NCT03623815

A Functional Magnetic Resonance Imaging Investigation of Transcranial Direct Current Stimulation

A Functional Magnetic Resonance Imaging Investigation Into the Effects of Transcranial Direct Current Stimulation on Information Processing in Healthy Volunteers

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 18 (actual)
• Sponsor: University of Oxford · Academic / Other
• Sex: Female
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

Summary

This study evaluates the effect of frontal cortex transcranial direct current stimulation (tDCS) on the neural correlates of threat processing in healthy volunteers with a high level of trait anxiety. All participants received both active and sham tDCS and underwent a functional imaging scan whilst carrying out an attentional control task with fearful distractors.

Detailed description

There is a growing body of evidence suggesting that repeated administration of prefrontal transcranial direct current stimulation (tDCS) is a potential effective treatment for depression through restoring a left/right imbalance in frontal brain activity (Boggio et al., 2008; Loo et al., 2012) and improving top down control of anxiety responses. An initial exploratory study was carried out in 2012 (Ironside et al 2015) to examine the effects of tDCS on emotional processing in healthy volunteers using a range of tasks and questionnaires. Using a dot probe task, which measures attention to happy or fearful faces, it was found that tDCS has the potential ability to reverse an attentional bias to fearful faces seen in the placebo group. This indicates that anxiety responses may be modified using tDCS and therefore this follow on study seeks to further explore the role of tDCS in trait anxiety and investigate the neural correlates of this with fMRI. The present study uses behavioural and neuroimaging results to examine how tDCS affects emotional processing relevant to trait anxiety. A within-subjects design increases the power of the study, given limited resources to carry out extensive neuroimaging. Our working hypothesis is that tDCS may alter activity in cortical regions relevant to attentional control and anxiety. The findings of this study will be used to determine parameters for future patient studies, involving participants with generalized anxiety disorder or major depression. The ultimate aim, explored through further studies, is to understand and improve how tDCS might be used in the treatment of these disorders.

Conditions

• Anxiety State

Interventions

Type	Name	Description
OTHER	transcranial direct current stimulation	Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulatory technique that uses weak electrical current to increase (with anodal) or decrease (with cathodal) the probability of brain activity in the stimulated region. This typically has acute effects relating to cortical activity levels which last up to one hour. This intervention delivers 20 minutes of 2mA bipolar balanced tDCS, with anodal tDCS delivered to the left dorsolateral prefrontal cortex (DLPFC) and simultaneously cathodal tDCS delivered to the right DLPFC. In the sham condition 40 seconds of stimulation is delivered.

Timeline

• Start date: 2015-02-05
• Primary completion: 2015-09-08
• Completion: 2015-10-06
• First posted: 2018-08-09
• Last updated: 2018-08-09