Harnessing the power of placebo with prefrontal transcranial direct current stimulation: an experimental psychopathological research line

01 November 2022 → 31 October 2025
Research Foundation - Flanders (FWO)
Research disciplines
  • Social sciences
    • Psychophysiology
    • Psychopathology
    • Cognitive processes
    • Motivation and emotion
    • Research methods and experimental design
transcranial direct current stimulation psychological functioning placebo
Project description

Depression is highly prevalent, and is characterized by aberrant prefrontal and fronto-limbic connectivity, associated with difficulties in executive functions (e.g., working memory) and maladaptive emotion regulatory processes. Prefrontal transcranial direct current stimulation (tDCS; i.e., a non-invasive brain modulation technique that influences neural activity) is rising in popularity as a potential low-cost, easy to use, and self-administrable treatment for depression. However, effect sizes of tDCS protocols are rather modest and there is a large variability in the clinical response. Based on placebo-mechanisms, the expectancies that people have surrounding the efficacy of a treatment can significantly influence clinical response. It is suggested that a considerable portion of tDCS responsivity could be due to these non-specific, expectancy effects, although the specific contributions remain unclear. In addition, research suggests that tDCS is more efficacious when applied in a context (e.g., cognitive task, training) that engages the same neural network(s) as the targeted network of tDCS. In this way, positive expectancies could boost the effects of prefrontal tDCS, as expectancies also rely on prefrontal networks. In view of this, the aim of this project is to investigate a) the contribution of non-specific effects, and b) how explicit expectancies may interact with tDCS, on processes (working memory and emotion regulation) related to the pathogenesis of depression.