Effects of tDCS-enhanced Cognitive Control Training on Depression

Summary

Deficient cognitive control (CC) is one of the central characteristics of major depression (MD). Hypoactivation of the dorsolateral prefrontal cortex (dlPFC) has been linked with this deficit. Antidepressants and cognitive-behavioral therapies modify CC most-likely as a common mechanism of treatment. Transcranial direct current stimulation (tDCS) is a safe, simple and effective non-invasive method to modulate the cortical excitability. It has been shown, that the activity of the dlPFC can be modulated by transcranial direct current stimulation (tDCS) with polarity-dependent learning-phase specific effects on performance that, when combined with training, can outlast the stimulation.

The goal of this randomized, sham-controlled, rater blind clinical trial is to investigate the effect of a tDCS-enhanced CC Training (CCT) on depressive symptom severity and compare the stimulation intensities 1mA, 2mA and sham tDCS. Overall, the study will include 57 participants (n = 19 per group). Each participant will complete 12 training sessions with online sham/ anodal tDCS.

As a training task we will use an adaptive version of the paced auditory serial addition task (PASAT). In the PASAT, digits are presented auditive and participants have to add the current digit to the digit they heard before. In the adaptive version the interstimulus-intervals decrease (increase) when four consecutive trials are correct (incorrect). The PASAT is known to elicit frustration. Participants have to exert cognitive control over these emotions to complete the task successfully.

Before, during and after the training symptom severity will be assessed. Baseline and post-training performance in the PASAT and in a transfer task (delayed working memory task, DWM) will be measured.

To further explore variables that influence the effect of tDCS on depressive symptom severity we will measure brain activity (EEG, NIRS), heart rate, global functioning (GAF), emotion regulation strategies, self-esteem, mood ratings and subjective performance ratings before and after the training and collect genetic factors.

Sustainability of the training effects will be measured at a follow-up visit (3 months later).

Conditions

• Depression Unipolar

Interventions

OTHER

1mA tDCS

transcranial direct current stimulation with the intensity of 1mA

OTHER

2mA tDCS

transcranial direct current stimulation with the intensity of 2mA

BEHAVIORAL

Cognitive control training

cognitive control training with the PASAT

Sponsors & Collaborators

• German Federal Ministry of Education and Research

  collaborator OTHER_GOV

• Universität Tübingen

  collaborator OTHER

• University Hospital Tuebingen

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2018-03-19

Primary Completion

2019-10-01

Completion

2019-12-31

Countries

• Germany

Study Locations