Related Experiment Video
Updated: May 16, 2026
High-definition Transcranial Direct Current Stimulation over Right Dorsolateral Prefrontal Cortex to Enhance Metacognitive Sensitivity
Published on: September 26, 2025
Electric field intensity and EEG microstate dynamics in obsessive-compulsive disorder: a secondary analysis of a
Yang Wang1, Jiayue Cheng1, Puzhe Li2
1Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 600 Wan Ping Nan Road, Shanghai, 200030, China.
Background:
Obsessive-compulsive disorder (OCD) affects 2-3% of the population and is often accompanied by sleep disturbances, which can aggravate symptoms and hinder treatment. High-definition transcranial direct current stimulation (HD-tDCS) shows promise for alleviating both OCD symptoms and sleep-related issues, though its mechanisms remain unclear. This study aimed to explore the role of electric field (EF) intensity and EEG microstates in HD-tDCS outcomes.
Methods:
This study is a secondary analysis based on a previously published clinical trial. Forty-four drug-naïve OCD patients participated in a randomized controlled trial, with 34 undergoing MRI and EEG assessments. Participants received either active (n = 18) or sham (n = 16) HD-tDCS targeting the orbitofrontal cortex over 10 sessions in two weeks. The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and Pittsburgh Sleep Quality Index (PSQI) assessed OCD symptoms and sleep quality. EF modeling quantified stimulation intensity, and EEG microstate analysis evaluated brain dynamics.
Results:
No significant treatment × time interaction was found for Y-BOCS or PSQI scores. However, in the active group, higher EF intensity in right frontal regions was significantly associated with improved sleep quality. EEG microstate analysis showed stable topographies. EF intensity in medial orbitofrontal gyrus (mOFG) and rostral anterior cingulate gyrus (rACG) was related to changes in microstate A dynamics and exploratory mediation analysis suggested that the rACG EF-PSQI association may be partly mediated by changes in microstate A coverage.
Conclusion:
In patients with OCD, higher electric field intensity in prefrontal and anterior cingulate regions was associated with changes in microstate A parameters, which were in turn associated with improvements in sleep quality. Due to the limited sample size, the associations observed between electric field measures and EEG microstates should be considered preliminary and primarily hypothesis-generating.
Trial Registration:
The original clinical trial has been duly registered under the title "Transcranial Direct Current Stimulation (tDCS) in the Treatment of Drug-naïve obsessive-compulsive disorder (OCD)", with the research protocol registered at ClinicalTrials.gov under the identifier NCT04086446. The registration can be accessed via the following URL: https://clinicaltrials.gov/study/NCT04086446 .
