Alcohol use in emerging adults associated with lower rich-club connectivity and greater connectome network disorganization.

BACKGROUND: Emerging adulthood is a critical neurodevelopmental stage, with alcohol use during this period consistently associated with brain abnormalities and damage in anatomical structure and white matter integrity. However, it is less clear how alcohol use is associated with the brain's structural organization (i.e., white matter connections between anatomical regions). Recent connectome research has focused on rich-club regions, a collection of highly-interconnected hubs that are critical in brain communication and global network organization and disproportionately vulnerable to insults. METHODS: For the first time, we examined alcohol use associations with structural rich-club and connectome organization in emerging adults (N = 66). RESULTS: Greater lifetime drinks and current monthly drinks were significantly associated with lower rich-club organization (rs =-0.38, ps < 0.003) and lower rich-club connectivity (rs <-0.34, ps < 0.007). Additionally, rich-club connectivity was significantly more negatively correlated with alcohol use than connectivity among non-rich-club regions (ps < 0.035). Examining overall structural organization, greater lifetime drinks and current monthly drinks were significantly associated with lower network density (i.e., lower network resilience; rs <-0.36, ps = 0.004). Additionally, greater lifetime drinks and current monthly drinks were significantly associated with higher network segregation (i.e., network's tendency to divide into subnetworks; rs >0.33, ps<0.008). Alcohol use was not significantly associated with network integration (i.e., network's efficiency in combining information across the brain; ps > 0.064). CONCLUSIONS: Results provide novel evidence that alcohol use is associated with decreased rich-club connectivity and structural network disorganization. Given that both are critical in global brain communication, these results highlight the importance of examining alcohol use and brain relationships in emerging adulthood.

Functional connectivity between the ventral anterior cingulate and amygdala during implicit emotional conflict regulation and daily-life emotion dysregulation.

Emotional conflict adaptation involving ventral anterior cingulate cortex (ACC) suppression of the amygdala is thought to be important in emotion regulation, with evidence of impaired implicit emotion regulation in emotional distress disorders. However, it is unclear how this impairment is associated with daily-life emotion dysregulation in emotional distress disorders. In the current study, female participants with an emotional distress disorder (N = 27) were scanned with MRI while completing an implicit emotion conflict regulation task that involved identifying the facial expression of an image while ignoring an overlaid congruent or incongruent affect label. Participants then completed two weeks of ambulatory assessment of daily-life emotion dysregulation. Consistent with previous research on comorbid emotional distress disorders (Etkin and Schatzberg, 2011), there was no behavioral effect of emotional conflict adaptation (p = .701) but a significant effect of congruent adaptation (p = .006), suggesting impairment is specific to implicit emotional conflict regulation. Additionally, there was no neural evidence of emotional conflict adaptation in the ventral ACC and amygdala (ps > .766). Further, in our primary psychophysiological interactions analyses, we examined ventral ACC-amygdala functional connectivity. As hypothesized, increased ventral ACC-amygdala functional connectivity for emotional conflict adaptation was associated with increased daily-life affective instability (p = .022), but not mean daily-life negative affect (p = .372). Overall, results provide behavioral and neural evidence of impaired implicit emotional conflict adaptation in individuals with emotional distress disorders and suggests that this impairment is related to daily-life affective instability in these disorders.