Altered functional connectivity of the amygdala across variants of callous-unemotional traits: A resting-state fMRI study in children and adolescents.

Over the past years, research has shown that primary (high callousness and low anxiety) and secondary (high callousness and anxiety) variants of CU traits may be associated with opposite amygdala activity (hypo- and hyper-reactivity, respectively). However, their differences in amygdala functional connectivity remains largely unexplored. We conducted a Latent Profile Analysis on a large sample of adolescents (n = 1416) to identify homogeneous subgroups with different levels of callousness and anxiety. We then performed a seed-to-voxel connectivity analysis on resting-state fMRI data to compare subgroups on connectivity patterns of the amygdala. We examined the results in relation to conduct problems to identify potential neural risk factors. The Latent Profile Analysis revealed four subgroups, including the primary and secondary variants, anxious, and typically developing adolescents. The seed-to-voxel analyses showed that the primary variant was mainly characterized by increased connectivity between the left amygdala and left thalamus. The secondary variant exhibited deficient connectivity between the amygdala and the dorsomedial prefrontal cortex, temporo-parietal junction, premotor, and postcentral gyrus. Both variants showed increased connectivity between the left amygdala and the right thalamus but exhibited opposite functional connectivity between the left amygdala and the parahippocampal gyrus. Dimensional analyses indicated that conduct problems may play a mediating role between callousness and amygdala-dmPFC functional connectivity across youths with already high levels of callousness. Our study highlights that both variants differ in the functional connectivity of the amygdala. Our results support the importance of disentangling the heterogeneity of adolescents at risk for conduct problems in neuroimaging.