Transcranial direct current stimulation (tDCS) for depression: analysis of response using a three-factor structure of the Montgomery-Åsberg depression rating scale

tDCS efficacy and utility of anhedonia and rumination as clinical predictors of response to tDCS in major depressive disorder (MDD)

BACKGROUND

Anhedonia and rumination are mental disorders' transdiagnostic features but remain difficult to treat. Transcranial direct current stimulation (tDCS) is a proven treatment for depression, but its effects on anhedonia and rumination and whether anhedonia and rumination can be used as a predictive biomarker of treatment response is not well known. This study aimed to investigate the tDCS efficacy and identify the predictive role of anhedonia and rumination in response to tDCS in patients with MDD.

METHODS

182 patients received 10 tDCS sessions delivered at 2 mA to left (anode) dorsolateral prefrontal cortex (DLPFC). Hamilton Rating Scale for Depression (HRSD-17), Snaith-Hamilton Pleasure Scale (SHAPS), and the 10-item Ruminative Response Scale (RRS-10) was administered to patients with MDD before treatment, following it, and after two weeks of tDCS.

RESULTS

There was an overall significant improvement in anhedonia from pre- to post-treatment. Regression analyses revealed that responders had higher baseline anhedonia and rumination (reflective pondering) scores. We found that the reduction in HRSD scores after tDCS was significantly associated with anhedonia's baseline values while no relation was found between baseline rumination and tDCS treatment response.

CONCLUSION

These results provide new evidence that pronounced anhedonia may be a significant clinical predictor of response to tDCS. Patients with severe or low baseline rumination had an equal chance of achieving clinical response. Prospective tDCS studies are necessary to validate the predictive value of the derived model.

Reduced isometric knee extensor force following anodal transcranial direct current stimulation of the ipsilateral motor cortex

BACKGROUND

The goal of this study was to determine if 10-min of anodal transcranial direct current stimulation (a-tDCS) to the motor cortex (M1) is capable of modulating quadriceps isometric maximal voluntary contraction (MVC) force or fatigue endurance contralateral or ipsilateral to the stimulation site.

METHODS

In a randomized, cross-over design, 16 (8 females) individuals underwent two sessions of a-tDCS and two sham tDCS (s-tDCS) sessions targeting the left M1 (all participants were right limb dominant), with testing of either the left (ipsilateral) or right (contralateral) quadriceps. Knee extensor (KE) MVC force was recorded prior to and following the a-tDCS and s-tDCS protocols. Additionally, a repetitive MVC fatiguing protocol (12 MVCs with work-rest ratio of 5:10-s) was completed following each tDCS protocol.

RESULTS

There was a significant interaction effect for stimulation condition x leg tested x time [F(1,60) = 7.156, p = 0.010, ηp2 = 0.11], which revealed a significant absolute KE MVC force reduction in the contralateral leg following s-tDCS (p < 0.001, d = 1.2) and in the ipsilateral leg following a-tDCS (p < 0.001, d = 1.09). A significant interaction effect for condition x leg tested [F(1,56) = 8.12, p = 0.006, ηp2 = 0.13], showed a significantly lower ipsilateral quadriceps (to tDCS) relative MVC force with a-tDCS, versus s-tDCS [t(15) = -3.07, p = 0.016, d = -0.77]. There was no significant difference between the relative contralateral quadriceps (to tDCS) MVC force for a-tDCS and s-tDCS. Although there was an overall significant [F(1,56) = 8.36, p < 0.001] 12.1% force decrease between the first and twelfth MVC repetitions, there were no significant main or interaction effects for fatigue index force.

CONCLUSION

a-tDCS may be ineffective at increasing maximal force or endurance and instead may be detrimental to quadriceps force production.

Home-based transcranial direct current stimulation in dual active treatments for symptoms of depression and anxiety: A case series

Transcranial direct current stimulation (tDCS) is a potential treatment strategy across some psychiatric conditions. However, there is high heterogeneity in tDCS efficacy as a stand-alone treatment. To increase its therapeutic potential, researchers have begun to explore the efficacy of combining tDCS with psychological and pharmacological interventions. The current case series details the effect of 6-10 weeks of self-administered tDCS paired with a behavioral therapy smartphone app (Flow™), on depressive and anxiety symptoms, in seven patients (26-51 years old; four female) presenting distinctive psychiatric disorders (major depression, dysthymia, illness anxiety disorder, obsessive-compulsive disorder, and anxiety disorders). tDCS protocol consisted of an acute phase of daily 30 min sessions, across 10 workdays (2 weeks Monday-to-Friday; Protocol 1) or 15 workdays (3 weeks Monday-to-Friday; Protocol 2). A maintenance phase followed, with twice-weekly sessions for 4 or 3 weeks, corresponding to 18 or 21 sessions in total (Protocol 1 or 2, respectively). The Flow tDCS device uses a 2 mA current intensity, targeting the bilateral dorsolateral prefrontal cortex. The Flow app offers virtually guided behavioral therapy courses to be completed during stimulation. We assessed depressive symptoms using MADRS-S and BDI-II, anxious symptoms using STAI-Trait, acceptability using ACCEPT-tDCS, and side effects using the Adverse Effects Questionnaire, at baseline and week 6 of treatment. Six patients underwent simultaneous cognitive-behavioral psychotherapy and two were on antidepressants and benzodiazepines. According to the Reliable Change Index (RCI), for depressive symptoms, we found clinically reliable improvement in five patients using MADRS-S (out of seven; RCI: -1.45, 80% CI; RCI: -2.17 to -4.82, 95% CI; percentage change: 37.9-66.7%) and in four patients using BDI-II (out of five; RCI: -3.61 to -6.70, 95% CI; percentage change: 57.1-100%). For anxiety symptoms, clinically reliable improvement was observed in five patients (out of six; RCI: -1.79, 90% CI; RCI: -2.55 to -8.64, 95% CI; percentage change: 12.3-46.4%). Stimulation was well-tolerated and accepted, with mild tingling sensation and scalp discomfort being the most common side effects. This case series highlights the applicability, acceptability, and promising results when combining home-based tDCS with psychotherapy and pharmacotherapy to manage depression and anxiety symptoms in clinical practice.

Antidepressant action of transcranial direct current stimulation in olfactory bulbectomised adolescent rats

BACKGROUND

Antidepressant drugs in adolescent depression are sometimes mired by efficacy issues and paradoxical effects. Transcranial direct current stimulation (tDCS) could represent an alternative.

AIMS/METHODS

We tested the antidepressant action of prefrontal tDCS and paroxetine (20 mg/kg, intraperitoneal) in olfactory bulbectomised (OBX) adolescent rats. Using enzyme-linked immunosorbent assays and in situ hybridisation, we examined treatment-induced changes in plasma brain-derived neurotrophic factor (BDNF) and brain serotonin transporter (SERT) and 5-HT-1A mRNA.

RESULTS

OBX-induced anhedonia-like reductions in sucrose preference (SP) correlated with open field (OF) hyperactivity. These were accompanied by decreased zif268 mRNA in the piriform/amygdalopiriform transition area, and increased zif268 mRNA in the hypothalamus. Acute paroxetine (2 days) led to a profound SP reduction, an effect blocked by combined tDCS-paroxetine administration. Chronic (14 days) tDCS attenuated hyperlocomotion and its combination with paroxetine blocked OBX-induced SP reduction. Correlations among BDNF, SP and hyperlocomotion scores were altered by OBX but were normalised by tDCS-paroxetine co-treatment. In the brain, paroxetine increased zif268 mRNA in the hippocampal CA1 subregion and decreased it in the claustrum. This effect was blocked by tDCS co-administration, which also increased zif268 in CA2. tDCS-paroxetine co-treatment had variable effects on 5-HT1A receptors and SERT mRNA. 5-HT1A receptor changes were found exclusively within depression-related parahippocampal/hippocampal subregions, and SERT changes within fear/defensive response-modulating brainstem circuits.

CONCLUSION

These findings point towards potential synergistic efficacies of tDCS and paroxetine in the OBX model of adolescent depression via mechanisms associated with altered expression of BDNF, 5-HT1A, SERT and zif268 in discrete corticolimbic areas.

Clinical and demographic predictors of response to anodal tDCS treatment in major depression disorder (MDD)

Transcranial direct current stimulation (tDCS) of the prefrontal cortex is known as a promising intervention in major depression disorder (MDD). However, limited information on predictors of therapeutic response to tDCS are available. This study aimed to investigate clinical and demographic predictors of therapeutic response in patients taking no medications. For this purpose, the required data were collected from 2 independent tDCS trials on 116 MDD patients. Accordingly, 84 patients underwent 10 sessions of 2 mA tDCS daily each one lasted for 20 min and 32 patients received 10 twice sessions of 2 mA tDCS daily each one lasted for 20 min. Anodal electrode was located over the left dorsolateral prefrontal cortex (DLPFC), and cathode was over the right supraorbital region. Depression symptoms and the underlying clinical dimensions were assessed using the Beck Depression Inventory (BDI-II) at baseline and after the tDCS treatment. Of the included 116 patients, 47.4% showed an antidepressant response. Results of logistic regression analysis showed that the reduction in BDI-II scores after tDCS was associated with the baseline values of cognitive-affective symptoms factor, loss of pleasure, loss of interest, and sleep problems. Pronounced sleep disturbances and cognitive-affective symptoms were identified as the potential clinical predictors of response to tDCS. However, more prospective tDCS studies are necessary to validate the predictive value of the derived model.

Influence of Transcranial Direct Current Stimulation on Psychomotor Symptoms in Major Depression

Background: Transcranial direct current stimulation (tDCS) applied to the left dorsolateral prefrontal cortex (dlPFC) might be a promising treatment strategy for depression. As disturbances in psychomotor activity are one of the key features of unipolar depression are, we aimed to evaluate the behavioral effects of ten tDCS sessions over a 5-day period on psychomotor retardation in depressed patients. Methods: Twenty-three treatment-resistant depressed patients received either active or sham anodal tDCS to the left dorsolateral prefrontal cortex (2 mA, 10 sessions over 1 week). Psychomotor functioning was registered by means of observer ratings (Salpêtrière Retardation Rating Scale—SRRS) and objective measures (kinematical analysis of movements, automatic imitation). Results: tDCS sessions resulted in improvements on SRRS scores, although active tDCS was not significantly superior to sham tDCS on the kinematical parameters. Furthermore, no general additional antidepressant effect of tDCS was observed. The relatively small sample size and the short periods of observation should be considered when interpreting these results. Conclusion: tDCS did not induce a clinically relevant effect on psychomotor function in active and sham stimulation groups.

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.

Neurocognitive effects of transcranial direct current stimulation (tDCS) in unipolar and bipolar depression: Findings from an international randomized controlled trial

OBJECTIVE

Transcranial direct current stimulation (tDCS) has been found to have antidepressant effects and may have beneficial neurocognitive effects. However, prior research has produced an unclear understanding of the neurocognitive effects of repeated exposure to tDCS. The study's aim was to determine the neurocognitive effects following tDCS treatment in participants with unipolar or bipolar depression.

METHOD

The study was a triple-masked, randomized, controlled clinical trial across six international academic medical centers. Participants were randomized to high dose (2.5 mA for 30 min) or low dose (0.034 mA, for 30 min) tDCS for 20 sessions over 4 weeks, followed by an optional 4 weeks of open-label high dose treatment. The tDCS anode was centered over the left dorsolateral prefrontal cortex at F3 (10/20 EEG system) and the cathode over F8. Participants completed clinical and neurocognitive assessments before and after tDCS. Genotype (BDNF Val66Met and catechol-o-methyltransferase [COMT] Val158Met polymorphisms) were explored as potential moderators of neurocognitive effects.

RESULTS

The study randomized 130 participants. Across the participants, tDCS treatment (high and low dose) resulted in improvements in verbal learning and recall, selective attention, information processing speed, and working memory, which were independent of mood effects. Similar improvements were observed in the subsample of participants with bipolar disorder. There was no observed significant effect of tDCS dose. However, BDNF Val66Met and COMT Val158Met polymorphisms interacted with tDCS dose and affected verbal memory and verbal fluency outcomes, respectively.

CONCLUSIONS

These findings suggest that tDCS could have positive neurocognitive effects in unipolar and bipolar depression. Thus, tDCS stimulation parameters may interact with interindividual differences in BDNF and COMT polymorphisms to affect neurocognitive outcomes, which warrants further investigation.

Effect of home-based transcranial direct current stimulation (tDCS) on cognitive function in patients with mild cognitive impairment: a study protocol for a randomized, double-blind, cross-over study

Background

The possible effect of transcranial direct current stimulation (tDCS) in improving cognitive function is clear from studies involving pre-dementia stage mild cognitive impairment (MCI). However, the application of tDCS in actual clinical practice entails repeated hospital visits almost every day for treatment. The objective of this study is to confirm the possibility of self-application of tDCS at home by elderly patients with declined cognitive function and the significant clinical effect of tDCS administered at home.

Methods/design

This study will be conducted in 20 elderly people aged 60 to 80 years with complaints of subjective memory impairment while maintaining general functions with limited activities of daily living. This study involves a cross-over design that will include 2-week active or sham stimulation of both dorsolateral prefrontal cortexes (left, anode; right, cathode) randomly with a 2-week wash-out phase. Changes in cognitive function will be evaluated using visual recognition tasks and neuropsychological tests. In this study, tDCS will be carried out by each patient at his/her home and its safety and suitability will be evaluated.

Discussion

In this study, patients will apply a portable tDCS, developed for home use, for more than 2 weeks. Such studies can contribute to the use of tDCS as a realistic therapy. In addition, the utility of home-based tDCS will be confirmed by application of tDCS at home by the elderly with declined cognitive function. Furthermore, confirmation of tDCS as a significant therapeutic method can facilitate treatment of Alzheimer’s dementia at an early stage, including MCI.

Trial registration

Clinical Research Information Service (CRIS), KCT0002721. Registered on 9 March 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3360-1) contains supplementary material, which is available to authorized users.

A review of transcranial direct current stimulation (tDCS) for the individualized treatment of depressive symptoms

Transcranial direct current stimulation (tDCS) is a low intensity neuromodulation technique shown to elicit therapeutic effects in a number of neuropsychological conditions. Independent randomized sham-controlled trials and meta- and mega-analyses demonstrate that tDCS targeted to the left dorsolateral prefrontal cortex can produce a clinically meaningful response in patients with major depressive disorder (MDD), but effects are small to moderate in size. However, the heterogeneous presentation, and the neurobiology underlying particular features of depression suggest clinical outcomes might benefit from empirically informed patient selection. In this review, we summarize the status of tDCS research in MDD with focus on the clinical, biological, and intrinsic and extrinsic factors shown to enhance or predict antidepressant response. We also discuss research strategies for optimizing tDCS to improve patient-specific clinical outcomes. TDCS appears suited for both bipolar and unipolar depression, but is less effective in treatment resistant depression. TDCS may also better target core aspects of depressed mood over vegetative symptoms, while pretreatment patient characteristics might inform subsequent response. Peripheral blood markers of gene and immune system function have not yet proven useful as predictors or correlates of tDCS response. Though further research is needed, several lines of evidence suggest that tDCS administered in combination with pharmacological and cognitive behavioral interventions can improve outcomes. Tailoring stimulation to the functional and structural anatomy and/or connectivity of individual patients can maximize physiological response in targeted networks, which in turn could translate to therapeutic benefits.

Differences in Speed of Response of Depressive Symptom Dimensions in Older Persons During Electroconvulsive Therapy

INTRODUCTION

Electroconvulsive therapy (ECT) is an important and effective treatment for depression. However, research on course trajectories of depressive symptoms during ECT is limited. Insight into putative differences in speed of response of depressive symptom dimensions may enable clinicians to optimally inform patients and their relatives. Therefore, we aim to examine course trajectories of depressive symptom dimensions in depressed older persons during ECT.

METHODS

Data were derived from the Mood Disorders in Elderly treated with Electro Convulsive Therapy study, including 110 persons, aged 55 years or more, with a current diagnosis of major depressive disorder and referred for ECT. Exploratory factor analysis was used to identify symptom dimensions, using the 10 depression items of the Montgomery-Åsberg Depression Rating Scale (MADRS). Differences in course trajectories of symptom dimension during 2 weeks were examined by multilevel analyses.

RESULTS

Three symptom dimensions were identified: a "mood," "melancholic," and "suicidal" dimension. Mood showed a significantly greater severity decline as compared with melancholic and suicidal at the 1-week follow-up. At the 2-week follow-up, both mood and melancholic demonstrated a significantly greater decline as compared with suicidal. However, because scores on the suicidality item of the Montgomery-Asberg Depression Rating Scale were already lower at baseline compared with the other items, a floor effect cannot be ruled out.

DISCUSSION

All symptom dimensions of depression showed a rapid response to ECT. Our findings did not support the general assumption that suicidal symptoms may be the first to improve. However, a floor effect on the suicidality item cannot be ruled out.

Low-dose augmentation with buprenorphine increases emotional reactivity but not reward activity in treatment resistant mid- and late-life depression

Buprenorphine is currently being studied for treatment-resistant depression because of its rapid effect, relative safety, and unique pharmacodynamics. To understand the neural impact of buprenorphine in depression, we examined acute limbic and reward circuit changes during an intervention with low-dose buprenorphine augmentation pharmacotherapy. Mid and late-life adults with major depression (N = 31) who did not completely respond to an adequate trial of venlafaxine were randomized to augmentation with low-dose buprenorphine or matching placebo. We investigated early neural changes using functional magnetic resonance imaging (fMRI) from pre-randomization to 3 weeks using both an emotional reactivity task and a gambling task. We tested if: 1) there were significant neural changes acutely per intervention group, and 2) if acute neural changes were associated with depressive symptom change over 8 weeks using both the total score and the dysphoria subscale of the Montgomery Asberg Depression Rating Scale. Participants in both the buprenorphine and placebo groups showed similar changes in depressive symptoms. Neither the emotional reactivity nor gambling task resulted in significant neural activation changes from pre-randomization to 3-weeks. In both groups, increases in rostral anterior cingulate (rACC) and ventromedial prefrontal cortex (vmPFC) activation during the emotional reactivity task were associated with overall symptom improvement. In the buprenorphine but not the placebo group, increased activation in left anterior insula (aINS) and bilateral middle frontal gyrus (MFG) was associated with improvement on the dysphoria subscale. Activation changes in the reward task were not associated with buprenorphine. This is the first study to show an association between acute neural changes during emotion reactivity and changes in depression severity with buprenorphine treatment.

Anisotropic conductivity tensor imaging for transcranial direct current stimulation (tDCS) using magnetic resonance diffusion tensor imaging (MR-DTI)

Transcranial direct current stimulation (tDCS) is a widely used non-invasive brain stimulation technique by applying low-frequency weak direct current via electrodes attached on the head. The tDCS using a fixed current between 1 and 2 mA has relied on computational modelings to achieve optimal stimulation effects. Recently, by measuring the tDCS current induced magnetic field using an MRI scanner, the internal current pathway has been successfully recovered. However, up to now, there is no technique to visualize electrical properties including the electrical anisotropic conductivity, effective extracellular ion-concentration, and electric field using only the tDCS current in-vivo. By measuring the apparent diffusion coefficient (ADC) and the magnetic flux density induced by the tDCS, we propose a method to visualize the electrical properties. We reconstruct the scale parameter, which connects the anisotropic conductivity tensor to the diffusion tensor of water molecules, by introducing a repetitive scheme called the diffusion tensor J-substitution algorithm using the recovered current density and the measured ADCs. We investigate the proposed method to explain why the iterative scheme converges to the internal conductivity. We verified the proposed method with an anesthetized canine brain to visualize electrical properties including the electrical properties by tDCS current.

Transcranial Direct Current Stimulation (tDCS): A Promising Treatment for Major Depressive Disorder?

Background: Transcranial direct current stimulation (tDCS) opens new perspectives in the treatment of major depressive disorder (MDD), because of its ability to modulate cortical excitability and induce long-lasting effects. The aim of this review is to summarize the current status of knowledge regarding tDCS application in MDD. Methods: In this review, we searched for articles published in PubMed/MEDLINE from the earliest available date to February 2018 that explored clinical and cognitive effects of tDCS in MDD. Results: Despite differences in design and stimulation parameters, the examined studies indicated beneficial effects of tDCS for MDD. These preliminary results, the non-invasiveness of tDCS, and its good tolerability support the need for further research on this technique. Conclusions: tDCS constitutes a promising therapeutic alternative for patients with MDD, but its place in the therapeutic armamentarium remains to be determined.

Clinical predictors of acute response to transcranial direct current stimulation (tDCS) in major depression

BACKGROUND

Transcranial direct current stimulation (tDCS) is a promising neuromodulation intervention for poor-responding or refractory depressed patients. However, little is known about predictors of response to this therapy. The present study aimed to analyze clinical predictors of response to tDCS in depressed patients.

METHODS

Clinical data from 3 independent tDCS trials on 171 depressed patients (including unipolar and bipolar depression), were pooled and analyzed to assess predictors of response. Depression severity and the underlying clinical dimensions were measured using the Hamilton Depression Rating Scale (HDRS) at baseline and after the tDCS treatment. Age, gender and diagnosis (bipolar/unipolar depression) were also investigated as predictors of response. Linear mixed models were fitted in order to ascertain which HDRS factors were associated with response to tDCS.

RESULTS

Age, gender and diagnosis did not show any association with response to treatment. The reduction in HDRS scores after tDCS was strongly associated with the baseline values of "Cognitive Disturbances" and "Retardation" factors, whilst the "Anxiety/Somatization" factor showed a mild association with the response.

LIMITATIONS

Open-label design, the lack of control group, and minor differences in stimulation protocols.

CONCLUSIONS

No differences in response to tDCS were found between unipolar and bipolar patients, suggesting that tDCS is effective for both conditions. "Cognitive disturbance", "Retardation", and "Anxiety/Somatization", were identified as potential clinical predictors of response to tDCS. These findings point to the pre-selection of the potential responders to tDCS, therefore optimizing the clinical use of this technique and the overall cost-effectiveness of the psychiatric intervention for depressed patients.

The efficacy of levomilnacipran ER across symptoms of major depressive disorder: a post hoc analysis of 5 randomized, double-blind, placebo-controlled trials

OBJECTIVE

A post hoc analysis evaluated the effects of levomilnacipran ER on individual symptoms and symptom domains in adults with major depressive disorder (MDD).

METHODS

Data were pooled from 5 Phase III trials comprising 2598 patients. Effects on depression symptoms were analyzed based on change from baseline in individual Montgomery-Åsberg Depression Rating Scale (MADRS) item scores. A1dditional evaluations included resolution of individual symptoms (defined as a MADRS item score ≤1 at end of treatment) and concurrent resolution of all 10 MADRS items, all MADRS6 subscale items, and all items included in different symptom clusters (Dysphoria, Retardation, Vegetative Symptoms, Anhedonia).

RESULTS

Significantly greater mean improvements were found on all MADRS items except Reduced Appetite with levomilnacipran ER treatment compared with placebo. Resolution of individual symptoms occurred more frequently with levomilnacipran ER than placebo for each MADRS item (all P<.05), with odds ratios (ORs) ranging from 1.26 to 1.75; resolution of all 10 items was also greater with levomilnacipran ER (OR=1.57; P=.0051). Significant results were found for the MADRS6 subscale (OR=1.73; P<.0001) and each symptom cluster (OR range, 1.39 [Vegetative Symptoms] to 1.84 [Retardation]; all clusters, P<.01).

CONCLUSION

Adult MDD patients treated with levomilnacipran ER improved across a range of depression symptoms and symptom domains.

Effects of smoking status and MADRS retardation factor on response to low frequency repetitive transcranial magnetic stimulation for depression

BACKGROUND

Despite growing evidence supporting the clinical interest of repetitive transcranial magnetic stimulation (rTMS) in treatment-resistant depression (TRD), little is known regarding the effects of clinical and sociodemographic factors on the clinical outcome in patients.

METHODS

We retrospectively investigated the effects of clinical (using the 3-factor model of the Montgomery-Åsberg depression rating scale [MADRS] encompassing dysphoria, retardation and vegetative symptoms) and sociodemographic characteristics of participants on clinical outcome in a sample of 54 TRD patients receiving low frequency rTMS (1Hz, 360 pulses) applied over the right dorsolateral prefrontal cortex combined with sham venlafaxine.

RESULTS

Responders (n=29) displayed lower retardation baseline scores (13.6±2.9) than non-responders (15.6±2.9; n=25; P=0.02). We also observed a significant difference between the numbers of ex-smokers in responders and non-responders groups; all ex-smokers (n=8) were responders to rTMS (P=0.005).

CONCLUSION

Low MADRS retardation factor and ex-smoker status is highly prevalent in responders to low frequency rTMS. Further studies are needed to investigate the predictive value of these factors.

A systematic review of the clinical efficacy of transcranial direct current stimulation (tDCS) in psychiatric disorders

Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique, which can be used to selectively disrupt patterns of neural activity that are associated with symptoms of mental illness. tDCS has been implemented in numerous therapeutic trials across a range of patient populations, with a rapidly increasing number of studies being published each year. This systematic review aimed to evaluate the efficacy of tDCS in the treatment of psychiatric disorders. Four electronic databases were searched from inception until December 2015 by two independent reviewers, and 66 eligible studies were identified. Depression was the most extensively researched condition, followed by schizophrenia and substance use disorders. Data on obsessive compulsive disorder, generalised anxiety disorder, and anorexia nervosa were also obtained. The quality of included studies was appraised using a standardised assessment framework, which yielded a median score corresponding to "weak" on the three-point scale. This improved to "moderate" when case reports/series were excluded from the analysis. Overall, data suggested that tDCS interventions comprising multiple sessions can ameliorate symptoms of several major psychiatric disorders, both acutely and in the long-term. Nevertheless, the tDCS field is still in its infancy, and several methodological and ethical issues must be addressed before clinical efficacy can truly be determined. Studies probing the mechanisms of action of tDCS and those facilitating the definition of optimised stimulation protocols are warranted. Furthermore, evidence from large-scale, multi-centre randomised controlled trials is required if the transition of this therapy from the laboratory to the clinic is to be considered.

Decreased expression of the APOA1-APOC3-APOA4 gene cluster is associated with risk of Alzheimer's disease

Background

Apolipoprotein is genetically associated with the risk of Alzheimer’s disease (AD). The APOA1, APOC3, and APOA4 genes are closely linked and located on human chromosome 11. Therefore, this gene cluster may be related to the risk of AD.

Patients and methods

A total of 147 AD patients and 160 healthy controls were randomly recruited from June 2013 to August 2014. APOA1, APOC3, and APOA4 levels were measured using real-time quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay.

Results

APOA1, APOC3 and APOA4 levels were significantly lower in AD patients than controls (P<0.01). APOA1, APOC3, and APOA4 levels were negatively related with the severities of AD determined by Clinical Dementia Rating scores (P<0.01). APOA1, APOC3, and APOA4 levels showed a negative relation with Montgomery–Åsberg Depression Rating Scale scores and a positive relation with RAND 36-item health-survey scores (P<0.01). There was a decreased trend for levels of APOA1, APOC3, and APOA4 in AD patients.

Conclusion

Low levels of APOA1, APOC3, and APOA4 are associated with risk of AD. APOA1, APOC3, and APOA4 should be developed as combined drugs for the therapy of AD.

The impacts of a GO-game (Chinese chess) intervention on Alzheimer disease in a Northeast Chinese population

A GO game can enhance mental health, but its effects on Alzheimer Disease (AD) remains unknown. To address the issue, 147 AD patients were randomly assigned into control (without GO-game intervention), Short-time GO-Game Intervention (SGGI, 1 h daily) and Long-time GO-game Intervention (LGGI, 2 h daily) groups. After 6-month follow-up, the game reduced the mean score of Montgomery-Asberg Depression Rating Scales (MADRS) of 4.72 (95% CI, 0.69 to 9.12) and Hospital Anxiety and Depression Scale (HADS) of 1.75 (95% CI, 0.17–3.68), and increased the mean score of Global Assessment of Functioning (GAF) of 4.95 (95% CI, −1.37–9.18) and RAND-36 of 4.61 (95% CI, −2.75–11.32) (P < 0.05 via controls). A GO-game intervention improved 9 of 11 items of KICA-dep (Kimberley Indigenous Cognitive Assessment of Depression). Meanwhile, serum levels of brain derived neurotrophic factor (BDNF) were higher in SGGI and LGGI groups (24.02 ± 7.16 and 28.88 ± 4.12 ng/ml respectively, P = 0.051) than those in controls (17.28 ± 7.75 ng/ml) (P < 0.001). The serum levels of BDNF showed a negative relation with MADRS and a positive relation with RAND-36 (P < 0.01). A GO-game intervention ameliorates AD manifestations by up-regulating BDNF levels.

Emerging antidepressants to treat major depressive disorder

Depression is a common disorder with an annual risk of a depressive episode in the United States of 6.6%. Only 30-40% of patients remit with antidepressant monotherapy, leaving 60-70% of patients who do not optimally respond to therapy. Unremitted depressive patients are at increased risk for suicide. Considering the prevalence of treatment resistant depression and its consequences, treatment optimization is imperative. This review summarizes the latest treatment modalities for major depressive disorder including pharmacotherapy, electroconvulsive therapy, repetitive transcranial magnetic stimulation and psychotherapy. Through advancements in research to better understand the pathophysiology of depression, advances in treatment will be realized.

Cytokines plasma levels during antidepressant treatment with sertraline and transcranial direct current stimulation (tDCS): results from a factorial, randomized, controlled trial

RATIONALE

The inflammatory hypothesis of depression states that increased levels of pro-inflammatory cytokines triggered by external and internal stressors are correlated to the acute depressive state. This hypothesis also suggests that pharmacotherapy partly acts in depression through anti-inflammatory effects. Transcranial direct current stimulation (tDCS) is a novel, promising, non-invasive somatic treatment for depression, although its antidepressant mechanisms are only partly understood.

OBJECTIVES

We explored the effects of tDCS and sertraline over the immune system during an antidepressant treatment trial.

METHODS

In a 6-week, double-blind, placebo-controlled trial, 73 antidepressant-free patients with unipolar depression were randomized to active/sham tDCS and sertraline/placebo (2 × 2 design). Plasma levels of several cytokines (IL-2, IL-4, IL-6, IL-10, IL-17a, IFN-γ, and TNF-α) were determined to investigate the effects of the interventions and of clinical response on them.

RESULTS

All cytokines, except TNF-α, decreased over time, these effects being similar across the different intervention-groups and in responders vs. non-responders.

CONCLUSIONS

tDCS and sertraline (separately and combined) acute antidepressant effects might not specifically involve normalization of the immune system. In addition, being one of the first placebo-controlled trials measuring cytokines over an antidepressant treatment course, our study showed that the decrease in cytokine levels during the acute depressive episode could involve a placebo effect, highlighting the need of further placebo-controlled trials and observational studies examining cytokine changes during depression treatment and also after remission of the acute depressive episode.

Differential improvement in depressive symptoms for tDCS alone and combined with pharmacotherapy: an exploratory analysis from the Sertraline vs. Electrical Current Therapy for Treating Depression Clinical Study

Transcranial direct current stimulation (tDCS) is a promising therapy for major depression treatment, although little is known of its effects in ameliorating distinct symptoms of depression. Thus, it is important, not only to increase knowledge of its antidepressant mechanisms, but also to guide its potential use in clinical practice. Using data from a recent factorial, double-blinded, placebo-controlled trial applying tDCS-alone and combined with sertraline to treat 120 depressed outpatients over 6 wk (Brunoni et al., 2013), we investigated the pattern of improvement in symptoms of depression from the Montgomery-Asberg depression scale (MADRS). First, we performed one multivariate analysis of variance with the score improvement of the 10 MADRS items as dependent variables. Significant (p < 0.05) results were further explored with follow-up analyses of variance. TDCS (alone and combined with sertraline) improved concentration difficulties and pessimistic and suicidal thoughts. The combined treatment also improved apparent and reported sadness, lassitude and inability to feel. Indeed, tDCS/sertraline significantly ameliorated all but the 'vegetative' depression symptoms (inner tension, sleep and appetite items). We further discuss whether bifrontal tDCS over the dorsolateral prefrontal cortex could be associated with improvement in cognitive (concentration) and affective (pessimistic/suicidal thoughts) processing, while the combined treatment might have a more widespread antidepressant effect by simultaneously acting on different depression pathways. We also identified patterns of antidepressant improvement for tDCS that might aid in tailoring specific interventions for different subtypes of depressed patients, e.g. particularly those with suicidal ideation.