Aligning the many definitions of treatment resistance in anxiety disorders: A systematic review

Is lack of goal-conflict-specific rhythmicity a biomarker for treatment resistance in generalised anxiety but not social anxiety or major depression?

BACKGROUND

Anxiety and depression cause major detriment to the patient, family, and society - particularly in treatment-resistant (TR) cases, which are highly prevalent. TR prevalence may be due to current diagnoses being based not on biological measures but on symptom lists that suffer from clinical subjectivity, variation in symptom presentation, and comorbidity.

AIMS

Goal-conflict-specific rhythmicity (GCSR) measured using the Stop-Signal Task (SST) may provide the first neural biomarker for an anxiety process and disorder. This GCSR has been validated with selective drugs for anxiety. So, we proposed that GCSR could differ between TR and non-TR individuals and do so differently between those diagnoses normally sensitive to selective anxiolytics and those not.

METHODS

We recorded electroencephalograms (EEG) from 20 TR participants (4 GAD, 5 SAD and 11 MDD) and 24 non-TR participants (4 GAD, 5 SAD and 15 Comorbid GAD/MDD (GMD)) while they performed the SST.

RESULTS

There was significant positive GCSR in all groups except the GAD-TR group. GAD-TR lacked GCSR in the low-frequency range. However, TR had little effect in SAD or MDD/GMD populations with apparent increases not decreases.

CONCLUSIONS

Overall, these results suggest that GAD may occur in two forms: one resulting from excessive GCSR and so being drug sensitive, and the other resulting from some other mechanism and so being TR. In SAD and MDD groups, heightened GCSR could be a consequence rather than the cause, driven by mechanisms that are normally more sensitive to non-selective panicolytic antidepressants.

When rare meets common: Treatable genetic diseases are enriched in the general psychiatric population

Mental illnesses are one of the biggest contributors to the global disease burden. Despite the increased recognition, diagnosis and ongoing research of mental health disorders, the etiology and underlying molecular mechanisms of these disorders are yet to be fully elucidated. Moreover, despite many treatment options available, a large subset of the psychiatric patient population is nonresponsive to standard medications and therapies. There has not been a comprehensive study to date examining the burden and impact of treatable genetic disorders (TGDs) that can present with neuropsychiatric features in psychiatric patient populations. In this study, we test the hypothesis that TGDs that present with psychiatric symptoms are more prevalent within psychiatric patient populations compared to the general population by performing targeted next-generation sequencing of 129 genes associated with 108 TGDs in a cohort of 2301 psychiatric patients. In total, 48 putative affected and 180 putative carriers for TGDs were identified, with known or likely pathogenic variants in 79 genes. Despite screening for only 108 genetic disorders, this study showed a two-fold (2.09%) enrichment for genetic disorders within the psychiatric population relative to the estimated 1% cumulative prevalence of all single gene disorders globally. This strongly suggests that the prevalence of these, and most likely all, genetic diseases is greatly underestimated in psychiatric populations. Increasing awareness and ensuring accurate diagnosis of TGDs will open new avenues to targeted treatment for a subset of psychiatric patients.

[Treatment resistance in anxiety disorders-Definition and treatment options]

Treatment resistance in anxiety disorders represents a clinical challenge, contributes to the chronicity of the diseases as well as sequential comorbidities, and is associated with a significant individual and socioeconomic burden. This narrative review presents the operational definition of treatment resistance in anxiety disorders according to international consensus criteria (< 50% reduction in the Hamilton Anxiety Scale, HAM‑A, score or < 50% reduction in the Beck Anxiety Inventory, BAI, score or a clinical global impression-improvement, CGI‑I, score > 2). At least two unsuccessful guideline-based treatment attempts with pharmacological monotherapy or at least one unsuccessful treatment attempt with adequately delivered cognitive behavioral therapy are required. Pharmacotherapeutically, after excluding pseudo-resistance, switching the medication within one class or to another class and augmentation strategies with other antidepressants (mirtazapine, agomelatine), antipsychotics (quetiapine) or anticonvulsants (valproate) are recommended. Psychotherapeutically, third-wave therapies, psychodynamic therapy, systemic therapy and physical exercise can be considered for therapy resistance. In cases of no response to psychotherapy or pharmacotherapy, the respective other form of therapy or a combination of both should be offered. Compounds targeting the glutamatergic and endocannabinoid systems as well as neuropeptides are being tested as potential innovative pharmaceuticals for treatment-resistant anxiety disorders. There is an urgent need for further research to identify predictive markers and mechanisms as well as to develop innovative pharmacological and psychotherapeutic interventions for treatment-resistant anxiety disorders.

[Non-response to psychotherapy: concepts, problems and referral options]

AIM

In this paper we review the current literature on the clinical problem that some patients do not achieve response after adequately conducted psychotherapy. We explicate our understanding of nonresponse and treatment resistance including the operational definitions, summarize the theoretical explanations and empirical studies and put forward possible study designs and treatment options.

METHODS

Literature search using PubMed and Web of Science.

RESULTS

For the domain of psychotherapy, the term treatment resistance does not seem appropriate; instead, we use the more descriptive terms nonresponse and recurrent nonresponse. Generally, this topic is far less represented in psychotherapy than in pharmacotherapy. Controlled switching studies with a switch from pharmacotherapy to psychotherapy are rare and those switching from one psychotherapeutic approach to another are nearly nonexistent. Building on clinical considerations, we propose a flow-chart for clinical decision making after nonresponse in psychotherapy.

DISCUSSION

Learning from errors is highly beneficial. This principle should be more consistently followed up in psychotherapy research as well as in supervision and training. Guidelines should include consensual and evidence-based advice on how to deal with nonresponse and recurring nonresponse.

The definition of treatment resistance in anxiety disorders: a Delphi method-based consensus guideline

Anxiety disorders are very prevalent and often persistent mental disorders, with a considerable rate of treatment resistance which requires regulatory clinical trials of innovative therapeutic interventions. However, an explicit definition of treatment-resistant anxiety disorders (TR-AD) informing such trials is currently lacking. We used a Delphi method-based consensus approach to provide internationally agreed, consistent and clinically useful operational criteria for TR-AD in adults. Following a summary of the current state of knowledge based on international guidelines and an available systematic review, a survey of free-text responses to a 29-item questionnaire on relevant aspects of TR-AD, and an online consensus meeting, a panel of 36 multidisciplinary international experts and stakeholders voted anonymously on written statements in three survey rounds. Consensus was defined as ≥75% of the panel agreeing with a statement. The panel agreed on a set of 14 recommendations for the definition of TR-AD, providing detailed operational criteria for resistance to pharmacological and/or psychotherapeutic treatment, as well as a potential staging model. The panel also evaluated further aspects regarding epidemiological subgroups, comorbidities and biographical factors, the terminology of TR-AD vs. "difficult-to-treat" anxiety disorders, preferences and attitudes of persons with these disorders, and future research directions. This Delphi method-based consensus on operational criteria for TR-AD is expected to serve as a systematic, consistent and practical clinical guideline to aid in designing future mechanistic studies and facilitate clinical trials for regulatory purposes. This effort could ultimately lead to the development of more effective evidence-based stepped-care treatment algorithms for patients with anxiety disorders.

Individual cognitive therapy reduces frontal-thalamic resting-state functional connectivity in social anxiety disorder

Introduction

Previous neuroimaging studies in social anxiety disorders (SAD) have reported potential neural predictors of cognitive behavioral therapy (CBT)-related brain changes. However, several meta-analyses have demonstrated that cognitive therapy (CT) was superior to traditional exposure-based CBT for SAD.

Objective

To explore resting-state functional connectivity (rsFC) to evaluate the response to individual CT for SAD patients.

Methods

Twenty SAD patients who attended 16-week individual CT were scanned pre- and post-therapy along with twenty healthy controls (HCs). The severity of social anxiety was assessed with the Liebowitz Social Anxiety Scale (LSAS). Multi-voxel pattern analysis (MVPA) was performed on the pre-CT data to extract regions associated with a change in LSAS (∆LSAS). Group comparisons of the seed-based rsFC analysis were performed between the HCs and pre-CT patients and between the pre-and post-CT patients.

Results

MVPA-based regression analysis revealed that rsFC between the left thalamus and the frontal pole/inferior frontal gyrus was significantly correlated with ∆LSAS (adjusted R2 = 0.65; p = 0.00002). Compared with HCs, the pre-CT patients had higher rsFCs between the thalamus and temporal pole and between the thalamus and superior/middle temporal gyrus/planum temporale (p < 0.05). The rsFC between the thalamus and the frontal pole decreased post-CT (p < 0.05).

Conclusion

SAD patients had significant rsFC between the thalamus and temporal pole, superior/middle temporal gyrus, and planum temporale, which may be indicators of extreme anxiety in social situations. In addition, rsFC between the thalamus and the frontal pole may be a neuromarker for the effectiveness of individual CT.

Pharmacological Treatment of Generalised Anxiety Disorder: Current Practice and Future Directions

INTRODUCTION

Generalized Anxiety Disorder (GAD) is a common psychiatric condition, characterized by the presence of general apprehensiveness and excessive worry. Current management consists of a range of pharmacological and psychological treatments. However, many patients do not respond to first-line pharmacological treatments and novel anxiolytic drugs are being developed.

AREAS COVERED

In this review, the authors first discuss the diagnostic criteria and epidemiology of GAD. The effective pharmacological treatments for GAD and their tolerability are addressed. Current consensus guidelines for treatment of GAD are discussed, and maintenance treatment, the management of treatment resistance, and specific management of older adults and children/adolescents are considered. Finally, novel anxiolytics under development are discussed, with a focus on those which have entered clinical trials.

EXPERT OPINION

A range of effective treatments for GAD are available, particularly duloxetine, escitalopram, pregabalin, quetiapine, and venlafaxine. There is a limited evidence base to support the further pharmacological management of patients with GAD who have not responded to initial treatment. Although many novel anxiolytics have progressed to clinical trials, translation from animal models has been mostly unsuccessful. However, the potential of several compounds including certain psychedelics, ketamine, oxytocin, and agents modulating the orexin, endocannabinoid, and immune systems merits further study.

Preliminary Evaluation of Translated and Culturally Adapted Internet-Delivered Cognitive Therapy for Social Anxiety Disorder: Multicenter, Single-Arm Trial in Japan

BACKGROUND

Internet-delivered cognitive therapy for social anxiety disorder (iCT-SAD), which is a therapist-guided modular web-based treatment, has shown strong efficacy and acceptability in English-language randomized controlled trials in the United Kingdom and Hong Kong. However, it is not yet known whether iCT-SAD can retain its efficacy following linguistic translation and cultural adaptation of treatment contents and implementation in other countries such as Japan.

OBJECTIVE

This study aimed to examine the preliminary efficacy and acceptability of the translated and culturally adapted iCT-SAD in Japanese clinical settings.

METHODS

This multicenter, single-arm trial recruited 15 participants with social anxiety disorder. At the time of recruitment, participants were receiving usual psychiatric care but had not shown improvement in their social anxiety and required additional treatment. iCT-SAD was provided in combination with usual psychiatric care for 14 weeks (treatment phase) and for a subsequent 3-month follow-up phase that included up to 3 booster sessions. The primary outcome measure was the self-report version of the Liebowitz Social Anxiety Scale. The secondary outcome measures examined social anxiety-related psychological processes, taijin kyofusho (the fear of offending others), depression, generalized anxiety, and general functioning. The assessment points for the outcome measures were baseline (week 0), midtreatment (week 8), posttreatment (week 15; primary assessment point), and follow-up (week 26). Acceptability was measured using the dropout rate from the treatment, the level of engagement with the program (the rate of module completion), and participants' feedback about their experience with the iCT-SAD.

RESULTS

Evaluation of the outcome measures data showed that iCT-SAD led to significant improvements in social anxiety symptoms during the treatment phase (P<.001; Cohen d=3.66), and these improvements were maintained during the follow-up phase. Similar results were observed for the secondary outcome measures. At the end of the treatment phase, 80% (12/15) of participants demonstrated reliable improvement, and 60% (9/15) of participants demonstrated remission from social anxiety. Moreover, 7% (1/15) of participants dropped out during treatment, and 7% (1/15) of participants declined to undergo the follow-up phase after completing the treatment. No serious adverse events occurred. On average, participants completed 94% of the modules released to them. Participant feedback was positive and highlighted areas of strength in treatment, and it included further suggestions to improve suitability for Japanese settings.

CONCLUSIONS

Translated and culturally adapted iCT-SAD demonstrated promising initial efficacy and acceptability for Japanese clients with social anxiety disorder. A randomized controlled trial is required to examine this more robustly.

Ketamine treatment for refractory anxiety: A systematic review

There is a growing interest in the psychiatric properties of the dissociative anaesthetic ketamine, as single doses have been shown to have fast-acting mood-enhancing and anxiolytic effects, which persist for up to a week after the main psychoactive symptoms have diminished. Therefore, ketamine poses potential beneficial effects in patients with refractory anxiety disorders, where other conventional anxiolytics have been ineffective. Ketamine is a noncompetitive antagonist of the N-methyl-d-aspartate (NMDA) glutamate receptor, which underlies its induction of pain relief and anaesthesia. However, the role of NMDA receptors in anxiety reduction is still relatively unknown. To fill this paucity in the literature, this systematic review assesses the evidence that ketamine significantly reduces refractory anxiety and discusses to what extent this may be mediated by NMDA receptor antagonism and other receptors. We highlight the temporary nature of the anxiolytic effects and discuss the high discrepancy among the study designs regarding many fundamental factors such as administration routes, complementary treatments and other treatments.

Mindfulness-based cognitive group therapy for treatment-refractory anxiety disorder: A pragmatic randomized controlled trial

BACKGROUND

This study aimed: (a) to examine the effectiveness of Mindfulness-Based Cognitive Therapy (MBCT) for patients with a treatment-refractory anxiety disorders compared to Relapse Prevention-Cognitive Behavioral Therapy (CBT-RP); and (b) to explore candidate mediating variables.

METHODS

We conducted a pragmatic randomized controlled trial comparing MBCT with CBT-RP in a group format for 136 outpatients with treatment-refractory DSM-IV defined anxiety disorder, who insufficiently responded to first-line psychological treatment.

RESULTS

At post-treatment, the MBCT group showed a significantly larger decrease in self-reported anxiety (Beck Anxiety Inventory), avoidance (Fear Questionnaire), difficulties in emotion regulation (Difficulties in Emotion Regulation Strategies), and worry (Penn State Worry Questionnaire), as well as a significantly larger increase in mindfulness skills (Five Facet Mindfulness Questionnaire). After a 6-month follow-up treatment gains were somewhat diminished. Effects of MBCT on anxiety at post-treatment did not prove to be mediated by mindfulness skills, difficulties in emotion regulation strategies, worry, or rumination (Rumination on Sadness Scales) at mid-treatment.

CONCLUSIONS

MBCT seems to be a promising intervention in routine clinical care for persons with an anxiety disorder who insufficiently responded to first-line psychological treatment. Future research in larger samples assessing long-term effects and using intensive longitudinal designs to identify possible working mechanisms is called for.

Right Frontal Theta: Is It a Response Biomarker for Ketamine’s Therapeutic Action in Anxiety Disorders?

Anxiety disorders are the most prevalent mental disorders in the world, creating huge economic burdens on health systems and impairing the quality of life for those affected. Recently, ketamine has emerged as an effective anxiolytic even in cases resistant to conventional treatments (TR); but its therapeutic mechanism is unknown. Previous data suggest that ketamine anxiety therapy is mediated by reduced right frontal electroencephalogram (EEG) theta power measured during relaxation. Here we test for a similar theta reduction between population-sample, presumed treatment-sensitive, (TS) anxiety patients and healthy controls. Patients with TS DSM-5 anxiety disorder and healthy controls provided EEG during 10 min of relaxation and completed anxiety-related questionnaires. Frontal delta, theta, alpha1, alpha2, beta, and gamma power, Higuchi’s fractal dimension (HFD) and frontal alpha asymmetry (FAA) values were extracted to match ketamine testing; and we predicted that the controls would have less theta power at F4, relative to the TS anxious patients, and no differences in HFD or FAA. We provide graphical comparisons of our frontal band power patient-control differences with previously published post-pre ketamine TR differences. As predicted, theta power at F4 was significantly lower in controls than patients and FAA was not significantly different. However, HFD was unexpectedly reduced at lateral sites. Gamma power did not increase between controls and patients suggesting that the increased gamma produced by ketamine relates to dissociation rather than therapy. Although preliminary, and indirect, our results suggest that the anxiolytic action of ketamine is mediated through reduced right frontal theta power.

In silico study of dimethyltryptamine analogues against 5-HT1B receptor: Molecular docking, dynamic simulations and ADMET prediction

Introduction: The 5-HT1B receptor has a potential role in various psychiatric disorders such as depression, anxiety, and post-traumatic stress disorder. The objective of this study was to perform docking and molecular dynamics simulation to evaluate at atomic level the behavior of N,N-dimethyltryptamine (DMT) on 5-HT1B receptor.Methods: In this study, initially, a search for DMT was performed using the PubChem database. Subsequently, molecular docking was executed using AutoDock Vina based in PyRx 0.8 with a 95% analogy. Additionally, ergotamine (ERG) and serotonin were used as control. Then, it ran a total of 100 ns molecular dynamics simulations on 5-HT1B bound with DMT, serotonin, 112814775, and ERG. Finally, pharmacokinetic prediction and IV acute toxicity for analogues and DMT were performed.Results: It was possible to show that 112814775 had the lowest binding energy with the receptor. In addition, 112814775 presented great conformational stability, low mobility, and stiffness compared to the control ligands: ERG, serotonin, and DMT subsequent dynamic analysis. With respect to the free energy calculation, contributions such as Van der Waals, electrostatics, and nonpolar interactions for all systems, were highlighted.Conclusion: 112814775 showed affinities with 5-HT1B receptor and evidenced notable behavior by molecular dynamic simulation according to root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), solvent-accessible surface area (SASA), the radius of gyration, number of hydrogen bond, and free energy calculated. These results established the possible relevance of in-silico studies in search of DMT analogues against the 5-HT1B receptor, which may be associated with alterations such as depression and anxiety, and may become future study molecules for the treatment of this type of disorder.

Efficacy and acceptability of pharmacotherapy for comorbid anxiety symptoms in bipolar disorder: A systematic review and meta-analysis

OBJECTIVE

Anxiety symptoms are highly prevalent among individuals with bipolar disorder (BD) but there is little guidance on pharmacotherapy for these symptoms. The objective of this systematic review and meta-analysis was to evaluate the available evidence for pharmacotherapy of comorbid anxiety symptoms in BD.

METHODS

Completed randomized clinical trials (RCTs) of medications for BD published prior to December 2020 were identified through a systematic search of MEDLINE, Embase, PsycInfo, Web of Science, clinicaltrials.gov, and the ISRCTN. Data from RCTs measuring anxiety symptoms at baseline and endpoint and all-cause discontinuation were pooled to compare the efficacy and acceptability of medications with control conditions.

RESULTS

Thirty-seven RCTs met our inclusion criteria; 13 placebo-controlled RCTs with 2175 participants had sufficient data to be included in the meta-analysis assessing anxiety symptoms. Compared with placebo, the overall effect size of medications (primarily atypical antipsychotics) on anxiety symptoms was small with a standardized mean difference (SMD) = -0.22 (95% CI: -0.34 to -0.11). Study heterogeneity was low (I²  = 26%). The acceptability of these medications was comparable with placebo with odds ratio of discontinuation from all causes = 0.98 (95% CI: 0.91-1.06).

CONCLUSION

There is limited evidence for a small anxiolytic effect and good acceptability of pharmacotherapy (primarily atypical antipsychotics) in the treatment of comorbid anxiety symptoms in BD. These results highlight the need for further research on medications other than atypical antipsychotics.

Systematic review and meta-analysis of randomized controlled trials of ketamine in the treatment of refractory anxiety spectrum disorders

BACKGROUND

Anxiety disorders are common, associated with significant burden of disease, and have high levels of treatment resistance. Low-dose ketamine has been extensively studied in treatment-resistant depression, with fewer reports in treatment-resistant anxiety disorders.

AIMS

This systematic review and meta-analysis collected efficacy, safety, and tolerability data for ketamine as a treatment for anxiety spectrum disorders.

METHODS

We conducted a systematic search for randomized controlled trials (RCTs) of acute ketamine treatment for patients with anxiety disorders. Open-label trials of ketamine maintenance therapy were also considered. Qualitative and, where possible, quantitative syntheses of findings were performed using Review Manager software (RevMan). Acute dose-response and maintenance treatment data were also collected.

RESULTS

There were six eligible acute RCTs - two in social anxiety disorder (SAD), three in post-traumatic stress disorder (PTSD), and one in obsessive-compulsive disorder (OCD). Four of the six showed significant improvement in anxiety rating scores in ketamine compared with control groups. Pooled analysis showed ketamine was associated with an increased likelihood of treatment response for SAD (odds ratio (OR): 28.94; 95% confidence interval [CI]: 3.45-242.57; p = 0.002) but not for PTSD (OR: 2.03; 95% CI: 0.67-6.15; p = 0.21). A dose-response profile was observed for ketamine and changes in SAD symptoms, with doses ⩾0.5 mg/kg associated with greater reduction in anxiety rating scores than lower doses. Ketamine maintenance therapy was associated with sustained anxiolytic effects and improved social and/or work functioning.

CONCLUSION

These preliminary analyses suggest that acute ketamine may be broadly effective across treatment-resistant anxiety spectrum disorders. These effects can be prolonged with maintenance treatment. Future studies will be needed to provide critical knowledge gaps around off-label use, side effects, and potential risks for abuse in clinical settings.

Precision clinical trials: a framework for getting to precision medicine for neurobehavioural disorders

The goal of precision medicine (individually tailored treatments) is not being achieved for neurobehavioural conditions such as psychiatric disorders. Traditional randomized clinical trial methods are insufficient for advancing precision medicine because of the dynamic complexity of these conditions. We present a pragmatic solution: the precision clinical trial framework, encompassing methods for individually tailored treatments. This framework includes the following: (1) treatment-targeted enrichment, which involves measuring patients' response after a brief bout of an intervention, and then randomizing patients to a full course of treatment, using the acute response to predict long-term outcomes; (2) adaptive treatments, which involve adjusting treatment parameters during the trial to individually optimize the treatment; and (3) precise measurement, which involves measuring predictor and outcome variables with high accuracy and reliability using techniques such as ecological momentary assessment. This review summarizes precision clinical trials and provides a research agenda, including new biomarkers such as precision neuroimaging, transcranial magnetic stimulation-electroencephalogram digital phenotyping and advances in statistical and machine-learning models. Validation of these approaches - and then widespread incorporation of the precision clinical trial framework - could help achieve the vision of precision medicine for neurobehavioural conditions.

Refractory Gilles de la Tourette Syndrome-Many Pieces That Define the Puzzle

Gilles de la Tourette syndrome (GTS) is a childhood onset neuropsychiatric disorder characterized by the presence of motor and vocal tics. The clinical spectrum of GTS is heterogeneous and varies from mild cases that do not require any medical attention to cases that are refractory to standard treatments. One of the unresolved issues is the definition of what constitutes treatment-refractory GTS. While for some other neuropsychiatric disorders, such as obsessive-compulsive disorder (OCD), a clear definition has been established, there is still no consensus with regard to GTS. One important issue is that many individuals with GTS also meet criteria for one or more other neurodevelopmental and neuropsychiatric disorders. In many individuals, the severity of these comorbid conditions contributes to the degree to which GTS is treatment refractory. The scope of this paper is to present the current state-of-the-art regarding refractory GTS and indicate possible approaches to define it. In closing, we discuss promising approaches to the treatment of individuals with refractory GTS.

Comparative efficacy and safety of traditional Chinese patent medicine for anxiety disorders in children or adolescence: A protocol for systematic review and network meta-analysis

BACKGROUND

Anxiety is the most common mental illness among adolescents and children, and its incidence is increasing year by year, which has a serious adverse effect on the academic and growth of adolescents and children. Conventional treatment methods such as oral administration of western medicine and psycho-behavioral therapy have obvious limitations. Chinese patent medicines play an irreplaceable role in the treatment of this disease. At present, there is no comparison of the safety and effectiveness of various Chinese patent medicines curing anxiety in adolescents. So we take advantage of the method of network meta-analysis to systematically compare the efficacy of various Chinese patent medicines curing this disease.

METHODS

We will systematically and comprehensively search the following databases, including PubMed, Web of Science, EMBASE, The Cochrane Library, China BioMedical Literature (CBM), China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP), and Wanfang database. We will include all RCT trials that meet the inclusion criteria, starting from the establishment of the database until August 2020. Two researchers will independently screen the literature based on inclusion criteria. While extracting data, we also assess the risk of bias in the included studies. All the data and evidence obtained will be evaluated by the method of Bayesian network meta-analysis. STATA and WinBUGS software will be used.

RESULTS

This study will evaluate the effectiveness and safety of various TCPMs for anxiety disorders in children or adolescence.

CONCLUSION

The results of this study will provide valuable references for the clinical application of Traditional Chinese patent medicines, and assist clinicians in formulating more reasonable diagnosis and treatment strategies.

ETHICS AND DISSEMINATION

This study does not require ethical approval.

INPLASY REGISTRATION NUMBER

INPLASY202080048.

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.

Aligning the many definitions of treatment resistance in anxiety disorders: A systematic review

Anxiety Disorders often show a chronic course, even when treated with one of the various effective treatments available. Lack of treatment effect could be due to Treatment Resistance (TR). Consensus on a definition for TR Anxiety Disorders (TR-AD) is highly needed as currently many different operationalizations are in use. Therefore, generalizability in current TR-AD research is suboptimal, hampering improvement of clinical care. The objective of this review is to evaluate the currently used definitions of TR-AD by performing a systematic review of available literature. Out of a total of n = 13 042, 62 studies that operationalized TR-AD were included. The current review confirms a lack of consensus on TR-AD criteria. In 62.9% of the definitions, TR was deemed present after the first treatment failure. Most studies (93.0%) required pharmacological treatment failures, whereas few (29.0%) required psychological treatment failures. However, criteria for what constitutes "treatment failure" were not provided in the majority of studies (58.1%). Definitions for minimal treatment duration ranged from at least 4 weeks to at least 6 months. Almost half of the TR-AD definitions (46.8%) required elevated anxiety severity levels in TR-AD. After synthesis of the results, the consensus definition considers TR-AD present after both at least one first-line pharmacological and one psychological treatment failure, provided for an adequate duration (at least 8 weeks) with anxiety severity remaining above a specified threshold. This definition could contribute to improving course prediction and identifying more targeted treatment options for the highly burdened subgroup of TR-AD patients.