The relationship between irritability and emotional responding and residential care effects.

• In Event: 2-014 - Charting the Biological Underpinnings of the Development of Maladaptive Aggression

Integrative Statement

Introduction
Reactive aggression reflects a violent response to social provocation, threat or frustration. It is significantly increased in individuals showing heightened levels of irritability (defined as an increased propensity to exhibit anger relative to one’s peers). However, the neurobiology of irritability is only beginning to be understood. Models suggest irritability may relate to heightened emotional processing, reduced cognitive regulation or both. The current study aimed to distinguish between these positions in a sample of youth using an affective Stroop task. In addition, this study aimed to determine the extent to which aberrant neurobiology was ameliorated as a function of the Boys Town intervention.

Methods
Participants were 155 youth (93 male; average age=15.3 [sd=2.17], average IQ=102.97 [sd=11.72]) recruited from either Boys Town (N=98) or the local community. The children and adolescents recruited from the treatment program had been referred for behavioral and mental health problems. Children/adolescents from the community were recruited via local flyers and included both typically developing adolescents as well as adolescents with significant psychopathology. For the current study, assessments included an fMRI scan during performance of the affective Stroop task (Blair et al., 2007), a self-report questionnaire to assess irritability during adolescence (the affective reactivity index [ARI]; Stringaris et al., 2012) and parental report measures of reactive and instrumental aggression ((The Reactive-Proactive Questionnaire [RPQ]; Raine et al., 2006). In the aST, participants either perform goal-directed activity (counting the number of numerals) in the context of emotional and neutral distracters or simply view the emotional/neutral images. All participants were scanned at least once. However, a sub-group of participants (N=50) were also scanned a second time shortly before their completion of the intervention at Boys Town.

Results
Consistent with our hypotheses, irritability was highly correlated with level of reactive aggression. Moreover, and also consistent with our hypotheses, we found that level of irritability/reactive aggression was positively associated with responsiveness within ventromedial prefrontal and posterior cingulate cortices to the representation of emotional distracter information (see Figure 1). This aberrant signaling was significantly reduced following the Boys Town intervention and this reduction was associated with a decrease in expressed irritability.

Discussion
The current results provide evidence to support the hypothesis that irritability/reactive aggression is associated with heightened processing of emotional stimuli within regions implicated in representation of subjective value (ventromedial prefrontal and posterior cingulate cortices) – though, in this study, not the amygdala. Moreover, Boys Town residential care was associated with a reduction in this signal and concomitant reduction in irritability/reactive aggression.

Authors

• R. James Blair, Boys Town National Research Hospital
  Presenting Author

• Harma Meffert, Boys Town National Research Hospital
  Non-Presenting Author

• Stuart F. White, Boys Town National Research Hospital
  Non-Presenting Author

• Laura C Thornton, Boys Town National Research Hospital
  Non-Presenting Author

• Emily K. Leiker, Boys Town National Research Hospital
  Non-Presenting Author

• Kimberly R. Johnson, Boys Town National Research Hospital
  Non-Presenting Author

• Heba Abdel-Rahim, Boys Town National Research Hospital
  Non-Presenting Author

• Matthew Dobbertin, Boys Town National Research Hospital
  Non-Presenting Author

• Karina S. Blair, Boys Town National Research Hospital
  Non-Presenting Author