Parsing the neural correlates of anxious apprehension and anxious arousal in the grey-matter of healthy youth.

Neuroscientific and psychological research posits that there are two transdiagnostic facets of anxiety: anxious arousal and anxious apprehension. Though these two facets of anxiety are distinct, they are often subsumed into one domain (e.g., trait anxiety). The primary goal of the current study was to delineate the relationship between anxious arousal and cortical thickness versus the relationship between anxious apprehension and cortical thickness in a sample of typically functioning youth. The secondary aim was to determine where in the brain cortical thickness significantly correlated with both components of anxiety. Results indicated that the right anterior insula has a stronger relationship to anxious arousal, whereas the dorsolateral prefrontal cortex and left anterior insula were found to correlate with both anxious arousal and apprehension. We also observed volumetric differences in the amygdala and hippocampus between anxious arousal and anxious apprehension. Whereas anxious arousal, but not apprehension, predicted left amygdala volume, anxious apprehension, but not arousal, predicted right hippocampal volume. These findings demonstrated that there are both differences and similarities in the neural regions that contribute to independent facets of anxiety. Results are discussed in terms of previous findings from the affective and developmental cognitive neurosciences.