tDCS in Depression Treatment: How Effective is it Compared to Placebo?

Author Names

Paulo S. Boggio, Sergio P. Rigonatti, Rafael B. Ribeiro, Martin L. Myczkowski, Michael A. Nitsche, Alvaro Pascual-Leone and Felipe Fregni

Published Date: June 2007

Journal Name: International Journal of Neuropsychopharmacology

Abstract

This study evaluates the efficacy of transcranial direct current stimulation (tDCS) in treating major depression through a randomized, double-blind, placebo-controlled clinical trial. Forty medication-free patients with major depressive disorder were randomized into three groups: active tDCS targeting the left dorsolateral prefrontal cortex (DLPFC), active tDCS targeting the occipital cortex (as a control), and sham tDCS. The study found significant reductions in depression scores for the DLPFC group compared to the other groups, with effects lasting for at least one month post-treatment. The findings suggest that tDCS targeting the DLPFC may be an effective treatment for major depression.

Key Concepts

• Transcranial Direct Current Stimulation (tDCS): A non-invasive brain stimulation technique that uses a low-intensity electrical current to modulate neuronal activity and potentially alleviate depressive symptoms.

• Major Depressive Disorder (MDD): A mental health condition characterized by persistent sadness, loss of interest, and impaired daily functioning.

• Sham-Controlled Trials: Research design in which a placebo treatment is used to evaluate the efficacy of an active treatment, ensuring that the effects are due to the intervention itself.

• Literature Review: Previous studies on tDCS have shown promise in treating depression but with varying results. This study seeks to clarify the effectiveness by comparing active tDCS with both an active control and sham treatment.

Procedure Highlights - Research Methodology

1. Study Design: A double-blind, randomized, sham-controlled clinical trial with a follow-up phase.

2. Participants: 40 adults with major depressive disorder, all medication-free, randomly assigned to one of three groups: active DLPFC tDCS, active occipital tDCS, or sham tDCS.

3. tDCS Protocol: Active tDCS groups received 10 sessions of 2 mA stimulation over 20 minutes during 2 weeks. The DLPFC group received stimulation targeting the left dorsolateral prefrontal cortex, while the occipital group received stimulation over the occipital cortex. The sham group received a placebo treatment mimicking the active procedure without delivering significant current.

4. Outcome Measures: Depression severity was assessed using the Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI) at baseline, immediately after treatment, 15 days, and 30 days post-treatment.

Results - Findings of the Research

• Mood Improvement: The DLPFC tDCS group showed a significant reduction in HDRS scores by 40.4% compared to a 21.3% reduction in the occipital group and a 10.4% reduction in the sham group. These effects were sustained for 30 days post-treatment.

• Responder and Remission Rates: The DLPFC group had 8 responders (50% reduction in HDRS) and 5 patients achieving remission (HDRS ≤ 7), compared to 2 responders and no remissions in the sham group, and no responders in the occipital group.

• Adverse Effects: Minimal side effects were reported, including mild transient headaches, itching at the stimulation site, and mild skin redness. These side effects were evenly distributed across the groups and resolved shortly after the sessions.

Discussion and Conclusion of the Research

The study demonstrates that tDCS targeting the DLPFC is an effective treatment for major depression, with significant and sustained reductions in depression scores compared to both an active control and sham treatment. The results support the potential of tDCS as a non-invasive, cost-effective treatment option for depression. The study also suggests that further research should explore different stimulation parameters, the combination of tDCS with other therapies, and its application in diverse populations.

Link to the Original Paper

A randomized, double-blind clinical trial on the efficacy of cortical direct current stimulation for the treatment of major depression

Author Information

• Paulo S. Boggio: Núcleo de Neurociências, Centro de Ciências Biológicas e da Saúde, Universidade Presbiteriana Mackenzie, Sao Paulo, Brazil

• Sergio P. Rigonatti: Department of Psychiatry, University of Sao Paulo, Sao Paulo, Brazil

• Rafael B. Ribeiro: Department of Psychiatry, University of Sao Paulo, Sao Paulo, Brazil

• Martin L. Myczkowski: Department of Psychiatry, University of Sao Paulo, Sao Paulo, Brazil

• Michael A. Nitsche: Department of Clinical Neurophysiology, Georg-August-University, Goettingen, Germany

• Alvaro Pascual-Leone: Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA

• Felipe Fregni: Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA

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