Reduced frontocingulate theta connectivity during emotion regulation in major depressive disorder

Background: Cognitive reappraisal is an essential emotion regulation skill for social life and psychological health. However, individuals with major depressive disorder (MDD) cannot use this skill effectively. Successful cognitive reappraisal in healthy controls (HC) has been shown to be associated with theta activity in a frontal and subcortical network. In the present study, we investigated whether MDD patients are characterized by altered theta power and connectivity pattern during cognitive reappraisal compared to HC. Methods: Using EEG and eLORETA, we examined both theta activity and connectivity when 25 controls and 24 patients with MDD were asked to complete the emotion cognitive reappraisal task of viewing neutral and negative pictures and reappraise negative pictures. Habitual use of emotion regulation skills was collected using the Cognitive Emotion Regulation Questionnaire (CERQ). Results: The results showed that MDD patients had (1) reduced theta activity in the left dorsolateral (dlPFC), dorsomedial prefrontal (dmPFC), and rostral-ventral cingulate cortices (rvACC), as well as (2) reduced dlPFC-rvACC theta connectivity than HC during reappraisal. In addition, left dlPFC-rvACC theta connectivity was positively correlated with self-reported cognitive reappraisal in HC. This relation was not observed in MDD. In contrast, CERQ revealed significantly greater use of inadequate regulations skills and significantly lower use of adaptive skills in MDD. Limitation: Sample size, limited solution space to cortical grey matter excluding regions such as the amygdala. Conclusion: This study may indicate a putative frontocingulate dysfunction leading either to an increased use of inadequate emotion regulation or a decreased use of skills that serve to boost positive emotion.