Attention shifting in the context of emotional faces: Disentangling neural mechanisms of irritability from anxiety

Abstract

Background: Irritability predicts concurrent and prospective psychiatric disorders across the lifespan. Anxiety commonly co-occurs with irritability, and such comorbidity complicates care. Understanding the mechanisms of comorbid traits is necessary to inform treatment decisions. This study aimed to disentangle neural mechanisms of irritability from anxiety in the context of attentional shifting toward and away from emotional faces in youths from treatment-seeking families.

Methods: Youths (N = 45), mean age = 14.01 years (standard deviation = 1.89) completed a dot-probe task during functional magnetic resonance imaging acquisition. Whole-brain activation analyses evaluated the effect of irritability on neural reactivity in the context of varying attentional shifting toward and away from emotional faces, both depending on and above and beyond anxiety (i.e., with anxiety as [a] a moderator and [b] a covariate, respectively).

Results: Higher irritability levels related to distinct task-related patterns of cuneus activation, depending on comorbid anxiety levels. Increased irritability also related to distinct task-related patterns of parietal, temporal, occipital, and cerebellar activation, controlling for anxiety. Overall, youths with higher levels of irritability evinced more pronounced fluctuations in neural reactivity across task conditions.

Conclusion: The present study contributes to a literature delineating the unique and shared neural mechanisms of overlapping symptom dimensions, which will be necessary to ultimately build a brain- and behavior-based nosology that forms the basis for more targeted and effective treatments.

Keywords: adolescents; anxiety; attention; children; dot-probe task; fMRI; irritability.

FIGURE 1

Irritability × Anxiety × Emotion × Congruence interaction predicts activation in the right cuneus. Irritability and anxiety were used as continuous variables in the analyses. For illustrative purposes, predicted activation was plotted at minimum and maximum values of irritability (low = 0, high = 10) and anxiety (low = 0, high = 44), resulting in four patterns of predicted cuneus activation: low-low, low-high, high-low, and high-high. For this and all figures, brain images represent axial sections (left = left) with threshold set at whole-brain-corrected p < .05, and the x-axis represents face emotion categories

FIGURE 2

Irritability x emotion x congruence, above and beyond anxiety, predicts neural activation controlling for anxiety. In (a) right inferior parietal lobule, (b) left lingual gyrus, and (c) right superior temporal gyrus. Irritability was used as a continuous variable in the analyses. For illustrative purposes, predicted activation was plotted at minimum and maximum irritability values (i.e., low = 0, high = 10)