Several studies showed that transcranial direct current stimulation (tDCS) enhances cognition in patients with mild cognitive impairment (MCI), however, whether tDCS leads to additional gains when combined with cognitive training remains unclear. This study aims to compare the effects of a concurrent tDCS-cognitive training intervention with either tDCS or cognitive training alone on a group of patients with MCI.

The study was a 3-parallel-arm study. The intervention consisted of 20 daily sessions of 20 minutes each. Patients (n = 62) received anodal tDCS to the left dorsolateral prefrontal cortex, cognitive training on 5 cognitive domains (orientation, attention, memory, language, and executive functions), or both. To examine intervention gains, we examined global cognitive functioning, verbal short-term memory, visuospatial memory, and verbal fluency pre- and post-intervention.

All outcome measures improved after the intervention in the 3 groups. The improvement in global cognitive functioning and verbal fluency was significantly larger in patients who received the combined intervention. Instead, the intervention gain in verbal short-term memory and visuospatial memory was similar across the 3 groups.

tDCS, regardless of the practicalities, could be an efficacious treatment in combination with cognitive training given the increased effectiveness of the combined treatment.

Future studies will need to consider individual differences at baseline, including genetic factors and anatomical differences that impact the electric field generated by tDCS and should also consider the feasibility of at-home treatments consisting of the application of tDCS with cognitive training.

DSM-5 defines non-suicidal self-injury (NSSI) as socially unaccepted, direct, repeated and deliberate harm done to one’s own body. It is estimated that in a general population approximately 13-29% of adolescents present NSSI, and 70-80% among hospitalized youth. It seems that emotional dysregulation is the core characteristic of NSSI manifesting by self-harm behaviors, impulsiveness, lack of emotional awareness and experiencing high intensity of negative emotion. Emotional dysregulation is a pivotal characteristic of NSSI. Rationale of this theory is provided by the results of psychological and psychophysiological studies as well as those presenting brain activity. Neuroimaging data point to a variant pattern of brain activity of adolescents with NSSI during perception of emotionally negative stimuli i.e. hyperactivity in amygdala – a structure responsible for fear and automatic reaction to exciting stimuli and low activity of inferior frontal gyrus area – a structure responsible for inhibition and interpretation of social interactions. This activity pattern suggests a disorder of cortico-subcortical neuronal connections.

The aim was to verify tDCS as a therapeutic aid for patients who exhibit NSSI despite implementation of pharmacotherapy and psychotherapy.

We investigated the modulation effect of tDCS treatment at the right inferior frontal gyrus (rIFG) in hospitalized adolescents with NSSI.

Preliminary tDCS stimulation results indicate potential usefulness of this method in regulating emotions and improving executive functions.

Prefrontal cortex stimulation may restore balance in aforementioned connections and, as a result, positively influence an emotional regulation i.e. lower the impulsiveness, agitation and, by doing so, decrease NSSI frequency.

No significant relationships.

Patients with OCD often show unsatisfactory response to first-line treatment, giving rise to a need for novel therapeutic approaches. Recent studies using tDCS for OCD treatment have shown promise.

To assess efficacy and safety of add-on c-tDCS over pre-SMA compared to sham stimulation in patients with OCD.

In this double-blinded study, fourteen patients with OCD were randomized to receive 10 sessions of either active (Cathode over pre-SMA, anode over right deltoid, 2mA, 20 minutes per session, 2 sessions per day, 2 hours apart) or sham tDCS. YBOCS, HAM-D, HAM-A, CGI, Wisconsin Card Sorting Test (WCST), and Stroop Test were administered at baseline, post-tDCS, and 1 month post-tDCS.

Group×time interaction effect for YBOCS scores with Repeated Measures ANOVA was not statistically significant, however, reduction in scores in active group was higher, with large effect size (YBOCS scores: Obsessions-ηp2=.344, Compulsions-ηp2= .384, Total-ηp2=.392) (Fig.1 & 2). At 1 month, 42.9% patients in active group and none in sham group showed response. CGI-S score (p=0.016, ηp2=.531) (Fig. 3) and four parameters of WCST (Perseverative responses:p=0.038, ηp2=.448;Percent perseverative responses:p=0.026, ηp2=.485;Percent perseverative errors:p=0.038, ηp2=.447;Trials to complete first category:p=0.011, ηp2=.563) significantly reduced in active group. No significant difference in change in depressive and anxiety symptoms between groups, or change in Stroop Test performance was noted. Adverse effects included transient headache and tingling sensation.

Cathodal tDCS over pre-SMA may be effective in reduction of obsessions, compulsions, illness severity, and enhancing cognitive flexibility in patients with OCD, with no major adverse effects. Larger studies are required to confirm these findings.

No significant relationships.

Transcranial direct current stimulation (tDCS) could be a side-effect-free alternative to psychostimulants in attention-deficit/hyperactivity disorder (ADHD). Although there is limited evidence for clinical and cognitive effects, most studies were small, single-session and stimulated left dorsolateral prefrontal cortex (dlPFC). No sham-controlled study has stimulated the right inferior frontal cortex (rIFC), which is the most consistently under-functioning region in ADHD, with multiple anodal-tDCS sessions combined with cognitive training (CT) to enhance effects. Thus, we investigated the clinical and cognitive effects of multi-session anodal-tDCS over rIFC combined with CT in double-blind, randomised, sham-controlled trial (RCT, ISRCTN48265228).

Fifty boys with ADHD (10–18 years) received 15 weekday sessions of anodal- or sham-tDCS over rIFC combined with CT (20 min, 1 mA). ANCOVA, adjusting for baseline measures, age and medication status, tested group differences in clinical and ADHD-relevant executive functions at posttreatment and after 6 months.

ADHD-Rating Scale, Conners ADHD Index and adverse effects were significantly lower at post-treatment after sham relative to anodal tDCS. No other effects were significant.

This rigorous and largest RCT of tDCS in adolescent boys with ADHD found no evidence of improved ADHD symptoms or cognitive performance following multi-session anodal tDCS over rIFC combined with CT. These findings extend limited meta-analytic evidence of cognitive and clinical effects in ADHD after 1–5 tDCS sessions over mainly left dlPFC. Given that tDCS is commercially and clinically available, the findings are important as they suggest that rIFC stimulation may not be indicated as a neurotherapy for cognitive or clinical remediation for ADHD.

Previous studies have examined the effect of transcranial direct current stimulation (tDCS) on the in-vivo concentrations of neuro-metabolites assessed through magnetic resonance spectroscopy (MRS) in neurological and psychiatry disorders. This review aims to systematically evaluate the data on the effect of tDCS on MRS findings and thereby attempt to understand the potential mechanism of tDCS on neuro-metabolites.

The relevant literature was obtained through PubMed and cross-reference (search till June 2020). Thirty-four studies were reviewed, of which 22 reported results from healthy controls and 12 were from patients with neurological and psychiatric disorders.

The evidence converges to highlight that tDCS modulates the neuro-metabolite levels at the site of stimulation, which, in turn, translates into alterations in the behavioural outcome. It also shows that the baseline level of these neuro-metabolites can, to a certain extent, predict the outcome after tDCS. However, even though tDCS has shown promising effects in alleviating symptoms of various psychiatric disorders, there are limited studies that have reported the effect of tDCS on neuro-metabolite levels.

There is a compelling need for more systematic studies examining patients with psychiatric/neurological disorders with larger samples and harmonised tDCS protocols. More studies will potentially help us to understand the tDCS mechanism of action pertinent to neuro-metabolite levels modulation. Further, studies should be conducted in psychiatric patients to understand the neurological changes in this population and potentially unravel the neuro-metabolite × tDCS interaction effect that can be translated into individualised treatment.

Les addictions comportementales (AC), ou addictions sans drogues, ont en commun la perte de contrôle sur le comportement et la poursuite de ce comportement malgré les dommages. Les principales AC sont : le jeu pathologique, l’addiction sexuelle, l’exercice physique excessif, les achats compulsifs et certains troubles du comportement alimentaire. Associées à des comorbidités psychiatriques et addictives, à des conséquences sociales, leur prise en charge repose essentiellement sur des psychothérapies et des mesures sociales. L’utilisation des techniques de stimulation cérébrale est encore relativement récente, notamment dans le champ des addictions. La tDCS a principalement été testée dans les addictions avec substances, mais très peu dans les AC. Cette revue de la littérature a pour objectif de faire une mise au point méthodologique et clinique sur les premiers travaux couvrant cette question.

Une recherche bibliographique a été réalisée sur Pubmed et ScienceDirect, jusqu’au 30 juillet 2014. Les critères d’inclusion étaient : articles de revue, articles didactiques, essais thérapeutiques, études physiopathologiques.

Quatorze revues et études ont été retenues. Elles portent sur les troubles du comportement alimentaire, l’obésité, et les processus décisionnels et de prise de risque. Les études cliniques ont montré l’intérêt de la tDCS bilatérale dans la diminution de la prise de risque, et du craving alimentaire. La tDCS présente des avantages prometteurs dans le traitement des AC. Non invasive, bien tolérée, avec un dispositif portable, peu coûteuse comparée à la TMS, elle pourrait être dispensée dans un cadre ambulatoire.

Auditory hallucinations are resistant to pharmacotherapy in about 25% of adults with schizophrenia. Treatment with noninvasive brain stimulation would provide a welcomed additional tool for the clinical management of auditory hallucinations. A recent study found a significant reduction in auditory hallucinations in people with schizophrenia after five days of twice-daily transcranial direct current stimulation (tDCS) that simultaneously targeted left dorsolateral prefrontal cortex and left temporo-parietal cortex.

We hypothesized that once-daily tDCS with stimulation electrodes over left frontal and temporo-parietal areas reduces auditory hallucinations in patients with schizophrenia.

We performed a randomized, double-blind, sham-controlled study that evaluated five days of daily tDCS of the same cortical targets in 26 outpatients with schizophrenia and schizoaffective disorder with auditory hallucinations.

We found a significant reduction in auditory hallucinations measured by the Auditory Hallucination Rating Scale (F2,50 = 12.22, P < 0.0001) that was not specific to the treatment group (F2,48 = 0.43, P = 0.65). No significant change of overall schizophrenia symptom severity measured by the Positive and Negative Syndrome Scale was observed.

The lack of efficacy of tDCS for treatment of auditory hallucinations and the pronounced response in the sham-treated group in this study contrasts with the previous finding and demonstrates the need for further optimization and evaluation of noninvasive brain stimulation strategies. In particular, higher cumulative doses and higher treatment frequencies of tDCS together with strategies to reduce placebo responses should be investigated. Additionally, consideration of more targeted stimulation to engage specific deficits in temporal organization of brain activity in patients with auditory hallucinations may be warranted.

Aphasia recovery depends on neural reorganization, which can be enhanced by speech-language therapy and noninvasive brain stimulation. Several studies suggested that transcranial direct current stimulation (tDCS) associated with speech-language therapy may improve verbal performance evaluated by analytic tests, but none focused on spontaneous speech. We explored the effect of bihemispheric tDCS on spontaneous speech in patients with poststroke aphasia.

In this multicentric controlled randomized cross-over double-blind study, we included 10 patients with poststroke aphasia (4 had aphasia >6 months and 6 with aphasia <6 months). We combined the sessions of speech-language therapy and bihemispheric tDCS (2 mA, 20 min). After three baseline speech evaluations (1/week), two different conditions were randomly consecutively proposed: active and sham tDCS over 3 weeks with 1 week of washout in between. The main outcome measure was the number of different nouns used in 2 min to answer the question “what is your job.”

There was no significant difference between conditions concerning the main outcome measure (p = .47) nor in the number of verbs, adjectives, adverbs, pronouns, repetitions, blank ideas, ideas, utterances with grammatical errors or paraphasias used. Other cognitive functions (verbal working memory, neglect, or verbal fluency) were not significantly improved in the tDCS group. No adverse events occurred.

Our results differed from previous studies using tDCS to improve naming in patients with poststroke aphasia possibly due to bihemispheric stimulation, rarely used previously. The duration of the rehabilitation period was short given the linguistic complexity of the measure. This negative result should be confirmed by larger studies with ecological measures.

Current treatments for smoking cessation are not effective for most smokers. This study aims to examine the effectiveness of transcranial Direct Current Stimulation (tDCS) on smoking cessation.

In this randomized, sham-controlled trial study, tobacco-dependent (by DSM-5) male participants were recruited from the general public invitation. Participants were randomly allocated to 5 groups; (A), treatment with 300mg bupropion for 8 weeks; (B), active tDCS (20 sessions for 4 weeks); (C), sham for group B ; (D), active tDCS (20 sessions for 12 weeks), and (E), sham for group D. The electrode montage was anode F3 and cathode F4. Study outcomes include salivary cotinine, Fagerstrom test for nicotine dependence, and smoked cigarette per day, were examined on three time points. Repeated-measures analysis of variances and the generalized estimation equation (GEE) model were employed for data analysis.

Among 210 volunteers, 170 participants completed the study. Mean age of participants was 42.9 years, ranging from 21 to 64 years. The 6-month point abstinence rates in groups A, B and D were 20%, 7% and 25.7%, and in C, D sham groups were 3.1% and 3% respectively. Results of the GEE model showed that although group D was not different from group A in abstinence rate, i.e., salivary cotinine >4 (p = 0.266), nicotine dependency by Fagerstrom test was lower in this group compared to group A (p = 0.019).

The 12-week tDCS had a clinically good therapeutic effect on smoking cessation and its dependency. It may be a substitute for bupropion treatment.

Obsessive-compulsive disorder (OCD) is a severe mental disorder with poor response to the available treatments. Neuroimaging studies have identified dysfunctions within the orbito-fronto-striato-pallido-thalamic network in patients with OCD. Here, we assessed the efficacy and safety of transcranial direct current stimulation (tDCS) applied with the cathode over the orbitofrontal cortex (OFC) and the anode over the right cerebellum to decrease OCD symptoms in patients with treatment-resistant OCD.

In a randomized sham-controlled double-blind study, 21 patients with OCD were assigned to receive ten 20-min sessions (two sessions per day) of either active (2 mA) or sham tDCS. The clinical symptoms were measured using the Yale-Brown Obsessive and Compulsive Scale (YBOCS). Acute effects on the symptoms were measured from baseline to immediately after the 10 tDCS sessions. Long-lasting effects were measured 1 and 3 months after the 10th tDCS session.

Compared with the sham tDCS, active tDCS significantly decreased OCD symptoms immediately after the 10th tDCS session (F(1,19) = 5.26, p = 0.03). However, no significant differences were observed between the active and sham groups in terms of changes in YBOCS score or the number of responders one and 3 months after tDCS.

Despite significant acute effects, tDCS with the cathode placed over the left OFC and the anode placed over the right cerebellum was not significantly effective in inducing a long-lasting reduction of symptoms in patients with treatment-resistant OCD.

Findings from single-session online studies highlighted the potential of using anodal prefrontal transcranial direct current stimulation (tDCS) to enhance executive functions (EF) in the context of aging. However, tDCS must be executed as a multi-session offline intervention to ascertain its viability in this context. Relatedly, findings from multi-session studies remained inconclusive. To this end, we examined the effects of multi-session anodal prefrontal tDCS on EF in an intervention.

The intervention consisted of 15 sessions; in each, healthy older participants (Agemean = 66.7) received either 15 min of 1.5 mA tDCS (Ncompleted = 35) or sham stimulation (Ncompleted = 33) while performing EF training tasks. EF measures were assessed at baseline, post-intervention, and 1-month follow-up. Hierarchical linear models were used to examine the effect of tDCS on EF outcomes.

Both groups of participants did not differ significantly in side effect ratings and attendance. There were no significant tDCS-associated gains in any EF outcomes in the intervention.

Multi-session prefrontal tDCS did not lead to any significant gains in EF in the current intervention. More research is needed to optimize the use of tDCS before it can be effectively used to enhance EF among older adults.

Recent observations demonstrate a significant ameliorative effect of add-on transcranial direct current stimulation (tDCS) on auditory verbal hallucinations (AVHs) in schizophrenia. Of the many SNPs, NRG1 rs35753505 and catechol-o-methyl transferase (COMT) rs4680 polymorphisms have shown to have a strong association with neuroplasticity effect in schizophrenia.

Schizophrenia patients (n=32) with treatment resistant auditory hallucinations were administered with an add-on tDCS. The COMT (rs4680) and NRG1 (rs35753505) genotypes were determined. The COMT genotypes were categorised into Val group (GG; n=15) and Met group (GG/AG; n=17) and NRG1 genotypes were categorised into AA group (n=12) and AG/GG group (n=20).

The reduction in auditory hallucination sub-scale score was significantly affected by COMT-GG genotype [Time×COMT interaction: F(1,28)=10.55, p=0.003, ɳ2=0.27]. Further, COMT-GG effect was epistatically influenced by the co-occurrence of NRG1-AA genotype [Time×COMT×NRG1 interaction: F(1,28)=8.09, p=0.008, ɳ2=0.22]. Irrespective of genotype, females showed better tDCS response than males [Time×Sex interaction: F(1,21)=4.67, p=0.04, ɳ2=0.18].

COMT-GG and NRG1-AA genotypes aid the tDCS-induced improvement in AVHs in schizophrenia patients. Our preliminary observations need replication and further systematic research to understand the neuroplastic gene determinants that modulate the effect of tDCS.