***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Two recent sham-controlled studies found that transcranial direct current stimulation ( tDCS ) was an effective treatment for  depression .  As tDCS is painless , relatively safe and inexpensive , its efficacy in treating depression warrants further investigation . This double-blind , r and omized study tested tDCS at the same stimulation parameters as a previous positive study ( 1 mA current strength , five treatment sessions , active or sham , given on alternate days ) in 40 depressed participants .  Anodal stimulation was centred over the left dorsolateral prefrontal cortex , with the cathode placed on the lateral aspect of the contralateral orbit . tDCS was continued up to a total of ten active sessions per participant . Mood outcomes were measured by psychiatrist raters blind to treatment condition using the Montgomery-Asberg and other depression rating scales . Psychomotor speed was assessed immediately before and after a single tDCS session and attention , frontal executive function , working memory and verbal learning were assessed after each group of five sessions . Overall depression scores improved significantly over ten tDCS treatments , but there was no between-group difference in the five-session , sham-controlled phase . tDCS was found to be safe , with no adverse effects on neuropsychological function , and only minor side-effects . It is recommended that the efficacy of tDCS in depression be further evaluated over a longer treatment period , using enhanced stimulation parameters Computer-administered cognitive training ( CT ) tasks are a common component of cognitive remediation treatments . There is growing evidence that transcranial direct current stimulation ( tDCS ) , when given during cognitive tasks , improves performance . This r and omized , controlled trial explored the potential synergistic effects of CT combined with tDCS in healthy participants . Altogether , 60 healthy participants were r and omized to receive either active or sham tDCS administered during training on an adaptive CT task ( dual n-back task ) , or tDCS alone , over 10 daily sessions . Cognitive testing ( working memory , processing speed , executive function , reaction time ) was conducted at baseline , end of the 10 sessions , and at 4-wk follow-up to examine potential transfer effects to non-trained tasks . Altogether , 54 participants completed the study . Over the 10 ' online ' sessions , participants in the active tDCS+CT condition performed more accurately on the CT task than participants who received sham tDCS+CT . The performance enhancing effect , however , was present only during tDCS and did not result in greater learning ( i.e. improvement over sessions ) on the CT task . These results confirm prior reports of enhancement of cognitive function during tDCS stimulation . At follow-up , the active tDCS+CT group , but not the sham tDCS+CT group , showed greater gains on a non-trained test of attention and working memory than the tDCS-only group ( p < 0.01 ) . Although this gain can mainly be attributable to training , this result suggests that active tDCS may have a role in further enhancing outcomes BACKGROUND Transcranial direct current stimulation ( tDCS ) is a non-invasive brain stimulation modality that has been increasingly used for major depressive disorder ( MDD ) treatment . Although studies in healthy volunteers showed that the technique is well-tolerated , tDCS safety and acceptability have not been sufficiently explored in patients with MDD . METHODS We collected individual patient data from 6 r and omized clinical trials that had been previously identified in a systematic review and meta- analysis . Primary outcomes were safety ( rate of adverse events ) and acceptability ( rate of dropouts ) . Secondary outcomes were clinical , demographic and treatment predictors of the primary outcomes . RESULTS Dropout rates between active ( 8.8 % ) and sham ( 12 % ) groups were not significantly different ( OR= 0.7 , p=0.38 ) . Adverse event rates between active ( 73.5 % ) and sham ( 68.3 % ) groups were not significantly different ( OR= 1.4 , p= 0.23 ) . Higher current densities were associated with lower adverse event rates . LIMITATIONS Dropout reasons were not systematic ally reported and adverse events were not collected using question naires st and ardized across studies . CONCLUSIONS Active tDCS is as acceptable and safe as sham tDCS , as found in r and omized clinical trials of MDD Attentional deficits are considered key cognitive symptoms in major depressive disorder ( MDD ) arising from abnormal activation patterns within dorsolateral prefrontal cortex ( dlPFC ) alertness networks . Altering these activity patterns with transcranial direct current stimulation ( tDCS ) might thus ameliorate alertness-dependent cognitive deficits in MDD patients . In a double-blind , r and omized , sham-controlled study , we investigated the effect of a single session of anodal tDCS ( 2 mA ) applied to the left dlPFC on different parameters of visual attention based on Bundesen ’s theory of visual attention ( Psychol Rev 97(4):523–547 , 1990 ) in a group of 20 patients with MDD and a control group of 20 healthy participants . The parametric attention assessment took place before , immediately after and 24 h after tDCS intervention . It revealed a selective impairment in visual processing speed as a primary functional deficit in MDD at baseline assessment . Furthermore , a significant stimulation condition × time point interaction showed that verum tDCS over the left dlPFC result ed in a processing speed enhancement 24 h post-stimulation in MDD patients . In healthy control participants , we did not find similar tDCS-induced effects . Our results suggest that even a single session of tDCS over the dlPFC can induce enduring neurocognitive benefits that indicate an amelioration of cortical under-arousal in MDD patients in a time frame beyond that of immediate , excitability increases that are directly induced by the current BACKGROUND Transcranial direct current stimulation ( tDCS ) is a promising new treatment for depression , however , clinical trials to- date indicate variable efficacy , thereby raising the need to identify inter-individual predictors of response . In the current study we aim ed to investigate pre-treatment neurocognitive performance as a predictor of antidepressant response to tDCS . METHODS Data was pooled from five clinical trials , including two r and omised controlled trials ( RCTs ) , which investigated the antidepressant effects of anodal tDCS administered to the prefrontal cortex . Data from 57 patients were included in the analysis . Mood was assessed before and after an acute course of treatment using the Montgomery-Åsberg Depression Rating Scale . The following neurocognitive tests were administered prior to treatment : Simple and choice reaction time , the Symbol Digit Modalities Test ( SDMT ) , Rey Auditory Verbal Memory Task ( RAVLT ) , Digit Span , and the Controlled Oral Word Association Test ( COWAT ) . RESULTS Better pre-treatment letter fluency performance measured using the COWAT predicted antidepressant response to tDCS after controlling for confounds . LIMITATIONS Small sample size and analysis included data from both RCTs and open label studies . CONCLUSION Pre-treatment letter fluency performance , an ability subserved by the left prefrontal cortex , the primary site of stimulation , is a predictor of response for tDCS treatment for depression . This study highlights the importance of inter-individual neurobiological differences in mediating tDCS antidepressant effects BACKGROUND Major depressive disorder ( MDD ) is frequently associated with underactivity of the dorsolateral prefrontal cortex ( DLPFC ) which has led to this brain region being identified as an important target for the development of neurobiological treatments . Transcranial direct current stimulation ( tDCS ) administered to the DLPFC has antidepressant efficacy , however the magnitude of antidepressant outcomes are limited . Concurrent cognitive activity has been shown to enhance tDCS induced stimulation effects . Cognitive control training ( CCT ) is a new cognitive therapy for MDD that aims to enhance DLPFC activity via behavioral methods . HYPOTHESIS We tested the hypothesis that co-administration of DLPFC tDCS and CCT would result in a greater reduction in depressive symptomology than administration of tDCS or CCT alone . METHODS 27 adult participants with MDD were r and omized into a three-arm sham-controlled between-groups pilot study comparing the efficacy of 2 mA tDCS + CCT , sham tDCS + CCT and sham CCT + 2 mA tDCS ( 5 sessions administered on consecutive working days ) . Blinded assessment s of depression severity and cognitive control were conducted at baseline , end of treatment and a three week follow up review . RESULTS All three treatment conditions were associated with a reduction in depression severity at the end of five treatment sessions . However , only administration of tDCS + CCT result ed in sustained antidepressant response at follow up , the magnitude of which was greater than that observed immediately following conclusion of the treatment course . CONCLUSIONS The results provide preliminary evidence that concurrent CCT enhances antidepressant outcomes from tDCS . In the current sample , participants receiving concurrent tDCS and CCT continued to improve following cessation of treatment . The clinical superiority of a combined therapeutic approach was apparent even in a small sample and following a relatively short treatment course Dorsolateral prefrontal cortex ( DLPFC ) hypoactivity and subcortical hyperactivity have been associated to cognitive impairment for non-emotional ( " cold " ) and emotional ( " hot " ) working memory tasks in major depressive disorder ( MDD ) . We investigated whether an increase of DLPFC activity using transcranial direct current stimulation ( tDCS ) would differently influence the performance in working memory tasks in depressed and healthy subjects . Forty young adult participants ( 20 with MDD and 20 healthy controls ) were r and omized to a single , sham-controlled , bifrontal ( left anodal/right cathodal ) , 2mA , 30min tDCS session in a parallel design . The n-back and the internal shift task ( IST ) were used as proxies of cold and hot working memory performance , respectively . Active tDCS compared to sham promoted more accurate and faster responses to the n-back task for both patients and controls . Conversely , only patients presented an improvement in response times for the IST task . Our findings suggest that the mechanisms of tDCS in MDD involve modulation of both cold and hot working memory . We discuss these findings considering the modulatory top-down effects of tDCS on subcortical structures via prefrontal activation , and how spreading of activation might be different for healthy volunteers versus depressed patients . We also discuss the role of tDCS in cognitive amelioration for depressed patients . Finally , the distinct effects of tDCS in the " hot " cognition task for healthy and depressed participants are indicative that tDCS outcomes are also regulated by differences in baseline activity of the stimulated network BACKGROUND We tested whether transcranial magnetic stimulation ( TMS ) over the left dorsolateral prefrontal cortex ( DLPFC ) is effective and safe in the acute treatment of major depression . METHODS In a double-blind , multisite study , 301 medication-free patients with major depression who had not benefited from prior treatment were r and omized to active  ( n = 155 ) or  sham TMS  ( n = 146 ) conditions . Sessions were conducted five times per week with TMS at 10 pulses/sec , 120 % of motor threshold , 3000 pulses/session , for 4 - 6 weeks . Primary outcome was the symptom score change as assessed at week 4 with the Montgomery-Asberg Depression Rating Scale ( MADRS ) . Secondary outcomes included changes on the 17- and 24-item Hamilton Depression Rating Scale ( HAMD ) and response and remission rates with the MADRS and HAMD . RESULTS Active TMS was significantly superior to sham TMS on the MADRS at week 4 ( with a post hoc correction for ine quality in symptom severity between groups at baseline ) , as well as on the HAMD17 and HAMD24 scales at weeks 4 and 6 . Response rates were significantly higher with active TMS on all three scales at weeks 4 and 6 . Remission rates were approximately twofold higher with active TMS at week 6 and significant on the MADRS and HAMD24 scales ( but not the HAMD17 scale ) . Active TMS was well tolerated with a low dropout rate for adverse events ( 4.5 % ) that were generally mild and limited to transient scalp discomfort or pain . CONCLUSIONS Transcranial magnetic stimulation was effective in treating major depression with minimal side effects reported . It offers clinicians a novel alternative for the treatment of this disorder BACKGROUND We compared transcranial direct‐current stimulation ( tDCS ) with a selective serotonin‐reuptake inhibitor for the treatment of depression . METHODS In a single‐center , double‐blind , noninferiority trial involving adults with unipolar depression , we r and omly assigned patients to receive tDCS plus oral placebo , sham tDCS plus escitalopram , or sham tDCS plus oral placebo . The tDCS was administered in 30‐minute , 2‐mA prefrontal stimulation sessions for 15 consecutive weekdays , followed by 7 weekly treatments . Escitalopram was given at a dose of 10 mg per day for 3 weeks and 20 mg per day thereafter . The primary outcome measure was the change in the 17‐item Hamilton Depression Rating Scale ( HDRS‐17 ) score ( range , 0 to 52 , with higher scores indicating more depression ) . Noninferiority of tDCS versus escitalopram was defined by a lower boundary of the confidence interval for the difference in the decreased score that was at least 50 % of the difference in the scores with placebo versus escitalopram . RESULTS A total of 245 patients underwent r and 
    Output:
    
HighlightsIt remains unclear whether tDCS treatment has cognitive benefits in depression .
Results showed no cognitive enhancement  after active tDCS compared to sham for the 12 cognitive outcomes investigated .
Active tDCS treatment for depression did not show cognitive benefits independent of mood effects .
Rather , tDCS treatment relative to sham stimulation for major depression may instead be associated with a reduced practice effect for processing speed