Treatment of depression in the elderly with repetitive transcranial magnetic stimulation using theta-burst stimulation: Study protocol for a randomized, double-blind, controlled trial.

Introduction: Transcranial magnetic stimulation (TMS) is a consolidated procedure for the treatment of depression, with several meta-analyses demonstrating its efficacy. Theta-burst stimulation (TBS) is a modification of TMS with similar efficacy and shorter session duration. The geriatric population has many comorbidities and a high prevalence of depression, but few clinical trials are conducted specifically for this age group. TBS could be an option in this population, offering the advantages of few side effects and no pharmacological interactions. Therefore, our aim is to investigate the efficacy of TBS in geriatric depression. Clinical trial registration: [https://clinicaltrials.gov/ct2/], identifier [NCT04842929].

Association between tDCS computational modeling and clinical outcomes in depression: data from the ELECT-TDCS trial.

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation intervention investigated for the treatment of depression. Clinical results have been heterogeneous, partly due to the variability of electric field (EF) strength in the brain owing to interindividual differences in head anatomy. Therefore, we investigated whether EF strength was correlated with behavioral changes in 16 depressed patients using simulated electric fields in real patient data from a controlled clinical trial. We hypothesized that EF strength in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC), brain regions implicated in depression pathophysiology, would be associated with changes in depression, mood and anxiety scores. SimNIBS were used to simulate individual electric fields based on the MRI structural T1-weighted brain scans of depressed subjects. Linear regression models showed, at the end of the acute treatment phase, that simulated EF strength was inversely associated with negative affect in the bilateral ACC (left: ß = - 160.463, CI [- 291.541, - 29.385], p = 0.021; right: ß = - 189.194, CI [- 289.479, - 88.910], p = 0.001) and DLPFC (left: ß = - 93.210, CI [- 154.960, - 31.461], p = 0.006; right: ß = - 82.564, CI [- 142.867, - 22.262], p = 0.011) and with depression scores in the left ACC (ß = - 156.91, CI [- 298.51, - 15.30], p = 0.033). No association between positive affect or anxiety scores, and simulated EF strength in the investigated brain regions was found. To conclude, our findings show preliminary evidence that EF strength simulations might be associated with further behavioral changes in depressed patients, unveiling a potential mechanism of action for tDCS. Further studies should investigate whether individualization of EF strength in key brain regions impact clinical response.

The Flow brain stimulation headset for the treatment of depression: overview of its safety, efficacy and portable design.

INTRODUCTION: Major depressive disorder (MDD) is a prevalent and debilitating condition. First-line treatments include antidepressants and cognitive-behavioral psychotherapy (CBT). However, several patients present treatment-resistance and/or adverse effects. Transcranial direct current stimulation (tDCS), a noninvasive neuromodulation technique, is an effective alternative for MDD. AREAS COVERED: We hereby review a portable tDCS device designed to be combined with a cognitive-behavioral intervention. This home-use device was developed by Flow Neuroscience™ and was recently approved in the UK and European Union. We discuss present evidence on tDCS efficacy and safety, both as a monotherapy and as a combined treatment. Moreover, we show a computer modeling tDCS procedure based on Flow parameters and montage. EXPERT OPINION: Electric field simulations revealed that Flow's tDCS device targets prefrontal cortical areas involved in MDD pathophysiology. In addition, the safety and efficacy profile revealed from prior tDCS studies support its use in depression. Finally, combining tDCS with cognitive-behavioral interventions might further enhance overall efficacy, although this aspect should be investigated in upcoming randomized, placebo-controlled trials.

Non-invasive brain stimulation therapies / Terapias de neuroestimulação não invasivas

Noninvasive brain stimulation therapies are a promising field for the development of new protocols for the treatment of neuropsychiatric disorders. They are based on the stimulation of neural networks with the intent of modeling their synaptic activity to adequate levels. For this, it is necessary to precisely determine which networks are related to which brain functions, and the normal activation level of each of these networks, so that it is possible to direct the stimulation to the affected networks in order to induce the desired effects. These relationships are under intense investigation by the scientific community, and will contribute to the advancement of treatments by neurostimulation, with the emergence of increasingly accurate and effective protocols for different disorders. Currently, the most used techniques are Transcranial Direct Current Stimulation and Transcranial Magnetic Stimulation, with the most common applications being for treating Major Depressive Disorder. The advancement of research in this field may determine new target networks for stimulation in the treatment of other disorders, extending the application of these techniques and also our knowledge about brain functioning.

As terapias biológicas não invasivas se apresentam como um campo promissor para o desenvolvimento de novos protocolos de tratamento de transtornos neuropsiquiátricos. Elas se baseiam na estimulação de redes neurais com intuito de modular sua atividade sináptica para níveis adequados. Para isso, é necessário a determinação precisa de quais redes estão relacionadas a quais funções cerebrais, e do nível de ativação normal de cada uma dessas redes, para que então seja possível direcionar a estimulação às redes afetadas a fim de induzir os efeitos desejados. Essas relações estão sob intensa investigação pela comunidade científica, e vão contribuir para o avanço dos tratamentos por neuroestimulação, com o surgimento de protocolos cada vez mais precisos e efetivos para diferentes transtornos. Atualmente, as técnicas mais utilizadas são a Estimulação Transcraniana por Corrente Contínua e a Estimulação Magnética Transcraniana, sendo a aplicação mais comum no tratamento do Transtorno Depressivo Maior. O avanço das pesquisas possivelmente determinará novas redes alvo para estimulação no tratamento de outros transtornos, estendendo a aplicação dessas técnicas e também do nosso conhecimento sobre o funcionamento cerebral.