[How to define treatment-resistant depression?]

Cognitive impairment and therapeutic response in resistant depression

OBJECTIVES

Therapeutic response in depression is a major challenge since more than one third of patients are not in remission after two attempts of antidepressant treatment and will present a treatment-resistant depression. In order to better adapt therapeutic strategies for treatment-resistant patients, predictive indicators and markers of therapeutic response still need to be identified. In parallel, patients with depression exhibit disturbances in cognitive functioning. This study aims to describe and compare cognitive performances collected at inclusion of patients presenting treatment-resistant depression who will be responders at 6 months to those of non-responders, and to evaluate the predictive value of cognitive indicators on clinical therapeutic response at 6 months after a therapeutic modification.

METHODS

Observational study. Patients were evaluated at the clinical (HDRS and BDI-II) and cognitive levels using standardized tools assessing memory, executive functions, attention, and social cognition, prior to a change in antidepressant treatment. Six months after inclusion, they were reassessed and classified into two groups based on the presence or absence of therapeutic response, defined by a 50% improvement on HDRS and BDI-II. The cognitive scores collected at inclusion were then compared. Additionally, univariate logistic regression models were used.

RESULTS

Thirty patients were included in this study. Only 13 could be evaluated at 6 months. Among these patients, four had responded to the new treatment while nine were non-responders. Both groups of patients presented deviant cognitive performances compared to norms on tests evaluating executive functions and attention. Statistical analyses did not reveal any difference between the cognitive performances of responders and non-responders at 6 months. Regression analyses showed no association between cognitive scores and therapeutic response at 6 months.

CONCLUSION

Executive functioning plays a significant role in treatment-resistant depression. In order to improve the understanding and identification of subtypes of depression, cognitive indicators should be systematically integrated into future research.

The priming effect of repetitive transcranial magnetic stimulation on clinical response to electroconvulsive therapy in treatment-resistant depression: a randomized, double-blind, sham-controlled study

BACKGROUND

Electroconvulsive therapy (ECT) is one of the most effective treatments for treatment-resistant depression (TRD). However, due to response delay and cognitive impairment, ECT remains an imperfect treatment. Compared to ECT, repetitive transcranial magnetic stimulation (rTMS) is less effective at treating severe depression, but has the advantage of being quick, easy to use, and producing almost no side effects. In this study, our objective was to assess the priming effect of rTMS sessions before ECT on clinical response in patients with TRD.

METHODS

In this multicenter, randomized, double-blind, sham-controlled trial, 56 patients with TRD were assigned to active or sham rTMS before ECT treatment. Five sessions of active/sham neuronavigated rTMS were administered over the left dorsolateral prefrontal cortex (20 Hz, 90% resting motor threshold, 20 2 s trains with 60-s intervals, 800 pulses/session) before ECT (which was active for all patients) started. Any relative improvements were then compared between both groups after five ECT sessions, in order to assess the early response to treatment.

RESULTS

After ECT, the active rTMS group exhibited a significantly greater relative improvement than the sham group [43.4% (28.6%) v. 25.4% (17.2%)]. The responder rate in the active group was at least three times higher. Cognitive complaints, which were assessed using the Cognitive Failures Questionnaire, were higher in the sham rTMS group compared to the active rTMS group, but this difference was not corroborated by cognitive tests.

CONCLUSIONS

rTMS could be used to enhance the efficacy of ECT in patients with TRD. ClinicalTrials.gov: NCT02830399.

Efficacy and Safety of Intranasal Esketamine in Patients With Treatment-Resistant Depression and Comorbid Chronic Post-traumatic Stress Disorder: Open-Label Single-Arm Pilot Study

INTRODUCTION

Major depressive disorder (MDD) is more likely to resist to usual treatment when it is associated with post-traumatic stress disorder (PTSD). Capitalizing on the effect of ketamine in both treatment-resistant depression (TRD) and PTSD, we conducted a study in order to assess the efficacy of intranasal (IN) Esketamine in patients having TRD with comorbid PTSD.

MATERIALS AND METHODS

In this open-label, single arm, retrospective pilot study, 11 patients were treated with IN Esketamine (56 or 84 mg) with a longitudinal follow-up of 6 months. IN Esketamine was administered twice weekly during the first month, once weekly during the second month, and then once every 1 or 2 weeks. Patients were assessed with Montgomery-Åsberg Depression Rating Scale (MADRS), Patient Health Questionnaire 9 items, Global Assessment of Functioning (GAF), and Clinical Global Impression-Suicide Scale (CGI-SS).

RESULTS

We included 9 women and 2 men (mean age 47.3 ± 11.1 years). The mean (SD) MADRS scores decreased significantly from 38.6 (6.4) at baseline to 18.2 (10.03) after 6 months of IN Esketamine; 7 patients were responders and 3 patients were in remission. The percentage of patients who were moderately to severely suicidal declined from 63.6% at baseline to 27.3% after 1 month of IN Esketamine sessions. No serious adverse reactions were observed.

CONCLUSION

This study reports the outcomes of 11 severely ill patients with comorbid TRD and PTSD after IN Esketamine treatment. Esketamine significantly improved depression symptoms, suggesting that it is likely to be a treatment of choice in this specific population.

A clinical approach to treatment resistance in depressed patients: What to do when the usual treatments don't work well enough?

BACKGROUND

Major depressive disorder is a common, recurrent, disabling and costly disorder that is often severe and/or chronic, and for which non-remission on guideline concordant first-line antidepressant treatment is the norm. A sizeable percentage of patients diagnosed with MDD do not achieve full remission after receiving antidepressant treatment. How to understand or approach these 'refractory', 'TRD' or 'difficult to treat' patients need to be revisited. Treatment resistant depression (TRD) has been described elsewhere as failure to respond to adequate treatment by two different antidepressants. This definition is problematic as it suggests that TRD is a subtype of major depressive disorder (MDD), inferring a boundary between TRD and depression that is not treatment resistant. However, there is scant evidence to suggest that a discrete TRD entity exists as a distinct subtype of MDD, which itself is not a discrete or homogeneous entity. Similarly, the boundary between TRD and other forms of depression is predicated at least in part on regulatory and research requirements rather than biological evidence or clinical utility.

AIM

This paper aims to investigate the notion of treatment failure in order to understand (i) what is TRD in the context of a broader formulation based on the understanding of depression, (ii) what factors make an individual patient difficult to treat, and (iii) what is the appropriate and individualised treatment strategy, predicated on an individual with refractory forms of depression?

METHOD

Expert contributors to this paper were sought internationally by contacting representatives of key professional societies in the treatment of MDD - World Federation of Societies for Biological Psychiatry, Australasian Society for Bipolar and Depressive Disorders, International Society for Affective Disorders, Collegium Internationale Neuro-Psychopharmacologium and the Canadian Network for Mood and Anxiety Treatments. The manuscript was prepared through iterative editing.

OUTCOMES

The concept of TRD as a discrete subtype of MDD, defined by failure to respond to pharmacotherapy, is not supported by evidence. Between 15 and 30% of depressive episodes fail to respond to adequate trials of 2 antidepressants, and 68% of individuals do not achieve remission from depression after a first-line course of antidepressant treatment. Failure to respond to antidepressant treatment, somatic therapies or psychotherapies may often reflect other factors including; biological resistance, diagnostic error, limitations of current therapies, psychosocial variables, a past history of exposure to childhood maltreatment or abuse, job satisfaction, personality disorders, co-morbid mental and physical disorders, substance use or non-adherence to treatment. Only a subset of patients not responding to antidepressant treatment can be explained through pharmacokinetic or pharmacodynamics mechanisms. We propose that non remitting MDD should be personalised, and propose a strategy of 'deconstructing depression'. By this approach, the clinician considers which factors contribute to making this individual both depressed and 'resistant' to previous therapeutic approaches. Clinical formulation is required to understand the nature of the depression. Many predictors of response are not biological, and reflect a confluence of biological, psychological, and sociocultural factors, which may influence the illness in a particular individual. After deconstructing depression at a personalised level, a personalised treatment plan can be constructed. The treatment plan needs to address the factors that have contributed to the individual's hard to treat depression. In addition, an individual with a history of illness may have a lot of accumulated life issues due to consequences of their illness, and these should be addressed in a recovery plan.

LIMITATIONS

A 'deconstructing depression' qualitative rubric does not easily provide clear inclusion and exclusion criteria for researchers wanting to investigate TRD.

CONCLUSIONS

MDD is a polymorphic disorder and many individuals who fail to respond to standard pharmacotherapy and are considered hard to treat. These patients are best served by personalised approaches that deconstruct the factors that have contributed to the patient's depression and implementing a treatment plan that adequately addresses these factors. The existence of TRD as a discrete and distinct subtype of MDD, defined by two treatment failures, is not supported by evidence.

[Treatments for depression in consultation-liaison psychiatry: From theory to practice]

Treatments for depression include an adapted lifestyle, physical activity, psychotherapies, antidepressant and mood stabilizing drugs, neuromodulation, chronotherapy, spa treatments. Drug treatments used for major depressive episode are antidepressants and mood stabilizers. For a mild episode, psychotherapy is indicated. It should be combined with an antidepressant (serotonin reuptake inhibitor) for moderate and severe episodes. Suicide risk assessment is essential throughout the depressive episode. It is recommended to monitor at the start of antidepressant treatment for suicidal behavior, a change in mood suggesting an underlying bipolar disorder. The effectiveness of the treatment is evaluated after 4 to 8 weeks. The total duration of antidepressant treatment for an EDC is between 6 months and 1 year after remission, in order to prevent relapses. The use of liaison psychiatry, a real healthcare system within the general hospital, is strongly recommended for better screening and treatment of depression, thus reducing the length of hospital stays, improving the prognosis of depression. The aim of this article is to provide clinicians with a summary of validated data on the efficacy/tolerance of treatment for depression, and to suggest practical action to be taken on the main daily clinical situations: treating comorbid conditions, taking into account interactions drugs, manage the serotonin syndrome, lead to withdrawal from antidepressants, manage treatment in the elderly.

Treatment-Resistant Depression in a Real-World Setting: First Interim Analysis of Characteristics, Healthcare Resource Use, and Utility Values of the FondaMental Cohort

Background: Major depressive disorder (MDD) is among the most common psychiatric disorders. One-third of patients are usually unresponsive to several lines of treatment. This study aimed to describe the FondaMental French cohort of patients with treatment-resistant depression (TRD) and to estimate utility and healthcare resource use outcomes. Methods: Patients with TRD were evaluated prospectively over four years (baseline, 6, 12, 18, 24, 36 and 48 months) in a real-world clinical setting. Interim analyses focused on the first two consecutive years. Four MDD-related states (major depressive episode (MDE), response, remission, recovery) were defined based on the MADRS (Montgomery–Åsberg depression rating scale) and other clinical events. Health status was assessed with the EuroQol 5 Dimensions 5 Level (EQ-5D-5L) questionnaire. Utility values were estimated as preference measures that the patients assigned to their overall health status. Results: This study was based on 252 patients with TRD. The mean utility value by health state was 0.41, 0.63, 0.80, and 0.90, for MDE, response, remission, and recovery, respectively. At baseline, 59% of patients had an MADRS score of at least 28. Their baseline average utility value was lower compared to the other patients (0.43 versus 0.58, p < 0.001). This significant difference persisted at the following visits. The rate of patients in MDEs having at least one hospitalisation for depression or other reasons than depression was generally higher than that in the other health states. Conclusion: This study documented patterns in healthcare resource consumption, quality of life, and other characteristics in patients with TRD, both globally and by health state and depression severity.

Brain SPECT perfusion and PET metabolism as discordant biomarkers in major depressive disorder

Background

Brain SPECT perfusion and PET metabolism have been, most often interchangeably, proposed to study the underlying pathological process in major depressive disorder (MDD). The objective of this study was to specify similarities and inconsistencies between these two biomarkers according to global characteristics of the disease. We conducted a retrospective study in 16 patients suffering from treatment-resistant MDD who underwent, during the same current episode, a cerebral perfusion SPECT with ^99mTc-HMPAO and a metabolic PET with ¹⁸F-FDG. Whole-brain voxel-based SPM(T) maps were generated in correlation with the number of depressive episodes and in correlation with the depression duration, separately for the two exams (p-voxel < 0.001 uncorrected, k > 20).

Results

No significant correlations were found between brain metabolism and either the number of depressive episodes or the duration of the disease, even at an uncorrected p-voxel < 0.005. On the other hand, the increased number of depressive episodes was correlated with decreased perfusion of the right middle frontal cortex, the right anterior cingulum cortex, the right insula, the right medial temporal cortex and the left precuneus. The increased depression duration was correlated with decreased perfusion of the right anterior cingulum cortex.

Conclusions

This preliminary study demonstrates more significant results with brain perfusion compared with glucose metabolism in treatment-resistant MDD, highlighting the value of brain SPECT despite less favourable instrumentation detection compared to PET.

Treatment resistant depression incidence and prevalence using the French nationwide claims database

PURPOSE

To estimate annual incidence and prevalence of Treatment-Resistant Depression (TRD) in France.

METHODS

We identified all adult patients (≥ 18 years) with a TRD episode between 1 January 2012 and 31 December 2014 in the EGB (Échantillon généraliste des bénéficiaires), a permanent random sample of the French nationwide claims database. After a 6-month washout period without hospitalization for depression or any antidepressants (AD), and after exclusion of psychotic or bipolar affective disorders, Parkinson's disease and dementia, a TRD episode was defined by three successive sequences of different AD over a 3-month treatment period (6 months for a sensitive analysis), with at least 3 weeks before each sequence change and a Medication Possession Ratio ≥ 80%; or by the dispensing of >two different AD together; or of an AD with a potentiator (lithium, antiepileptic drugs, antipsychotic drugs, thyroid hormones) over the same treatment period. The annual incidence rate was estimated from 2012 to 2014 and the prevalence using a Gamma parametric function based on treatment duration and a 30-year prediction.

RESULTS

Between 2012 and 2014, 700 patients were identified in EGB with a TRD episode. The mean age was 47.4 years (±15.3); 52.7% were women. Annual incidence and prevalence of TRD were estimated at 5.8 and 25.8 per 10 000 patients, respectively and at 7.8 and 37.6 per 10 000 patients, respectively in the sensitivity analysis.

CONCLUSION

This study provides the first population-based estimates for incidence and prevalence of TRD in France.

Cost-utility analysis of transcranial direct current stimulation (tDCS) in non-treatment-resistant depression: the DISCO randomised controlled study protocol

INTRODUCTION

Depression is among the most widespread psychiatric disorders in France. Psychiatric disorders are associated with considerable social costs, amounting to €22.6 billion for treatment and psychotropic medication in 2011. Treatment as usual (TAU), mainly consisting of pharmacotherapy and psychotherapy, is effective for only a third of patients and in most cases fails to prevent treatment resistance and chronicity. Transcranial direct current stimulation (tDCS) consists in a non-invasive and painless application of low-intensity electric current to the cerebral cortex through the scalp. Having proved effective in depressed patients, it could be used in combination with TAU to great advantage. The objective is to compare, for the first time ever, the cost-utility of tDCS-TAU and of TAU alone for the treatment of a depressive episode that has been refractory to one or two drug treatments.

METHODS AND ANALYSIS

This paper, based on the DISCO study protocol, focuses on the design of a prospective, randomised, controlled, open-label multicentre economic study to be conducted in France. It will include 214 patients with unipolar or bipolar depression, assigning them to two parallel arms: group A (tDCS-TAU) and group B (TAU alone). The primary outcome is the incremental cost-effectiveness ratio, that is, the ratio of the difference in cost between each strategy to the difference in their effects. Their effects will be expressed as numbers of quality-adjusted life-years, determined through administration of the EuroQol Five-Dimension questionnaire over a 12-month period to patients (EQ-5D-5L). Expected benefits are the reduction of treatment resistance and suicidal ideation as well as social and professional costs of depression. Should depression-related costs fall significantly, tDCS might be considered an efficient treatment for depression.

ETHICS AND DISSEMINATION

This protocol has been approved by a French ethics committee, the CPP--Est IV (Comité de Protection des Personnes-Strasbourg). Data are to be published in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

RCB 2018-A00474-51; NCT03758105.

Vagus Nerve Stimulation For Treatment Resistant Depression: Case Series Of Six Patients - Retrospective Efficacy And Safety Observation After One Year Follow Up

OBJECTIVE

One year observation and evaluation of the VNS (vagus nerve stimulation) efficacy and safety for patients with treatment resistant depression in Polish conditions.

METHODS

An open label, uncontrolled and one center retrospective study of VNS therapy was implemented with stable pharmacotherapy in 6 patients with treatment resistant depression (TRD). For the first 3 months, only VNS parameters were altered but the pharmacological treatment was unchanged and in the following 9 months, medication and VNS dosing parameters were altered according to the clinical state of the patients.

RESULTS

The baseline 24-item Hamilton Depression Rating Scale (HAMD-24) score averaged 24. Both response (>50% reduction in baseline scores) and remission rates after 3 months of treatment were only 40%. After 1 year of VNS therapy, the response rates increased to 86%. Most frequent side-effects were voice alteration (86% at 3 months of stimulation) and headaches (40%).

CONCLUSION

VNS treatment was safe and effective in TRD patients and its efficacy increased with time. Efficacy ratings are similar to the previously reported studies using a congenial protocol.

Vagus Nerve Stimulation (VNS) and Other Augmentation Strategies for Therapy-Resistant Depression (TRD): Review of the Evidence and Clinical Advice for Use

In addition to electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS), vagus nerve stimulation (VNS) is one of the approved neurostimulation tools for treatment of major depression. VNS is particularly used in therapy-resistant depression (TRD) and exhibits antidepressive and augmentative effects. In long-term treatment, up to two-thirds of patients respond. This mini-review provides a comprehensive overview of augmentation pharmacotherapy and neurostimulation-based treatment strategies, with a special focus on VNS in TRD, and provides practical clinical advice for how to select TRD patients for add-on neurostimulation treatment strategies.

Investigational drugs in recent clinical trials for treatment-resistant depression

INTRODUCTION

The authors describe the medications for treatment-resistant depression (TRD) in phase II/III of clinical development in the EU and USA and provide an opinion on how current treatment can be improved in the near future. Areas covered: Sixty-two trials were identified in US and EU clinical trial registries that included six investigational compounds in recent phase III development and 12 others in recent phase II clinical trials. Glutamatergic agents have been the focus of many studies. A single intravenous dose of the glutamatergic modulator ketamine produces a robust and rapid antidepressant effect in persons with TRD; this effect continues to remain significant for 1 week. This observation was a turning point that opened the way for other, more selective glutamatergic modulators (intranasal esketamine, AVP-786, AVP-923, AV-101, and rapastinel). Of the remaining compounds, monoclonal antibodies open highly innovative therapeutic options, based on new pathophysiological approaches to depression. Expert commentary: Promising new agents are emerging for TRD treatment. Glutamatergic modulators likely represent a very promising alternative to monoaminergic antidepressant monotherapy. We could see the arrival of the first robust and rapid acting antidepressant drug in the near future, which would strongly facilitate the ultimate goal of recovery in persons with TRD.