While brooding rumination may be associated with

While brooding rumination may be associated with atypical emotion regulation in MDD, It has been suggested that rumination may take a more adaptive form in healthy non-depressed individuals. In particular “reflective pondering” – a type of rumination with an emphasis on problem solving and addressing or alleviating negative emotions – is more prevalent than brooding rumination in healthy individuals (Joormann et al., 2006). Further, unlike brooding rumination, it is not associated with depressive measures in healthy individuals (Joormann et al., 2006). In contrast, in MDD brooding rumination is more prevalent than reflective pondering (Joormann et al., 2006) and both types of rumination are associated with increased depression (Raichle et al., 2001; Mazoyer et al., 2001), though reflective pondering is associated with decreases in depressive symptoms at follow-up (Treynor et al., 2003). If reflective pondering is indeed adaptive in healthy subjects, it is possible that greater use of this form of rumination in the absence of brooding rumination may be associated with more effective emotion regulation in healthy subjects. As the use of brooding rumination appears to decrease following peak use in late childhood and early adolescence (Hampel and Petermann, 2005; Hankin, 2008; Rood et al., 2009), it is possible that healthy development in this period involves decreasing ruminative thought and/or shifting to a more adaptive reflective style of rumination. In this context, the continued use of brooding rumination may contribute to MDD risk. It is important to note that prefrontal activity has regularly been associated with both effective emotion regulation as well as rumination, both of which involve reflecting upon and interpreting emotional content. As such, simply measuring activity of prefrontal regions during a reappraisal task may provide incomplete evidence as to whether that activity represents effective emotional regulation. Rather, a stronger indicator of effective regulation is whether such increased prefrontal activity is associated with decreased activity of regions associated with reactivity to emotional stimuli. PPI is an ideal method to evaluate this question, as it measures changes in the strength and direction of functional connectivity across task states, indicating, for example, whether reappraisal leads to stronger negative connectivity between prefrontal ion channels and amygdala than is seen during passive viewing of negative stimuli. The current study used PPI functional connectivity analyses to specifically evaluate how FC of the amygdala and of the sACC change between passively viewing and reappraising sad images, and how differences in rumination influences those changes in children with a history of MDD (MDD-ever) and healthy control (HC) children. If rumination is indicative of ineffective emotion regulation in MDD-ever, individuals with greater tendency to ruminate should show less moderation of amygdala activity during reappraisal. As rumination is also associated with increased activation of prefrontal regions, Short-period interspersion may also be associated with increased FC between amygdala and frontal regions in MDD-ever, indicating inefficient or ineffective control by those regions. We further hypothesized that rumination would be associated with increased FC of the sACC during reappraisal in MDD-ever, as ineffective regulation of the sACC could lead to increased attention to the effort to reappraise, including self-referential attention to one\'s emotional response (Cooney et al., 2010). For control subjects, we hypothesized that to the extent that this group endorsed rumination, these measures might index reflective pondering, and would thus be associated with greater FC anti-correlations between amygdala and prefrontal control regions during reappraisal, as indicative of effective regulation.
Methods
Results
Discussion The goal of the current study was to examine the relationship between individual differences in rumination and functional connectivity observed during cognitive reappraisal of emotions in children with a history of MDD relative to healthy controls. Overall, findings indicated a relationship between rumination and functional connectivity of the amygdala and subgenual cingulate that was greater in MDD-ever children than healthy children during emotion regulation (cognitive reappraisal). In regions where a group by rumination interaction was found, children with a history of MDD showed greater Reappraise>View Sad differences in connectivity with amygdala and sACC as rumination increased. As effective reappraisal would be expected to decrease connectivity with those regions, this finding suggests that rumination is associated with inefficient regulation of affect-processing regions in MDD-ever children, but not in healthy controls. This may reflect group differences in rumination styles, with rumination in MDD-ever children more closely fitting a maladaptive “brooding” pattern than in healthy controls. Main effects of rumination were only seen in a few focal areas, in which connectivity in HC and MDD-ever children were similarly associated with rumination scores. Additionally, main effects of group were seen in several regions that did not show an association with rumination, which were driven by FC differences between MDD-ever and healthy children in passive viewing of sad stimuli.