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Obsessive-compulsive (OC) disorder is a disabling disorder resulting in tremendous individual and social burden. It has a large overlap with depression and anxiety disorders and shows treatment resistance in a relevant proportion of patients. Since a couple of years, different noninvasive brain stimulation methods have been investigated to improve OC symptoms. The application of transcranial direct current stimulation (tDCS) has shown inconsistent results which can probably be attributed to a lack in randomized controlled trials with adequate sample size. Anodal stimulation of pre-supplementary motor areas has shown promising results, and there is also sparse data on orbitofrontal and prefrontal stimulation. Here, we provide the first report on a patient with treatment-refractory OC disorder treated with sertraline and an enhanced prefrontal tDCS protocol (twice per day, 10 days) with a classic left-anodal/right cathodal montage, experiencing a 22% reduction of OC symptoms as well as reduction in depression (-10%) and anxiety symptoms (-21%). Due to multifactorial origin of OC disorder and the variety of brain circuits involved, there are probably multiple approaches for brain stimulation regarding site, polarity, and frequency to be assessed in future studies.

Major Depressive Disorder (MDD) is one of the most prevalent psychiatric disorders worldwide. About 20-30% of patients do not respond to the standard psychopharmacological and/or psychotherapeutic interventions. Mounting evidence from neuroimaging studies in MDD patients reveal altered activation patterns in lateral prefrontal brain areas. Successful cognitive behavioral therapy (CBT) is associated with a recovery of these neural alterations. Moreover, it has been demonstrated that transcranial direct current stimulation (tDCS) is capable of influencing prefrontal cortex activity and cognitive functions such as working memory and emotion regulation. Thus, a clinical trial investigating the effects of an antidepressant intervention combining CBT with tDCS seems promising. The present study investigates the antidepressant efficacy of a combined CBT-tDCS intervention as compared to CBT with sham-tDCS or CBT alone. A total of 192 patients (age range 20-65 years) with MDD (Hamilton Depression Rating Scale Score ≥ 15, 21-item version) will be recruited at four study sites across Germany (Berlin, Munich, Tuebingen, and Freiburg) and randomly assigned to one of the following three treatment arms: (1) CBT + active tDCS; (2) CBT + sham-tDCS; and (3) CBT alone. All participants will attend a 6-week psychotherapeutic intervention comprising 12 sessions of CBT each lasting 100 min in a closed group setting. tDCS will be applied simultaneously with CBT. Active tDCS includes stimulation with an intensity of 2 mA for 30 min with the anode placed over F3 and the cathode over F4 according to the EEG 10-20 system, if assigned. The primary outcome measure is the change in Montgomery-Åsberg Depression Rating Scale scores from baseline to 6, 18, and 30 weeks after the first session. Participants also undergo pre- and post-treatment neuropsychological testing and functional magnetic resonance imaging (fMRI) to assess changes in prefrontal functioning and connectivity. The study investigates whether CBT can be augmented by non-invasive brain stimulation techniques such as tDCS in the treatment of MDD. It is designed as a proof-of-principle trial for the combined tDCS-CBT treatment, but also allows the investigation of the neurobiological underpinnings of the interaction between both interventions in MDD. Trial registration ClinicalTrials.gov Identifier NCT02633449.

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Introduction: Current pathophysiological hypotheses of Gilles de la Tourette Syndrome (GTS) refer to temporally abnormal neuronal activation in cortico-striato-thalamo-cortical (CSTC) networks. Modifying cortical activity by non-invasive brain-stimulation appears to be a new treatment option in GTS.Background: Previous studies suggested therapeutic effects of cathodal transcranial direct current stimulation (tDCS) to pre-supplementary motor areas (SMA), however, treatment modalities concerning electrode placement, current intensity and stimulation-rate have not been systematically explored. Aim of this study was to assess efficacy of an alternative stimulation regime on GTS symptoms in a pilot study. To test a treatment protocol with tDCS twice a day, we administered 10 sessions over 5 days of bilateral cathodal tDCS (30 min, 2 mA) over the pre-SMA in three patients with severe GTS. Tic severity as well as obsessive-compulsive (OC) symptoms and affective scales were rated before and after tDCS treatment.Discussion: Only one out of three patients showed a 34.5% reduction in tic severity. The two other patients showed an increase in tic severity. All patients showed a mild increase in positive affect and a reduction in negative affect, OC symptom changes were heterogeneous. Our results do not support earlier findings of extensive therapeutic effects of cathodal tDCS on tics in patients with GTS and show that prediction of stimulation effects on a targeted brain area remains inaccurate.Concluding Remarks: Future research will have to focus on the determination of most effective stimulation modes regarding site, polarity and frequency of tDCS in GTS patients.