DBS with sensitivity and specificity, identifying the patient population that is most likely to benefit from DBS, selecting the optimal patient-specific surgical target and stimulation parameters, and understanding the mechanisms underpinning the therapeutic benefits of DBS in the context of MDD pathophysiology. In this review, we provide an overview of the latest clinical evidence of MDD DBS effectiveness and the recent technological advancements that could transform our understanding of MDD pathophysiology, improve the clinical outcomes for MDD DBS, and establish a path forward to develop more effective neuromodulation therapies to alleviate depressive symptoms.

Multiomics and blood-based biomarkers of electroconvulsive therapy in severe and treatment-resistant depression: study protocol of the DetECT study

Electroconvulsive therapy (ECT) is commonly used to treat treatment-resistant depression (TRD). However, our knowledge of the ECT-induced molecular mechanisms causing clinical improvement is limited. To address this issue, we developed the single-center, prospective observational DetECT study ("Multimodal Biomarkers of ECT in TRD"; registered 18/07/2022, www.clinicalTrials.gov , NCT05463562). Its objective is to identify molecular, psychological, socioeconomic, and clinical biomarkers of ECT response in TRD. We aim to recruit n = 134 patients in 3 years. Over the course of 12 biweekly ECT sessions (± 7 weeks), participant blood is collected before and 1 h after the first and seventh ECT and within 1 week after the twelfth session. In pilot subjects (first n = 10), additional blood draws are performed 3 and 6 h after the first ECT session to determine the optimal post-ECT blood draw interval. In blood samples, multiomic analyses are performed focusing on genotyping, epigenetics, RNA sequencing, neuron-derived exosomes, purines, and immunometabolics. To determine clinical response and side effects, participants are asked weekly to complete four standardized self-rating questionnaires on depressive and somatic symptoms. Additionally, clinician ratings are obtained three times (weeks 1, 4, and 7) within structured clinical interviews. Medical and sociodemographic data are extracted from patient records. The multimodal data collected are used to perform the conventional statistics as well as mixed linear modeling to identify clusters that link biobehavioural measures to ECT response. The DetECT study can provide important insight into the complex mechanisms of ECT in TRD and a step toward biologically informed and data-driven-based ECT biomarkers.

Targeting metaplasticity mechanisms to promote sustained antidepressant actions

The discovery that subanesthetic doses of (R, S)-ketamine (ketamine) and (S)-ketamine (esketamine) rapidly induce antidepressant effects and promote sustained actions following drug clearance in depressed patients who are treatment-resistant to other therapies has resulted in a paradigm shift in the conceptualization of how rapidly and effectively depression can be treated. Consequently, the mechanism(s) that next generation antidepressants may engage to improve pathophysiology and resultant symptomology are being reconceptualized. Impaired excitatory glutamatergic synapses in mood-regulating circuits are likely a substantial contributor to the pathophysiology of depression. Metaplasticity is the process of regulating future capacity for plasticity by priming neurons with a stimulation that alters later neuronal plasticity responses. Accordingly, the development of treatment modalities that specifically modulate the duration, direction, or magnitude of glutamatergic synaptic plasticity events such as long-term potentiation (LTP), defined here as metaplastogens, may be an effective approach to reverse the pathophysiology underlying depression and improve depression symptoms. We review evidence that the initiating mechanisms of pharmacologically diverse rapid-acting antidepressants (i.e., ketamine mimetics) converge on consistent downstream molecular mediators that facilitate the expression/maintenance of increased synaptic strength and resultant persisting antidepressant effects. Specifically, while the initiating mechanisms of these therapies may differ (e.g., cell type-specificity, N-methyl-D-aspartate receptor (NMDAR) subtype-selective inhibition vs activation, metabotropic glutamate receptor 2/3 antagonism, AMPA receptor potentiation, 5-HT receptor-activating psychedelics, etc.), the sustained therapeutic mechanisms of putative rapid-acting antidepressants will be mediated, in part, by metaplastic effects that converge on consistent molecular mediators to enhance excitatory neurotransmission and altered capacity for synaptic plasticity. We conclude that the convergence of these therapeutic mechanisms provides the opportunity for metaplasticity processes to be harnessed as a druggable plasticity mechanism by next-generation therapeutics. Further, targeting metaplastic mechanisms presents therapeutic advantages including decreased dosing frequency and associated diminished adverse responses by eliminating the requirement for the drug to be continuously present.

Risk factors for suicidal attempts in a sample of outpatients with treatment-resistant depression: an observational study

Introduction

Treatment-resistant depression (TRD) is commonly defined as the failure of at least two trials with antidepressant drugs, given at the right dose and for an appropriate duration. TRD is associated with increased mortality, compared to patients with a simple major depressive episode. This increased rate was mainly attributed to death from external causes, including suicide and accidents. The aim of our study is to identify socio-demographic and psychopathological variables associated with suicidal attempts in a sample of outpatients with TRD.

Material and methods

We performed a monocentric observational study with a retrospective design including a sample of 63 subjects with TRD referred to an Italian outpatient mental health centre. We collected socio-demographic and psychopathological data from interviews and clinical records.

Results

77.8% of the sample (N=49) were females, the mean age was 49.2 (15.9). 33.3% (N=21) of patients had attempted suicide. 54% (N=34) of patients had a psychiatric comorbidity. Among the collected variables, substance use (p=0.031), psychiatric comorbidities (p=0.049) and high scores of HAM-D (p=0.011) were associated with the occurrence of suicide attempts. In the regression model, substance use (OR 6.779), psychiatric comorbidities (OR 3.788) and HAM-D scores (OR 1.057) were predictive of suicide attempts. When controlling for gender, only substance use (OR 6.114) and HAM-D scores (OR 1.057) maintained association with suicide attempts.

Conclusion

The integrated treatment of comorbidities and substance abuse, which involves different mental health services, is fundamental in achieving the recovery of these patients. Our study supports the importance of performing a careful clinical evaluation of patients with TRD in order to identify factors associated with increased risk of suicide attempts.

Opportunities and challenges for the use of deep brain stimulation in the treatment of refractory major depression

Major Depressive Disorder continues to remain one of the most prevalent psychiatric diseases globally. Despite multiple trials of conventional therapies, a subset of patients fail to have adequate benefit to treatment. Deep brain stimulation (DBS) is a promising treatment in this difficult to treat population and has shown strong antidepressant effects across multiple cohorts. Nearly two decades of work have provided insights into the potential for chronic focal stimulation in precise brain targets to modulate pathological brain circuits that are implicated in the pathogenesis of depression. In this paper we review the rationale that prompted the selection of various brain targets for DBS, their subsequent clinical outcomes and common adverse events reported. We additionally discuss some of the pitfalls and challenges that have prevented more widespread adoption of this technology as well as future directions that have shown promise in improving therapeutic efficacy of DBS in the treatment of depression.

Patient-reported outcomes on sleep quality and circadian rhythm during treatment with intravenous ketamine for treatment-resistant depression

Background

Intravenous (IV) ketamine is a rapid acting antidepressant used primarily for treatment-resistant depression (TRD). It has been suggested that IV ketamine's rapid antidepressant effects may be partially mediated via improved sleep and changes to the circadian rhythm.

Objectives

This study explores IV ketamine's association with changes in patient-reported sleep quality and circadian rhythm in an adult population with TRD.

Methods

Adult patients (18-64 years) with TRD scheduled for IV ketamine treatment were recruited to complete patient rated outcomes measures on sleep quality using the Pittsburgh Sleep Quality Index (PSQI) and circadian rhythm using the Morningness-Eveningness Questionnaire (MEQ). Over a 4-week course of eight ketamine infusions, reports were obtained at baseline (T0), prior to second treatment (T1), prior to fifth treatment (T2), and 1 week after eighth treatment (T3).

Results

Forty participants with TRD (mean age = 42.8, 45% male) were enrolled. Twenty-nine (72.5%) had complete follow-up data. Paired t tests revealed statistically significant improvements at the end of treatment in sleep quality (PSQI) (p = 0.003) and depressive symptoms (Clinically Useful Depression Outcome Scale-Depression, p < 0.001) while circadian rhythm (MEQ) shifted earlier (p = 0.007). The PSQI subscale components of sleep duration (p = 0.008) and daytime dysfunction (p = 0.001) also improved. In an exploratory post hoc analysis, ketamine's impact on sleep quality was more prominent in patients with mixed features, while its chronobiotic effect was prominent in those without mixed features.

Conclusion

IV ketamine may improve sleep quality and advance circadian rhythm in individuals with TRD. Effects may differ in individuals with mixed features of depression as compared to those without. Since this was a small uncontrolled study, future research is warranted.

A genetic risk score to predict treatment nonresponse in psychotic depression

Psychotic depression is a severe and difficult-to-treat subtype of major depressive disorder for which higher rates of treatment-resistant depression were found. Studies have been performed aiming to predict treatment-resistant depression or treatment nonresponse. However, most of these studies excluded patients with psychotic depression. We created a genetic risk score (GRS) based on a large treatment-resistant depression genome-wide association study. We tested whether this GRS was associated with nonresponse, nonremission and the number of prior adequate antidepressant trials in patients with a psychotic depression. Using data from a randomized clinical trial with patients with a psychotic depression (n = 122), we created GRS deciles and calculated positive prediction values (PPV), negative predictive values (NPV) and odds ratios (OR). Nonresponse and nonremission were assessed after 7 weeks of treatment with venlafaxine, imipramine or venlafaxine plus quetiapine. The GRS was negatively correlated with treatment response (r = -0.32, p = 0.0023, n = 88) and remission (r = -0.31, p = 0.0037, n = 88), but was not correlated with the number of prior adequate antidepressant trials. For patients with a GRS in the top 10%, we observed a PPV of 100%, a NPV of 73.7% and an OR of 52.4 (p = 0.00072, n = 88) for nonresponse. For nonremission, a PPV of 100%, a NPV of 51.9% and an OR of 21.3 (p = 0.036, n = 88) was observed for patients with a GRS in the top 10%. Overall, an increased risk for nonresponse and nonremission was seen in patients with GRSs in the top 40%. Our results suggest that a treatment-resistant depression GRS is predictive of treatment nonresponse and nonremission in psychotic depression.

Exploring Novel Antidepressants Targeting G Protein-Coupled Receptors and Key Membrane Receptors Based on Molecular Structures

Major Depressive Disorder (MDD) is a complex mental disorder that involves alterations in signal transmission across multiple scales and structural abnormalities. The development of effective antidepressants (ADs) has been hindered by the dominance of monoamine hypothesis, resulting in slow progress. Traditional ADs have undesirable traits like delayed onset of action, limited efficacy, and severe side effects. Recently, two categories of fast-acting antidepressant compounds have surfaced, dissociative anesthetics S-ketamine and its metabolites, as well as psychedelics such as lysergic acid diethylamide (LSD). This has led to structural research and drug development of the receptors that they target. This review provides breakthroughs and achievements in the structure of depression-related receptors and novel ADs based on these. Cryo-electron microscopy (cryo-EM) has enabled researchers to identify the structures of membrane receptors, including the N-methyl-D-aspartate receptor (NMDAR) and the 5-hydroxytryptamine 2A (5-HT2A) receptor. These high-resolution structures can be used for the development of novel ADs using virtual drug screening (VDS). Moreover, the unique antidepressant effects of 5-HT1A receptors in various brain regions, and the pivotal roles of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and tyrosine kinase receptor 2 (TrkB) in regulating synaptic plasticity, emphasize their potential as therapeutic targets. Using structural information, a series of highly selective ADs were designed based on the different role of receptors in MDD. These molecules have the favorable characteristics of rapid onset and low adverse drug reactions. This review offers researchers guidance and a methodological framework for the structure-based design of ADs.

Patient perspectives and experiences with psilocybin treatment for treatment-resistant depression: a qualitative study

Psilocybin is the most researched classic psychedelic for Treatment-Resistant Depression (TRD). While optimizing set and setting are considered essential for efficacy and safety, patient perspectives on these aspects have rarely been investigated. To address this knowledge gap, the current paper explored the experiences of 11 TRD patients (8 women, 3 men) participating in a double-blind randomized clinical trial with a single session of oral (1, 10 or 25 mg) psilocybin treatment. After qualitative analysis, three major themes were identified: (1) challenges with trust-building and expectation management; (2) navigating the experience; and (3) the need for a more comprehensive treatment. Subthemes of the first theme include a general distrust in mental healthcare, trust in study therapists, limited time for preparation, and managing expectations. The second theme included the following subthemes: trusting to surrender, profound and overwhelming experiences, and music as a guide. The third theme addressed a desire for multiple psilocybin sessions, and challenges with sensemaking. Patients' perspectives provided important insights into potential optimization of psilocybin treatment of TRD, including individualized preparation, investment in trust-building, offering additional psilocybin sessions, providing access to sustained (psycho)therapy with trusted therapists, and personalizing treatment approaches, which may also enhance real-world adaption of these treatments.

Impact of Adjunctive VNS on Drug Load, Depression Severity, and Number of Neuromodulatory Maintenance Treatments

Vagus nerve stimulation (VNS) is a long-term adjunctive treatment option in patients with difficult-to-treat depression (DTD). A total of n = 20 patients (mean age 52.6 years) were included in the multicenter, prospective, observational, naturalistic RESTORE-LIFE study and were treated with adjunctive VNS as an add-on to treatment as usual. Exploratory and secondary outcome parameters from a single center were investigated for this present analysis. The overall mean drug load slightly decreased from 4.5 at baseline to 4.4 at 12 months (Z = -0.534, p = 0.594). The drug load was lower in previous electroconvulsive therapy (ECT) responders than in non-responders. There was a reduction in the mean number of hospitalizations per month after VNS implantation (Z = 1.975, p = 0.048) and a significant decrease in the mean Montgomery Åsberg Depression Rating Scale (MADRS) score from 27.3 at baseline to 15.3 at 12 months (T = 4.230, degree of freedom (df) = 19, p = 0.001). A history of ECT response at baseline was associated with greater improvement in the MADRS score after 12 months of VNS (F = 8.171, p = 0.013). The number of neuromodulatory maintenance treatments decreased during the follow-up period. In summary, there was an alleviation in the burden of illness among DTD patients treated with VNS.

Nitrogen-containing heterocyclic compounds: A ray of hope in depression?

Depression is not similar to daily mood fluctuations and temporary emotional responses to day-to-day activities. Depression is not a passing problem; it is an ongoing problem. It deals with different episodes consisting of several symptoms that last for at least 2 weeks. It can be seen for several weeks, months, or years. At its final stage, or can say, in its worst condition, it can lead to suicide. Antidepressants are used to inhibit the reuptake of the neurotransmitters by some selective receptors, which increase the concentration of specific neurotransmitters around the nerves in the brain. Drugs that are currently being used for the management of various types of depression include selective serotonin reuptake inhibitors, tricyclic antidepressants, atypical antidepressants, serotonin, noradrenaline reuptake inhibitors, etc. In this review, we have outlined different symptoms, causes, and recent advancements in nitrogen-containing heterocyclic drug candidates for the management of depression. This article highlights the various structural features along with the structure-activity relationship (SAR) of nitrogen-containing heterocyclics that play a key role in binding at target sites for potential antidepressant action. The in silico studies were carried out to determine the binding interactions of the target ligands with the receptor site to determine the potential role of substitution patterns at core pharmacophoric features. This article will help medicinal chemists, biochemists, and other interested researchers in identifying the potential pharmacophores as lead compounds for further development of new potent antidepressants.

Care pathways, prescribing practices and treatment outcomes in major depressive disorder and treatment-resistant depression: retrospective, population-based cohort study

BACKGROUND

Despite the availability of effective therapies, many patients with major depressive disorder (MDD) develop treatment-resistant depression (TRD).

AIMS

To evaluate and compare prescribing patterns, contact with specialist services and treatment outcomes in patients with MDD and TRD.

METHOD

This was a retrospective analysis of linked primary and secondary care National Health Service data in the north-west London Discover-NOW data-set. Eligible patients were adults who had diagnostic codes for depression and had been prescribed at least one antidepressant between 2015 and 2020.

RESULTS

A total of 110 406 patients were included, comprising 101 333 (92%) with MDD and 9073 (8%) with TRD. Patients with TRD had significantly higher risks of suicidal behaviour and comorbidities such as anxiety, asthma, and alcohol or substance misuse (all P < 0.0001). Citalopram, sertraline, fluoxetine and mirtazapine accounted for 83% of MDD and 71% of TRD prescriptions. Use of antidepressant switching (1% MDD, 7% TRD) and combination therapy (1%, 5%) was rare, whereas augmentation occurred more frequently in the TRD group (4%, 35%). Remission was recorded in 42 348 (42%) patients with MDD and 1188 (13%) with TRD (P < 0.0001), whereas relapse was seen in 20 970 (21%) and 4923 (54%), respectively (P < 0.0001). Mean times from diagnosis to first contact with mental health services were 38.9 (s.d. 33.6) months for MDD and 41.5 (s.d. 32.0) months for TRD (P < 0.0001).

CONCLUSIONS

There appears to be a considerable difference between treatment guidelines for depression and TRD and the reality of clinical practice. Long-term treatment with single antidepressants, poor remission, and high relapse rates among patients in primary care highlight the need to optimise treatment pathways and access to newer therapies.

Altered in vivo early neurogenesis traits in patients with depression: Evidence from neuron-derived extracellular vesicles and electroconvulsive therapy

BACKGROUND

The neurogenesis hypothesis is a promising candidate etiologic hypothesis for depression, and it is associated with electroconvulsive therapy (ECT). However, human in vivo molecular-level evidence is lacking.

OBJECTIVE

We used neuron-derived extracellular vesicles (NDEVs) as a "window to the neurons" to explore the in vivo neurogenesis status associated with ECT in patients with treatment-resistant depression (TRD).

METHODS

In this study, we enrolled 40 patients with TRD and 35 healthy controls (HCs). We isolated NDEVs from the plasma of each participant to test the levels of doublecortin (DCX), a marker of neurogenesis, and cluster of differentiation (CD) 81, a marker of EVs. We also assessed the plasma levels of brain-derived neurotrophic factor (BDNF), a protein that is known to be associated with ECT and neuroplastic processes.

RESULTS

Our findings indicated that both the levels of DCX in NDEVs and BDNF in plasma were significantly lower in TRD patients compared to HCs at baseline, but increased following ECTs. Conversely, levels of CD81 in NDEVs were found higher in TRD patients at baseline, but did not change after the ECT treatments. Exploratory analyses revealed that lower levels of BDNF in plasma and DCX in NDEVs, along with higher CD81 levels in NDEVs, were associated with more severe depressive symptoms and reduced cognitive function at baseline. Furthermore, higher baseline CD81 concentrations in NDEVs were correlated with greater decreases in depression symptoms.

CONCLUSIONS

We first present human in vivo evidence of early neurogenesis using DCX through NDEVs: decreased in TRD patients, increased after ECTs.

Evolution of Depressive Symptoms Among Depression Subtypes of Clinical and Functional Variables in Primary Care in Chile

OBJECTIVE

To compare the evolution of depressive symptoms among depressive subtypes based on clinical and functional variables in a sample of primary care in Chile.

METHODS

A longitudinal study was conducted in the Maule Region of Chile, focusing on 8 primary care from February 2014 to September 2015. Clinical and functional variables, including Mini International Neuro-psychiatric Interview, Outcome Questionnaire interpersonal and social sub-scales, were applied in a latent class analysis. This analysis categorized 210 patients into 3 subtypes: complex depression (N = 100), recurrent depression (n = 96), and unique depression (n = 14). Complex depression, exhibited a higher probability of suicide attempts, interpersonal and social dysfunction, and association with adverse childhood experiences according the Brief Physical and Sexual Abuse Questionnaire. Patients were monitored over 1 year with the Hamilton scale. The Kruskal-Wallis, non-parametric test, followed by paired Mann-Whitney test evaluated difference in the severity of depressive symptoms between the groups. Additionally, data on mental health interventions were collected.

RESULTS

Out of the 210 patients, 89% were women, with a median age of 50 (range 37-58), and 40.1% with only primary education. Sociodemographic characteristics not differ between groups. Significant differences in depressive symptom severity between the groups were found (X2 90.06, P < .001, Kruskal-Wallis test, η2 = 0.084). Post hoc analyses indicated higher depressive symptoms in complex depression compared to recurrent (Z = -9.501, P < .001) and unique (Z = -2.877, P = .004) depression, with no significant difference between recurrent and unique depression (Z = -1.58, P = .113). There were no differences in the number of medical and psychological controls between the groups. The patients with complex depression required greater modifications in the pharmacological prescriptions than those belonging to the other groups.

CONCLUSION

These results provide additional evidence of a complex depression subtype in primary care in Chile associated with adverse childhood experiences, that had worse resolution of depressive symptoms. Contrary to expectations, patients belonging to this group did not receive further medical and psychological interventions, probably due to a lack of specific clinical recommendations.

Structural brain plasticity and inflammation are independently related to changes in depressive symptoms six months after an index ECT course

BACKGROUND

Electroconvulsive therapy (ECT) is effective for treatment-resistant depression and leads to short-term structural brain changes and decreases in the inflammatory response. However, little is known about how brain structure and inflammation relate to the heterogeneity of treatment response in the months following an index ECT course.

METHODS

A naturalistic six-month study following an index ECT course included 20 subjects with treatment-resistant depression. Upon conclusion of the index ECT course and again after six months, structural magnetic resonance imaging scans and peripheral inflammation measures [interleukin-6 (IL-6), IL-8, tumor necrosis factor (TNF-α), and C-reactive protein] were obtained. Voxel-based morphometry processed with the CAT-12 Toolbox was used to estimate changes in gray matter volume.

RESULTS

Between the end of the index ECT course and the end of follow-up, we found four clusters of significant decreases in gray matter volume (p < 0.01, FWE) and no regions of increased volume. Decreased HAM-D scores were significantly related only to reduced IL-8 level. Decreased volume in one cluster, which included the right insula and Brodmann's Area 22, was related to increased HAM-D scores over six months. IL-8 levels did not mediate or moderate the relationship between volumetric change and depression.

CONCLUSIONS

Six months after an index ECT course, multiple regions of decreased gray matter volume were observed in a naturalistic setting. The independent relations between brain volume and inflammation to depressive symptoms suggest novel explanations of the heterogeneity of longer-term ECT treatment response.

Baseline characteristics of a European patient population with difficult-to-treat depression (RESTORE-LIFE) treated with adjunctive vagus nerve stimulation

BACKGROUND

Major depressive disorder is a complex heterogeneous disorder. Treatment is especially challenging for patients with "difficult-to-treat depression" (DTD): a less stigmatizing and more clinically relevant framework defining depression that continues to cause significant burden despite usual treatment efforts.

METHODS

RESTORE-LIFE is a prospective, observational, multicenter, post-market study being conducted in Europe and is designed to reflect real-world clinical application of adjunctive Vagus Nerve Stimulation Therapy (VNS) for DTD. Baseline characteristics of RESTORE-LIFE patients were analyzed and compared to published treatment-resistant depression (TRD) trials.

RESULTS

This analysis includes the initial 98 RESTORE-LIFE patients who commenced treatment with VNS. Patients had a mean of 11.4 failed anti-depressant treatments, 1.1 suicide attempts, 87 % had prior electroconvulsive therapy, and 36 % had an endocrine/metabolic comorbidity. On average, disease severity was comparable to that in TRD trials (n = 15,463). However, RESTORE-LIFE patients appear to have been experiencing DTD for a longer duration and their DTD was characterized by a lack of positive mental health and meaningfulness of life, to a greater degree than by excess of negative mood. Despite high comorbidity rates in RESTORE-LIFE, VNS implantation was performed safely with no discontinuations due to surgical adverse events.

LIMITATIONS

RESTORE-LIFE enrolls any patient receiving adjunctive VNS for DTD. Prescription of VNS may be biased by differences in practices amongst sites and countries.

CONCLUSIONS

The present analysis offers insight into contemporary real-world use of VNS Therapy for DTD in Europe representing a comprehensive characterization of DTD and how this population may differ from those in the TRD literature.

Preparation and Evaluation of Curcumin Derivatives Nanoemulsion Based on Turmeric Extract and Its Antidepressant Effect

Purpose

The early stage of this study verified that a turmeric extract (TUR) including 59% curcumin (CU), 22% demethoxycurcumin (DMC), and 18% bisdemethoxycurcumin (BDMC), could enhance the stability of CU and had greater antidepressant potential in vitro. The objective of the study was to develop a nano-delivery system containing TUR (TUR-NE) to improve the pharmacokinetic behavior of TUR and enhance its antidepressant effect.

Methods

The antidepressant potential of TUR was explored using ABTS, oxidative stress-induced cell injury, and a high-throughput screening model. TUR-NE was fabricated, optimized and characterized. The pharmacokinetic behaviors of TUR-NE were evaluated following oral administration to normal rats. The antidepressant effect of TUR-NE was assessed within chronic unpredictable mild stress model (CUMS) mice. The behavioral and biochemical indexes of mice were conducted.

Results

The results depicted that TUR had 3.18 and 1.62 times higher antioxidant capacity than ascorbic acid and CU, respectively. The inhibition effect of TUR on ASP+ transport was significantly enhanced compared with fluoxetine and CU. TUR-NE displayed a particle size of 116.0 ± 0.31 nm, polydispersity index value of 0.121 ± 0.007, an encapsulation rate of 98.45%, and good release and stability in cold storage. The results of pharmacokinetics indicated the AUC(0-t) of TUR-NE was 8.436 and 4.495 times higher than that of CU and TUR, while the Cmax was 9.012 and 5.452 times higher than that of CU and TUR, respectively. The pharmacodynamic study confirmed that the superior antidepressant effect of TUR-NE by significantly improving the depressant-like behaviors and elevating the content of 5-hydroxytryptamine in plasma and brain in CUMS mice. TUR-NE showed good safety with repeated administration.

Conclusion

TUR-NE, which had small and uniform particle size, enhanced the bioavailability and antidepressant effect of TUR. It could be a promising novel oral preparation against depression.

Early effects predict trajectories of response to esketamine in treatment-resistant depression

BACKGROUND

The efficacy of esketamine in treatment-resistant depression (TRD) has been confirmed. However, its administration is expensive and restrictive, with limited knowledge on how long the treatment should be continued. Predicting the treatment outcome would benefit patients and alleviate the global treatment cost. We aimed to define distinct trajectories of treatment response and assess their predictability.

METHODS

In this longitudinal study, two independent samples of patients with unipolar or bipolar TRD were treated with esketamine in real-world settings. Depression severity was assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS) before each esketamine administration. Latent class analyses were used to define trajectories of response.

RESULTS

In the original sample (N = 50), we identified two classes whose trajectories depicted response and non-response, respectively. The model was validated in the confirmatory sample (N = 55). Class membership was influenced by a few baseline characteristics such as concomitant benzodiazepine medication, number of depressive episodes or polarity. On the other hand, after only two esketamine administrations, the MADRS score predicted the 90-day trajectory of response with an accuracy of 80 %.

LIMITATIONS

This observational study is not placebo-controlled. Therefore, its results and their generalizability need to be confirmed in experimental settings.

CONCLUSIONS

After the first administrations of esketamine, the MADRS score has a good capacity to predict the most plausible trajectory of response. While thresholds and their predictive values need to be confirmed, this finding suggests that clinicians could base on MADRS scores their decision to discontinue treatment because of poor remaining chances of treatment response.

Human in vivo evidence of reduced astrocyte activation and neuroinflammation in patients with treatment-resistant depression following electroconvulsive therapy

AIM

The current study aimed to investigate the neuroinflammatory hypothesis of depression and the potential anti-inflammatory effect of electroconvulsive therapy (ECT) in vivo, utilizing astrocyte-derived extracellular vesicles (ADEVs) isolated from plasma.

METHODS

A total of 40 patients with treatment-resistant depression (TRD) and 35 matched healthy controls were recruited at baseline, and 34 patients with TRD completed the post-ECT visits. Blood samples were collected at baseline and post-ECT. Plasma ADEVs were isolated and confirmed, and the concentrations of two astrocyte markers (glial fibrillary acidic protein [GFAP] and S100β), an extracellular vesicle marker cluster of differentiation 81 (CD81), and nine inflammatory markers in ADEVs were measured as main analyses. In addition, correlation analysis was conducted between clinical features and ADEV protein levels as exploratory analysis.

RESULTS

At baseline, the TRD group exhibited significantly higher levels of two astrocyte markers GFAP and S100β, as well as CD81 compared with the healthy controls. Inflammatory markers interferon γ (IFN-γ), interleukin (IL) 1β, IL-4, IL-6, tumor necrosis factor α, IL-10, and IL-17A were also significantly higher in the TRD group. After ECT, there was a significant reduction in the levels of GFAP, S100β, and CD81, along with a significant decrease in the levels of IFN-γ and IL-4. Furthermore, higher levels of GFAP, S100β, CD81, and inflammatory cytokines were associated with more severe depressive symptoms and poorer cognitive function.

CONCLUSION

This study provides direct insight supporting the astrocyte activation and neuroinflammatory hypothesis of depression using ADEVs. ECT may exert an anti-inflammatory effect through inhibition of such activation of astrocytes.

Individual Prediction of Optimal Treatment Allocation Between Electroconvulsive Therapy or Ketamine using the Personalized Advantage Index

Introduction

Electroconvulsive therapy (ECT) and ketamine are two effective treatments for depression with similar efficacy; however, individual patient outcomes may be improved by models that predict optimal treatment assignment. Here, we adapt the Personalized Advantage Index (PAI) algorithm using machine learning to predict optimal treatment assignment between ECT and ketamine using medical record data from a large, naturalistic patient cohort. We hypothesized that patients who received a treatment predicted to be optimal would have significantly better outcomes following treatment compared to those who received a non-optimal treatment.

Methods

Data on 2526 ECT and 235 mixed IV ketamine and esketamine patients from McLean Hospital was aggregated. Depressive symptoms were measured using the Quick Inventory of Depressive Symptomatology (QIDS) before and during acute treatment. Patients were matched between treatments on pretreatment QIDS, age, inpatient status, and psychotic symptoms using a 1:1 ratio yielding a sample of 470 patients (n=235 per treatment). Random forest models were trained and predicted differential patientwise minimum QIDS scores achieved during acute treatment (min-QIDS) scores for ECT and ketamine using pretreatment patient measures. Analysis of Shapley Additive exPlanations (SHAP) values identified predictors of differential outcomes between treatments.

Results

Twenty-seven percent of patients with the largest PAI scores who received a treatment predicted optimal had significantly lower min-QIDS scores compared to those who received a non-optimal treatment (mean difference=1.6, t=2.38, q<0.05, Cohen's D=0.36). Analysis of SHAP values identified prescriptive pretreatment measures.

Conclusions

Patients assigned to a treatment predicted to be optimal had significantly better treatment outcomes. Our model identified pretreatment patient factors captured in medical records that can provide interpretable and actionable guidelines treatment selection.

[Vagus Nerve Stimulation (VNS) in Depression]

Major depressive disorder is a common mental health disease with a chronic and treatment-resistant course in about one-third of patients. Invasive vagus nerve stimulation (VNS) as a long-term adjunctive treatment option has increasingly been used in the last years. VNS was CE-certified in the European Union for use in chronic and treatment-resistant depression in 2001. Method In this narrative literature review we provide an overview on VNS as a treatment option in patients with depression. We particularly focus on aspects with high clinical relevance. Results Indication to conduct VNS is determined after comprehensive evaluation of the patients' symptoms and psychiatric history. After education of patients and caregivers and obtaining informed consent, a pacemaker-like pulse generator is implanted in the left chest in a short surgical procedure. In the first weeks after implantation, the stimulation is turned on stepwise in an outpatient setting. The left vagal nerve is stimulated for 30 sec. every 5 minutes. Hoarseness during stimulation is the most frequent side-effect. There is a delay in the onset of antidepressant action of about 6-12 months. In a large registry, the cumulative response rate after 5 years was significantly higher (67.6%) in patients treated with VNS plus treatment-as-usual (TAU) than TAU alone (40.9%). Long-term benefits of VNS on quality of life, cognition, morbidity and mortality have been described previously. Conclusion VNS is a long-term safe treatment option in severely affected patients with depression with positive impact on depression severity, quality of life and cognitive function. Increase of monoaminergic transmission and anti-inflammatory effects of VNS are possible mechanisms of action.

Association between NTRK2 Polymorphisms, Hippocampal Volumes and Treatment Resistance in Major Depressive Disorder

Despite the increasing availability of antidepressant drugs, a high rate of patients with major depression (MDD) does not respond to pharmacological treatments. Brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signaling is thought to influence antidepressant efficacy and hippocampal volumes, robust predictors of treatment resistance. We therefore hypothesized the possible role of BDNF and neurotrophic receptor tyrosine kinase 2 (NTRK2)-related polymorphisms in affecting both hippocampal volumes and treatment resistance in MDD. A total of 121 MDD inpatients underwent 3T structural MRI scanning and blood sampling to obtain genotype information. General linear models and binary logistic regressions were employed to test the effect of genetic variations related to BDNF and NTRK2 on bilateral hippocampal volumes and treatment resistance, respectively. Finally, the possible mediating role of hippocampal volumes on the relationship between genetic markers and treatment response was investigated. A significant association between one NTRK2 polymorphism with hippocampal volumes and antidepressant response was found, with significant indirect effects. Our results highlight a possible mechanistic explanation of antidepressant action, possibly contributing to the understanding of MDD pathophysiology.

Ketamine for Traumatic Assault-Induced Depression: A Case Report

BACKGROUND

This case report describes the use of ketamine as a rapid, effective treatment of depression in a 68-year-old female patient with no significant medical history of psychiatric disorders. Patients who experience intentional or unintentional traumas are at an increased risk for developing depression or posttraumatic stress disorder, and emerging evidence has supported the use of ketamine as an alternative treatment of depression.

CASE PRESENTATION

This is the case of a 68-year-old female patient who was assaulted, resulting in multiple stab wounds to both hands and the right upper quadrant. She underwent placement of a chest tube and surgical repair of the liver and was subsequently admitted to the intensive care unit. These events led to the development of severe depression symptoms, as evidenced by a Montgomery-Asberg Depression Rating Scale (MADRS) score of 37. As treatment of her acute depression, the patient received a single intravenous dose of ketamine (0.5 mg/kg) infused over 40 min and was monitored for side effects. The MADRS is a 10-item depression screening tool that assesses symptoms and changes over time. Within 4 hr of receiving ketamine, the patient reported a significant improvement in her mood and her MADRS score decreased to 16, classifying this patient as experiencing mild depression. The patient continued to improve, and 24 hr after receiving ketamine, her MADRS score was 4, indicating remission of her depression symptoms.

CONCLUSION

This case report aims to provide an account of the potential benefits of ketamine as a rapid treatment of depression in an adult trauma patient.

Which clinical factors and biochemical parameters are associated with late-life major depression?

INTRODUCTION

Late-life major depression (MD) is a frequent and high-cost psychiatric disorder. Our purpose was to detect clinical and biological factors possibly associated with this condition to better prevent and treat it.

METHODS

We recruited 343 patients, consecutively admitted for a Major Depressive Episode to the inpatient clinic of Policlinico of Milan and ASST Monza, Italy. A large set of clinical and biochemical variables was collected from clinical charts. Univariate analyses were performed both dividing the sample into two groups (age < or ≥65) and considering age as a continuous quantitative variable. Regression analyses were then performed considering as independent variables only those statistically significant at univariate analyses.

RESULTS

Patients aged ≥ 65 resulted in having longer duration of illness, shorter duration of last antidepressant therapy, higher number of antidepressants assumed in the past, higher frequency of treatment-resistant depression, higher frequency of overweight/obesity and diabetes. As for biochemical parameters, patients ≥ 65 showed lower total plasmatic proteins and albumin, higher uric acid and creatinine.

CONCLUSIONS

These preliminary results suggest less effectiveness of antidepressants, more susceptibility to metabolic disorders and poor nutritional status in patients with late-life depression; such aspects may consequently be taken into consideration for a proper therapeutic approach. KEY POINTSDepression in late life seems to be associated with poorer response to antidepressants;Clinicians should prefer compounds with minimal pharmacokinetic interactions and less risk of side effects including metabolic ones;The poor nutritional status and the higher risk of metabolic disorders in older patients points out the importance of proper diet and healthy lifestyle in this group of subjects;Further studies are needed to confirm the results of this research.

The Patient's Perspective on the Effects of Intranasal Esketamine in Treatment-Resistant Depression

The effectiveness of the esketamine nasal spray (ESK-NS) for treatment-resistant depression (TRD) has been confirmed by real-world studies. Available evidence derived from clinician-rated assessments might differ from patients' perceptions about the helpfulness of treatments. We aimed to verify the effect of ESK-NS from patients' view in 25 TRD patients (56% males, 55.1 ± 10.9 years) treated with ESK-NS (mean dose: 78.4 ± 11.43 mg) for three months and evaluated at different time-points through clinician-rated and self-administered scales, assessing changes in depression, anhedonia, sleep, cognition, suicidality, and anxiety. We observed an overall early improvement that lasted over time (endpoint total score reduction in Montgomery-Åsberg Depression Rating Scale, p < 0.001, Beck Depression Inventory, p = 0.003). Patients reported a significant self-rated decrease in anhedonia at two months (Snaith-Hamilton Pleasure Scale, p = 0.04) and in suicide ideation at endpoint (BDI subitem 9, p = 0.039) vs. earlier improvements detected by clinicians (one-month reduction in MADRS subitem 8, p = 0.005, and subitem 10, p = 0.007). These findings confirm the effectiveness of a three-month treatment with ESK-NS in TRD patients, highlighting an overall overlapping response from patients' and clinicians' perspectives, although with some differential effects on specific symptoms at given time-points. Including patients' viewpoints in routine assessments could inform clinical practice, ensuring a better characterization of clinical phenotypes to deliver personalized interventions.

Persistence and clinical consequences of post-traumatic and dissociative symptoms in people with depressive symptoms: a one-year follow-up study

BACKGROUND

Recent studies found that post-traumatic and dissociative symptoms are common in people with depressive symptoms. Although a trauma-related subtype of depression has been proposed, little is known about the persistence and clinical consequences of these symptoms.

OBJECTIVE

This one-year follow-up study investigated the persistence and clinical consequences of post-traumatic and dissociative symptoms in people with depressive symptoms.

METHODS

We analyzed longitudinal data from an international sample of people self-reporting depressive emotions (N = 152) (mean Patient Health Questionnaire-9 score = 17.27; SD = 6.31).

RESULTS

More than half (58.4%) of participants with baseline post-traumatic stress disorder (PTSD) still met the criteria for PTSD after one year. Participants with dissociative symptoms at baseline were significantly more likely to report lifetime psychiatric hospitalization (31.2% vs 14.7%), past-year use of psychiatric hospitalization (10.4% vs 0%) and emergency services (16.9% vs 4%) than those without dissociative symptoms. All post-traumatic and dissociative symptom clusters were cross-sectionally (r = .286 to .528, p < .001) and longitudinally (r = .181 to .462, p < .001) correlated with depressive symptoms. A sense of current threat (β = .146, p < .05) and negative self-concept (β = .173, p < .05) at baseline significantly predicted depressive symptoms after one year.

CONCLUSIONS

These findings contribute to the increasing body of knowledge regarding the PTSD/dissociation-depression comorbidity. Given their persistence and clinical consequences, we recommend that post-traumatic and dissociative symptoms be regularly screened for in clinical settings. The existence of a possible trauma-related subtype of depression should receive more attention in both research and clinical practice.

Clinical validation of an adapted Eleveld Model for high-dose propofol treatments for depression

Repeated administration of high doses of propofol to patients with treatment-resistant depression (TRD) has been shown to produce antidepressant effects in small clinical trials. These effects can be elicited when the patient's EEG burst-suppression ratio (BSR) is maintained at 70-90% for 15 min in repeated treatments. This deep anesthesia domain lies beyond the range of current propofol pharmacokinetic/pharmacodynamic (PK/PD) models. In this study, we adapt the Eleveld model for use at deep anesthesia levels with a BSR endpoint, with the goal of aiding the estimation of the dosage of propofol needed to achieve 70-90% BSR for 15 min. We test the ability of the adapted model to predict BSR for these treatments. Twenty participants underwent 6-9 treatments of high doses of propofol (5-9 of which were included in this analysis) for a total of 115 treatments. To adapt the Eleveld model for this endpoint, we optimized the model parameters Ke0, γ and Ce50. These parameters were then used in the adapted model to estimate second-by-second BSR for each treatment. Estimated BSR was compared with observed BSR for each treatment of each participant. Median absolute performance error (MdAPE) between the estimated and observed BSR (25th-75th percentile) was 6.63 (3.79-12.96) % points and 8.51 (4.32-16.74) % between the estimated and observed treatment duration. This predictive performance is statistically significantly better at predicting BSR compared with the standard Eleveld model at deep anesthesia levels. Our adapted Eleveld model provides a useful tool to aid dosing propofol for high-dose anesthetic treatments for depression.

Association of Neurofilament Light Chain With the Antidepressant Effects of Low-Dose Ketamine Infusion Among Patients With Treatment-Resistant Depression

BACKGROUND

The role of neurofilament light chain (NFL) in treatment-resistant depression (TRD) is unclear. Whether baseline NFL concentrations are associated with the antidepressant effects of low-dose ketamine infusion has not been determined.

METHODS

The NFL concentrations of 71 patients with TRD and 17 healthy controls were assessed. Patients with TRD were randomly administered a single infusion of 0.5 mg/kg ketamine, 0.2 mg/kg ketamine, or normal saline. Depressive symptoms were assessed before infusion and sequentially at postinfusion timepoints (after 240 minutes and after 2-7 and 14 days) using the Hamilton Depression Rating Scale (HDRS).

RESULTS

After adjustment for age, sex, and body mass index, patients with TRD were more likely to have higher concentrations of NFL than healthy controls (P < .001). A generalized estimating equation model with adjustments for infusion group, age, sex, body mass index, and baseline HDRS scores showed that baseline NFL concentrations were positively associated with subsequent HDRS scores following low-dose ketamine infusion (P = .038).

DISCUSSION

Higher concentrations of NFL were observed among patients with TRD compared with healthy controls. Baseline NFL concentrations may predict the antidepressant effects of low-dose ketamine infusion.

Changes in Adipokine, Resitin, and BDNF Concentrations in Treatment-Resistant Depression after Electroconvulsive Therapy

OBJECTIVES

One of the current challenges in psychiatry is the search for answers on how to effectively manage drug-resistant depression. The occurrence of drug resistance in patients is an indication for the use of electroconvulsive therapy (ECT). This method is highly effective and usually results in relatively quick health improvement. Despite the knowledge of how ECT works, not all of the biological pathways activated during its use have been identified. Hence, based on the neuroinflammatory hypothesis of depression, we investigated the concentration of two opposite-acting adipokines (anti-inflammatory adiponectin and proinflammatory resistin) and BDNF in antidepressant-resistant patients undergoing ECT.

METHODS

The study group comprised 52 patients hospitalized due to episodes of depression in the course of unipolar and bipolar affective disorder. The serum concentration of adipokines and BDNF was determined before and after the therapeutic intervention using an ELISA method. In the analyses, we also included comparisons considering the type of depression, sex, and achieving remission.

RESULTS

Adiponectin, resistin, and BDNF concentrations change after ECT treatment. These changes are correlated with an improvement in the severity of depressive symptoms and are more or less pronounced depending on the type of depression.

CONCLUSIONS

Although not all observed changes reach statistical significance, adipokines in particular remain exciting candidates for biomarkers in assessing the course of the disease and response to ECT treatment.

Latin American consensus recommendations for the management and treatment of patients with treatment-resistant depression (TRD)

Despite the abundance of literature on treatment-resistant depression (TRD), there is no universally accepted definition of TRD, and available treatment pathways for the management of TRD vary across the Latin American region, highlighting the need for a uniform definition and treatment principles to optimize the management of TRD in Latin America.

METHODS

Following a thematic literature review and pre-meeting survey, a Latin America expert panel comprising 14 psychiatrists with clinical experience in managing patients with TRD convened and utilized the RAND/UCLA appropriateness method to develop consensus-based recommendations on the appropriate definition of TRD and principles for its management.

RESULTS

The expert panel agreed that 'treatment-resistant depression' (TRD) is defined as 'failure of two drug treatments of adequate doses, for 4-8 weeks duration with adequate adherence, during a major depressive episode'. A stepwise treatment approach should be employed for the management of TRD - treatment strategies can include maximizing dose, switching to a different class, and augmenting or combining treatments. Nonpharmacological treatments, such as electroconvulsive therapy, are also appropriate options for patients with TRD.

CONCLUSION

These consensus recommendations on the operational definition of TRD and approved treatments for its management can be adapted to local contexts in the Latin American countries but should not replace clinical judgement. Individual circumstances and benefit-risk balance should be carefully considered while determining the most appropriate treatment option for patients with TRD.

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.

Clinical specificity profile for novel rapid acting antidepressant drugs

Mood disorders are recurrent/chronic diseases with variable clinical remission rates. Available antidepressants are not effective in all patients and often show a relevant response latency, with a range of adverse events, including weight gain and sexual dysfunction. Novel rapid agents were developed with the aim of overcoming at least in part these issues. Novel drugs target glutamate, gamma-aminobutyric acid, orexin, and other receptors, providing a broader range of pharmacodynamic mechanisms, that is, expected to increase the possibility of personalizing treatments on the individual clinical profile. These new drugs were developed with the aim of combining a rapid action, a tolerable profile, and higher effectiveness on specific symptoms, which were relatively poorly targeted by standard antidepressants, such as anhedonia and response to reward, suicidal ideation/behaviours, insomnia, cognitive deficits, and irritability. This review discusses the clinical specificity profile of new antidepressants, namely 4-chlorokynurenine (AV-101), dextromethorphan-bupropion, pregn-4-en-20-yn-3-one (PH-10), pimavanserin, PRAX-114, psilocybin, esmethadone (REL-1017/dextromethadone), seltorexant (JNJ-42847922/MIN-202), and zuranolone (SAGE-217). The main aim is to provide an overview of the efficacy/tolerability of these compounds in patients with mood disorders having different symptom/comorbidity patterns, to help clinicians in the optimization of the risk/benefit ratio when prescribing these drugs.

Dexmedetomidine in the Treatment of Depression: An Up-to-date Narrative Review

Depressive disorders (DD) are common, and their prevalence is expected to rise over the next decade. Depressive disorders are linked to significant morbidity and mortality. The clinical conundrum of depressive disorders lies in the heterogeneity of their phenomenology and etiology. Further, the currently available antidepressants have several limitations, including a delayed onset of action, limited efficacy, and an unfavorable side effect profile. In this review, Dexmedetomidine (DEX), a highly selective and potent α2-adrenergic receptor (α2-AR) agonist, is proposed as a potentially novel antidepressant with multiple mechanisms of action targeting various depression pathophysiological processes. These mechanisms include modulation of the noradrenergic system, regulation of neuroinflammation and oxidative stress, influence on the Brain-Derived Neurotrophic Factor (BDNF) levels, and modulation of neurotransmitter systems, such as glutamate. The review begins with an introduction before moving on to a discussion of DEX's pharmacological features. The pathophysiological and phenomenological targets of DD are also explored, along with the review of the existing preclinical and clinical evidence for DEX's putative anti-depressant effects. Finally, the review ends by presenting the pertinent conclusions and future directions.