Repetitive transcranial magnetic stimulation (rTMS) for panic disorder in adults

Impaired implicit emotion regulation in patients with panic disorder: An event-related potential study on affect labeling

BACKGROUND

Panic disorder (PD) involves emotion dysregulation, but its underlying mechanisms remain poorly understood. Previous research suggests that implicit emotion regulation may play a central role in PD-related emotion dysregulation and symptom maintenance. However, there is a lack of studies exploring the neural mechanisms of implicit emotion regulation in PD using neurophysiological indicators.

AIM

To study the neural mechanisms of implicit emotion regulation in PD with event-related potentials (ERP).

METHODS

A total of 25 PD patients and 20 healthy controls (HC) underwent clinical eva-luations. The study utilized a case-control design with random sampling, selecting participants for the case group from March to December 2018. Participants performed an affect labeling task, using affect labeling as the experimental condition and gender labeling as the control condition. ERP and behavioral data were recorded to compare the late positive potential (LPP) within and between the groups.

RESULTS

Both PD and HC groups showed longer reaction times and decreased accuracy under the affect labeling. In the HC group, late LPP amplitudes exhibited a dynamic pattern of initial increase followed by decrease. Importantly, a significant group × condition interaction effect was observed. Simple effect analysis revealed a reduction in the differences of late LPP amplitudes between the affect labeling and gender labeling conditions in the PD group compared to the HC group. Furthermore, among PD patients under the affect labeling, the late LPP was negatively correlated with disease severity, symptom frequency, and intensity.

CONCLUSION

PD patients demonstrate abnormalities in implicit emotion regulation, hampering their ability to mobilize cognitive resources for downregulating negative emotions. The late LPP amplitude in response to affect labeling may serve as a potentially valuable clinical indicator of PD severity.

Pre-clinical indications of brain stimulation treatments for non-affective psychiatric disorders, a status update

Over the past two decades noninvasive brain stimulation (NIBS) techniques have emerged as powerful therapeutic options for a range of psychiatric and neurological disorders. NIBS are hypothesized to rebalance pathological brain networks thus reducing symptoms and improving functioning. This development has been fueled by controlled studies with increasing size and rigor aiming to characterize how treatments induce clinically effective change. Clinical trials of NIBS for specific indications have resulted in federal approval for unipolar depression, bipolar depression, smoking cessation, and obsessive-compulsive disorder in the United States, and several other indications worldwide. As a rapidly emerging field, there are numerous pre-clinical indications currently in development using a variety of electrical and magnetic, non-convulsive, and convulsive approaches. This review discusses the state-of-the-science surrounding promising avenues of NIBS currently in pre-approval stages for non-affective psychiatric disorders. We consider emerging therapies for psychosis, anxiety disorders, obsessive-compulsive disorder, and borderline personality disorder, utilizing transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and magnetic seizure therapy (MST), with an additional brief section for early-stage techniques including transcranial focused ultrasound stimulation (tFUS) and transcranial alternating current stimulation (tACS). As revealed in this review, there is considerable promise across all four psychiatric indications with different NIBS approaches. Positive findings are notable for the treatment of psychosis using tDCS, MST, and rTMS. While rTMS is already FDA approved for the treatment of obsessive-compulsive disorder, methodologies such as tDCS also demonstrate potential in this condition. Emerging techniques show promise for treating non-affective disorders likely leading to future regulatory approvals.

Biological and cognitive theories explaining panic disorder: A narrative review

The current narrative review summarizes and examines several theories of panic disorder (PD) including biological theories, encompassing neurochemical factors, metabolic and genetic theories, respiratory and hyperventilation theories and cognitive theory. Biological theories have informed the development of psychopharmacological treatments; however, they may be limited in their utility given the efficacy of psychological treatments. In particular, behavioral and, more recently, cognitive models have garnered support due to the efficacy of cognitive-behavior therapy (CBT) in treating PD. The role of combination treatments has been found to be superior in the treatment of PD in particular cases, lending support for the need for an integrated approach and model for PD given that the etiology of PD is complex and multifactorial.

Pathological fear, anxiety and negative affect exhibit distinct neurostructural signatures: evidence from psychiatric neuroimaging meta-analysis

Internalizing disorders encompass anxiety, fear and depressive disorders, which exhibit overlap at both conceptual and symptom levels. Given that a neurobiological evaluation is lacking, we conducted a Seed-based D-Mapping comparative meta-analysis including coordinates as well as original statistical maps to determine common and disorder-specific gray matter volume alterations in generalized anxiety disorder (GAD), fear-related anxiety disorders (FAD, i.e., social anxiety disorder, specific phobias, panic disorder) and major depressive disorder (MDD). Results showed that GAD exhibited disorder-specific altered volumes relative to FAD including decreased volumes in left insula and lateral/medial prefrontal cortex as well as increased right putamen volume. Both GAD and MDD showed decreased prefrontal volumes compared to controls and FAD. While FAD showed less robust alterations in lingual gyrus compared to controls, this group presented intact frontal integrity. No shared structural abnormalities were found. Our study is the first to provide meta-analytic evidence for distinct neuroanatomical abnormalities underlying the pathophysiology of anxiety-, fear-related and depressive disorders. These findings may have implications for determining promising target regions for disorder-specific neuromodulation interventions (e.g. transcranial magnetic stimulation or neurofeedback).

Frontoparietal paired associative stimulation versus single-site stimulation for generalized anxiety disorder: a pilot rTMS study

BACKGROUND

At present, the use of repetitive transcranial magnetic stimulation (rTMS) for generalized anxiety disorder (GAD) is limited to single-site interventions. We investigated whether dual-site frontoparietal stimulation delivered using cortical-cortical paired associative stimulation (ccPAS) had stronger clinical efficacy than single-site stimulation in patients with GAD.

METHODS

We randomized 50 patients with GAD to 1 Hz rTMS (10 sessions) using 1 of the following protocols: single-site stimulation over the right dorsolateral prefrontal cortex (dlPFC; 1500 pulses per session); single-site stimulation over the right posterior parietal cortex (PPC; 1500 pulses per session); repetitive dual-site ccPAS (rds-ccPAS) over the right dlPFC and right PPC with 1500 pulses per session (rd-ccPAS-1500); or rds-ccPAS over the right dlPFC and right PPC with 750 pulses per session (rd-ccPAS-750). Both rds-ccPAS treatments used a between-site interval of 100 ms.

RESULTS

Clinical scores for anxiety, depression and insomnia were reduced in all 4 groups after treatment. We found greater improvements in anxiety symptoms in the rds-ccPAS-1500 group compared to the rds-ccPAS-750 and single-site groups. We found greater improvements in depression symptoms and insomnia in the rds-PAS-1500 group compared to the single-site groups. The rds-ccPAS-1500 group also showed significant or trend-level improvements in anxiety symptoms and insomnia at 10-day and 1-month followup. More patients responded to treatment with rds-ccPAS-1500 than with single-site stimulation. The between-group differences in response rates persisted to the 3-month follow-up. Treatment using rds-ccPAS with a between-site interval of 100 ms induced a more significant improvement than the between-site interval of 50 ms we evaluated in a previous study.

LIMITATIONS

These results need to be replicated in a larger sample using sham control and equal-pulse single-site stimulation.

CONCLUSION

Frontoparietal rds-ccPAS may be a better treatment option for GAD.

Neural basis of implicit cognitive reappraisal in panic disorder: an event-related fMRI study

Background

Panic disorder (PD) is thought to be related with deficits in emotion regulation, especially in cognitive reappraisal. According to the cognitive model, PD patients’ intrinsic and unconscious misappraisal strategies are the cause of panic attacks. However, no studies have yet been performed to explore the underlying neuromechanism of cognitive reappraisal that occur on an unconscious level in PD patients.

Methods

Twenty-six patients with PD and 25 healthy controls (HC) performed a fully-verified event-block design emotional regulation task aimed at investigating responses of implicit cognitive reappraisal during an fMRI scan. Participants passively viewed negatively valanced pictures that were beforehand neutrally, positively, or adversely portrayed in the task.

Results

Whole-brain analysis of fMRI data showed that PD patients exhibited less activation in the right dorsolateral prefrontal cortex (dlPFC) and right dorsomedial prefrontal cortex (dmPFC) compared to HC, but presented greater activation in parietal cortex when negative pictures were preceded by positive/neutral vs negative descriptions. Simultaneously, interactive effects of Group × Condition were observed in the right amygdala across both groups. Furthermore, activation in dlPFC and dmPFC was is negatively correlated to severity of anxiety and panic in PD when negative images were preceded by non-negative vs negative descriptions.

Conclusions

Emotional dysregulation in PD is likely the result of deficient activation in dlPFC and dmPFC during implicit cognitive reappraisal, in line with impaired automatic top-down regulation. Correlations between severity of anxiety and panic attack and activation of right dlPFC and dmPFC suggest that the failure to engage prefrontal region during implicit cognitive reappraisal might be associated wtih the severity of anxiety and panic; such functional patterns might be the target of possible treatments.

Repetitive Transcranial Magnetic Stimulation for People With Treatment-Resistant Depression: A Health Technology Assessment

BACKGROUND

Major depression is one of the most diagnosed mental illnesses in Canada. Generally, people are treated successfully with antidepressants or psychotherapy, but some people do not respond to these treatments (called treatment-resistant depression [TRD]). Repetitive transcranial magnetic stimulation (rTMS) delivers magnetic pulses to stimulate the areas of the brain associated with mood regulation. Several modalities of rTMS exist (e.g., high frequency rTMS, intermittent theta burst stimulation [iTBS], deep transcranial magnetic stimulation). We conducted a health technology assessment of rTMS for people with TRD, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding rTMS, and patient preferences and values.

METHODS

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Risk of Bias in Systematic Reviews (ROBIS) tool and Cochrane Risk of Bias for Randomized Controlled Trials and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 3-year horizon from a public payer perspective. We also analyzed the 5-year budget impact of publicly funding rTMS for people with TRD in Ontario. To assess the potential value of rTMS, we spoke with people who have TRD. Seven rTMS modalities were considered: low-frequency (1 Hz) stimulation, high-frequency (10-20 Hz) stimulation, unilateral stimulation, bilateral stimulation, iTBS, continuous theta burst stimulation, and deep transcranial magnetic stimulation.

RESULTS

We included 58 primary studies, 9 systematic reviews, and 1 network meta-analysis in the clinical evidence review. Most rTMS modalities were more effective than sham treatment for all outcomes (GRADE: Moderate to High). All rTMS modalities were similar to one another in response and remission rates (GRADE: not reported) and were similar to electroconvulsive therapy (ECT) in response and remission rates (GRADE: Moderate). Moreover, in both the reference case and scenario analyses, two rTMS modalities (rTMS or iTBS), followed by ECT when patients did not respond to initial treatment, were less expensive and more effective than ECT alone. They were cost-effective compared with pharmacotherapy alone at a willingness-to-pay amount of $50,000 per quality-adjusted life-year (QALY). The annual budget impact of publicly funding rTMS would range from $9.3 million in year 1 to $15.76 million in year 5, for a total of $63.2 million over the next 5 years. People with TRD we spoke with reported that their experiences were generally favourable, and their attitudes toward rTMS were positive. Similarly, psychiatrists had positive attitudes toward and acceptance of rTMS. Our quantitative literature review on preferences revealed some gaps in psychiatrists' knowledge of rTMS, which could have been influenced by their level of training on rTMS.

CONCLUSIONS

Most rTMS modalities are likely more effective than sham rTMS on all outcomes. All rTMS modalities are similar to ECT and to one another in response and remission rates. Compared with ECT alone, two rTMS modalities (high-frequency rTMS and iTBS), followed by ECT when necessary in a stepped care pathway, were less costly and more effective for managing adults with TRD. These types of rTMS (high-frequency rTMS and iTBS) were cost-effective compared with pharmacotherapy alone at a willingness-to-pay amount of $50,000 per QALY. Publicly funding rTMS (high-frequency rTMS and iTBS) for the treatment of adults with TRD in Ontario over the next 5 years would add $63.2 million in total costs. People with TRD had positive experiences and attitudes toward rTMS.

Current Research on Complementary and Alternative Medicine (CAM) in the Treatment of Anxiety Disorders: An Evidence-Based Review

Complementary and alternative medicine (CAM) encompasses a wide range of different nonmainstream therapies that have been increasingly used for treatment or adjunctive treatment of various ailments with anxiety/anxiety disorders being one of the commonly CAM (self)-medicated conditions. Thousands of published papers refer to use of CAM in various psychiatric disorders or in healthy or medically ill patients with mood or anxiety difficulties. In this chapter we focus specifically on clinically diagnosed (in line with the standard criteria) anxiety disorders and overview evidence of efficacy/safety of a range of CAM modalities: biologically based therapies (typically herbal preparations and less so nutraceuticals); manipulative and body-based therapies (acupuncture, aerobic exercise, massage, therapeutic touch, repetitive transcranial magnetic stimulation, balneotherapy, and others); mind-body therapies (yoga, Morita therapy, Tai Chi, reiki, Chinese cognitive therapy, religious and spiritual interventions, relaxation, mediation, and mindfulness-based interventions); and alternative medical systems (Ayurveda, homeopathy). We focus exclusively on randomized controlled trials and attempt to evaluate the existing body of evidence in the same manner that is applied to mainstream treatments.

Efficacy and safety of repetitive transcranial magnetic stimulation for generalised anxiety disorder: A meta-analysis

Background

Pharmacological and conventional non-pharmacological treatments are only moderately effective in treating generalised anxiety disorder (GAD). Recently, repetitive transcranial magnetic stimulation (rTMS) has attracted interest because of its potential therapeutic value.

Aim

To investigate the efficacy and safety of rTMS treatment for GAD.

Methods

Literature studies published in English or Chinese were screened in 10 electronic databases up to 5 December 2018. The included studies' bias risk was assessed using Cochrane risk of bias assessment tool. Meta-analysis was performed to compute the standardised mean difference (SMD) and risk ratio (RR) along with its 95% CIs through using RevMan V.5.3. Heterogeneity was inspected by I² and the χ² test. We performed subgroup analysis and meta-regression to investigate heterogeneity. We used funnel plot to assess publication bias. We used the GRADE approach to assess the whole quality of evidence.

Results

Twenty-one studies, with a total sample size of 1481, were analysed. The risk of bias in most studies included is moderate, the majority of which are lacking of blinding methods of treatment allocation. The treatment had beneficial effects in the rTMS group compared with the control group in mean anxiety score (SMD=-0.68; 95% CI -0.89 to -0.46). None of the 21 studies included here reported severe adverse events. As for dropout rates, there are no statistically significant differences between the two groups (RR 1.14, 95% CI 0.72 to 1.82) or adverse events (RR 0.95, 95% CI 0.77 to 1.18). No particular influence on the heterogeneity of any variable was observed. The risk of publication bias was low. According to the GRADE approach, the evidence levels of primary outcome (treatment effects) and secondary outcomes (acceptability and safety) were rated as 'medium'.

Conclusion

The use of rTMS combined with medication treatment may have a significant positive anti-anxiety effect on patients with GAD. However, we should interpret the results cautiously due to the relatively high heterogeneity of the meta-analysis. Future high-quality clinical trials are needed to confirm our results.

Pharmacological and Neuromodulatory Treatments for Panic Disorder: Clinical Trials from 2010 to 2018

OBJECTIVE

Treatment for panic disorder (PD) have evolved, although there is still a strong unmet need for more effective and tolerable options. The present study summarizes and discusses recent evidence regarding the pharmacological and neuromodulatory treatment of PD.

METHODS

MEDLINE, Cochrane Library, PsycINFO and Thomson Reuters's Web of Science were searched for clinical trials published between 2010 and 2018. We included all prospective experimental studies including randomized controlled trials (RCT) and other clinical trials with more than 10 patients.

RESULTS

Only 11 articles met the inclusion criteria, including 4 RCT, 3 open clinical trials and 5 comparative clinical trials. RCT demonstrated efficacy of transcranial magnetic stimulation (TMS) in only one of two trials. Neither pindolol nor d-fenfluramine were effective in blocking flumazenil-induced panic attacks. Augmentation with quetiapine was not superior to placebo. Open trials indicated that escitalopram, vortioxetine and TMS may be effective. Comparative trials did not demonstrate superiority from any drug, but confirmed tranylcypromine, paroxetine, clonazepam and alprazolam as effective options.

CONCLUSION

The current study confirmed the efficacy of tranylcypromine, paroxetine, clonazepam, alprazolam and escitalopram. Vortioxetine and TMS, with duration of 4 or more weeks, also seems to be effective. Quetiapine, pindolol and d-fenfluramine were not considered effective compounds.

Treatment of anxiety disorders in clinical practice: a critical overview of recent systematic evidence

The aim of this study was to review emerging evidence of novel treatments for anxiety disorders. We searched PubMed and EMBASE for evidence-based therapeutic alternatives for anxiety disorders in adults, covering the past five years. Eligible articles were systematic reviews (with or without meta-analysis), which evaluated treatment effectiveness of either nonbiological or biological interventions for anxiety disorders. Retrieved articles were summarized as an overview. We assessed methods, quality of evidence, and risk of bias of the articles. Nineteen systematic reviews provided information on almost 88 thousand participants, distributed across 811 clinical trials. Regarding the interventions, 11 reviews investigated psychological or nonbiological treatments; 5, pharmacological or biological; and 3, more than one type of active intervention. Computer-delivered psychological interventions were helpful for treating anxiety of low-to-moderate intensity, but the therapist-oriented approaches had greater results. Recommendations for regular exercise, mindfulness, yoga, and safety behaviors were applicable to anxiety. Transcranial magnetic stimulation, medication augmentation, and new pharmacological agents (vortioxetine) presented inconclusive benefits in patients with anxiety disorders who presented partial responses or refractoriness to standard treatment. New treatment options for anxiety disorders should only be provided to the community after a thorough examination of their efficacy.

Insula H-coil deep transcranial magnetic stimulation in severe and enduring anorexia nervosa (SE-AN): a pilot study

INTRODUCTION

Anorexia nervosa (AN) is a complex disorder of unknown etiology, characterized by obsessions and compulsions around body shape, weight, and calorie intake. In the course of AN, 10%-30% will recover, while the rest will develop a treatment-resistant course with a high mortality rate due to AN-related complications. The insula is a region in the brain of considerable interest to its role in gustatory modulation, feeding behavior, and processing of interoceptive stimuli.

OBJECTIVE

Recent advances in the neurophysiology of AN suggest insula dysfunction as a potential biomarker for people with severe and enduring AN (SE-AN). Deep transcranial magnetic stimulation (dTMS) is of particular interest in SE-AN because of its ability to target deep areas of the brain.

DESIGN

We conducted a pilot study to investigate the feasibility and safety of insula dTMS in subjects with SE-AN.

RESULTS

We found that dTMS is a safe and well-tolerated treatment. We also found a reduction in AN-related obsessions and compulsions, as well as depression and anxiety scores from baseline to the end of the trial. Due to small sample size, the results of this study should be interpreted with great caution.

DISCUSSION

The results suggest that dTMS is safe and well tolerated and may be of some clinical interest in patients with SE-AN. However, to determine the true efficacy of dTMS for SE-AN, there is a need to conduct a randomized controlled trial comparing real versus sham dTMS in a larger number of AN subjects.

Effect of high-frequency repetitive transcranial magnetic stimulation (rTMS) in patients with comorbid panic disorder and major depression

OBJECTIVE

To explore the role of dorsolateral prefrontal cortex (DLPFC) stimulation in the treatment of panic disorder with comorbid depression.

METHODS

The present study reports findings from retrospective analysis of 13 treatment-resistant patients diagnosed with comorbid panic disorder and depression, given 20 sessions of high-frequency transcranial magnetic stimulation (rTMS) over left-DLPFC over a period of 1 month.

RESULTS

There was a significant reduction in both the panic and depressive symptom severity, assessed by applying Panic Disorder Severity Scale (PDSS) and Hamilton Depression Rating Scale (HDRS) at baseline and after 20 sessions of rTMS. There was a 38% and 40% reduction of PDSS and HDRS scores, respectively, in the sample. The changes in PDSS and HDRS scores were not significantly correlated (ρ = -0.103, p = 0.737).

CONCLUSIONS

High-frequency rTMS delivered at left-DLPFC may have a potential role in treatment of comorbid panic disorder and depression. Future studies done on a larger sample in a controlled environment are required to establish its role.

Noninvasive Brain Stimulations for Unilateral Spatial Neglect after Stroke: A Systematic Review and Meta-Analysis of Randomized and Nonrandomized Controlled Trials

Background

Unilateral spatial neglect (USN) is the most frequent perceptual disorder after stroke. Noninvasive brain stimulation (NIBS) is a tool that has been used in the rehabilitation process to modify cortical excitability and improve perception and functional capacity.

Objective

To assess the impact of NIBS on USN after stroke.

Methods

An extensive search was conducted up to July 2016. Studies were selected if they were controlled and noncontrolled trials examining transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), and theta burst stimulation (TBS) in USN after stroke, with outcomes measured by standardized USN and functional tests.

Results

Twelve RCTs (273 participants) and 4 non-RCTs (94 participants) proved eligible. We observed a benefit in overall USN measured by the line bisection test with NIBS in comparison to sham (SMD -2.35, 95% CI -3.72, -0.98; p = 0.0001); the rTMS yielded results that were consistent with the overall meta-analysis (SMD -2.82, 95% CI -3.66, -1.98; p = 0.09). The rTMS compared with sham also suggested a benefit in overall USN measured by Motor-Free Visual Perception Test at both 1 Hz (SMD 1.46, 95% CI 0.73, 2.20; p < 0.0001) and 10 Hz (SMD 1.19, 95% CI 0.48, 1.89; p = 0.54). There was also a benefit in overall USN measured by Albert's test and the line crossing test with 1 Hz rTMS compared to sham (SMD 2.04, 95% CI 1.14, 2.95; p < 0.0001).

Conclusions

The results suggest a benefit of NIBS on overall USN, and we conclude that rTMS is more efficacious compared to sham for USN after stroke.

Updated Review on the Clinical Use of Repetitive Transcranial Magnetic Stimulation in Psychiatric Disorders

With the ability to modulate cortical activity, repetitive transcranial magnetic stimulation (rTMS) is becoming increasingly important in clinical applications for psychiatric disorders. Previous studies have demonstrated its promising efficacy in depression and schizophrenia, and emerging evidence has also been found in patients with anxiety disorder, obsessive-compulsive disorder, and substance or food craving. However, the overall literature features some conflicting results, varied quality of studies, and a lack of consensus on optimal rTMS parameters. Besides, the efficacy of rTMS in patients with medication-resistant symptoms has drawn most attention from clinicians. Here we review multi-site studies and double-blind randomized controlled trials (RCTs) in single sites, as well as meta-analyses of RCTs in the last three years, in order to update evidence on efficacy and the optimal protocol of rTMS in psychiatric disorders, especially for medication-resistant symptoms.

Morbid Anxiety: Identification and Treatment

Due to their prevalence, chronicity, and poorly understood pathophysiology, anxiety disorders remain an important public health problem. Despite clear diagnostic guidelines and the availability of excellent evidence-based treatments, most anxiety patients remain underrecognized and inadequately treated. This clinical synthesis highlights changes to anxiety disorder diagnosis that became effective with DSM-5. The article also provides some clinical perspective on clarifying differential diagnostic problems and building an alliance with the anxious patient. The quality and strength of the evidence base for current anxiolytic medications options (selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, benzodiazepines, and other agents), antianxiety psychotherapies (cognitive-behavioral therapy and brief dynamic therapies), and combination treatments are discussed. A brief update on newer treatment strategies, such as cognitive enhancement, complementary therapies, and neuromodulation, is included. Future directions for anxiety nosology and treatment are summarized, including the National Institute of Mental Health Research Domain Criteria initiative and the promising role of personalized medicine.

Neuro-stimulation Techniques for the Management of Anxiety Disorders: An Update

Neuro-stimulation techniques have gradually evolved over the decades and have emerged potential therapeutic modalities for the treatment of psychiatric disorders, especially treatment refractory cases. The neuro-stimulation techniques involves modalities like electroconvulsive therapy (ECT), repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), vagus nerve stimulation (VNS) and others. This review discusses the role of neuro-stimulation techniques in the treatment of anxiety disorders. The various modalities of neuro-stimulation techniques are briefly discussed. The evidence base relating to use of these techniques in the treatment of anxiety disorders is discussed further. The review then highlights the challenges in conducting research in relation to the use of neuro-stimulation techniques with reference to patients with anxiety disorders. The review provides the future directions of research and aimed at expanding the evidence base of treatment of anxiety disorders and providing neuro-stimulation techniques as promising effective and acceptable alternative in select cases.

Transcranial magnetic stimulation and transcranial direct current stimulation appear to be safe neuromodulatory techniques useful in the treatment of anxiety disorders and other neuropsychiatric disorders

ABSTRACT Transcranial magnetic stimulation (TMS) has recently been investigated as a possible adjuvant treatment for many neuropsychiatric disorders, and has already been approved for the treatment of drug-resistant depression in the United States and in Brazil, among other countries. Although its use in other neuropsychiatric disorders is still largely experimental, many physicians have been using it as an off-label add-on therapy for various disorders. More recently, another technique, transcranial direct current stimulation (tDCS), has also become available as a much cheaper and portable alternative to TMS, although its mechanisms of action are different from those of TMS. The use of off-label therapeutic TMS or tDCS tends to occur in the setting of diseases that are notoriously resistant to other treatment modalities. Here we discuss the case of anxiety disorders, namely panic and post-traumatic stress disorders, highlighting the uncertainties and potential problems and benefits of the clinical use of these neuromodulatory techniques at the current stage of knowledge.

Psychological therapies for panic disorder with or without agoraphobia in adults: a network meta-analysis

BACKGROUND

Panic disorder is characterised by the presence of recurrent unexpected panic attacks, discrete periods of fear or anxiety that have a rapid onset and include symptoms such as racing heart, chest pain, sweating and shaking. Panic disorder is common in the general population, with a lifetime prevalence of 1% to 4%. A previous Cochrane meta-analysis suggested that psychological therapy (either alone or combined with pharmacotherapy) can be chosen as a first-line treatment for panic disorder with or without agoraphobia. However, it is not yet clear whether certain psychological therapies can be considered superior to others. In order to answer this question, in this review we performed a network meta-analysis (NMA), in which we compared eight different forms of psychological therapy and three forms of a control condition.

OBJECTIVES

To assess the comparative efficacy and acceptability of different psychological therapies and different control conditions for panic disorder, with or without agoraphobia, in adults.

SEARCH METHODS

We conducted the main searches in the CCDANCTR electronic databases (studies and references registers), all years to 16 March 2015. We conducted complementary searches in PubMed and trials registries. Supplementary searches included reference lists of included studies, citation indexes, personal communication to the authors of all included studies and grey literature searches in OpenSIGLE. We applied no restrictions on date, language or publication status.

SELECTION CRITERIA

We included all relevant randomised controlled trials (RCTs) focusing on adults with a formal diagnosis of panic disorder with or without agoraphobia. We considered the following psychological therapies: psychoeducation (PE), supportive psychotherapy (SP), physiological therapies (PT), behaviour therapy (BT), cognitive therapy (CT), cognitive behaviour therapy (CBT), third-wave CBT (3W) and psychodynamic therapies (PD). We included both individual and group formats. Therapies had to be administered face-to-face. The comparator interventions considered for this review were: no treatment (NT), wait list (WL) and attention/psychological placebo (APP). For this review we considered four short-term (ST) outcomes (ST-remission, ST-response, ST-dropouts, ST-improvement on a continuous scale) and one long-term (LT) outcome (LT-remission/response).

DATA COLLECTION AND ANALYSIS

As a first step, we conducted a systematic search of all relevant papers according to the inclusion criteria. For each outcome, we then constructed a treatment network in order to clarify the extent to which each type of therapy and each comparison had been investigated in the available literature. Then, for each available comparison, we conducted a random-effects meta-analysis. Subsequently, we performed a network meta-analysis in order to synthesise the available direct evidence with indirect evidence, and to obtain an overall effect size estimate for each possible pair of therapies in the network. Finally, we calculated a probabilistic ranking of the different psychological therapies and control conditions for each outcome.

MAIN RESULTS

We identified 1432 references; after screening, we included 60 studies in the final qualitative analyses. Among these, 54 (including 3021 patients) were also included in the quantitative analyses. With respect to the analyses for the first of our primary outcomes, (short-term remission), the most studied of the included psychological therapies was CBT (32 studies), followed by BT (12 studies), PT (10 studies), CT (three studies), SP (three studies) and PD (two studies).The quality of the evidence for the entire network was found to be low for all outcomes. The quality of the evidence for CBT vs NT, CBT vs SP and CBT vs PD was low to very low, depending on the outcome. The majority of the included studies were at unclear risk of bias with regard to the randomisation process. We found almost half of the included studies to be at high risk of attrition bias and detection bias. We also found selective outcome reporting bias to be present and we strongly suspected publication bias. Finally, we found almost half of the included studies to be at high risk of researcher allegiance bias.Overall the networks appeared to be well connected, but were generally underpowered to detect any important disagreement between direct and indirect evidence. The results showed the superiority of psychological therapies over the WL condition, although this finding was amplified by evident small study effects (SSE). The NMAs for ST-remission, ST-response and ST-improvement on a continuous scale showed well-replicated evidence in favour of CBT, as well as some sparse but relevant evidence in favour of PD and SP, over other therapies. In terms of ST-dropouts, PD and 3W showed better tolerability over other psychological therapies in the short term. In the long term, CBT and PD showed the highest level of remission/response, suggesting that the effects of these two treatments may be more stable with respect to other psychological therapies. However, all the mentioned differences among active treatments must be interpreted while taking into account that in most cases the effect sizes were small and/or results were imprecise.

AUTHORS' CONCLUSIONS

There is no high-quality, unequivocal evidence to support one psychological therapy over the others for the treatment of panic disorder with or without agoraphobia in adults. However, the results show that CBT - the most extensively studied among the included psychological therapies - was often superior to other therapies, although the effect size was small and the level of precision was often insufficient or clinically irrelevant. In the only two studies available that explored PD, this treatment showed promising results, although further research is needed in order to better explore the relative efficacy of PD with respect to CBT. Furthermore, PD appeared to be the best tolerated (in terms of ST-dropouts) among psychological treatments. Unexpectedly, we found some evidence in support of the possible viability of non-specific supportive psychotherapy for the treatment of panic disorder; however, the results concerning SP should be interpreted cautiously because of the sparsity of evidence regarding this treatment and, as in the case of PD, further research is needed to explore this issue. Behaviour therapy did not appear to be a valid alternative to CBT as a first-line treatment for patients with panic disorder with or without agoraphobia.