Objective There has been no modern effort to replicate, further characterize, or quantify the dramatic effects on affect described in controlled studies from the 1960s using bilateral frontal electrodes with an extra-cephalic reference in a mixed group composed primarily of mildly depressed individuals. We performed a comprehensive, quantitative assessment of the effects of bifrontal TDCS on emotion in 21 healthy subjects. Methods In a double-blind crossover study, we administered tests of emotional state, affect, emotional decision-making, arousal, and psychomotor functions during sham, anodal, and cathodal TDCS. Results We found no systematic effects on any measure, despite two subjects who had pronounced mood effects in the predicted direction. There were no adverse events. Conclusions In line with some other studies, we found no consistent effects of bifrontal TDCS on measures of emotional function of psychomotor performance. Significance These results demonstrate the safety of bilateral anterior frontal TDCS with an extra-cephalic reference, but raise questions about its effectiveness as a modulator of mood and emotional cognition, at least in healthy subjects.

Approximately 50% of persons with multiple sclerosis experience cognitive impairment, which adversely affects daily functioning. Although patients report that fatigue contributes to cognitive difficulties, previous empirical studies do not show a clear association. This study assessed coping style as a moderator of the relationship between fatigue and cognition in a 3-year longitudinal sample. Scores on the Fatigue Impact Scale and the Coping Orientation to Problems Experienced (COPE) at baseline were modeled to predict later performance on a composite of cognitive tests to investigate the hypothesis that coping would have a significant moderating effect on fatigue in predicting cognitive performance. Findings partially supported hypotheses by showing that avoidant coping moderated the relationship between fatigue and cognitive performance. Patients who experienced relatively high fatigue performed better on cognitive tests if they used less avoidant coping. Those who reported lower fatigue had relatively good cognitive performance regardless of their coping style. This study provides evidence that coping style is associated with the ability to deal with stress, like fatigue, and their interaction can impact functional outcomes of disease. These results could benefit understanding of prognosis and improve treatment for patients with MS.

In the absence of baseline testing, the normative data presented here can be used clinically to assess athletes' cognitive functioning post-concussion.

The field is very young and many findings will require replication. Nevertheless, TDCS appears to have the potential to be a simple and safe means of neuromodulation.