Anterior cingulate cortex activity during attentional control corresponds with rumination in depression and social anxiety

Rumination and worry are transdiagnostic perseverative cognitions that have overlapping and distinct characteristics. While the mechanisms of perseverative cognitions remain incomplete, limited data indicate anterior cingulate cortex (ACC) as it relates to top-down functions contributes to perseverative cognitions in internalizing conditions. The current study extends this work in patients with major depression (n = 39) or social anxiety (n = 42). During fMRI, participants viewed images comprising letter strings superimposed on task-irrelevant threatening or neutral faces. To moderate task difficulty, there was a low perceptual load condition where the target letter was in a string of identical letters and high load condition with the target letter in a mixed letter string increasing task difficulty. Regions of interest (ROI) comprised dorsal ACC and rostral ACC. Bilateral amygdala was also examined. Results showed diagnostic groups had similar levels of rumination and worry. Exploratory hierarchical regression analysis comprising clinical measures, task performance, and the 4 ROIs revealed significantly less dorsal ACC engagement during low (vs. high) load to task-irrelevant faces corresponded with more rumination, but not worry, regardless of diagnostic status. However, the ACC finding did not survive Bonferroni correction. Preliminary results suggest dorsal ACC response during attentional control may serve as a transdiagnostic mechanism of rumination.