The cost-of-illness and burden-of-disease of treatment-resistant depression in Austria.

BACKGROUND: Treatment-resistant depression (TRD) in major depressive disorder (MDD) is most commonly defined as the failure to respond to at least two antidepressant (AD) treatments of adequate duration and adherence. While the health care utilization (RU) and costs of patients with MDD are well documented, little is known about patients with TRD. Therefore, the aim of this study was to determine the direct medical RU of complex therapy pathways and to analyze the total cost-of-illness and the burden-of-disease in Austria. METHODS: In order to quantify the cost-of-illness and burden-of-disease of TRD, the analysis was designed with two steps. First, RU data were collected through an extensive survey of Austrian experts and a systematic literature review. Second, direct, indirect, and intangible costs were calculated using the micro-costing method. The results are presented per patient and based on a patient flow for the entire cohort of TRD patients. RESULTS: In Austria, the derived prevalence of TRD is 43,732 patients or 583 per 100,000 population. For 2021, the annual direct costs of TRD were estimated at 345.0 million €. At 684.7 million €, the estimated indirect costs were higher than the direct costs, representing 66.5% of the total cost-of-illness. The average annual cost per TRD patient is 23,547 €, of which direct costs are 7,890 €. Adding the years lived with a disability to the years lost due to premature death attributed to TRD resulted in a total of 29,884 disability-adjusted life years (DALYs) for the Austrian society. CONCLUSION: Although TRD accounts for only 0.7% (range: 0.6%-1%) of the total health care budget, it represents a significant burden-of-disease. In addition, TRD is associated with a high level of lost productivity in the Austrian economy. These findings support efforts to prioritize TRD as a focus area to achieve health-related goals.

Esketamine in treatment-resistant depression patients comorbid with substance-use disorder: A viewpoint on its safety and effectiveness in a subsample of patients from the REAL-ESK study.

Esketamine, the S-enantiomer of ketamine, has recently emerged as a therapy for treatment-resistant depression (TRD), showing both rapid antidepressant action and good efficacy and high safety. It is also indicated for the acute short-term treatment of psychiatric emergency due to major depressive disorder (MDD) and for depressive symptoms in adults with MDD with acute suicidal thoughts/behavior. We here provide preliminary insights on esketamine nasal spray (ESK-NS) effectiveness and safety among patients with a substance use disorder (SUD) within the sample of patients with TRD collected for the observational, retrospective, multicentre REAL-ESK study. Twenty-six subjects were retrospectively selected according to the presence of a SUD in comorbidity. Subjects enrolled completed the three different follow-up phases (T0/baseline, T1/after one month, and T2/after three months) and there were no dropouts. A decrease in Montgomery-Asberg depression rating scale (MADRS) scores was recorded, thus highlighting the antidepressant efficacy of ESK-NS (MADRS decreased from T0 to T1, t = 6.533, df=23, p<0.001, and from T1 to T2, t = 2.029, df=20, p = 0.056). Considering tolerability and safety issues, one or more side effects were reported by 19/26 subjects (73%) after treatment administration. All reported side effects were time-dependent and did not cause significant sequelae; among them, dissociative symptoms (38%) and sedation (26%) were the most frequently reported. Finally, no cases of abuse or misuse of ESK-NS were reported. Despite study limitations related to the inherent nature of the study, a limited number of patients, and a short follow-up period, ESK-NS showed to be effective and safe in patients diagnosed with TRD comorbid with a SUD.

Real world effectiveness of repeated ketamine infusions for treatment-resistant depression with comorbid borderline personality disorder.

Borderline personality disorder (BPD) has high rates of comorbidity with mood disorders, including treatment-resistant depression (TRD). Comorbidity of BPD with depression is associated with poorer response to antidepressants. Intravenous ketamine is a novel treatment for TRD that has not been specifically evaluated in patients with comorbid BPD. In this retrospective analysis of data collected from participants who received care at the Canadian Rapid Treatment Centre of Excellence (CRTCE; Braxia Health; ClinicalTrials.gov: NCT04209296), we evaluated the effectiveness of intravenous ketamine in a TRD population with comorbid BPD (N=100; n=50 BPD-positive compared with n=50 BPD-negative). Participants were administered four doses of intravenous ketamine (0.5-0.75mg/kg over 40 minutes) over two weeks. The primary outcome measures were changes in depressive symptom severity (as measured by Quick Inventory of Depressive Symptomatology-Self Report 16-item (QIDS-SR16)) and borderline symptom severity (as measured by Borderline Symptom List 23-item (BSL-23)). Both BPD-positive and BPD-negative groups improved significantly on the QIDS-SR16, QIDS-SR16 suicide ideation item, anxiety, and functionality scales with large effect sizes. There was no significant difference between groups. The BPD-positive group exhibited significant reduction of 0.64 on BSL-23 scores and a significant reduction of 5.95 on QIDS-SR16 scores. Patients with TRD and comorbid BPD receiving ketamine exhibited a significant reduction in symptoms of depression, borderline personality, suicidality, and anxiety.

Comorbidity and healthcare utilization in patients with treatment resistant depression: A large-scale retrospective cohort analysis using electronic health records.

BACKGROUND: Medical comorbidity and healthcare utilization in patients with treatment resistant depression (TRD) is usually reported in convenience samples, making estimates unreliable. There is only limited large-scale clinical research on comorbidities and healthcare utilization in TRD patients. METHODS: Electronic Health Record data from over 3.3 million patients from the INSIGHT Clinical Research Network in New York City was used to define TRD as initiation of a third antidepressant regimen in a 12-month period among patients diagnosed with major depressive disorder (MDD). Age and sex matched TRD and non-TRD MDD patients were compared for anxiety disorder, 27 comorbid medical conditions, and healthcare utilization. RESULTS: Out of 30,218 individuals diagnosed with MDD, 15.2 % of patients met the criteria for TRD (n = 4605). Compared to MDD patients without TRD, the TRD patients had higher rates of anxiety disorder and physical comorbidities. They also had higher odds of ischemic heart disease (OR = 1.38), stroke/transient ischemic attack (OR = 1.57), chronic kidney diseases (OR = 1.53), arthritis (OR = 1.52), hip/pelvic fractures (OR = 2.14), and cancers (OR = 1.41). As compared to non-TRD MDD, TRD patients had higher rates of emergency room visits, and inpatient stays. In relation to patients without MDD, both TRD and non-TRD MDD patients had significantly higher levels of anxiety disorder and physical comorbidities. LIMITATIONS: The INSIGHT-CRN data lack information on depression severity and medication adherence. CONCLUSIONS: TRD patients compared to non-TRD MDD patients have a substantially higher prevalence of various psychiatric and medical comorbidities and higher health care utilization. These findings highlight the challenges of developing interventions and care coordination strategies to meet the complex clinical needs of TRD patients.

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

Importance: The totality of the societal and individual impact of treatment-resistant depression (TRD) is unknown, as is the potential to prognosticate TRD. The generalizability of many observational studies on TRD is limited. Objective: To estimate the burden of TRD in a large population-wide cohort in an area with universal health care by including data from both health care types (psychiatric and nonpsychiatric) and, further, to develop a prognostic model for clinical use. Design, Setting, and Participants: This cohort study, a population-based observational study, assessed data from the Stockholm MDD Cohort for episodes of major depressive disorder (MDD) between 2010 and 2017 that fulfilled predefined criteria for TRD (≥3 consecutive antidepressant treatments). Data analysis was performed from August 2020 to May 2022. Main Outcomes and Measures: Outcomes were psychiatric and nonpsychiatric comorbid conditions, antidepressant treatments, health care resource utilization, lost workdays, all-cause mortality, and intentional self-harm and, in the prognostic model, TRD. Results: A total of 158 169 unipolar MDD episodes (in 145 577 patients) were identified between January 1, 2012, and December 31, 2017 (64.7% women; median [IQR] age, 42 years [30-56]). Of these, 12 793 episodes (11%) fulfilled criteria for TRD. The median (IQR) time from the start of MDD episode to TRD was 552 days (294-932). Selective serotonin reuptake inhibitor was the most common class of antidepressant treatment in all treatment steps, and 5907 patients (46.2%) received psychotherapy at some point before initiation of the third pharmacological antidepressant treatment. Compared with matched non-TRD episodes, TRD episodes had more inpatient bed-days (mean, 3.9 days; 95% CI, 3.6-4.1, vs 1.3 days; 95% CI, 1.2-1.4) and more lost workdays (mean, 132.3 days; 95% CI, 129.5-135.1, vs 58.7 days; 95% CI, 56.8-60.6) 12 months after the index date. Anxiety, stress, sleep disorder, and substance use disorder were all more common comorbid conditions in TRD episodes. Intentional self-harm was more than 4 times more common in TRD episodes. The all-cause mortality rate for patients with MDD with TRD episodes was 10.7/1000 person-years at risk, compared with 8.7/1000 person-years at risk for patients with MDD without TRD episodes (hazard ratio, 1.23; 95% CI, 1.07-1.41). Median time from start of the first antidepressant treatment to start of the second, and from start of the second antidepressant treatment to start of the third, was 165 and 197 days, respectively. The severity of MDD, defined using the self-rating Montgomery-Åsberg Depression Rating Scale (MADRS-S) at time of MDD diagnosis, was found to be the most important prognostic factor for TRD (C index = 0.69). Conclusions and Relevance: In this cohort study, TRD was a common variant of MDD when including patients from both health care types, which is associated with a high disease burden for both patients and society. The median time between initiation of new antidepressant treatments was longer than recommended in current treatment guidelines, suggesting room for more structured and timely depression care.

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

BACKGROUND: Determining the proportion of patients with treatment-resistant depression (TRD) among patients with unipolar depression receiving adequate pharmacological treatment (pharmaceutically treated depression [PTD]) is clinically important and may affect health care utilization. In Taiwan, these issues can be assessed by analyzing population-based data. METHODS: The present study included data from the Taiwan National Health Insurance Research Database from 2010 to 2017. Among patients with depression, PTD was defined by the receipt of at least one adequate antidepressant treatment, and TRD was defined as receiving a third adequate antidepressant treatment after failure to respond to two prior treatments. Time of progression from PTD to TRD was estimated via the Kaplan-Meier function. A propensity-matched case-comparison cohort approach was used to compare resource utilization between patients with non-TRD PTD and TRD. RESULTS: TRD was defined in 11.2 % of patients with unipolar depression and 37.1 % of PTD patients. The time of progression from PTD to TRD was approximately 1 year. Most TRD patients were women, middle-aged, and treated in general practice clinics. Antidepressant monotherapy, followed by antidepressant with augmentation, was the most common treatment strategy applied to TRD patients. Medical utilization was significantly higher in patients with TRD than those with non-TRD PTD across most aspects. LIMITATIONS: TRD was defined based on pharmacological treatment patterns, as the reasons for changes in antidepressant regimens were not available. CONCLUSION: Approximately one-third of patients with PTD developed TRD, often soon after receiving adequate pharmacological treatment. Patients with TRD used more medical resources than patients with non-TRD PTD.

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

OBJECTIVE: Investigate incidence, risk factors and courses of treatment for treatment-resistant depression (TRD) in primary and special healthcare. METHODS: All patients identified from nationwide registers, aged 16-65 years, diagnosed with depression in Finland during 2004-2016 were included. New antidepressant users were identified with six-month washout period and followed-up for two years to observe for presence of TRD, which was defined as initiation of a third trial after having failed two pharmacological treatment trials with adequate duration. RESULTS: During follow-up, 177,144 persons had their first registered antidepressant treated depression (mean age: 39.5, 62.5% women). Of them, 10.9% (N = 19,322) met TRD criteria. Among the TRD patients, most common first and second antidepressants trials were: SSRIs (44.6%), mirtazapine (19.0%) and SNRIs (16.5%). As the third treatment line, antidepressant monotherapy (44.2% of TRD patients) was most common, followed by a combination of ≥2 antidepressants (32.1%), antipsychotic or mood stabilizer augmentation and an antidepressant (15.8%), both combination of antidepressants and an augmentation with a mood stabilizer or antipsychotic (4.9%), antipsychotic or mood stabilizer monotherapy (2.7%) and ECT (0.3%). Of TRD patients, 16.5% (N = 3188) progressed to the fifth treatment line, in which the most common treatments were antidepressant monotherapy (33.4%), antidepressant combinations (27.5%) and augmentation (24.2%). Factors associated with higher risk of TRD included male gender, younger age, higher initial disease severity and hospitalization at initial onset of depression. CONCLUSIONS: Antidepressant monotherapies were still the most common fifth line of depression treatment. Severe depression, hospitalization due to depression, young age and male gender may predispose to TRD.

One-year incidence rate of Treatment Resistant Depression (TRD) and treatment characteristics in China.

BACKGROUND: Little is known about the characteristics of Treatment-Resistant Depression (TRD) in China. In previous studies various identification approaches have led to a wide range of results, and it is unclear how Chinese patients compare to those in other studies. METHODS: This is a retrospective cohort study using electronic health records (EHR) from two major psychiatric hospitals in China. Adult major depressive disorder (MDD) patients who initiated pharmaceutical treatment during 2010-2018 were enrolled and follow-up was 1 year. TRD was primarily identified by consensus definition of two failures of adequate (≥4 weeks) regimens. Alternative regimens of 2-weeks and 6-weeks duration, and a data-driven definition were also applied. RESULTS: In the two hospitals, 12,257 (mean age: 40.8y, 63.6% female) and 8314 (mean age: 42.4y, 68.4% female) eligible patients were included. The 1-year incidence rate of TRD was estimated to be 5.2%-7.7% using the primary definition. TRD patients had mean treatment duration of 302.5 days and 285.7 days; had 3.6 and 3.7 treatment steps on average; 94.0% and 72.6% were prescribed polypharmacy regimens, which were all marginally greater than that of non-TRD patients. Alternative definitions resulted in a wide range of incidence estimates (0.5%-20.0%). LIMITATIONS: Medications were assumed to be consumed as prescribed and lack of rating scales from EHRs may limit our TRD identification. CONCLUSIONS: The incidence of TRD among Chinese MDD patients was comparable to other countries under similar settings and more complex treatment characteristics were observed among TRD patients. Alternative TRD definitions revealed the need for better treatment management in practices.

Cerebral Small Vessel Disease and Depression Among Intracerebral Hemorrhage Survivors.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) is an acute manifestation of cerebral small vessel disease (CSVD), usually cerebral amyloid angiopathy or hypertensive arteriopathy. CSVD-related imaging findings are associated with increased depression incidence in the general population. Neuroimaging may, therefore, provide insight on depression risk among ICH survivors. We sought to determine whether CSVD CT and magnetic resonance imaging markers are associated with depression risk (before and after ICH), depression remission, and effectiveness of antidepressant treatment. METHODS: We analyzed data from the single-center longitudinal ICH study conducted at Massachusetts General Hospital. Participants underwent CT and magnetic resonance imaging imaging and were followed longitudinally. We extracted information for neuroimaging markers of CSVD subtype and severity. Outcomes of interest included pre-ICH depression, new-onset depression after ICH, resolution of depressive symptoms, and response to antidepressant treatment. RESULTS: We followed 612 ICH survivors for a median of 47.2 months. Multiple CSVD-related markers were associated with depression risk. Survivors of cerebral amyloid angiopathy-related lobar ICH were more likely to be diagnosed with depression before ICH (odds ratio, 1.68 [95% CI, 1.14-2.48]) and after ICH (sub-hazard ratio, 1.52 [95% CI, 1.12-2.07]), less likely to achieve remission of depressive symptoms (sub-hazard ratio, 0.69 [95% CI, 0.51-0.94]), and to benefit from antidepressant therapy (P=0.041). Cerebral amyloid angiopathy disease burden on magnetic resonance imaging was associated with depression incidence and treatment resistance (interaction P=0.037), whereas hypertensive arteriopathy disease burden was only associated with depression incidence after ICH. CONCLUSIONS: CSVD severity is associated with depression diagnosis, both before and after ICH. Cerebral amyloid angiopathy-related ICH survivors are more likely to experience depression (both before and after ICH) than patients diagnosed with hypertensive arteriopathy-related ICH, and more likely to report persistent depressive symptoms and display resistance to antidepressant treatment.

A piece of the puzzle: Does bipolarity partly explain the high prevalence of treatment resistance in depression?

In this cross-sectional study we examined whether the prevalence of treatment resistant depression (TRD) can be partly attributed to level of bipolarity. We included data of 201 patients with either episodic depression or TRD, who received treatment for their depression at either an outpatient or 2nd opinion/daytime setting, within a specialised mental healthcare department in the Netherlands. Whether level of TRD, assessed by the 'Dutch Measure for quantification of Treatment Resistance in Depression', can be partly explained by level of bipolarity, assessed by 'the Bipolarity Index', was examined using linear regression. We found no direct association between level of TRD and level of bipolarity, nor did comorbid anxiety disorders obscure an existing association. In this study we found no evidence for overlooked bipolarity contributing to the high prevalence of TRD. If replicated, we could state that additional screening on bipolarity with an instrument such as the 'Bipolarity Index' in the specialised mental health care is unnecessary.

Epidemiology of Treatment-Resistant Depression in the United States.

Background: The prevalence of treatment-resistant depression (TRD) among patients with pharmaceutically treated depression (PTD) varies greatly in publications. The aim of this study is to estimate the prevalence of TRD using 2 large claims databases in the US.Methods: This cross-sectional study used data from the Humana and Optum databases. Patients aged ≥ 18 years who had at least 1 diagnosis of major depressive disorder (ICD-10-CM codes: F32.xx, F33.xx) and 1 antidepressant prescription filled in 2018 were identified as having PTD. Among patients with PTD, TRD was defined as experiencing failure of treatment with at least 2 antidepressants with ≥ 4 weeks of adequate treatment. We estimated the age- and gender-standardized prevalence of TRD and then used logistic regression to investigate if TRD risk varies by age, sex, race, and geographic region. Finally, we described the timeline of TRD development in incident PTD patients.Results: We identified 296,055 and 277,941 patients with PTD in the Humana and Optum databases, among whom 17,640 (6.0%) and 16,131 (5.8%) had TRD. After age and sex standardization, TRD prevalence among PTD patients was 6.8% in Humana vs 5.8% in Optum. Females, middle-aged adults, and White patients had higher risk of TRD. The median time from index antidepressant use to TRD was about 6 months in incident PTD patients.Conclusions: The prevalence of TRD among patients with PTD was similar in the 2 databases. TRD prevalence varies by sex, race, and age, with a higher prevalence in females, White patients, and those in the age group of 45-64 years. However, the absolute differences were small.

Remission and Treatment Augmentation of Depression in the United States.

Objective: To determine the proportion of adults treated for depression in the US who achieve remission and, among those not achieving remission, the proportion receiving augmentation treatment.Methods: Using data from the US National Health and Nutrition Examination Survey (NHANES) for years 2013-2014, 2015-2016, and 2017-2018, we identified 869 adults who reported using antidepressant medications for depression for at least 3 months. This sample was partitioned into remitted (score < 5) and non-remitted (score ≥ 5) respondents based on 9-item Patient Health Questionnaire (PHQ-9) score-a questionnaire based on the DSM-IV criteria for major depressive disorder. Among the non-remitted group, the proportion receiving antidepressant augmentation with another antidepressant medication of a different class or other medications was also assessed.Results: An estimated 43.5% of adults receiving antidepressant medications for depression were in remission when assessed. Among those not in remission, 28.1% were using augmentation treatment, which in most cases was another antidepressant medication from a different class. As compared to depressed adults without any mental health contact in the past year, those with such contact had significantly higher odds of using augmentation treatment (adjusted odds ratio = 2.72; 95% CI, 1.56-4.76; P = .001).Conclusions: The low percentage of US adults treated with antidepressants for depression that achieves remission represents a missed clinical and public health opportunity to optimize depression treatment. Closer monitoring of symptoms through measurement-based care and setting symptom remission as a goal can help improve outcomes for adults with depression.

Economic impact of treatment-resistant depression: A retrospective observational study.

BACKGROUND: To determine the incidence of Treatment-Resistant Depression (TRD) in Spain and to estimate its economic burden, using real world data. METHODS: A retrospective, observational-study was carried out using data from the BIG-PAC database®. Patients aged ≥18 years with a diagnosis of major depressive-disorder (MDD) who initiated a new antidepressant treatment in 2015-2017 were included. The patients were classified as TRD and non-TRD. Patients were classified as TRD if they had, during the first year of antidepressant treatment: a) failure with ≥2 antidepressants including the prescription of ≥3 antidepressants (N06A) or ≥2 antidepressant and ≥1 antipsychotic (N05A; including lithium) b) antidepressants administered for ≥ 4 weeks each, and c) the time between the end of one treatment and the initiation of the next was ≤ 90 days. Inherent limitations of data collection from databases should also be considered in this analysis (e.g., lack of information about adherence to treatment). Follow-up period: 18 months. The incidence rate was calculated as the number of TRD patients per 1,000 persons-year divided by the population attended. OUTCOMES: direct healthcare and indirect costs. Two sensitivity analyses were performed varying the index date and the period used to define TRD patients (6 vs.12 months). RESULTS: 21,630 patients with MDD aged ≥ 18 years (mean age: 53.2 years; female: 67.2%) were analyzed, of whom 3,559 met TRD criteria, yielding a 3-year cumulative incidence of 16.5% (95%CI: 16%-17%) among MDD patients. The annual population incidence rate of TRD in 2015-2017, was 0.59, 1.02 and 1.18/1,000 person-years, respectively (mean: 0.93/1,000 person-year). Overall, mean total costs per MDD patient were €4,147.9, being higher for TRD than for non-TRD patients (€6,096 vs. €3,846; p<0.001): a) direct costs (€1,341 vs. €624; p<0.001), b) lost productivity (€1,274 vs. €821; p<0.001) and c) permanent disability (€3,481 vs. €2,401; p<0.001, adjusted). Sensitivity analyses showed no differences with the reported results. CONCLUSIONS: The population based TRD incidence in Spain was similar to recent data from other European countries. TRD is associated with greater resource use and higher costs compared with non-TRD patients.

The effect of esketamine in patients with treatment-resistant depression with and without comorbid anxiety symptoms or disorder.

BACKGROUND: Comorbid anxiety is generally associated with poorer response to antidepressant treatment. This post hoc analysis explored the efficacy of esketamine plus an antidepressant in patients with treatment-resistant depression (TRD) with or without comorbid anxiety. METHODS: TRANSFORM-2, a double-blind, flexible-dose, 4-week study (NCT02418585), randomized adults with TRD to placebo or esketamine nasal spray, each with a newly-initiated oral antidepressant. Comorbid anxiety was defined as clinically noteworthy anxiety symptoms (7-item Generalized Anxiety Disorder scale [GAD-7] score ≥10) at screening and baseline or comorbid anxiety disorder diagnosis at screening. Treatment effect based on change in Montgomery-Åsberg Depression Rating Scale (MADRS) total score, and response and remission were examined by presence/absence of comorbid anxiety using analysis of covariance and logistic regression models. RESULTS: Approximately 72% (162/223) of patients had baseline comorbid anxiety. Esketamine-treated patients with and without anxiety demonstrated significant reductions in MADRS (mean [SD] change from baseline at day 28: -21.0 [12.51] and -22.7 [11.98], respectively). Higher rates of response and remission, and a significantly greater decrease in MADRS score at day 28 were observed compared to antidepressant/placebo, regardless of comorbid anxiety (with anxiety: difference in LS means [95% CI] -4.2 [-8.1, -0.3]; without anxiety: -7.5 [-13.7, -1.3]). There was no significant interaction of treatment and comorbid anxiety (p = .371). Notably, in the antidepressant/placebo group improvement was similar in those with and without comorbid anxiety. CONCLUSION: Post hoc data support efficacy of esketamine plus an oral antidepressant in patients with TRD, regardless of comorbid anxiety.

Replication of machine learning methods to predict treatment outcome with antidepressant medications in patients with major depressive disorder from STAR*D and CAN-BIND-1.

OBJECTIVES: Antidepressants are first-line treatments for major depressive disorder (MDD), but 40-60% of patients will not respond, hence, predicting response would be a major clinical advance. Machine learning algorithms hold promise to predict treatment outcomes based on clinical symptoms and episode features. We sought to independently replicate recent machine learning methodology predicting antidepressant outcomes using the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) dataset, and then externally validate these methods to train models using data from the Canadian Biomarker Integration Network in Depression (CAN-BIND-1) dataset. METHODS: We replicated methodology from Nie et al (2018) using common algorithms based on linear regressions and decision trees to predict treatment-resistant depression (TRD, defined as failing to respond to 2 or more antidepressants) in the STAR*D dataset. We then trained and externally validated models using the clinical features found in both datasets to predict response (≥50% reduction on the Quick Inventory for Depressive Symptomatology, Self-Rated [QIDS-SR]) and remission (endpoint QIDS-SR score ≤5) in the CAN-BIND-1 dataset. We evaluated additional models to investigate how different outcomes and features may affect prediction performance. RESULTS: Our replicated models predicted TRD in the STAR*D dataset with slightly better balanced accuracy than Nie et al (70%-73% versus 64%-71%, respectively). Prediction performance on our external methodology validation on the CAN-BIND-1 dataset varied depending on outcome; performance was worse for response (best balanced accuracy 65%) compared to remission (77%). Using the smaller set of features found in both datasets generally improved prediction performance when evaluated on the STAR*D dataset. CONCLUSION: We successfully replicated prior work predicting antidepressant treatment outcomes using machine learning methods and clinical data. We found similar prediction performance using these methods on an external database, although prediction of remission was better than prediction of response. Future work is needed to improve prediction performance to be clinically useful.

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.

Bidirectional associations between treatment-resistant depression and general medical conditions.

Depression is associated with general medical conditions (GMCs), but it is not known if treatment-resistant depression (TRD) affects GMC risk and vice versa. We estimated bidirectional associations between TRD and GMCs (prior and subsequent). All individuals aged 18-69 years, born and living in Denmark, with a first-time prescription for an antidepressant between 2005 and 2012 were identified in the Danish Prescription Registry (N = 154,513). TRD was defined as at least two shifts in treatment regimes. For prior GMCs, we estimated odds ratios (ORs) using conditional logistic regression comparing TRD patients with matched non-TRD controls adjusted for other GMCs and number of other GMCs. For subsequent GMCs, we used Cox regression to calculate hazard ratios (HRs) in TRD vs. non-TRD patients adjusted for age at first prescription, calendar time, other GMCs and number of other GMCs. Patients with TRD had higher prevalence of prior GMCs related to the immune or neurological systems; musculoskeletal disorders (women aOR: 1.35, 95% CI: 1.26-1.46, men aOR: 1.30, 95% CI: 1.19-1.42) and migraine (women aOR: 1.22, 95% CI: 1.09-1.36, men aOR: 1.25, 95% CI: 1.00-1.56). Subsequent GMCs were related to a broader spectrum; cardiovascular (women aHR: 1.43, 95% CI: 1.32-1.54, men aHR: 1.31, 95% CI: 1.19-1.43), endocrine (women aHR: 1.52, 95% CI: 1.37-1.67, men aHR: 1.24, 95% CI: 1.07-1.44), and neurological disorders (women aHR: 1.24, 95% CI: 1.13-1.35, men aHR: 1.19, 95% CI: 1.07-1.34). Our study presents a broad overview of comorbid medical conditions in patients with TRD and further studies are needed to explore the associations in detail.

Challenges and pitfalls in anesthesia for electroconvulsive therapy.

Electroconvulsive therapy (ECT) refers to the application of electricity to the patients' scalp to treat psychiatric disorders, most notably, treatment-resistant depression. It is a safe, effective, and evidence-based therapy that is performed with general anesthesia. Muscle relaxation is used to prevent injuries related to the tonic-clonic seizure caused by ECT. Hypnotics are administered to induce amnesia and unconsciousness, so that, patients do not experience the period of muscle relaxation, while the generalized seizure is left unnoticed. For the anesthesiologist, ECT is associated with the challenges and pitfalls that are related to informed consent, social acceptance of ECT, airway management (especially in COVID-19 patients), and the interaction between ventilation and anesthetics from one viewpoint, and seizure induction and maintenance from another. The exact mode of action of the therapy is as unknown as the optimal choice or combination of anesthetics used.

The Prevalence and National Burden of Treatment-Resistant Depression and Major Depressive Disorder in the United States.

OBJECTIVE: Estimates of prevalence and burden of treatment-resistant depression (TRD) vary widely in the literature. This study evaluated the prevalence and burden of TRD and the share of TRD in the burden of medication-treated major depressive disorder (MDD) using the most commonly accepted definition of TRD and a novel bottom-up approach. METHODS: Prevalence and health care burden of TRD were estimated by synthetizing inputs across 4 similarly designed claims studies in adults covered by Medicare, Medicaid, commercial plans, and the US Veterans Health Administration (VHA). Productivity (absenteeism and presenteeism) and unemployment burden were estimated based on inputs from a study conducted with data from the Kantar National Health and Wellness Survey (NHWS; 2017). A targeted literature search for additional inputs was performed. A cost model was developed to estimate the burden of TRD and medication-treated DSM-5-defined MDD in the United States. Study outcomes were the 12-month prevalence of TRD and the annual health care, productivity, and unemployment burden of TRD and medication-treated MDD in the United States. RESULTS: The estimated 12-month prevalence of medication-treated MDD in the United States was 8.9 million adults, and 2.8 million (30.9%) had TRD. The total annual burden of medication-treated MDD among the US population was $92.7 billion, with $43.8 billion (47.2%) attributable to TRD. The share of TRD was 56.6% ($25.8 billion) of the health care burden, 47.7% ($8.7 billion) of the unemployment burden, and 32.2% ($9.3 billion) of the productivity burden of medication-treated MDD. CONCLUSIONS: TRD is associated with disproportionate health care costs and unemployment, suggesting potentially large economic and societal gains with effective management.

Economic burden of treatment-resistant depression among veterans in the United States.

OBJECTIVE: Evidence is limited on the economic burden associated with treatment-resistant depression (TRD) among US veterans. We evaluated the economic burden among patients with major depressive disorder (MDD) with and without TRD, and those without MDD in the Veterans Health Administration (VHA). METHODS: Three cohorts were identified using VHA claims data (01APR2014-31MAR2018). Patients with MDD (aged ≥18) who failed ≥2 antidepressant treatments of adequate dose and duration were defined as having TRD; patients with MDD not meeting this criterion constituted the non-TRD MDD cohort (index: first antidepressant claim). The non-MDD cohort included those without MDD diagnosis (index: randomly assigned). Patients with psychosis, schizophrenia, manic/bipolar disorder, or dementia in the 6-month pre-index period were excluded. Patients with non-TRD MDD and non-MDD were matched 1:1 to patients with TRD based on demographic characteristics (age, gender, race, index year). Health care resource utilization (HRU) and costs were analyzed during the post-index period using a negative binomial model and ordinary least squares regression model, respectively. RESULTS: After 1:1 exact matching, 10,449 patients were included in each cohort (mean age: 48.9 years). Patients with TRD had higher per patient per year (PPPY) HRU than non-TRD MDD (all-cause inpatient visits: incidence rate ratio [IRR]: 1.70 [95% confidence interval: 1.57-1.83]) and non-MDD (IRR: 5.04 [95% confidence interval: 4.51-5.63]), and incurred higher total all-cause health care costs PPPY than non-TRD MDD (mean difference: $5,906) and non-MDD (mean difference: $11,873; all p<.0001). CONCLUSION: Among US veterans, TRD poses a significant incremental economic burden relative to non-TRD MDD and non-MDD.