Prefrontal TDCS attenuates medial prefrontal connectivity upon being criticized in individuals scoring high on perceived criticism

The mechanisms by which transcranial direct current stimulation (tDCS) influences emotional processing - and whether this is related to individual vulnerability for psychopathology - are still poorly understood. The present study aimed to investigate if one prefrontal tDCS session modulates mood and neural functional connectivity after being exposed to negative information differently in individuals low or high in perceived criticism (PC), which has been related to vulnerability for psychiatric illness. In a randomized cross-over design, one session of MRI-compatible prefrontal tDCS (neuronavigated placement of the anodal electrode at the left dorsolateral prefrontal cortex and the cathodal electrode at the right supraorbital region; vs. sham) was administered to healthy females, prior to listening to self-referential criticism. PC-dependent (low vs. high PC) changes in mood and resting-state functional connectivity patterns following tDCS and after hearing criticism were explored. After being criticized all females (low and high PC) felt angrier and more depressed, both in the active tDCS or sham tDCS condition. However, in contrast to low PC females, in high PC females prefrontal tDCS reduced connectivity between the left dorsal anterior cingulate cortex and the right dorsomedial prefrontal cortex following criticism. Despite having no differential effects on self-reported mood, prefrontal tDCS reduces medial prefrontal neural connectivity after being criticized in high PC females compared to low PC females. Depending on individual vulnerability for psychopathology, a single tDCS session differentially affects neural processing of negative emotional information, especially in brain regions involved in monitoring, experiencing and appraising/evaluating emotional material.