Noninvasive brain stimulation in psychiatric disorders: a primer

Objective: Noninvasive brain stimulation (NIBS) techniques, such as transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS), are increasingly being used to treat mental disorders, particularly major depression. The aim of this comprehensive review is to summarize the main advances, limitations, and perspectives of the field. Methods: We searched PubMed and other databases from inception to July 2017 for articles, particularly systematic reviews and meta-analyses, evaluating the use of NIBS in psychiatric disorders. Results: We reviewed the mechanisms of action, safety, tolerability, efficacy, and relevant clinical parameters of NIBS. Repetitive TMS is already an established technique for the treatment of depression, and there is theoretically room for further methodological development towards a high-end therapeutic intervention. In contrast, tDCS is a technically easier method and therefore potentially suitable for wider clinical use. However the evidence of its antidepressant efficacy is less sound, and a recent study found tDCS to be inferior to antidepressant pharmacotherapy. Clinical trials using rTMS for other mental disorders produced mixed findings, whereas tDCS use has not been sufficiently appraised. Conclusion: The most promising results of NIBS have been obtained for depression. These techniques excel in safety and tolerability, although their efficacy still warrants improvement.

The Escitalopram versus Electric Current Therapy for Treating Depression Clinical Study (ELECT-TDCS): rationale and study design of a non-inferiority, triple-arm, placebo-controlled clinical trial / Estudo clínico Escitalopram versus Eletroterapia no Tratamento da Depressão (ELECT-TDCS): racional e desenho de estudo de um ensaio de não inferioridade, de três braços, placebo-controlado

CONTEXT AND OBJECTIVE: Major depressive disorder (MDD) is a common psychiatric condition, mostly treated with antidepressant drugs, which are limited due to refractoriness and adverse effects. We describe the study rationale and design of ELECT-TDCS (Escitalopram versus Electric Current Therapy for Treating Depression Clinical Study), which is investigating a non-pharmacological treatment known as transcranial direct current stimulation (tDCS). DESIGN AND SETTING: Phase-III, randomized, non-inferiority, triple-arm, placebo-controlled study, ongoing in São Paulo, Brazil. METHODS: ELECT-TDCS compares the efficacy of active tDCS/placebo pill, sham tDCS/escitalopram 20 mg/day and sham tDCS/placebo pill, for ten weeks, randomizing 240 patients in a 3:3:2 ratio, respectively. Our primary aim is to show that tDCS is not inferior to escitalopram with a non-inferiority margin of at least 50% of the escitalopram effect, in relation to placebo. As secondary aims, we investigate several biomarkers such as genetic polymorphisms, neurotrophin serum markers, motor cortical excitability, heart rate variability and neuroimaging. RESULTS: Proving that tDCS is similarly effective to antidepressants would have a tremendous impact on clinical psychiatry, since tDCS is virtually devoid of adverse effects. Its ease of use, portability and low price are further compelling characteristics for its use in primary and secondary healthcare. Multimodal investigation of biomarkers will also contribute towards understanding the antidepressant mechanisms of action of tDCS. CONCLUSION: Our results have the potential to introduce a novel technique to the therapeutic arsenal of treatments for depression. .

CONTEXTO E OBJETIVO: O transtorno depressivo maior (TDM) é uma condição psiquiátrica comum, tratada com medicamentos antidepressivos, os quais são limitados devido à refratariedade e efeitos adversos. Descrevemos o racional e o desenho do Estudo Clínico Escitalopram versus Eletroterapia no Tratamento da Depressão (ELECT-TDCS), que investiga um tratamento não farmacológico, conhecido como estimulação transcraniana por corrente contínua (ETCC). DESENHO E LOCAL: Ensaio de fase III, randomizado, de não inferioridade, de três braços, placebo-controlado, em execução em São Paulo, Brasil. MÉTODOS: O estudo compara a eficácia da ETCC ativa/pílula placebo, ETCC simulada/escitalopram 20 mg/dia e ETCC simulada/pílula placebo durante 10 semanas, randomizando 240 pacientes em uma proporção 3:3:2, respectivamente. O objetivo principal é demostrar que a ETCC não é inferior ao escitalopram com uma margem de não inferioridade de pelo menos 50% do efeito de escitalopram em relação ao placebo. Como objetivos secundários, investigamos biomarcadores como polimorfismos genéticos, marcadores séricos, excitabilidade cortical motora, variabilidade da frequência cardíaca e neuroimagem. RESULTADOS: Provar que ETCC é igualmente eficaz a antidepressivos teria um tremendo impacto na psiquiatria clínica, uma vez que a ETCC é praticamente isenta de efeitos adversos. Sua facilidade de uso, portabilidade e preço baixo são outras características atraentes para uso na atenção primária e secundária de saúde. A investigação multimodal de biomarcadores também contribuirá para a compreensão dos mecanismos de ação antidepressivos da ETCC. CONCLUSÃO: Os nossos resultados podem introduzir uma nova técnica no arsenal terapêutico do tratamento da depressão. .