PsychotherapyPlus: augmentation of cognitive behavioral therapy (CBT) with prefrontal transcranial direct current stimulation (tDCS) in major depressive disorder-study design and methodology of a multicenter double-blind randomized placebo-controlled trial

Treating depression at home with transcranial direct current stimulation: a feasibility study

Introduction

Treating major depressive disorder (MDD) with transcranial direct current stimulation (tDCS) devices at home has various logistic advantages compared to tDCS treatment in the clinic. However, preliminary (controlled) studies showed side effects such as skin lesions and difficulties in the implementation of home-based tDCS. Thus, more data are needed regarding the feasibility and possible disadvantages of home-based tDCS.

Methods

Ten outpatients (23-69 years) with an acute depressive episode were included for this one-arm feasibility study testing home-based tDCS. All patients self-administered prefrontal tDCS (2 mA, 20 min, anodal left, cathodal right) at home on 30 consecutive working days supported by video consultations. Correct implementation of the home-based treatment was analyzed with tDCS recordings. Feasibility was examined by treatment compliance. For additional analyses of effectiveness, three depression scores were used: Hamilton depression rating scale (HDRS-21), Major Depression Inventory (MDI), and the subscale depression of the Depression-Anxiety-Stress Scale (DASS). Furthermore, usability was measured with the user experience questionnaire (UEQ). Tolerability was analyzed by the number of reported adverse events (AEs).

Results

Eight patients did not stick to the protocol. AEs were minimal. Four patients responded to the home treatment according to the MDI. Usability was judged positive by the patients.

Conclusions

Regular video consultations or other safety concepts are recommended regardless of the number of video sessions actually conducted. Home-based tDCS seems to be safe and handy in our feasibility study, warranting further investigation.

Comparable Efficacy of Repeated Transcranial Direct Current Stimulation, Cognitive Behavioral Therapy, and Their Combination in Improvement of Cold and Hot Cognitive Functions and Amelioration of Depressive Symptoms

ABSTRACT

This study aimed to evaluate the effectiveness of repeated transcranial direct current stimulation (rtDCS), cognitive behavioral therapy (CBT), and their combination (rtDCS-CBT) in the treatment of cognitive dysfunction, social cognition, and depressive symptoms in women diagnosed with major depressive disorder (MDD). A total of 40 female participants with MDD were randomly assigned to one of four groups: rtDCS, CBT, rtDCS-CBT, and a control group. The participants' depressive symptoms, executive functions, and social cognition were assessed at baseline, preintervention, postintervention, and during a 1-month follow-up. The rtDCS group received 10 sessions of anodal dorsolateral and cathodal ventromedial prefrontal cortex (2 mA for 20 minutes). The CBT group received 10 sessions of traditional CBT, whereas the combined group received CBT after the tDCS sessions. The results of the analysis of variance indicated that all intervention groups demonstrated significant improvements in depressive symptoms, cognitive dysfunction, and social cognition compared with the control group (all p < 0.001). Furthermore, the rtDCS-CBT group exhibited significantly greater reductions in depressive symptoms when compared with each intervention alone (all p < 0.001). Notably, working memory improvements were observed only in the rtDCS group ( p < 0.001). In conclusion, this study suggests that both CBT and tDCS, either individually or in combination, have a positive therapeutic impact on enhancing executive functions, theory of mind, and depressive symptoms in women with MDD.

Non-invasive brain stimulation for patients and healthy subjects: Current challenges and future perspectives

Non-invasive brain stimulation (NIBS) techniques have a rich historical background, yet their utilization has witnessed significant growth only recently. These techniques encompass transcranial electrical stimulation and transcranial magnetic stimulation, which were initially employed in neuroscience to explore the intricate relationship between the brain and behaviour. However, they are increasingly finding application in research contexts as a means to address various neurological, psychiatric, and neurodegenerative disorders. This article aims to fulfill two primary objectives. Firstly, it seeks to showcase the current state of the art in the clinical application of NIBS, highlighting how it can improve and complement existing treatments. Secondly, it provides a comprehensive overview of the utilization of NIBS in augmenting the brain function of healthy individuals, thereby enhancing their performance. Furthermore, the article delves into the points of convergence and divergence between these two techniques. It also addresses the existing challenges and future prospects associated with NIBS from ethical and research standpoints.

Boosting psychological change: Combining non-invasive brain stimulation with psychotherapy

Mental health disorders and substance use disorders are a leading cause of morbidity and mortality worldwide, and one of the most important challenges for public health systems. While evidence-based psychotherapy is generally pursued to address mental health challenges, psychological change is often hampered by non-adherence to treatments, relapses, and practical barriers (e.g., time, cost). In recent decades, Non-invasive brain stimulation (NIBS) techniques have emerged as promising tools to directly target dysfunctional neural circuitry and promote long-lasting plastic changes. While the therapeutic efficacy of NIBS protocols for mental illnesses has been established, neuromodulatory interventions might also be employed to support the processes activated by psychotherapy. Indeed, combining psychotherapy with NIBS might help tailor the treatment to the patient's unique characteristics and therapeutic goal, and would allow more direct control of the neuronal changes induced by therapy. Herein, we overview emerging evidence on the use of NIBS to enhance the psychotherapeutic effect, while highlighting the next steps in advancing clinical and research methods toward personalized intervention approaches.

High-definition transcranial direct current stimulation modulates eye gaze on emotional faces in college students with alexithymia: An eye-tracking study

BACKGROUND

Atypical eye gaze on emotional faces is a core feature of alexithymia. The inferior frontal gyrus (IFG) is considered to be the neurophysiological basis of alexithymia-related emotional face fixation. Our aim was to examine whether anodal high-definition transcranial direct current stimulation (HD-tDCS) administered to the right (r)IFG would facilitate eye gaze of emotional faces in alexithymia individuals.

METHOD

Forty individuals with alexithymia were equally assigned to anodal or sham HD-tDCS of the rIFG according to the principle of randomization. The individuals then completed a free-viewing eye tracking task (including happy, sad, and neutral faces) before and after 5 consecutive days of stimulation (twice a day).

RESULTS

The results showed that twice a day anodal HD-tDCS of the rIFG significantly increased the fixation time and fixation count of the eye area on happy and neutral faces, but there was no significant effect on sad faces. According to the temporal-course analysis, after the intervention, the fixation time on neutral faces increased significantly at almost all time points of the eye tracking task. For happy faces, the improvement was demonstrated between 500 and 1000 ms and between 2500 and 3500 ms. For sad faces, the fixation time improved but not significantly.

CONCLUSIONS

Applying high-dose anodal HD-tDCS to the rIFG selectively facilitated eye gaze in the eye area of neutral and happy faces in individuals with alexithymia, which may improve their face processing patterns.

Efficacy of Augmentation of Cognitive Behavioral Therapy With Transcranial Direct Current Stimulation for Depression: A Randomized Clinical Trial

IMPORTANCE

Major depressive disorder (MDD) affects approximately 10% of the population globally. Approximately 20% to 30% of patients with MDD do not sufficiently respond to standard treatment. Therefore, there is a need to develop more effective treatment strategies.

OBJECTIVE

To investigate whether the efficacy of cognitive behavioral therapy (CBT) for the treatment of MDD can be enhanced by concurrent transcranial direct current stimulation (tDCS).

DESIGN, SETTING, AND PARTICIPANTS

The double-blind, placebo-controlled randomized clinical trial PsychotherapyPlus was conducted at 6 university hospitals across Germany. Enrollment took place between June 2, 2016, and March 10, 2020; follow-up was completed August 27, 2020. Adults aged 20 to 65 years with a single or recurrent depressive episode were eligible. They were either not receiving medication or were receiving a stable regimen of antidepressant medication (selective serotonin reuptake inhibitor and/or mirtazapine). A total of 148 women and men underwent randomization: 53 individuals were assigned to CBT alone (group 0), 48 to CBT plus tDCS (group 1), and 47 to CBT plus sham-tDCS (group 2).

INTERVENTIONS

Participants attended a 6-week group intervention comprising 12 sessions of CBT. If assigned, tDCS was applied simultaneously. Active tDCS included stimulation with an intensity of 2 mA for 30 minutes (anode over F3, cathode over F4).

MAIN OUTCOMES AND MEASURES

The primary outcome was the change in Montgomery-Åsberg Depression Rating Scale (MADRS) score from baseline to posttreatment in the intention-to-treat sample. Scores of 0 to 6 indicate no depression; 7 to 19, mild depression; 20 to 34, moderate depression; and 34 and higher, severe depression.

RESULTS

A total of 148 patients (89 women, 59 men; mean [SD] age, 41.1 [13.7] years; MADRS score at baseline, 23.0 [6.4]) were randomized. Of these, 126 patients (mean [SD] age, 41.5 [14.0] years; MADRS score at baseline, 23.0 [6.3]) completed the study. In each of the intervention groups, intervention was able to reduce MADRS scores by a mean of 6.5 points (95% CI, 3.82-9.14 points). The Cohen d value was -0.90 (95% CI, -1.43 to -0.50), indicating a significant effect over time. However, there was no significant effect of group and no significant interaction of group × time, indicating the estimated additive effects were not statistically significant. There were no severe adverse events throughout the whole trial, and there were no significant differences of self-reported adverse effects during and after stimulation between groups 1 and 2.

CONCLUSIONS AND RELEVANCE

Based on MADRS score changes, this trial did not indicate superior efficacy of tDCS-enhanced CBT compared with 2 CBT control conditions. The study confirmed that concurrent group CBT and tDCS is safe and feasible. However, additional research on mechanisms of neuromodulation to complement CBT and other behavioral interventions is needed.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02633449.

Promoting gaze toward the eyes of emotional faces in individuals with high autistic traits using group cognitive behavioral therapy: An eye-tracking study

BACKGROUND

Individuals with subclinical autistic traits exhibit a pattern of eye avoidance similar to that of typical autism. Our study aimed to test the efficacy of group cognitive behavioral therapy (G-CBT) in promoting gaze toward the eye area of facial expressions, specifically orienting to emotional faces, in individuals with high autistic traits (high AT).

METHODS

Twenty-six high AT individuals and 30 low AT individuals participated. High AT individuals were assigned to eight sessions of G-CBT intervention. Eye-tracking measurements were acquired before and after treatment.

RESULTS

We observed the following: (a) the eye avoidance in high AT individuals was prominent for all facial expressions in relative to low AT individuals; (b) G-CBT primarily improved gaze toward the eyes of happy and fearful faces but not for neutral face expressions in high AT individuals; (c) after 8 sessions of G-CBT, the fixation time on the eyes of emotional faces improved significantly. For happy faces, the fixation time on the eyes of faces was markedly increased in epochs between 500 ms and 1000 ms after the face onset; for fearful faces, the improvement in participants existed between about 1000 ms and 1500 ms after the face appeared.

LIMITATION

Our results may not be generalized to other patients with ASD.

CONCLUSIONS

Our findings demonstrate that G-CBT significantly promotes gaze toward the eyes of emotional faces in high AT individuals. These results are encouraging, and suggest that the emotional face processing in autism spectrum disorder (ASD) might stand to benefit from similar psychotherapeutic treatment.

Differences in electric field strength between clinical and non-clinical populations induced by prefrontal tDCS: A cross-diagnostic, individual MRI-based modeling study

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MDD and SCZ showed lower prefrontal tDCS-induced e-field strengths compared to HC.

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Average e-field strengths did not significantly differ between MDD and SCZ patients.

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Inter-individual variability of e-field intensities and distribution was prominent.

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Inter-rater variability emphasizes the importance of standardized positioning.

Introduction

Prefrontal cortex (PFC) regions are promising targets for therapeutic applications of non-invasive brain stimulation, e.g. transcranial direct current stimulation (tDCS), which has been proposed as a novel intervention for major depressive disorder (MDD) and negative symptoms of schizophrenia (SCZ). However, the effects of tDCS vary inter-individually, and dose–response relationships have not been established. Stimulation parameters are often tested in healthy subjects and transferred to clinical populations. The current study investigates the variability of individual MRI-based electric fields (e-fields) of standard bifrontal tDCS across individual subjects and diagnoses.

Method

The study included 74 subjects, i.e. 25 patients with MDD, 24 patients with SCZ, and 25 healthy controls (HC). Individual e-fields of a common tDCS protocol (i.e. 2 mA stimulation intensity, bifrontal anode-F3/cathode-F4 montage) were modeled by two investigators using SimNIBS (2.0.1) based on structural MRI scans.

Result

On a whole-brain level, the average e-field strength was significantly reduced in MDD and SCZ compared to HC, but MDD and SCZ did not differ significantly. Regions of interest (ROI) analysis for PFC subregions showed reduced e-fields in Sallet areas 8B and 9 for MDD and SCZ compared to HC, whereas there was again no difference between MDD and SCZ. Within groups, we generally observed high inter-individual variability of e-field intensities at a higher percentile of voxels.

Conclusion

MRI-based e-field modeling revealed significant differences in e-field strengths between clinical and non-clinical populations in addition to a general inter-individual variability. These findings support the notion that dose–response relationships for tDCS cannot be simply transferred from healthy to clinical cohorts and need to be individually established for clinical groups. In this respect, MRI-based e-field modeling may serve as a proxy for individualized dosing.

State-dependent effects of neural stimulation on brain function and cognition

Invasive and non-invasive brain stimulation methods are widely used in neuroscience to establish causal relationships between distinct brain regions and the sensory, cognitive and motor functions they subserve. When combined with concurrent brain imaging, such stimulation methods can reveal patterns of neuronal activity responsible for regulating simple and complex behaviours at the level of local circuits and across widespread networks. Understanding how fluctuations in physiological states and task demands might influence the effects of brain stimulation on neural activity and behaviour is at the heart of how we use these tools to understand cognition. Here we review the concept of such 'state-dependent' changes in brain activity in response to neural stimulation, and consider examples from research on altered states of consciousness (for example, sleep and anaesthesia) and from task-based manipulations of selective attention and working memory. We relate relevant findings from non-invasive methods used in humans to those obtained from direct electrical and optogenetic stimulation of neuronal ensembles in animal models. Given the widespread use of brain stimulation as a research tool in the laboratory and as a means of augmenting or restoring brain function, consideration of the influence of changing physiological and cognitive states is crucial for increasing the reliability of these interventions.

Improved Executive Functions and Reduced Craving in Youths with Methamphetamine Addiction: Evidence from Combined Transcranial Direct Current Stimulation with Mindfulness Treatment

Objective

Transcranial direct current stimulation (tDCS) and mindfulness practices have been proposed as a potential approach to improve executive functions (EFs) and reduce craving in persons with substance use disorders. Based on the neural mechanisms of action of each of these interventions, the combination of both non-pharmacological interventions might have additive effects. In the current study, the effects of tDCS combined with mindfulness-based substance abuse treatment (MBSAT) to improve EFs and reduce craving were investigated in early abstinent methamphetamine abuse.

Methods

Eighty (youths aged between 18 and 21) early-abstinent methamphetamine users were randomly assigned to the research groups (tDCS group [n = 20], mindfulness group [n = 20], combined mindfulness-tDCS group [n = 20], and sham group [n = 20]). Active tDCS (1.5 mA,20 min, 12 sessions) or sham tDCS was appliedover the left dorsolateral prefrontal cortex and the MBSAT protocol was used over twelve 50-min sessions.

Results

Both in the post-test phase (immediately after the intervention) and follow-up phase (one month after the intervention), performance in most EFs tasks significantly improved in the combination group which received real tDCS ＋ MBSAT, as compared to baseline values and sham stimulation group. Similarly, a significant reduction in craving was observed after intervention inall treatment groups, but not the sham stimulation group. Interestingly, the increase in EFs and the reduction in craving post versus pre tDCS ＋ MBSAT intervention were correlated.

Conclusion

Findings from the current study provide initial support for the clinical effectiveness of combination tDCS ＋ MBSAT, possibly influencing cognitive/affective processes.

Transcranial Magnetic and Direct Current Stimulation in the Treatment of Depression: Basic Mechanisms and Challenges of Two Commonly Used Brain Stimulation Methods in Interventional Psychiatry

Noninvasive neuromodulation, including repetitive trans-cranial magnetic stimulation (rTMS) and direct current stimulation (tDCS), provides researchers and health care professionals with the ability to gain unique insights into brain functions and treat several neurological and psychiatric conditions. Undeniably, the number of published research and clinical papers on this topic is increasing exponentially. In parallel, several methodological and scientific caveats have emerged in the transcranial stimulation field; these include less robust and reliable effects as well as contradictory clinical findings. These inconsistencies are maybe due to the fact that research exploring the relationship between the methodological aspects and clinical efficacy of rTMS and tDCS is far from conclusive. Hence, additional work is needed to understand the mechanisms underlying the effects of magnetic stimulation and low-intensity transcranial electrical stimulation (TES) in order to optimize dosing, methodological designs, and safety aspects.

Application of Transcranial Direct Current Stimulation in Psychiatry

Transcranial direct current stimulation (tDCS) is a neuromodulation technique, which noninvasively alters cortical excitability via weak polarizing currents between two electrodes placed on the scalp. Since it is comparably easy to handle, cheap to use and relatively well tolerated, tDCS has gained increasing interest in recent years. Based on well-known behavioral effects, a number of clinical studies have been performed in populations including patients with major depressive disorder followed by schizophrenia and substance use disorders, in sum with heterogeneous results with respect to efficacy. Nevertheless, the potential of tDCS must not be underestimated since it could be further improved by systematically investigating the various stimulation parameters to eventually increase clinical efficacy. The present article briefly explains the underlying physiology of tDCS, summarizes typical stimulation protocols and then reviews clinical efficacy for various psychiatric disorders as well as prevalent adverse effects. Future developments include combined and more complex interactions of tDCS with pharmacological or psychotherapeutic interventions. In particular, using computational models to individualize stimulation protocols, considering state dependency and applying closed-loop technologies will pave the way for tDCS-based personalized interventions as well as the development of home treatment settings promoting the role of tDCS as an effective treatment option for patients with mental health problems.

EffECTively Treating Depression: A Pilot Study Examining Manualized Group CBT as Follow-Up Treatment After ECT

Background: There is an urgent need for effective follow-up treatments after acute electroconvulsive therapy (ECT) in depressed patients. Preliminary evidence suggests psychotherapeutic interventions to be a feasible and efficacious follow-up treatment. However, there is a need for research on the long-term usefulness of such psychotherapeutic offers in a naturalistic setting that is more representative of routine clinical practice. Therefore, the aim of the current pilot study was to investigate the effects of a half-open continuous group cognitive behavioral therapy (CBT) with cognitive behavioral analysis system of psychotherapy elements as a follow-up treatment for all ECT patients, regardless of response status after ECT, on reducing depressive symptoms and promoting psychosocial functioning.

Method: Group CBT was designed to support patients during the often-difficult transition from inpatient to outpatient treatment. In a non-controlled pilot trial, patients were offered 15weekly sessions of manualized group CBT (called EffECTiv 2.0). The Montgomery-Åsberg Depression Rating Scale was assessed as primary outcome; the Beck Depression Inventory, WHO Quality of Life Questionnaire–BREF, and the Cognitive Emotion Regulation Questionnaire were assessed as secondary outcomes. Measurements took place before individual group start, after individual group end, and 6months after individual group end.

Results: During group CBT, Post-ECT symptom reduction was not only maintained but there was a tendency toward a further decrease in depression severity. This reduction could be sustained 6months after end of the group, regardless of response status after ECT treatment. Aspects of quality of life and emotion regulation strategies improved during group CBT, and these improvements were maintained 6months after the end of the group.

Conclusion: Even though the interpretability of the results is limited by the small sample and the non-controlled design, they indicate that manualized group CBT with cognitive behavioral analysis system of psychotherapy elements might pose a recommendable follow-up treatment option after acute ECT for depressed patients, regardless of response status after ECT. This approach might not only help to further reduce depressive symptoms and prevent relapse, but also promote long-term psychosocial functioning by improving emotion regulation strategies and psychological quality of life and thus could be considered as a valuable addition to clinical routine after future validation.

The effect of cognitive behavioral therapy on the release of interpersonal stress

BACKGROUND

interpersonal communication in workplace is a problem that is faced by every employee. It is common in all industries and increasingly lethal. When they are unable to bear such overload of psychological pressure, they tend to suffer from anxiety, irritability, depression, and other psychological disorders and even mental diseases. It is urgent to explore how to help employees relieve psychological stress.

OBJECTIVE

the study aimed to analyze the effects of cognitive behavioral therapy (CBT) on workplace interpersonal stress, and provide help for professionals, especially newcomers, to relieve social pressure.

METHODS

125 employees of Internet enterprises were given multi-baseline designed CBT (with baseline phase, treatment phase, and post-baseline phase). 43 subjects who did not finish the therapist program were set as the control group and 82 subjects who finished the treatment program were set as the experimental group. First, the differences of interpersonal stress of subjects with different gender, age, educational background, and monthly salary were analyzed. Then, social avoidance, distress, anxiety, and depression scores in baseline, treatment, and post-baseline periods were compared. Finally, the effects of gender, age, educational background, and monthly salary on social avoidance, distress, anxiety, and depression scores of the experimental group were analyzed by multiple regression. and the influence paths of the workplace interpersonal pressure was constructed.

RESULTS

Social avoidance, distress, anxiety, and depression of employees earning 10000 or more per month were less than those earning 10000 or more per month. Social avoidance, distress, anxiety, and depression of employees aged 30-50 were higher than those aged < 30 and > 50 (P < 0.05). Social avoidance, social distress, and depression in males were lower than those in females (P < 0.05). Social distress, anxiety, and depression of employees with master's degree or above were less than those with bachelor's degree or junior college degree. There were significant differences between the two groups in the post baseline phase. The monthly salary had the greatest influence on the social avoidance and distress, anxiety, and depression scores of the employees after treatment, with the path coefficients of -0.183, -0.169, and -0.184, respectively.

CONCLUSIONS

CBT can effectively relieve social avoidance and distress of workplace employees and can improve the symptoms of anxiety and depression. Educational level, age, and monthly salary had a certain influence on the improvement of social avoidance, distress, anxiety and depression.

Can a tDCS treatment enhance subjective and objective sleep among student-athletes?

INTRODUCTION

Previous studies have shown that student-athletes suffer from sleep difficulties. This study explored the impact of tDCS on sleep parameters among student-athletes.

METHOD

Thirty student-athletes (15 females, 15 males, age 21.1 ± 2.1 years) were recruited. All participants underwent a series of questions to rule out depressive and anxiety disorders or any specific tDCS exclusion criteria. All participants were advised to maintain their usual sleep schedule.

RESULTS

Compared polysomnographic and Psychomotor Vigilance Task data analyses did not show any improvement after experimental tDCS. Regardless of groups, PVT mean reaction time was decreased. Regarding the questionnaires, data analyses showed improvement on the PSQI (p < .001), ISI (p < .001) and ASSQ (p < .007) scores after tDCS.

DISCUSSION

tDCS appears to increase total sleep time and should be further explored. Improvements in subjective sleep suggest that tDCS bears interesting possibilities into the enhancement of sleep among student-athletes.

Efficacy and acceptability of transcranial direct current stimulation for treating depression: A meta-analysis of randomized controlled trials

BACKGROUND

Transcranial direct current stimulation (tDCS) is a promising nonpharmacological intervention for treating depression. We aimed to provide an updated meta-analysis assessing the anti-depressant efficacy of tDCS.

METHODS

We searched the literature from the first available date to 30 December 2020 to identify relevant randomized controlled trials (RCTs).

RESULTS

27 RCTs (N = 1204 patients, 653 in active tDCS and 551 in sham tDCS) were included. Active tDCS was superior to sham tDCS (g = 0.46, 95 % CI 0.15-0.76) in modulating depressive symptoms measured by depression rating scales. Active tDCS was also superior to sham tDCS in reducing response and remission rates, but these differences did not reach statistically significant levels (OR_response = 1.75, 95 % CI 0.85-3.58; OR_remission = 1.29, 95 % CI 0.59-2.83). The two groups had comparable dropout rates (OR = 1.28, 95 % CI 0.62-1.64).

CONCLUSION

For treatments of depressive episodes, tDCS may be efficacious. Specific tDCS parameters (e.g., a 2-mA stimulation current and 30-min sessions) and clinical characteristics (e.g., antidepressant-free) may augment the treatment efficacy of tDCS.

A narrative review on non-invasive stimulation of the cerebellum in neurological diseases

IMPORTANCE

The cerebellum plays an important role in motor, cognitive, and affective functions owing to its dense interconnections with basal ganglia and cerebral cortex. This review aimed at summarizing the non-invasive cerebellar stimulation (NICS) approaches used to modulate cerebellar output and treat cerebellar dysfunction in the motor domain.

OBSERVATION

The utility of NICS in the treatment of cerebellar and non-cerebellar neurological diseases (including Parkinson's disease, dementia, cerebellar ataxia, and stroke) is discussed. NICS induces meaningful clinical effects from repeated sessions alone in both cerebellar and non-cerebellar diseases. However, there are no conclusive data on this issue and several concerns need to be still addressed before NICS could be considered a valuable, standard therapeutic tool.

CONCLUSIONS AND RELEVANCE

Even though some challenges must be overcome to adopt NICS in a wider clinical setting, this tool might become a useful strategy to help patients with lesions in the cerebellum and cerebral areas that are connected with the cerebellum whether one could enhance cerebellar activity with the intention of facilitating the cerebellum and the entire, related network, rather than attempting to facilitate a partially damaged cortical region or inhibiting the homologs' contralateral area. The different outcome of each approach would depend on the residual functional reserve of the cerebellum, which is confirmed as a critical element to be probed preliminary in order to define the best patient-tailored NICS.

Non-invasive cortical stimulation: Transcranial direct current stimulation (tDCS)

Transcranial direct current stimulation (tDCS) is a re-emerging non-invasive brain stimulation technique that has been used in animal models and human trials aimed to elucidate neurophysiology and behavior interactions. It delivers subthreshold electrical currents to neuronal populations that shift resting membrane potential either toward depolarization or hyperpolarization, depending on stimulation parameters and neuronal orientation in relation to the induced electric field (EF). Although the resulting cerebral EFs are not strong enough to induce action potentials, spontaneous neuronal firing in response to inputs from other brain areas is influenced by tDCS. Additionally, tDCS induces plastic synaptic changes resembling long-term potentiation (LTP) or long-term depression (LTD) that outlast the period of stimulation. Such properties place tDCS as an appealing intervention for the treatment of diverse neuropsychiatric disorders. Although findings of clinical trials are preliminary for most studied conditions, there is already convincing evidence regarding its efficacy for unipolar depression. The main advantages of tDCS are the absence of serious or intolerable side effects and the portability of the devices, which might lead in the future to home-use applications and improved patient care. This chapter provides an up-to-date overview of a number tDCS relevant topics such as mechanisms of action, contemporary applications and safety. Furthermore, we propose ways to further develop tDCS research.

Distinct trajectories of response to prefrontal tDCS in major depression: results from a 3-arm randomized controlled trial

Transcranial direct current stimulation (tDCS) is a safe, effective treatment for major depressive disorder (MDD). While antidepressant effects are heterogeneous, no studies have investigated trajectories of tDCS response. We characterized distinct improvement trajectories and associated baseline characteristics for patients treated with prefrontal tDCS, an active pharmacotherapy (escitalopram), and placebo. This is a secondary analysis of a randomized, non-inferiority, double-blinded trial (ELECT-TDCS, N = 245). Participants were diagnosed with an acute unipolar, nonpsychotic, depressive episode, and presented Hamilton Depression Rating Scale (17-items, HAM-D) scores ≥17. Latent trajectory modeling was used to identify HAM-D response trajectories over a 10-week treatment. Top-down (hypothesis-driven) and bottom-up (data-driven) methods were employed to explore potential predictive features using, respectively, conservatively corrected regression models and a cross-validated stability ranking procedure combined with elastic net regularization. Three trajectory classes that were distinct in response speed and intensity (rapid, slow, and no/minimal improvement) were identified for escitalopram, tDCS, and placebo. Differences in response and remission rates were significant early for all groups. Depression severity, use of benzodiazepines, and age were associated with no/minimal improvement. No significant differences in trajectory assignment were found in tDCS vs. placebo comparisons (38.3, 34, and 27.6%; vs. 23.3, 43.3, and 33.3% for rapid, slow, and no/minimal trajectories, respectively). Additional features are suggested in bottom-up analyses. Summarily, groups treated with tDCS, escitalopram, and placebo differed in trajectory class distributions and baseline predictors of response. Our results might be relevant for designing further studies.

Transcranial direct current stimulation induces long-term potentiation-like plasticity in the human visual cortex

Transcranial direct current stimulation (tDCS) is increasingly used as a form of noninvasive brain stimulation to treat psychiatric disorders; however, its mechanism of action remains unclear. Prolonged visual stimulation (PVS) can enhance evoked EEG potentials (visually evoked potentials, VEPs) and has been proposed as a tool to examine long-term potentiation (LTP) in humans. The objective of the current study was to induce and analyze VEP plasticity and examine whether tDCS could either modulate or mimic plasticity changes induced by PVS. Thirty-eight healthy participants received tDCS, PVS, either treatment combined or neither treatment, with stimulation sessions being separated by one week. One session consisted of a baseline VEP measurement, one stimulation block, and six test VEP measurements. For PVS, a checkerboard reversal pattern was presented, and for tDCS, a constant current of 1 mA was applied via each bioccipital anodal target electrode for 10 min (Fig. S1). Both stimulation types decreased amplitudes of C1 compared to no stimulation (F = 10.1; p = 0.002) and led to a significantly smaller increase (PVS) or even decrease (tDCS) in N1 compared to no stimulation (F = 4.7; p = 0.034). While all stimulation types increased P1 amplitudes, the linear mixed effects model did not detect a significant difference between active stimulation and no stimulation. Combined stimulation induced sustained plastic modulation of C1 and N1 but with a smaller effect size than what would be expected for an additive effect. The results demonstrate that tDCS can directly induce LTP-like plasticity in the human cortex and suggest a mechanism of action of tDCS relying on the restoration of dysregulated synaptic plasticity in psychiatric disorders such as depression and schizophrenia.

Efficacy and Safety of tDCS and tACS in Treatment of Major Depressive Disorder: A Randomized, Double-Blind, Factorial Placebo-Controlled Study Design

BACKGROUND

Transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) are regarded as promising antidepressant treatments.

OBJECTIVE

To compare the efficacy and safety of tDCS, tACS, escitalopram, and placebo/sham stimulation controls.

DESIGN

Randomized, parallel, double-blind, placebo-controlled study.

METHODS

Sample sizes were calculated based on data from previous similar studies. Eligible non-treatment-resistant-depressive outpatient subjects with moderate-to-severe depression (HRDS ≥17) are randomized to receive (1) tDCS + placebo; (2) tACS + placebo; (3) escitalopram + placebo; or (4) sham stimulation + placebo. The intensity of electricity is 2 mA, lasting for 30 minutes over two consecutive working days (10 sessions in total). The medication lasts for 6 weeks. The primary outcome measure was the response rates within 6 weeks (week 6 is also the endpoint of the study), and secondary outcome measures included changes in other clinical measurements. Safety and acceptability are measured by adverse event rates and dropout rates. Exploring outcome consist of the performance of cognitive battery as well as neurophysiology results.

CONCLUSION

To the best of our knowledge, the present study is the first double-blind controlled study comparing tDCS, tACS, and clinically used antidepressants, which will provide further evidence for their efficacy and safety in possible clinical applications.

Effects of bifrontal transcranial direct current stimulation on brain glutamate levels and resting state connectivity: multimodal MRI data for the cathodal stimulation site

Transcranial direct current stimulation (tDCS) over prefrontal cortex (PFC) regions is currently proposed as therapeutic intervention for major depression and other psychiatric disorders. The in-depth mechanistic understanding of this bipolar and non-focal stimulation technique is still incomplete. In a pilot study, we investigated the effects of bifrontal stimulation on brain metabolite levels and resting state connectivity under the cathode using multiparametric MRI techniques and computational tDCS modeling. Within a double-blind cross-over design, 20 subjects (12 women, 23.7 ± 2 years) were randomized to active tDCS with standard bifrontal montage with the anode over the left dorsolateral prefrontal cortex (DLPFC) and the cathode over the right DLPFC. Magnetic resonance spectroscopy (MRS) was acquired before, during, and after prefrontal tDCS to quantify glutamate (Glu), Glu + glutamine (Glx) and gamma aminobutyric acid (GABA) concentration in these areas. Resting-state functional connectivity MRI (rsfcMRI) was acquired before and after the stimulation. The individual distribution of tDCS induced electric fields (efields) within the MRS voxel was computationally modelled using SimNIBS 2.0. There were no significant changes of Glu, Glx and GABA levels across conditions but marked differences in the course of Glu levels between female and male participants were observed. Further investigation yielded a significantly stronger Glu reduction after active compared to sham stimulation in female participants, but not in male participants. For rsfcMRI neither significant changes nor correlations with MRS data were observed. Exploratory analyses of the effect of efield intensity distribution on Glu changes showed distinct effects in different efield groups. Our findings are limited by the small sample size, but correspond to previously published results of cathodal tDCS. Future studies should address gender and efield intensity as moderators of tDCS induced effects.

Pain relief for osteoarthritis through combined treatment (PROACT): Protocol for a randomized controlled trial of mindfulness meditation combined with transcranial direct current stimulation in non-Hispanic black and white adults with knee osteoarthritis

Knee osteoarthritis (OA) is a leading cause of late life pain and disability, and non-Hispanic black (NHB) adults experience greater OA-related pain and disability than non-Hispanic whites (NHWs). Recent evidence implicates psychosocial stress, cognitive-attentional processes, and altered central pain processing as contributors to greater OA-related pain and disability among NHBs. To address these ethnic/race disparities, this clinical trial will test whether a mindfulness intervention (Breathing and Attention Training, BAT) combined with transcranial direct current stimulation (tDCS) will enhance pain modulatory balance and pain-related brain function, reduce clinical pain, and attenuate ethnic differences therein, among NHBs and NHWs with knee OA. Participants will complete assessments of clinical pain, function, psychosocial measures, and quantitative sensory testing (QST), including mechanical temporal summation and conditioned pain modulation. Neuroimaging will be performed to examine pain-related brain structure and function. Then, participants will be randomized to one of four groups created by crossing two BAT conditions (Real vs. Sham) with two tDCS conditions (Real vs. Sham). Participants will then undergo five treatment sessions during which the assigned BAT and tDCS interventions will be delivered concurrently for 20 min over one week. After the fifth intervention session, participants will undergo assessments of clinical pain and function, QST and neuroimaging identical to the pretreatment measures, and monthly follow-up assessments of pain will be conducted for three months. This will be the first study to determine whether mindfulness and tDCS treatments will show additive or synergistic effects when combined, and whether treatment effects differ across ethnic/race groups.

A systematic review and meta-analysis on the effects of transcranial direct current stimulation in depressive episodes

BACKGROUND

Transcranial direct current stimulation (tDCS) has shown mixed results for depression treatment.

OBJECTIVE

To perform a systematic review and meta-analysis of trials using tDCS to improve depressive symptoms.

METHODS

A systematic review was performed from the first date available to January 06, 2020 in PubMed, EMBASE, Cochrane Library, and additional sources. We included randomized, sham-controlled clinical trials (RCTs) enrolling participants with an acute depressive episode and compared the efficacy of active versus sham tDCS, including association with other interventions. The primary outcome was the Hedges' g for continuous depression scores; secondary outcomes included odds ratios (ORs) and number needed to treat (NNT) for response, remission, and acceptability. Random effects models were employed. Sources of heterogeneity were explored via metaregression, sensitivity analyses, subgroup analyses, and bias assessment.

RESULTS

We included 23 RCTs (25 datasets, 1,092 participants), most (57%) presenting a low risk of bias. Active tDCS was superior to sham regarding endpoint depression scores (k = 25, g = 0.46, 95% confidence interval [CI]: 0.22-0.70), and also achieved superior response (k = 18, 33.3% vs. 16.56%, OR = 2.28 [1.52-3.42], NNT = 6) and remission (k = 18, 19.12% vs. 9.78%, OR = 2.12 [1.42-3.16], NNT = 10.7) rates. Moreover, active tDCS was as acceptable as sham. No risk of publication bias was identified. Cumulative meta-analysis showed that effect sizes are basically unchanged since total sample reached 439 participants.

CONCLUSIONS

TDCS is modestly effective in treating depressive episodes. Further well-designed, large-scale RCTs are warranted.

New neuromodulation techniques for treatment resistant depression

In the treatment of depression, when pharmacotherapy, psychotherapy and the oldest brain stimulation techniques are deadlocked, the emergence of new therapies is a necessary development. The field of neuromodulation is very broad and controversial. This article provides an overview of current progress in the technological advances in neuromodulation and neurostimulation treatments for treatment-resistant depression: magnetic seizure therapy; focal electrically administered seizure therapy; low field magnetic stimulation; transcranial pulsed electromagnetic fields; transcranial direct current stimulation; epidural cortical stimulation; trigeminal nerve stimulation; transcutaneous vagus nerve stimulation; transcranial focussed ultrasound; near infra-red transcranial radiation; closed loop stimulation. The role of new interventions is expanding, probably with more efficacy. Nowadays, still under experimentation, neuromodulation will probably revolutionise the field of neuroscience. At present, major efforts are still necessary before that these therapies are likely to become widespread.Key pointsThere is a critical need for new therapies for treatment resistant depression.Newer therapies are expanding. In the future, these therapies, as an evidence-based adjunctive treatments, could offer a good therapeutic choice for the patients with a TRD.The current trend in the new neuromodulation therapies is to apply a personalised treatment.These news therapies can be complementary.That treatment approaches can provide clinically significant benefits.

Precision non-implantable neuromodulation therapies: a perspective for the depressed brain

Current first-line treatments for major depressive disorder (MDD) include pharmacotherapy and cognitive-behavioral therapy. However, one-third of depressed patients do not achieve remission after multiple medication trials, and psychotherapy can be costly and time-consuming. Although non-implantable neuromodulation (NIN) techniques such as transcranial magnetic stimulation, transcranial direct current stimulation, electroconvulsive therapy, and magnetic seizure therapy are gaining momentum for treating MDD, the efficacy of non-convulsive techniques is still modest, whereas use of convulsive modalities is limited by their cognitive side effects. In this context, we propose that NIN techniques could benefit from a precision-oriented approach. In this review, we discuss the challenges and opportunities in implementing such a framework, focusing on enhancing NIN effects via a combination of individualized cognitive interventions, using closed-loop approaches, identifying multimodal biomarkers, using computer electric field modeling to guide targeting and quantify dosage, and using machine learning algorithms to integrate data collected at multiple biological levels and identify clinical responders. Though promising, this framework is currently limited, as previous studies have employed small samples and did not sufficiently explore pathophysiological mechanisms associated with NIN response and side effects. Moreover, cost-effectiveness analyses have not been performed. Nevertheless, further advancements in clinical trials of NIN could shift the field toward a more “precision-oriented” practice.

Combination Therapy and Opioids: Effectiveness of Transcranial Direct-Current Stimulation (tDCS) and Emotion Regulation Training in Reducing Current Drug Craving

Background and objectives: Craving is the main symptom of addiction that is accompanied by dependence and relapse. The present study was aimed to compare the effectiveness of combined Transcranial Direct-Current Stimulation (tDCS) and emotion regulation training with that of separate tDCS and emotion regulation training in reducing current drug craving and thoughts and fantasies about drug use. Materials and methodology: This was a quasi-experimental study with a pretest-posttest design and three intervention groups. The statistical population included all patients dependent on opioids in medium-term residential drug rehabilitation centers in Zahedan, Iran, in 2018-2019. From eight randomly selected centers, a total of 54 patients were selected based on inclusion and exclusion criteria, and randomly divided into three intervention groups. Data were gathered using the Personal Drug Use Questionnaire, Desires for Drug Questionnaire (DDQ), and Drug Use Thoughts, Fantasies, and Temptations Questionnaire. All analyses were performed using SPSS-16. Results: The Kruskal-Wallis test indicated significant differences between the three intervention groups in current drug craving and thoughts and fantasies about drug use (P ..001). In addition, examination of the mean rank showed that t significant decrease was higher for the combined tDCS and emotion regulation training group. Conclusion: Addiction is very similar to other chronic disorders. Therefore, combined (integrated) therapies can have a very important role in treating addiction, especially in relapse prevention.

Searching for the optimal tDCS target for motor rehabilitation

BACKGROUND

Transcranial direct current stimulation (tDCS) has been investigated over the years due to its short and also long-term effects on cortical excitability and neuroplasticity. Although its mechanisms to improve motor function are not fully understood, this technique has been suggested as an alternative therapeutic method for motor rehabilitation, especially those with motor function deficits. When applied to the primary motor cortex, tDCS has shown to improve motor function in healthy individuals, as well as in patients with neurological disorders. Based on its potential effects on motor recovery, identifying optimal targets for tDCS stimulation is essential to improve knowledge regarding neuromodulation as well as to advance the use of tDCS in clinical motor rehabilitation.

METHODS AND RESULTS

Therefore, this review discusses the existing evidence on the application of four different tDCS montages to promote and enhance motor rehabilitation: (1) anodal ipsilesional and cathodal contralesional primary motor cortex tDCS, (2) combination of central tDCS and peripheral electrical stimulation, (3) prefrontal tDCS montage and (4) cerebellar tDCS stimulation. Although there is a significant amount of data testing primary motor cortex tDCS for motor recovery, other targets and strategies have not been sufficiently tested. This review then presents the potential mechanisms and available evidence of these other tDCS strategies to promote motor recovery.

CONCLUSIONS

In spite of the large amount of data showing that tDCS is a promising adjuvant tool for motor rehabilitation, the diversity of parameters, associated with different characteristics of the clinical populations, has generated studies with heterogeneous methodologies and controversial results. The ideal montage for motor rehabilitation should be based on a patient-tailored approach that takes into account aspects related to the safety of the technique and the quality of the available evidence.

Noninvasive Brain Stimulation and Psychotherapy in Anxiety and Depressive Disorders: A Viewpoint

Among the most prevalent psychiatric conditions stand anxiety and depression. Psychotherapy and medications are considered effective treatments in these clinical settings. However, pharmacotherapy and psychotherapy (i.e., cognitive behavioral therapy (CBT)) administered in monotherapy or in a combined regimen do not result in satisfactory outcomes in all patients. Therefore, finding new treatments would be of great help. In the last three decades, noninvasive brain stimulation (NIBS) has emerged as a safe tool to improve several neuropsychiatric symptoms. The following work revisits the available reports that assessed the add-on value of NIBS techniques when combined to psychotherapy (CBT or related interventions) in mood and anxiety disorders. The available protocols targeted the prefrontal cortex, a region that was previously found to have an enhanced activity or functional connectivity after psychotherapeutic interventions. Promising yet scarce evidence exists on this matter. A discrepancy exists among the available reports regarding the type and duration of interventions, the patients’ clinical profiles, and the presence of a sham intervention. NIBS may have acted by enhancing psychotherapy effects on the top-down cognitive control of emotions. Combining both therapies may result in promising effects, but future large-scale trials are needed to judge the utility of this combination in psychiatric populations.

Leveraging Neuroplasticity to Enhance Adaptive Learning: The Potential for Synergistic Somatic-Behavioral Treatment Combinations to Improve Clinical Outcomes in Depression

Until recently, therapeutic development in psychiatry was targeted solely toward symptom reduction. While this is a worthwhile goal, it has yielded little progress in improved therapeutics in the last several decades in the field of mood disorders. Recent advancements in our understanding of pathophysiology suggests that an impairment of neuroplasticity may be a critical part of the development of neuropsychiatric disorders. Interventions that enhance or modulate neuroplasticity often reduce depressive symptoms when applied as stand-alone treatments. Unfortunately, when treatments are discontinued, the disease state often returns as patients relapse. However, treatments that enhance or modulate plasticity not only reduce symptom burden, but also may provide an opportune window wherein cognitive or behavioral interventions could be introduced to harness a state of enhanced neuroplasticity and lead to improved longer-term clinical outcomes. Here, we review the potential of synergistically combining plasticity-enhancing and behavioral therapies to develop novel translational treatment approaches for depression. After reviewing relevant neuroplasticity deficits in depression, we survey biological treatments that appear to reverse such deficits in humans, including N-methyl-D-aspartate receptor modulators (ketamine, D-cycloserine), electroconvulsive therapy, and transcranial brain stimulation. We then review evidence that either directly or indirectly supports the hypothesis that a robust enhancement of neuroplasticity through these methods might promote the uptake of cognitive and behavioral interventions to enhance longer-term treatment outcomes through a synergistic effect. We identify key missing pieces of evidence and discuss future directions to enhance this emerging line of research.

Abnormal functional connectivity of the amygdala is associated with depressive symptoms in patients with multiple system atrophy

PURPOSE

Depressive symptoms are frequent nonmotor symptoms that occur in multiple system atrophy (MSA) patients. However, possible changes that can present in the amygdala (AMY) functional connectivity (FC) of the brain in MSA patients with depressive symptoms (DMSA patients) remain largely unknown.

MATERIALS AND METHODS

Resting-state functional magnetic resonance imaging scans were obtained from 29 DMSA patients, 28 MSA patients without depression symptoms (NDMSA patients), and 34 healthy controls (HCs). FC was analyzed by defining the bilateral AMY as the seed region. Correlation analysis was performed between the FC and clinical scores.

RESULTS

When compared with NDMSA patients, DMSA patients showed increased bilateral AMY FC in the left middle frontal gyrus (MFG) and decreased right AMY FC in the left middle occipital gyrus. Moreover, the AMY FC values in the left middle frontal cortex were positively correlated with the Hamilton Depression Rating Scale-17 item scores. Furthermore, relative to the HCs, DMSA patients presented decreased bilateral AMY FC values in the visuospatial cortex, sensorimotor networks, and limbic areas.

CONCLUSION

Depressive symptoms are associated with AMY-MFG FC anomalies in MSA patients. We propose that the middle frontal cortex may play an important role in the neuropathophysiology of depression in MSA patients.