Treatment resistant depression: methodological overview and operational criteria

Tolerability of High-Dose Venlafaxine After Switch From Escitalopram in Nonresponding Patients With Major Depressive Disorder

BACKGROUND

Within a single depressive episode, most patients receive different antidepressants because of an inadequate response to the first-line antidepressant. A commonly used strategy is to switch from a selective serotonin reuptake inhibitor to a selective serotonin-norepinephrine reuptake inhibitor. However, little is known about the tolerability of this switch with consideration of dose and drug concentration in blood.

METHODS

After 4 weeks of inadequate response to escitalopram (10-20 mg/d), medication was switched to another 4 weeks of venlafaxine (VF, 150-375 mg/d) in 234 depressed patients. Serum concentrations, depression severity, and adverse drug reactions (ADRs) were assessed weekly.

RESULTS

The switch of medication led to an increase of ADRs such as reduced salivation (+11%), orthostatic dizziness (+11%), and sweating (+9.8%). The most frequent ADRs during treatment with VF were reduced salivation (28.6%), sweating (24.6%), and orthostatic dizziness (15.8%). In patients receiving high-dose VF, a significant improvement of depressive symptomatology was observed, and most ADRs decreased during the course of treatment, even in patients above the therapeutic reference range.

LIMITATIONS

Patients and physicians were aware of medication, and there was no direct comparison with the herein presented switch of medication.

IMPLICATIONS

This study provides important information about the tolerability of a commonly used antidepressant treatment strategy. More detailed information about putative ADRs may help clinicians increase compliance through effective patient education. Because ADRs of VF were associated with the plasma concentration, therapeutic drug monitoring is recommended to guide the therapy and manage problems of tolerability.

Sex-related effects in major depressive disorder: Results of the European Group for the Study of Resistant Depression

BACKGROUND

Sex-related effects on the evolution and phenotype of major depressive disorder (MDD) were reported previously.

METHODS

This European multicenter cross-sectional study compared sociodemographic, clinical, and treatment patterns between males and females in a real-world sample of 1410 in- and outpatients with current MDD.

RESULTS

Male MDD patients (33.1%) were rather inpatients, suffered from moderate to high suicidality levels, received noradrenergic and specific serotonergic antidepressants (ADs) as first-line AD treatment, generally higher mean AD daily doses, and showed a trend towards a more frequent administration of add-on treatments. Female MDD patients (66.9%) were rather outpatients, experienced lower suicidality levels, comorbid thyroid dysfunction, migraine, asthma, and a trend towards earlier disease onset.

CONCLUSIONS

The identified divergencies may contribute to the concept of male and female depressive syndromes and serve as predictors of disease severity and course, as they reflect phenomena that were repeatedly related to treatment-resistant depression (TRD). Especially the greater necessity of inpatient treatment and more complex psychopharmacotherapy in men may reflect increased therapeutic efforts undertaken to treat suicidality and to avoid TRD. Hence, considering sex may guide the diagnostic and treatment processes towards targeting challenging clinical manifestations including comorbidities and suicidality, and prevention of TRD and chronicity.

A narrative review on invasive brain stimulation for treatment-resistant depression

While most patients with depression respond to pharmacotherapy and psychotherapy, about one-third will present treatment resistance to these interventions. For patients with treatment-resistant depression (TRD), invasive neurostimulation therapies such as vagus nerve stimulation, deep brain stimulation, and epidural cortical stimulation may be considered. We performed a narrative review of the published literature to identify papers discussing clinical studies with invasive neurostimulation therapies for TRD. After a database search and title and abstract screening, relevant English-language articles were analyzed. Vagus nerve stimulation, approved by the U.S. Food and Drug Administration as a TRD treatment, may take several months to show therapeutic benefits, and the average response rate varies from 15.2-83%. Deep brain stimulation studies have shown encouraging results, including rapid response rates (> 30%), despite conflicting findings from randomized controlled trials. Several brain regions, such as the subcallosal-cingulate gyrus, nucleus accumbens, ventral capsule/ventral striatum, anterior limb of the internal capsule, medial-forebrain bundle, lateral habenula, inferior-thalamic peduncle, and the bed-nucleus of the stria terminalis have been identified as key targets for TRD management. Epidural cortical stimulation, an invasive intervention with few reported cases, showed positive results (40-60% response), although more extensive trials are needed to confirm its potential in patients with TRD.

Risk of serious medical events in patients with depression treated with electroconvulsive therapy: a propensity score-matched, retrospective cohort study

BACKGROUND

Previous studies examining the risk of medical complications from electroconvulsive therapy have been confounded and this might contribute to its underuse. This study aimed to compare the risk of serious medical events, defined as those resulting in hospitalisation or death, among patients with depression who received electroconvulsive therapy versus patients who did not receive electroconvulsive therapy.

METHODS

This was a propensity score-matched, retrospective cohort study using linked population-based administrative health data for adults admitted to designated psychiatric facilities in Ontario, Canada, for more than 3 days with depression between April 1, 2007, to Feb 28, 2017. Electroconvulsive therapy exposure was defined as one or more physician billing procedure codes during hospitalisation. The unit of analysis was individual admissions and propensity score matching was used to match each exposed admission to an unexposed admission to estimate the average treatment effect of electroconvulsive therapy among those treated. The primary outcome was serious medical events, a composite of hospitalisation for medical (ie, non-psychiatric) reasons or non-suicide death within 30 days from electroconvulsive therapy exposure or matched date in the unexposed group. Effect modification was examined using tests of interaction for three clinically relevant prespecified subgroups (sex, presence of psychotic symptoms, and illness polarity). Secondary outcomes were medical hospitalisation and non-suicide death separately, suicide death, and specific serious medical events.

FINDINGS

In propensity score matched analyses, there were 10 016 psychiatric hospitalisation records (6628 women, 3388 men) with mean age 56·6 years (SD 16·3) and no ethnicity data available. 65 818 admissions were eligible for matching and 5008 were matched (1:1) in each exposure group. In the propensity score matched cohort, the incidence of serious medical events was 0·25 per person-year in the exposed group and 0·33 per person-year in the unexposed group (cause-specific hazard ratio 0·78 [95% CI 0·61-1·00]). Suicide death as a competing risk did not alter this finding. The risk of suicide death was significantly lower in the exposed (≤5 of 5008 admissions) versus the unexposed group (11 [0·2%] of 5008 admissions; p<0·03). Bipolar depression, compared with unipolar depression, was associated with a greater reduction in the risk of serious medical events with electroconvulsive therapy. Electroconvulsive therapy was not associated with medical hospitalisation or non-suicide death separately, nor with any specific serious medical event.

INTERPRETATION

Among individuals hospitalised with depression, we found no evidence for a clinically significant increased risk for serious medical events with exposure to electroconvulsive therapy, and the risk of suicide was found to be significantly reduced, suggesting the benefits of electroconvulsive therapy for depression outcomes might outweigh its risks in this population.

FUNDING

Norris Scholars Award, Department of Psychiatry, University of Toronto; the Canadian Institutes for Health Research.

Practical recommendations for the management of treatment-resistant depression with esketamine nasal spray therapy: Basic science, evidence-based knowledge and expert guidance

OBJECTIVES

Despite the available therapies for treatment-resistant depression (TRD), there are a limited number that are evidence-based and effective in this hard-to-treat population. Esketamine nasal spray, an intranasal N-methyl-d-aspartate (NMDA) glutamate receptor antagonist, is a novel, fast-acting option in this patient population. This manuscript provides expert guidance on the practicalities of using esketamine nasal spray.

METHODS

A group of six European experts in major depressive disorder (MDD) and TRD, with clinical experience of treating patients with esketamine nasal spray, first generated practical recommendations, before editing and voting on these to develop consensus statements during an online meeting.

RESULTS

The final consensus statements encompass not only pre-treatment considerations for patients with TRD, but also specific guidelines for clinicians to consider during and post-administration of esketamine nasal spray.

CONCLUSIONS

Esketamine nasal spray is a novel, fast-acting agent that provides an additional treatment option for patients with TRD who have previously failed several therapies. The guidance here is based on the authors' experience and the available literature; however, further real-world use of esketamine nasal spray will add to existing knowledge. The recommendations offer practical guidance to clinicians who are unfamiliar with esketamine nasal spray.

Real-world evidence from a European cohort study of patients with treatment resistant depression: Treatment patterns and clinical outcomes

BACKGROUND

Treatment resistant depression (TRD) characterizes a subgroup of 10-30% of patients with major depressive disorder, and is associated with considerable morbidity and mortality. A consensus treatment for TRD does not exist, which often leads to wide variations in treatment strategies. Real-world studies on treatment patterns and outcomes in TRD patients in Europe are lacking and could help elucidate current treatment strategies and their efficacy.

METHODS

This non-interventional cohort study of patients with TRD (defined as treatment failure on ≥2 oral antidepressants given at adequate dose and duration) with moderate to severe depression collected real-world data on treatment patterns and outcomes in several European countries. Patients were started on a new treatment for depression according to routine clinical practice.

RESULTS

Among 411 patients enrolled, after 6 months, only 16.7% achieved remission and 73.5% showed no response. At Month 12, while 19.2% achieved remission and 69.2% showed no response, 33.3% of those in remission at Month 6 were no longer in remission. Pharmacological treatments employed were heterogenous; 54 different drugs were recorded at baseline, and the top 5 treatment types according to drug classes accounted for 40.0% of patients. Even though remission rates were very low, at Month 12, 60.0% of patients had not changed treatment since enrolment.

CONCLUSIONS

The heterogeneity of treatments highlights a lack of consensus. Moreover, despite low response rates, patients often remained on treatments for substantial periods of time. These data further support existence of an unmet treatment need for TRD patients in Europe.

The Role of Relationship Status in Major Depressive Disorder - Results of the European Group for the Study of Resistant Depression

BACKGROUND

While the association between relationship status and the development of depressive symptoms in the general population were reported previously, its relation to the severity and the course of major depressive disorder (MDD) as well as the treatment patterns and response rates needs to be elucidated.

METHODS

The present international multicenter cross-sectional study performed by the European Group for the Study of Resistant Depression (GSRD) investigated socio-demographic and clinical patterns of relationship status in a real-world sample of 1410 adult in- and outpatients with MDD as primary diagnosis.

RESULTS

While 49.9% of all MDD patients were partnered, 25.4% were separated, and 24.8% were single. Single relationship status was linked to younger mean age, earlier mean age of onset, and current suicidal risk. Being separated was related to older mean age, unemployment, greater symptom severity, current suicidal risk, and add-on treatment strategies. Partnered relationship status was associated with less frequent current suicidal risk.

LIMITATIONS

The retrospective assessment of treatment response that was exclusively based on psychopharmacotherapeutic strategies should be critically considered and weighed while interpreting the present results providing novel insights into the complex interaction of relationship status with the clinical phenotype of MDD.

CONCLUSIONS

Although MDD patients living in relationships do not seem to be omitted from the evolution of MDD, they may be spared from chronicity and suicidality. Hence, being aware of the current relationship status might support clinicians in the diagnostic and therapeutic process towards optimized management of such challenging clinical phenomena and their negative consequences.

The Genetics of Major Depression: Perspectives on the State of Research and Opportunities for Precision Medicine

Major depression (MD) is a leading cause of disability worldwide; it arises from the action and interaction between genetic and environmental factors, and is often comorbid with other psychiatric and medical conditions. To date, upwards of 100 genetic loci have been associated with MD, giving clues to biological underpinnings. Although recent progress has yielded modest insight into the genetic architecture of MD, most studies have been in populations with European ancestry, seriously limiting precision medicine efforts. Broadening diversity of study populations will empower genomic research by expanding discovery and enhancing our understanding of the role of genomic variation in disease etiology. To fully realize the potential of pharmacogenetics and precision medicine, we will need to address the major gaps in our knowledge of the genetic and environmental risk architecture of MD across ancestries, including sex differences, to improve etiologic understanding, diagnosis, prevention, and treatment for all.

Protocol for a systematic review and meta-analysis of the placebo response in treatment-resistant depression: comparison of multiple treatment modalities

INTRODUCTION

The high placebo response in depression treatment trials is a major contributing factor for randomised control trial failure to establish efficacy of novel or repurposed treatments in treatment-resistant depression (TRD) and major depressive disorder in general. Though there have been a number of meta-analyses and primary research studies evaluating the placebo response in non-TRD, placebo response in TRD is poorly understood. It is important to understand the placebo response of TRD as treatments are only moderately effective and up to 1/3 of patients will experience TRD.

METHODS AND ANALYSIS

We will conduct a search of electronic databases (MEDLINE and PsychINFO) from inception to 24th January 2020 including randomised, placebo-controlled trials of pharmacological, somatic and psychological interventions for adults with TRD. TRD will be defined as a failure to respond to at least two interventions of adequate dose or duration. We will also search reference lists from review articles. We will perform several meta-analyses to quantify the placebo response for each treatment modality. Regression analysis will explore potential contributing demographic and clinical variables to the placebo response. We will use Cochrane risk of bias tool.

ETHICS AND DISSEMINATION

There is no research ethics board approval required. The dissemination plan is to publish results in a peer-reviewed academic journal.

PROSPERO REGISTRATION NUMBER

190 465.

Chronic stress has different immediate and delayed effects on hippocampal calretinin- and somatostatin-positive cells

Past studies find that chronic stress alters inhibitory, GABAergic circuitry of neurons in distinct hippocampal subregions. Less clear is whether these effects persist weeks after chronic stress ends, and whether these effects involve changes in the total number of hippocampal GABAergic neurons or modulates the function of specific GABAergic subtypes. A transgenic mouse line (VGAT:Cre Ai9) containing an indelible marker for GABAergic neurons (tdTomato) throughout the brain was used to determine whether chronic stress alters total GABAergic neuronal number or the expression of two key GABAergic cell subtypes, calretinin expressing (CR+) and somatostatin expressing (SOM+) neurons, and whether these changes endure weeks later. Male and female mice were chronically stressed in wire mesh restrainers for 6h/d/21d (Str) or not (Con), and then allowed a 3 week rest period (Str-Rest) and compared to those without a rest period (Str-NoRest). Epifluorescent microscope images of immunohistochemistry-processed brains were quantified to estimate the total number of fluorescently-labeled hippocampal GABAergic neurons and the proportion that were CR+ or SOM+. Neither chronic stress nor sex altered the total number of GABAergic cells. In contrast, chronic stress reduced the expression of CR+ in the CA3 region of the hippocampus in both males and females, with robust reductions in the DG region of males, but not females, and these changes reversed following a rest period. Chronic stress also reduced the proportion of hippocampal SOM+ neurons and this reduction persisted even with a rest period. These results show chronic stress dynamically reduced CR expression without changing total inhibitory neuronal number and point to CR as a potential new lead to understand mechanisms by which chronic stress alters hippocampal function.

Augmentation with Atypical Antipsychotics for Treatment-Resistant Depression

BACKGROUND

Treatment-resistant depression (TRD) is considered a common clinical condition often associated with relevant suicidal ideation and characterized by a severe functional impairment lifetime. Among the available drugs for the TRD treatment, second-generation antipsychotics (SGAs) have been reported as effective. In this context, the aim of this study was to review the clinical studies evaluating the efficacy of SGAs as add-on therapy in TRD.

METHODS

A comprehensive search on PubMed, Medline and PsychINFO of all randomized clinical trials (RCTs) assessing the augmentation with antipsychotics in TRD, published from January 2000 until March 2020, was performed. Sixteen RCTs studies met the inclusion criteria.

RESULTS

The reviewed studies showed that the add-on therapy with aripiprazole could be beneficial in the treatment of TRD. Furthermore, RCTs on quetiapine augmentation support its use in TRD, especially when comorbid anxiety or insomnia are present. The effects of risperidone and olanzapine as add-on in TRD were less studied, but preliminary data indicated an efficacy respect to placebo, making them a possible therapeutic option in TRD.

LIMITATIONS

The lack of consistency in the definition of TRD together with the small sample sizes and the heterogeneity of antipsychotics dosages used in the reviewed RCTs may have limited the strength of evidences obtained.

CONCLUSION

Overall, the available RCTs studies seem to support the hypothesis that the augmentation with SGAs, in particular aripiprazole and quetiapine, is a valid therapeutic option for TRD. However, to improve the therapeutic outcome of patients with TRD, larger and more homogeneous RCTs are needed.

Drug repositioning for treatment-resistant depression: Hypotheses from a pharmacogenomic study

About 20-30% of patients with major depressive disorder (MDD) develop treatment-resistant depression (TRD) and finding new effective treatments for TRD has been a challenge. This study aimed to identify new possible pharmacological options for TRD. Genes in pathways included in predictive models of TRD in a previous whole exome sequence study were compared with those coding for targets of drugs in any phase of development, nutraceuticals, proteins and peptides from Drug repurposing Hub, Drug-Gene Interaction database and DrugBank database. We tested if known gene targets were enriched in TRD-associated genes by a hypergeometric test. Compounds enriched in TRD-associated genes after false-discovery rate (FDR) correction were annotated and compared with those showing enrichment in genes associated with MDD in the last Psychiatric Genomics Consortium genome-wide association study. Among a total of 15,475 compounds, 542 were enriched in TRD-associated genes (FDR p < .05). Significant results included drugs which are currently used in TRD (e.g. lithium and ketamine), confirming the rationale of this approach. Interesting molecules included modulators of inflammation, renin-angiotensin system, proliferator-activated receptor agonists, glycogen synthase kinase 3 beta inhibitors and the rho associated kinase inhibitor fasudil. Nutraceuticals, mostly antioxidant polyphenols, were also identified. Drugs showing enrichment for TRD-associated genes had a higher probability of enrichment for MDD-associated genes compared to those having no TRD-genes enrichment (p = 6.21e-55). This study suggested new potential treatments for TRD using a in silico approach. These analyses are exploratory only but can contribute to the identification of drugs to study in future clinical trials.

Treatment-resistant depression: Neurobiological correlates and the effect of sleep deprivation with sleep phase advance for the augmentation of pharmacotherapy

OBJECTIVES

To assess the neurobiology of treatment-resistant depression (TRD), and factors connected with improvement after total sleep deprivation (TSD) with sleep phase advance (SPA), for the augmentation of pharmacotherapy.

METHODS

The study comprised 43 patients with TRD, (15 male, 28 female), aged 48 ± 13 years, with the illness duration 12 ± 9 years, and the depressive episode 8 ± 7 months. TRD was defined as a lack of significant improvement despite at least two antidepressant treatments and the augmentation with mood-stabilisers. Clinical improvement (response) was a reduction of ≥50% of points in the Hamilton Depression Rating Scale (HDRS), and the remission criterion was ≤7 points in HDRS, lasting until the 14th day after TSD + SPA.

RESULTS

TRD severity was associated with greater activity of the hypothalamic-pituitary-adrenal axis, the pro-inflammatory status of the immune system and lower reactivity of the hypothalamic-pituitary-thyroid axis. The response was achieved by 18 of 42 subjects, and connected with the later onset and shorter duration of the disease. In responders, there was a decrease in cortisol and interferon-gamma. In all subjects, a decrease in thyroid hormones was observed.

CONCLUSIONS

TRD can improve after augmentation of pharmacotherapy by TSD + SPA and some biological changes may be compatible with a decrease in allostatic load.

Small-molecule control of neurotransmitter sulfonation

Controlling unmodified serotonin levels in brain synapses is a primary objective when treating major depressive disorder-a disease that afflicts ∼20% of the world's population. Roughly 60% of patients respond poorly to first-line treatments and thus new therapeutic strategies are sought. To this end, we have constructed isoform-specific inhibitors of the human cytosolic sulfotransferase 1A3 (SULT1A3)-the isoform responsible for sulfonating ∼80% of the serotonin in the extracellular brain fluid. The inhibitor design includes a core ring structure, which anchors the inhibitor into a SULT1A3-specific binding pocket located outside the active site, and a side chain crafted to act as a latch to inhibit turnover by fastening down the SULT1A3 active-site cap. The inhibitors are allosteric, they bind with nanomolar affinity and are highly specific for the 1A3 isoform. The cap-stabilizing effects of the latch can be accurately calculated and are predicted to extend throughout the cap and into the surrounding protein. A free-energy correlation demonstrates that the percent inhibition at saturating inhibitor varies linearly with cap stabilization - the correlation is linear because the rate-limiting step of the catalytic cycle, nucleotide release, scales linearly with the fraction of enzyme in the cap-open form. Inhibitor efficacy in cultured cells was studied using a human mammary epithelial cell line that expresses SULT1A3 at levels comparable with those found in neurons. The inhibitors perform similarly in ex vivo and in vitro studies; consequently, SULT1A3 turnover can now be potently suppressed in an isoform-specific manner in human cells.

Combining machine learning algorithms for prediction of antidepressant treatment response

OBJECTIVES

Predictors for unfavorable treatment outcome in major depressive disorder (MDD) applicable for treatment selection are still lacking. The database of a longitudinal multicenter study on 1079 acutely depressed patients, performed by the German research network on depression (GRND), allows supervised and unsupervised learning to further elucidate the interplay of clinical and psycho-sociodemographic variables and their predictive impact on treatment outcome phenotypes.

EXPERIMENTAL PROCEDURES

Treatment response was defined by a change of HAM-D 17-item baseline score ≥50% and remission by the established threshold of ≤7, respectively, after up to eight weeks of inpatient treatment. After hierarchical symptom clustering and stratification by treatment subtypes (serotonin reuptake inhibitors, tricyclic antidepressants, antipsychotic, and lithium augmentation), prediction models for different outcome phenotypes were computed with random forest in a cross-center validation design. In total, 88 predictors were implemented.

RESULTS

Clustering revealed four distinct HAM-D subscores related to emotional, anxious, sleep, and appetite symptoms, respectively. After feature selection, classification models reached moderate to high accuracies up to 0.85. Highest accuracies were observed for the SSRI and TCA subgroups and for sleep and appetite symptoms, while anxious symptoms showed poor predictability.

CONCLUSION

Our results support a decisive role for machine learning in the management of antidepressant treatment. Treatment- and symptom-specific algorithms may increase accuracies by reducing heterogeneity. Especially, predictors related to duration of illness, baseline depression severity, anxiety and somatic symptoms, and personality traits moderate treatment success. However, prospectives application of machine learning models will be necessary to prove their value for the clinic.

Add-on benzodiazepine treatment in patients with major depressive disorder - results from a European cross-sectional multicenter study

Since many patients with major depressive disorder (MDD) do not satisfactorily respond to initial antidepressant monotherapy, add-on treatment strategies with other psychiatric compounds are often established. The present European multicenter cross-sectional study comprising 1410 MDD in- and outpatients investigated the prescription pattern of benzodiazepines as add-on treatment in the psychopharmacotherapy of MDD. Analyses of variance, chi-squared tests, and logistic regression analyses were conducted to examine differences in socio-demographic, clinical, and treatment characteristics between benzodiazepine users and non-users. The prescription rate for adjunctive benzodiazepine treatment amounted to 31.35%. The most often administered benzodiazepines were lorazepam (11.13%), clonazepam (6.74%), and alprazolam (6.60%). Benzodiazepine users exhibited more severe depressive symptoms expressed by a higher mean Montgomery and Åsberg Depression Rating Scale total score at study entry (26.92 ± 11.07 vs 23.55 ± 11.23, p<.0001) and at the beginning of the current major depressive episode (35.74 ± 8.08 vs 33.31 ± 7.40, p<.0001). Furthermore, they were characterized by a higher proportion of patients receiving additional augmentation/combination medications with antidepressants (40.95% vs 24.28%, p<.0001), antipsychotics (41.63% vs 18.39%, p<.0001), and low-potency antipsychotics (10.18% vs 4.75%, p<.0001). Moreover, benzodiazepine prescription was associated with older age, unemployment, inpatient treatment, suicide risk, psychotic and melancholic features, comorbid panic disorder, agoraphobia, social phobia, and obsessive-compulsive disorder. Taken together, our findings indicate that benzodiazepine augmentation in MDD is first of all established in severe/difficult-to-treat conditions and serves as predictor for the use of additional augmentation/combination treatment strategies.

Acute changes in cerebral blood flow after single-infusion ketamine in major depression: a pilot study

BACKGROUND

Ketamine provides rapid antidepressant response in those struggling with major depressive disorder (MDD). This study measured acute changes in brain activity over 24 hours after a single infusion of ketamine using arterial spin labeled (ASL) functional magnetic resonance imaging (fMRI) in patients with MDD. ASL is a novel technique that provides quantitative values to measure cerebral blood flow (CBF).

METHODS

A single sub-anesthetic dose (0.5 mg/kg) of ketamine was delivered intravenously. Treatment-refractory patients (n=11) were assessed at: Baseline (pre-infusion), and approximately 1hr, 6hrs, and 24hrs post-infusion. Linear mixed-effects models detected changes in CBF with respect to treatment outcome, and results were corrected for false discovery rate (FDR).

RESULTS

After ketamine infusion, increased CBF was observed in the thalamus, while decreased CBF was observed in lateral occipital cortex in all patients. Time-by-response interactions were noted in ventral basal ganglia and medial prefrontal cortex, where CBF change differed according to antidepressant response.

LIMITATIONS

Modest sample size is a limitation of this pilot study; strict statistical correction and visualization of single-subject data attempted to ameliorate this issue.

CONCLUSION

In this pilot study, a sub-anesthetic dose of ketamine was associated with acute neurofunctional changes that may be consistent with altered attention, specifically increased thalamus activity coupled with decreased cortical activity. By contrast, antidepressant response to ketamine was associated with changes in reward-system regions, specifically ventral basal ganglia and medial prefrontal cortex. Further work is needed to determine whether these results generalize to larger samples and/or serial ketamine infusions associated with longer-lasting clinical effects.

Electroconvulsive Therapy Versus Fluoxetine in Suicidal Resolution for Patients With Major Depressive Disorder

OBJECTIVE

Resolution of suicidal ideation for patients with major depressive disorder is an important public health challenge. We aimed to determine whether electroconvulsive therapy (ECT) or fluoxetine was more efficacious in resolving suicidal ideation and achieving long-term protective effect against suicidality.

METHODS

The data used in this study were drawn from 2 open-label trials for major depressive disorder patients receiving ECT or fluoxetine for acute treatment, together with continuation medication in the 12-week follow-up. We compared the effects of ECT and fluoxetine on suicidal ideation as scored by the suicide item on the 17-item Hamilton Rating Scale for Depression.

RESULTS

The differences between these 2 groups in time to resolution of suicidal ideation (suicide item = 0) in the acute treatment period, and time to relapse of suicidal ideation (suicide item score ≥1 or rehospitalization for suicidality) in the follow-up period were analyzed. Electroconvulsive therapy-treated patients (n = 111) had significantly shorter time to resolution of suicidal ideation than fluoxetine-treated patients (n = 114) during acute treatment. However, there was no statistically significant difference in time to relapse of suicidal ideation between 2 groups in the 12-week follow-up period.

CONCLUSIONS

Electroconvulsive therapy was superior to fluoxetine in resolving suicidal ideation during acute treatment. Therefore, ECT should be an early consideration for suicidal patients. Electroconvulsive therapy and fluoxetine were equally effective in preventing recurrence of suicidal ideation in the 12-week follow-up period. Routine suicide risk assessments from hospital care to outpatient care are required to identify any signs of suicidal relapse.

Esketamine for treatment-resistant depression

Generic name: Esketamine hydrochloride Brand name: Spravato Formulation: 28mg in 0.2ml nasal spray solution Market Authorisation holder: Janssen-Cilag International NV Indication: Treatment resistant major depressive disorder in adults who have failed to respond to at least two different antidepressants during the current moderate to severe episode. To be used in combination with a selective serotonin reuptake inhibitor (SSRI) or serotonin-noradrenaline reuptake inhibitor (SNRI). Dose: The starting dose is 56 mg for adults aged <65 years and 28 mg for adults aged ≥65 years ¹ Subsequent doses (56 mg or 84 mg for those <65 years; 28 mg, 56 mg or 84 mg for those ≥65 years) are given twice a week for 4 weeks, followed by once a week for 4 weeks, and then once a week or once every 2 weeks from week 9. Treatment is recommended for at least 6 months after symptoms improve. Cost: £163 for 28 mg (one device) Classification: Prescription only medicine (POM) subject to additional monitoring (▼). Controlled drug schedule 2.

Predicting Antidepressant Citalopram Treatment Response via Changes in Brain Functional Connectivity After Acute Intravenous Challenge

Introduction: The early and therapy-specific prediction of treatment success in major depressive disorder is of paramount importance due to high lifetime prevalence, and heterogeneity of response to standard medication and symptom expression. Hence, this study assessed the predictability of long-term antidepressant effects of escitalopram based on the short-term influence of citalopram on functional connectivity. Methods: Twenty nine subjects suffering from major depression were scanned twice with resting-state functional magnetic resonance imaging under the influence of intravenous citalopram and placebo in a randomized, double-blinded cross-over fashion. Symptom factors were identified for the Hamilton depression rating scale (HAM-D) and Beck's depression inventory (BDI) taken before and after a median of seven weeks of escitalopram therapy. Predictors were calculated from whole-brain functional connectivity, fed into robust regression models, and cross-validated. Results: Significant predictive power could be demonstrated for one HAM-D factor describing insomnia and the total score (r = 0.45-0.55). Remission and response could furthermore be predicted with an area under the receiver operating characteristic curve of 0.73 and 0.68, respectively. Functional regions with high influence on the predictor were located especially in the ventral attention, fronto-parietal, and default mode networks. Conclusion: It was shown that medication-specific antidepressant symptom improvements can be predicted using functional connectivity measured during acute pharmacological challenge as an easily assessable imaging marker. The regions with high influence have previously been related to major depression as well as the response to selective serotonin reuptake inhibitors, corroborating the advantages of the current approach of focusing on treatment-specific symptom improvements.

The clinical characterization of the adult patient with depression aimed at personalization of management

Depression is widely acknowledged to be a heterogeneous entity, and the need to further characterize the individual patient who has received this diagnosis in order to personalize the management plan has been repeatedly emphasized. However, the research evidence that should guide this personalization is at present fragmentary, and the selection of treatment is usually based on the clinician's and/or the patient's preference and on safety issues, in a trial-and-error fashion, paying little attention to the particular features of the specific case. This may be one of the reasons why the majority of patients with a diagnosis of depression do not achieve remission with the first treatment they receive. The predominant pessimism about the actual feasibility of the personalization of treatment of depression in routine clinical practice has recently been tempered by some secondary analyses of databases from clinical trials, using approaches such as individual patient data meta-analysis and machine learning, which indicate that some variables may indeed contribute to the identification of patients who are likely to respond differently to various antidepressant drugs or to antidepressant medication vs. specific psychotherapies. The need to develop decision support tools guiding the personalization of treatment of depression has been recently reaffirmed, and the point made that these tools should be developed through large observational studies using a comprehensive battery of self-report and clinical measures. The present paper aims to describe systematically the salient domains that should be considered in this effort to personalize depression treatment. For each domain, the available research evidence is summarized, and the relevant assessment instruments are reviewed, with special attention to their suitability for use in routine clinical practice, also in view of their possible inclusion in the above-mentioned comprehensive battery of measures. The main unmet needs that research should address in this area are emphasized. Where the available evidence allows providing the clinician with specific advice that can already be used today to make the management of depression more personalized, this advice is highlighted. Indeed, some sections of the paper, such as those on neurocognition and on physical comorbidities, indicate that the modern management of depression is becoming increasingly complex, with several components other than simply the choice of an antidepressant and/or a psychotherapy, some of which can already be reliably personalized.

Comparison of the efficacy of electroconvulsive therapy (ECT) plus agomelatine to ECT plus placebo in treatment-resistant depression

OBJECTIVE

Electroconvulsive therapy (ECT) is commonly used to treat patients with treatment-resistant depression. We aimed to investigate whether combining an antidepressant agent with ECT might enhance therapeutic efficacy and prevent early relapse.

METHOD

During the acute ECT phase, patients (N = 97) with treatment-resistant depression were randomized to receive ECT plus agomelatine 50 mg/day (n = 48) or ECT plus placebo (n = 49). Symptom severity measures, including the 17-item Hamilton Depression Rating Scale (HAMD-17) and other scales, functional impairment, quality of life, neuropsychological tests, adverse events and attitudes toward ECT, were assessed regularly. Remission was defined as a HAMD-17 score ≤7. If patients achieved post-ECT remission, they were prescribed agomelatine 50 mg/day and participated in a 12-week follow-up trial. HAMD-17 was rated at 4-week intervals. Relapse was defined as a HAMD-17 score ≥14, or rehospitalization for a psychiatric reason.

RESULTS

The two treatment groups were comparable at (i) baseline variables; (ii) score changes in all symptom measures, functional impairment, quality of life, and neuropsychological tests; (iii) frequency of adverse events and attitudes toward ECT; and (iv) post-ECT response/remission rates. There were no statistically significant differences following ECT in relapse rates and time to relapse between these two groups.

CONCLUSION

Adding agomelatine to ECT yielded comparable response/remission rates to ECT without agomelatine in the acute ECT phase. Starting agomelatine in combination with ECT did not seem to be more efficacious in preventing relapse than starting agomelatine after the acute ECT course. More research is needed to guide clinical recommendations.

A register-based approach to identifying treatment-resistant depression-Comparison with clinical definitions

BACKGROUND

Several definitions of treatment-resistant depression (TRD) are used for clinical research, but no verified model for use in register data exists. We aimed to compare a novel model created for use in register data-the Karolinska Institutet Model (KIM)-to the clinical definitions regarding the proportion of patients identified with TRD, their characteristics and clinical outcomes.

METHODS

All patients in Sweden initiating antidepressant treatment with a diagnosis of depression in specialized healthcare 2006-2014 were identified and followed in national registers. In KIM, patients who initiated a third sequential, >28-day antidepressant treatment trial were defined as having TRD. Proportion of TRD and patient characteristics were compared with register adaptations of the European Staging Model (ESM), Massachusetts General Hospital Staging Method (MGH-s), and Maudsley Staging Model (MSM). Differences in patient characteristics were assessed with Chi-square tests and one-way ANOVAs. Hazard ratios for psychiatric hospitalization and for death from external causes were estimated by Cox proportional hazard regressions.

RESULTS

Out of 127,108 antidepressant initiators with depression, the highest proportion of TRD was found using the MGH-s (19.0%), followed by MSM (15.3%), KIM (12.9%), and ESM (9.5%). Clinical characteristics were similar across the models. Compared with TRD patients identified by KIM, those identified by ESM had a marginally higher risk for psychiatric hospitalization (adjusted hazard ratio [aHR] 1.03, 95%CI 1.00-1.05), whereas those identified by MGH-s (aHR 0.92; 0.90-0.94) and MSM (aHR 0.95; 0.94-0.97) had a slightly reduced risk. Patients identified by MGH-s showed a reduced mortality compared with KIM (aHR 0.84; 0.72-0.98).

CONCLUSIONS

This study provides insight into the differing characteristics of patients captured by various TRD models when used for register research. Models yielding lower proportions of TRD seemed to identify patients with greater morbidity. The KIM may be useful for register based research in TRD.

Inflammatory Pathways in Psychiatric Disorders: The case of Schizophrenia and Depression

Purpose of Review

A better understanding of the key molecules/pathways underlying the pathophysiology of depression and schizophrenia may contribute to novel therapeutic strategies. In this review, we have discussed the recent developments on the role of inflammatory pathways in the pathogenesis of depression and schizophrenia.

Recent Findings

Inflammation is an innate immune response that can be triggered by various factors, including pathogens, stress and injury. Under normal conditions, the inflammatory responses quiet after pathogen clearance and tissue repair. However, abnormal long-term or chronic inflammation can lead to damaging effects. Accumulating evidence suggest that dysregulated inflammation is linked to the pathogenesis of neuropsychiatric disorders. In this review, we have discussed the roles of complement system, infiltration of peripheral immune cells into the central nervous system (CNS), the gut-brain axis, and the kynurenine pathway in depression and schizophrenia.

Summary

There is a large body of compelling evidence on the role of inflammatory pathways in depression and schizophrenia. Although most of these findings show their roles in the pathophysiology of the above disorders, additional studies are warranted to investigate the therapeutic potential of various immune signaling targets discussed in this article.

A toolbox for brain network construction and classification (BrainNetClass)

Brain functional network has been increasingly used in understanding brain functions and diseases. While many network construction methods have been proposed, the progress in the field still largely relies on static pairwise Pearson's correlation-based functional network and group-level comparisons. We introduce a "Brain Network Construction and Classification (BrainNetClass)" toolbox to promote more advanced brain network construction methods to the filed, including some state-of-the-art methods that were recently developed to capture complex and high-order interactions among brain regions. The toolbox also integrates a well-accepted and rigorous classification framework based on brain connectome features toward individualized disease diagnosis in a hope that the advanced network modeling could boost the subsequent classification. BrainNetClass is a MATLAB-based, open-source, cross-platform toolbox with both graphical user-friendly interfaces and a command line mode targeting cognitive neuroscientists and clinicians for promoting reliability, reproducibility, and interpretability of connectome-based, computer-aided diagnosis. It generates abundant classification-related results from network presentations to contributing features that have been largely ignored by most studies to grant users the ability of evaluating the disease diagnostic model and its robustness and generalizability. We demonstrate the effectiveness of the toolbox on real resting-state functional MRI datasets. BrainNetClass (v1.0) is available at https://github.com/zzstefan/BrainNetClass.

Is cognitive dysfunction involved in difficult-to-treat depression? Characterizing resistance from a cognitive perspective

BACKGROUND

This study aimed to identify clinical and cognitive factors associated with increased risk for difficult-to-treat depression (DTD) or treatment-resistant depression (TRD).

METHODS

A total of 229 adult outpatients with major depression were recruited from the mental health unit at a public hospital. Participants were subdivided into resistant and nonresistant groups according to their Maudsley Staging Model score. Sociodemographic, clinical, and cognitive (objective and subjective measures) variables were compared between groups, and a logistic regression model was used to identify the factors most associated with TRD risk.

RESULTS

TRD group patients present higher verbal memory impairment than the nonresistant group irrespective of pharmacological treatment or depressive symptom severity. Logistic regression analysis showed that low verbal memory scores (odds ratio [OR]: 2.02; 95% confidence interval [CI]: 1.38-2.95) together with high depressive symptom severity (OR: 1.29; CI95%: 1.01-1.65) were associated with TRD risk.

CONCLUSIONS

Our findings align with neuroprogression models of depression, in which more severe patients, defined by greater verbal memory impairment and depressive symptoms, develop a more resistant profile as a result of increasingly detrimental neuronal changes. Moreover, our results support a more comprehensive approach in the evaluation and treatment of DTD in order to improve illness course. Longitudinal studies are warranted to confirm the predictive value of verbal memory and depression severity in the development of TRD.

Cost analysis of depression using the national insurance system in South Korea: a comparison of depression and treatment-resistant depression

Background

The incidence and burden of depressive disorders are increasing in South Korea. There are many differences between pharmaceutically treated depression (PTD) and treatment-resistant depression (TRD), including the economic consequences; however, to our knowledge, the economic burden of depression is understudied in South Korea. Therefore, the objective of the present study was to calculate the different economic costs of PTD and TRD in South Korea, specifically by comparing several aspects of medical care.

Methods

This study comprised patients aged 18 and over who were newly prescribed antidepressants for more than 28 days with a depression code included from January 1, 2012, to December 31, 2012, by the Health Insurance Review and Assessment Service (HIRA). TRD was classified as more than two antidepressant regimen failures in PTD patients. The cost was calculated based on the cost reflected on the receipt registered with HIRA.

Results

Of the 834,694 patients with PTD, 34,812 patients (4.17%) were converted to TRD. The cost of medical care for TRD (6,610,487 KRW, 5881 USD) was approximately 5 times higher than the cost of non-TRD (1,273,045 KRW, 1133 USD) and was significantly higher for patients with or without depression and suicide codes. Medical expenses incurred by non-psychiatrists were roughly 1.7 times higher than those incurred by psychiatrists.

Conclusions

TRD patients had significantly higher healthcare costs than PTD patients. Identifying these financial aspects of care for depression can help to establish a more effective policy to reduce the burden on mentally ill patients.

Buprenorphine: prospective novel therapy for depression and PTSD

BACKGROUND

Depression and post-traumatic stress disorder (PTSD) are leading causes of disability and loss of life by suicide. Currently, there are less than satisfactory medical solutions to treat these mental disorders. Here, we explore recent preclinical and clinical studies demonstrating the potential of using buprenorphine to treat major depressive disorder, treatment-resistant depression, and PTSD.

METHOD

Bibliographic databases were searched to include preclinical and clinical studies demonstrating the therapeutic potential of buprenorphine and the involvement of the kappa opioid receptor (KOR) in mediating these effects.

RESULTS

Original clinical studies examining the effectiveness of buprenorphine to treat depression were mixed. The majority of participants in the PTSD studies were males and suffer from chronic pain and/or substance use disorders. Nonetheless, these recent studies and analyses established proof of concept warranting farther investigations. Additionally, KOR likely mediates the antidepressant and some of the anxiolytic effects of buprenorphine. Still, it appears that the full spectrum of buprenorphine's beneficial effects might be due to activity at other opioid receptors as well.

CONCLUSIONS

Pharmaceuticals' abilities to treat medical conditions directly relates to their ability to act upon the endogenous biological systems related to the conditions. Thus, these recent findings are likely a reflection of the central role that the endogenous opioid system has in these mental illnesses. Further studies are necessary to study the involvement of endogenous opioid systems, and specifically KOR, in mediating buprenorphine's beneficial effects and the ability to treat these medical conditions while minimizing risks for misuse and diversion.

Efficacy and safety of adjunctive therapy using esketamine or racemic ketamine for adult treatment-resistant depression: A randomized, double-blind, non-inferiority study

BACKGROUND

Ketamine and its enantiomers have recently been highlighted as one of the most effective therapeutic options in refractory depression. However, racemic ketamine and esketamine have not been directly compared. The aim of this study is to assess the efficacy and safety of esketamine compared to ketamine in patients with treatment-resistant depression (TRD).

METHODS

This is a randomized, double-blind, active-controlled, bicentre, non-inferiority clinical trial, with two parallel groups. Participants were randomly assigned to a 40-min single intravenous infusion of ketamine 0.5 mg/kg or esketamine 0.25 mg/kg. The primary outcome was the difference in remission rates for depression 24 h following intervention using the Montgomery-Åsberg Depression Rating Scale (MADRS), with a non-inferiority margin of 20%.

RESULTS

63 subjects were included and randomly assigned (29 to receive ketamine and 34 to receive esketamine). At 24 h, 24.1% of participants in the ketamine group and 29.4% of participants in the esketamine group showed remission, with a difference of 5.3% (95% CILB -13.6%), confirming non-inferiority. MADRS scores improved from 33 (SD 9.3) to 16.2 (SD 10.7) in the ketamine group and from 33 (SD 5.3) to 17.5 (SD 12.2) in the esketamine one, with a difference of -5.27% (95% CILB, -13.6). Both groups presented similar mild side effects.

CONCLUSIONS

Esketamine was non-inferior to ketamine for TRD 24 h following infusion. Both treatments were effective, safe, and well tolerated.

TRIAL REGISTRATION

Registered in Japan Primary Registries Network: UMIN000032355.

Annual Research Review: Defining and treating pediatric treatment-resistant depression

BACKGROUND

Adolescent major depressive disorder (MDD) is a significant health problem, associated with substantial morbidity, cost, and mortality. Depression is a significant risk factor for suicide, which is now the second leading cause of death in young people. Up to twenty per cent of adolescents will experience MDD before adulthood, and while a substantial proportion will improve with standard-of-care treatments (psychotherapy and medication), roughly one third will not.

METHODS

Here, we have reviewed the literature in order to discuss the concept of treatment-resistant depression (TRD) in adolescence, examine risk factors, diagnostic difficulties, and challenges in evaluating symptom improvement, and providing guidance on how to define adequate medication and psychotherapy treatment trials.

RESULTS

We propose a staging model for adolescent TRD and review the treatment literature. The evidence base for first- and second-line treatments primarily derives from four large pediatric clinical trials (TADS, TORDIA, ADAPT, and IMPACT). After two medications and a trial of evidence-based psychotherapy have failed to alleviate depressive symptoms, the evidence becomes quite thin for subsequent treatments. Here, we review the evidence for the effectiveness of medication switches, medication augmentation, psychotherapy augmentation, and interventional treatments (i.e., transcranial magnetic stimulation, electroconvulsive therapy, and ketamine) for adolescent TRD. Comparisons are drawn to the adult TRD literature, and areas for future pediatric depression research are highlighted.

CONCLUSIONS

As evidence is limited for treatments in this population, a careful consideration of the known risks and side effects of escalated treatments (e.g., mood stabilizers and atypical antipsychotics) is warranted and weighed against potential, but often untested, benefits.

Genetics of Treatment Outcomes in Major Depressive Disorder: Present and Future

Pharmacogenetic testing is a useful and increasingly widespread tool to assist in antidepressant prescription. More than ten antidepressants (including tricyclics, selective serotonin reuptake inhibitors and venlafaxine) have already genetic biomarkers of response/side effects in clinical guidelines and drug labels. These are represented by functional genetic variants in genes coding for cytochrome enzymes (CYP2D6 and CYP2C19). Depending on the predicted metabolic activity, guidelines provide recommendations on drug choice and dosing. Despite not conclusive, the current evidence suggests that testing can be useful in patients who did not respond or tolerate at least one previous pharmacotherapy. However, the current recommendations are based on pharmacokinetic genes only (CYP450 enzymes), while pharmacodynamic genes (modulating antidepressant mechanisms of action in the brain) are still being studied because of their greater complexity. This may be captured by polygenic risk scores, which reflect the cumulative contribution of many genetic variants to a trait, and they may provide future clinical applications of pharmacogenetics. A more extensive use of genotyping in clinical practice may lead to improvement in treatment outcomes thanks to personalized treatments, but possible ethical issues and disparities should be taken into account and prevented.

A polygenic predictor of treatment-resistant depression using whole exome sequencing and genome-wide genotyping

Treatment-resistant depression (TRD) occurs in ~30% of patients with major depressive disorder (MDD) but the genetics of TRD was previously poorly investigated. Whole exome sequencing and genome-wide genotyping were available in 1209 MDD patients after quality control. Antidepressant response was compared to non-response to one treatment and non-response to two or more treatments (TRD). Differences in the risk of carrying damaging variants were tested. A score expressing the burden of variants in genes and pathways was calculated weighting each variant for its functional (Eigen) score and frequency. Gene-based and pathway-based scores were used to develop predictive models of TRD and non-response using gradient boosting in 70% of the sample (training) which were tested in the remaining 30% (testing), evaluating also the addition of clinical predictors. Independent replication was tested in STAR*D and GENDEP using exome array-based data. TRD and non-responders did not show higher risk to carry damaging variants compared to responders. Genes/pathways associated with TRD included those modulating cell survival and proliferation, neurodegeneration, and immune response. Genetic models showed significant prediction of TRD vs. response and they were improved by the addition of clinical predictors, but they were not significantly better than clinical predictors alone. Replication results were driven by clinical factors, except for a model developed in subjects treated with serotonergic antidepressants, which showed a clear improvement in prediction at the extremes of the genetic score distribution in STAR*D. These results suggested relevant biological mechanisms implicated in TRD and a new methodological approach to the prediction of TRD.

Descriptive analysis of the economic burden of treatment resistance in a major depressive episode

Objectives: To assess characteristics and healthcare costs associated with pharmacologically treated episodes of treatment-resistant depression (TRD) in patients with major depressive disorder (MDD).Methods: Patients aged ≥18 years with continuous health plan enrollment for ≥12 months before and after a newly observed MDD diagnosis (observed between 1 January 2010 and 31 December 2015) were included in this retrospective claims-based analysis. A pharmacologically treated episode was defined as beginning at the date of the first MDD diagnosis and ending when a gap of 180 days occurred between MDD diagnoses, or when a gap of 180 days occurred following the end of the antidepressant (AD)/antipsychotic (AP) drug supply. When such a gap occurred, the episode end date was determined to be either the date of the last MDD diagnosis or date of the end of AD/AP drug supply, whichever was later. An episode was considered TRD if ≥3 AD regimens occurred. Episode duration, medication regimens used, and relapse hospitalization were reported for TRD and non-TRD MDD episodes. Total all-cause and per-patient-per-month (PPPM) healthcare costs (in 2016 $) were estimated.Results: Of 48,440 patients identified with ≥1 AD-treated MDD episode, the mean (SD) age was 39 (15) years, and 62% were female. Of all episodes, 7% were TRD, with a mean duration of 571 (285) days vs. 200 (198) days for non-TRD MDD episodes. Mean total all-cause costs were $19,626 ($44,160) for TRD and $7440 ($25,150) for non-TRD MDD episodes.Conclusions: Results show TRD episodes are longer and costlier than non-TRD MDD episodes, and that higher costs are driven by episode duration. Longer episodes imply protracted suffering for patients with TRD and increased burden on caregivers. Effective intervention to shorten TRD episodes may lessen disease burden and reduce costs.

Defining treatment-resistant depression

BACKGROUND

Varying conceptualizations of treatment-resistant depression (TRD) have made translating research findings or systematic reviews into clinical practice guidelines challenging and inconsistent.

METHODS

We conducted a review for the Centers for Medicare & Medicaid Services and the Agency for Healthcare Research and Quality to clarify how experts and investigators have defined TRD and to review systematically how well this definition comports with TRD definitions in clinical trials through July 5, 2019.

RESULTS

We found that no consensus definition existed for TRD. The most common TRD definition for major depressive disorder required a minimum of two prior treatment failures and confirmation of prior adequate dose and duration. The most common TRD definition for bipolar disorder required one prior treatment failure. No clear consensus emerged on defining adequacy of either dose or duration. Our systematic review found that only 17% of intervention studies enrolled samples meeting the most frequently specified criteria for TRD. Depressive outcomes and clinical global impressions were commonly measured; functional impairment and quality-of-life tools were rarely used.

CONCLUSIONS

Two key steps are critical to advancing TRD research: (a) Developing a consensus definition of TRD that addresses how best to specify the number of prior treatment failures and the adequacy of dose and duration; and (b) identifying a core package of outcome measures that can be applied in a standardized manner. Our recommendations about stronger approaches to designing and conducting TRD research will foster better evidence to translate into clearer guidelines for treating patients with this serious condition.

Chronic unpredictable intermittent restraint stress disrupts spatial memory in male, but not female rats

Chronic stress leads to sex-dependent outcomes on spatial memory by producing deficits in males, but not in females. Recently it was reported that compared to daily restraint, intermittent restraint (IR) produced more robust stress and anxiety responses in male rats. Whether IR would be sufficiently robust to impair hippocampal-dependent spatial memory in both male and female rats was investigated. IR involved mixing restraint with non-restraint days over weeks before assessing spatial memory and anxiety profile on the radial arm water maze, object placement, novel object recognition, Y-maze, open field and novelty suppressed feeding. Experiments 1 and 2 used Sprague-Dawley male rats only and determined that IR for 6 h/d (IR6), but not 2 h/d, impaired spatial memory and that task order was important. In experiment 3, IR6 was extended for 6wks before spatial memory testing commenced using both sexes. Unexpectedly, an extended IR6 paradigm failed to impair spatial memory in either sex, suggesting that by 6wks IR6 may have become predictable. In experiment 4, an unpredictable IR (UIR) paradigm was implemented, in which restraint duration (30 or 60-min) combined with orbital shaking, time of day, and the days off from UIR were varied. UIR impaired spatial memory in males, but not in females. Together with other reports, these findings support the interpretation that chronic stress negatively impairs hippocampal-dependent function in males, but not in females. We interpret these findings to show that females are more resilient to chronic stress than are males as it pertains to spatial ability.

Quantifying the level of difficulty to treat major depressive disorder with antidepressants: Treatment Resistance to Antidepressants Evaluation Scale

BACKGROUND

The present study aimed to develop a new scale to evaluate the level of difficulty in treating major depressive disorder with antidepressants based on the lifetime treatment profile.

METHODS

In addition to evaluating the difficulty of treatment with antidepressants (A subscale), the Treatment Resistance to Antidepressants Evaluation Scale (TRADES) is comprised of a subscale to account for the attributes that compromise the efficacy of treatment (B subscale). One hundred and six participants aged 18 to 65 years with remitted major depressive disorder were enrolled. Eligible cases were those with at least 2 years from disease onset until the scoring date of the TRADES (the index date), with a complete treatment record. Various psychosocial and clinical features, such as neuroticism, harm avoidance, and utilization of psychiatric services, were used to validate the TRADES.

RESULTS

The mean duration of the course before and after the index date were 5.5 ± 3.5 and 3.1 ± 1.7 years, respectively. In a multiple regression analysis, the final total scores of the TRADES independently correlated with higher levels of neuroticism and harm avoidance. Total scores were also associated with a higher utilization of psychiatric outpatient and admission services before the index date. Furthermore, it is thought that total scores could predict a higher number of visits to psychiatric outpatient, emergency, and admission services following the index date.

CONCLUSIONS

The TRADES has acceptable validity and could help to quantify the level of treatment difficulty with antidepressants in major depressive disorder.

Recognition of personality disorder and anxiety disorder comorbidity in patients treated for depression in secondary psychiatric care

OBJECTIVES

Depression is a common illness with substantial economic consequences for society and a great burden for affected individuals. About 30% of patients with depression do not respond to repeated treatments. Psychiatric comorbidity is known to affect duration, recurrence and treatment outcome of depression. However, there is a lack of knowledge on the extent to which psychiatric comorbidity is identified in the clinical setting for depressed patients in secondary psychiatric care. Therefore, the aim of this study was to compare the agreement between traditional diagnostic assessment (TDA) and a structured and comprehensive diagnostic procedure (SCDP) for identification of personality and anxiety disorder comorbidity in depressed patients in secondary psychiatric care.

METHODS

274 patients aged 18-77 were referred from four secondary psychiatric care clinics in Sweden during 2012-2017. ICD-10 diagnoses according to TDA (mostly unstructured by psychiatric specialist and residents in psychiatry), were retrieved from medical records and compared to diagnoses resulting from the SCDP in the study. This included the Mini International Neuropsychiatric Interview, the Structured Interview for DSM Axis II Personality Disorders and semi-structured questions on psychosocial circumstances, life-events, psychiatric symptoms, psychiatric treatments, substance use, and suicidal and self-harm behaviour. The assessment was carried out by psychiatric specialists or by residents in psychiatry with at least three years of psychiatric training.

RESULTS

SCDP identified personality disorder comorbidity in 43% of the patients compared to 11% in TDA (p<0,0001). Anxiety disorder comorbidity was identified in 58% with SCDP compared to 12% with TDA (p<0,0001).

CONCLUSIONS

Important psychiatric comorbidity seems to be unrecognized in depressive patients when using TDA, which is routine in secondary psychiatric care. Comorbidities are better identified using the proposed model involving structured and semi-structured interviews together with clinical evaluations by clinical experts.

Genome-wide association study of antidepressant treatment resistance in a population-based cohort using health service prescription data and meta-analysis with GENDEP

Antidepressants demonstrate modest response rates in the treatment of major depressive disorder (MDD). Despite previous genome-wide association studies (GWAS) of antidepressant treatment response, the underlying genetic factors are unknown. Using prescription data in a population and family-based cohort (Generation Scotland: Scottish Family Health Study; GS:SFHS), we sought to define a measure of (a) antidepressant treatment resistance and (b) stages of antidepressant resistance by inferring antidepressant switching as non-response to treatment. GWAS were conducted separately for antidepressant treatment resistance in GS:SFHS and the Genome-based Therapeutic Drugs for Depression (GENDEP) study and then meta-analysed (meta-analysis n = 4213, cases = 358). For stages of antidepressant resistance, a GWAS on GS:SFHS only was performed (n = 3452). Additionally, we conducted gene-set enrichment, polygenic risk scoring (PRS) and genetic correlation analysis. We did not identify any significant loci, genes or gene sets associated with antidepressant treatment resistance or stages of resistance. Significant positive genetic correlations of antidepressant treatment resistance and stages of resistance with neuroticism, psychological distress, schizotypy and mood disorder traits were identified. These findings suggest that larger sample sizes are needed to identify the genetic architecture of antidepressant treatment response, and that population-based observational studies may provide a tractable approach to achieving the necessary statistical power.

Management of Treatment-Resistant Depression: Challenges and Strategies

Treatment-resistant depression (TRD) is a subset of Major Depressive Disorder which does not respond to traditional and first-line therapeutic options. There are several definitions and staging models of TRD and a consensus for each has not yet been established. However, in common for each model is the inadequate response to at least 2 trials of antidepressant pharmacotherapy. In this review, a comprehensive analysis of existing literature regarding the challenges and management of TRD has been compiled. A PubMed search was performed to assemble meta-analyses, trials and reviews on the topic of TRD. First, we address the confounds in the definitions and staging models of TRD, and subsequently the difficulties inherent in assessing the illness. Pharmacological augmentation strategies including lithium, triiodothyronine and second-generation antipsychotics are reviewed, as is switching of antidepressant class. Somatic therapies, including several modalities of brain stimulation (electroconvulsive therapy, repetitive transcranial magnetic stimulation, magnetic seizure therapy and deep brain stimulation) are detailed, psychotherapeutic strategies and subsequently novel therapeutics including ketamine, psilocybin, anti-inflammatories and new directions are reviewed in this manuscript. Our review of the evidence suggests that further large-scale work is necessary to understand the appropriate treatment pathways for TRD and to prescribe effective therapeutic options for patients suffering from TRD.

Rumination-focused cognitive behaviour therapy for non-responsive chronic depression: an uncontrolled group study

BACKGROUND

One-third of patients with depression do not respond satisfactorily to treatment, and approximately 20% of all patients treated for depression develop a chronic depression. One approach to more effective treatment of chronic and treatment-resistant depression is to target rumination - an underlying mechanism implicated in the development and maintenance of depression.

AIM

The purpose of this uncontrolled group study was to investigate the feasibility of individual rumination-focused cognitive behavioural therapy (RfCBT) for patients with chronic and treatment-resistant depression.

METHOD

A total of 10 patients with chronic and treatment-resistant depression were offered 12-16 individual sessions of RfCBT. The primary outcome was depressive symptoms as measured by Hamilton Depression Scale at pre-, post- and 3-month follow-up. Secondary symptoms measured included self-reported rumination and worry.

RESULTS

There was a significant reduction in depressive symptoms (p < 0.05), rumination (p < 0.01) and worry (p < 0.5) from pre- to post-treatment. Half of the participants (n = 5) showed significant reliable change on levels of depressive symptoms post-treatment. The reduction in depressive symptoms, rumination and worry were maintained at follow-up.

CONCLUSIONS

RfCBT was associated with significant reductions in depressive symptoms in a small sample with chronic and treatment-resistant depression. Despite limitations of being a small uncontrolled study with limited follow-up, these results are promising in a difficult to treat population. RfCBT warrants further systematic evaluation.

Does rTMS reduce depressive symptoms in young people who have not responded to antidepressants?

AIM

Depression is common in young people, and there is a need for safe, effective treatments. This study examined the efficacy of repetitive transcranial magnetic stimulation in a sample of young people aged 17 to 25 years.

METHODS

This retrospective study included 15 people aged 17 to 25 years referred by their private psychiatrists affiliated with Ramsay Health Care, South Australia Mental Health Services. All patients met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for treatment-resistant Major Depressive Disorder. Eleven patients received right unilateral treatment and four patients received bilateral treatment. Patients were assessed at baseline and after treatment.

RESULTS

There was a significant improvement on the Hamilton Rating Scale for Depression (t(14) = 4.71, P < 0.0001); Montgomery-Åsperg Depression Rating Scale (t(14) = 3.96, P < 0.01) and the Zung Self-Rating Depression Scale (t(14) = 4.13, P < 0.01). There was no difference in response by gender or age. The response rates in these young people did not differ significantly from those of adults aged 25 to 82 years.

CONCLUSION

This open label, naturalistic study suggests that repetitive transcranial magnetic stimulation is an effective treatment in young adults who have treatment-resistant depression. Randomized sham-controlled studies are needed to further investigate the efficacy of this treatment in this age group.

Implementation of intermittent theta burst stimulation compared to conventional repetitive transcranial magnetic stimulation in patients with treatment resistant depression: A cost analysis

Background

Repetitive transcranial magnetic stimulation (rTMS) is an evidence-based treatment for depression that is increasingly implemented in healthcare systems across the world. A new form of rTMS called intermittent theta burst stimulation (iTBS) can be delivered in 3 min and has demonstrated comparable effectiveness to the conventional 37.5 min 10Hz rTMS protocol in patients with depression.

Objectives

To compare the direct treatment costs per course and per remission for iTBS compared to 10Hz rTMS treatment in depression.

Methods

We conducted a cost analysis from a healthcare system perspective using patient-level data from a large randomized non-inferiority trial (THREE-D). Depressed adults 18 to 65 received either 10Hz rTMS or iTBS treatment. Treatment costs were calculated using direct healthcare costs associated with equipment, coils, physician assessments and technician time over the course of treatment. Cost per remission was estimated using the proportion of patients achieving remission following treatment. Deterministic sensitivity analyses and non-parametric bootstrapping was used to estimate uncertainty.

Results

From a healthcare system perspective, the average cost per patient was USD$1,108 (SD 166) for a course of iTBS and $1,844 (SD 304) for 10Hz rTMS, with an incremental net savings of $735 (95% CI 688 to 783). The average cost per remission was $3,695 (SD 552) for iTBS and $6,146 (SD 1,015) for 10Hz rTMS, with an average incremental net savings of $2,451 (95% CI 2,293 to 2,610).

Conclusions

The shorter session durations and treatment capacity increase associated with 3 min iTBS translate into significant cost-savings per patient and per remission when compared to 10Hz rTMS.

Treatment-naïve first episode depression classification based on high-order brain functional network

BACKGROUND

Recent functional connectivity (FC) studies have proved the potential value of resting-state functional magnetic resonance imaging (rs-fMRI) in the study of major depressive disorder (MDD); yet, the rs-fMRI-based individualized diagnosis of MDD is still challenging.

METHODS

We enrolled 82 treatment-naïve first episode depression (FED) adults and 72 matched normal control (NC). A computer-aided diagnosis framework was utilized to classify the FEDs from the NCs based on the features extracted from not only traditional "low-order" FC networks (LON) based on temporal synchronization of original rs-fMRI signals, but also "high-order" FC networks (HON) that characterize more complex functional interactions via correlation of the dynamic (time-varying) FCs. We contrasted a classifier using HON feature (C_HON) and compared its performance with using LON only (C_LON). Finally, an integrated classification model with both features was proposed to further enhance FED classification.

RESULTS

The C_HON had significantly improved diagnostic accuracy compared to the C_LON (82.47% vs. 67.53%). Joint classification further improved the performance (83.77%). The brain regions with potential diagnostic values mainly encompass the high-order cognitive function-related networks. Importantly, we found previously less-reported potential imaging biomarkers that involve the vermis and the crus II in the cerebellum.

LIMITATIONS

We only used one imaging modality and did not examine data from different subtypes of depression.

CONCLUSIONS

Depression classification could be significantly improved by using HON features that better capture the higher-level brain functional interactions. The findings suggest the importance of higher-level cerebro-cerebellar interactions in the pathophysiology of MDD.

Post-stroke Depression Increases Disability More Than 15% in Ischemic Stroke Survivors: A Case-Control Study

We performed a retrospective, case-control study in consecutive ischemic stroke patients admitted to our stroke rehabilitation unit. Patients were matched for severity of neurological impairment (evaluated with the Canadian Neurological Scale, CNS), age (difference within 1 year), and onset admission interval (difference within 3 days). Participants were divided into two subgroups according to the presence or absence of PSD. Aim was to assess the specific influence of post-stroke depression (PSD) and antidepressant treatment on both basal functional status and rehabilitation outcomes. All PSD patients were treated primarily with serotoninergic antidepressants (AD). The final sample included 280 patients with depression (out of 320 found in a whole case series of 993 ischemic patients, i.e., 32.25%) and 280 without depression. Forty patients with depression were excluded because they had a history of severe psychiatric illness or aphasia, with a severe comprehension deficit. On one hand, PSD patients obtained lower Barthel Index (BI) and Rivermead Mobility Index (RMI) scores at both admission and discharge, with minor effectiveness of rehabilitative treatment and longer length of stay; on the other hand, this group had a lower percentage of dropouts. Lastly, PSD patients showed a different functional outcome, based on their response to antidepressant therapy, that was significantly better in responders than in non-responders (13.13%). Our results confirm the unfavorable influence of PSD on functional outcome, despite pharmacological treatment.

Treatment response classes in major depressive disorder identified by model-based clustering and validated by clinical prediction models

The identification of generalizable treatment response classes (TRC[s]) in major depressive disorder (MDD) would facilitate comparisons across studies and the development of treatment prediction algorithms. Here, we investigated whether such stable TRCs can be identified and predicted by clinical baseline items. We analyzed data from an observational MDD cohort (Munich Antidepressant Response Signature [MARS] study, N = 1017), treated individually by psychopharmacological and psychotherapeutic means, and a multicenter, partially randomized clinical/pharmacogenomic study (Genome-based Therapeutic Drugs for Depression [GENDEP], N = 809). Symptoms were evaluated up to week 16 (or discharge) in MARS and week 12 in GENDEP. Clustering was performed on 809 MARS patients (discovery sample) using a mixed model with the integrated completed likelihood criterion for the assessment of cluster stability, and validated through a distinct MARS validation sample and GENDEP. A random forest algorithm was used to identify prediction patterns based on 50 clinical baseline items. From the clustering of the MARS discovery sample, seven TRCs emerged ranging from fast and complete response (average 4.9 weeks until discharge, 94% remitted patients) to slow and incomplete response (10% remitted patients at week 16). These proved stable representations of treatment response dynamics in both the MARS and the GENDEP validation sample. TRCs were strongly associated with established response markers, particularly the rate of remitted patients at discharge. TRCs were predictable from clinical items, particularly personality items, life events, episode duration, and specific psychopathological features. Prediction accuracy improved significantly when cluster-derived slopes were modelled instead of individual slopes. In conclusion, model-based clustering identified distinct and clinically meaningful treatment response classes in MDD that proved robust with regard to capturing response profiles of differently designed studies. Response classes were predictable from clinical baseline characteristics. Conceptually, model-based clustering is translatable to any outcome measure and could advance the large-scale integration of studies on treatment efficacy or the neurobiology of treatment response.