tDCS & Mindfulness: Anxiety Reduction in a Double-Blind Study

Author Names

Keiichiro Nishida, Yosuke Morishima, Roberto D. Pascual-Marqui, Shota Minami, Tomonari Yamane, Masahito Michikura, Hideki Ishikawa and Toshihiko Kinoshita

Published Date: November 2021

Journal Name: Scientific Reports

Abstract

This study explores whether combining transcranial direct current stimulation (tDCS) with mindfulness-based therapy can effectively reduce anxiety. In a double-blind, randomized study, 58 healthy adults were assigned to either active tDCS or sham tDCS, with both groups participating in mindfulness exercises on a treadmill. Anxiety levels were measured before and after the intervention using the State-Trait Anxiety Inventory (STAI). The results showed a significant reduction in anxiety in the active tDCS group one week after the intervention, suggesting that the combined therapy may have lasting effects on anxiety.

Key Concepts

• Transcranial Direct Current Stimulation (tDCS): A non-invasive brain stimulation technique that uses weak electrical currents to modulate neuronal activity, potentially enhancing the effects of psychological therapies.

• Mindfulness-Based Therapy: A form of therapy that focuses on awareness and acceptance of the present moment, often used to manage anxiety and depression.

• State-Trait Anxiety Inventory (STAI): A psychological assessment tool that measures both state and trait anxiety, providing insights into a person’s current anxiety level and general anxiety tendencies.

• Literature Review: Previous studies have shown that both tDCS and mindfulness can reduce anxiety, but their combined effect has not been thoroughly explored. This study aims to fill that gap by investigating the potential synergistic effects of tDCS and mindfulness.

Procedure Highlights - Research Methodology

1. Study Design: This was a randomized, double-blind study conducted at Kansai Medical University, Japan, from February 2019 to May 2020. Participants were randomly assigned to either the active tDCS or sham tDCS group.

2. Participants: 58 healthy right-handed individuals aged 20–60 years, with no history of psychiatric or neurological disorders, were included in the study.

3. Intervention: Participants underwent treadmill walking for focused mindfulness (TW-FM) while receiving either active tDCS (1 mA for 20 minutes) or sham stimulation. The anodal electrode was placed on the left dorsolateral prefrontal cortex (DLPFC), and the cathodal electrode was placed on the left shoulder.

4. Outcome Measures: Anxiety levels were assessed using the State-Trait Anxiety Inventory (STAI) at several points: before the intervention, immediately after, 60 minutes after, and one week after the intervention. EEG data were also collected to measure changes in brain activity.

Results - Findings of the Research

• Anxiety Reduction: The active tDCS group showed a significant reduction in state anxiety one week after the intervention compared to the sham group. The reduction was associated with decreased alpha activity in the rostral anterior cingulate cortex (rACC), a brain region linked to anxiety regulation.

• EEG Analysis: EEG data revealed that alpha-band activity in the rACC was significantly reduced in the active tDCS group compared to the sham group, suggesting a neurophysiological mechanism underlying the observed anxiety reduction.

• Adverse Effects: Mild adverse effects such as skin redness and discomfort at the electrode site were reported, but these were transient and did not significantly impact the study’s outcomes.

Discussion and Conclusion of the Research

The study demonstrated that combining tDCS with mindfulness exercises could effectively reduce anxiety, with effects lasting up to one-week post-intervention. The findings suggest that tDCS enhances the anxiolytic effects of mindfulness by modulating brain activity in areas associated with anxiety, such as the rACC. This combination therapy could offer a promising approach to managing anxiety, especially for individuals who may benefit from non-pharmacological interventions. Future research should explore the long-term effects of this combined therapy and its applicability to clinical populations with anxiety disorders.

Link to the Original Paper

Mindfulness augmentation for anxiety through concurrent use of transcranial direct current stimulation: a randomized double-blind study

Author Information

• Keiichiro Nishida: Department of Neuropsychiatry, Kansai Medical University, Osaka, Japan

• Yosuke Morishima: Translational Research Center, University Hospital of Psychiatry, University of Bern, Switzerland

• Roberto D. Pascual-Marqui: The KEY Institute for Brain-Mind Research, University Hospital of Psychiatry, Zurich, Switzerland

• Shota Minami: Kansai Medical University, Osaka, Japan

• Tomonari Yamane: Graduate School of Psychology, Kansai University, Osaka, Japan

• Masahito Michikura: Medical Research Support, Osaka, Japan

• Hideki Ishikawa: Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Osaka, Japan

• Toshihiko Kinoshita: Kansai Medical University, Osaka, Japan

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