Emotion processing deficits in youth with conduct disorder and youth with autism spectrum disorders: potential transdiagnostic factors and neurobiological correlates

Many disorders exhibit impairments in emotion processing. Yet, studies investigating potentially shared and disorder-specific deficits at the behavioral and neural levels are lacking. The main aim of this study is thus, to compare two disorders showing emotion processing deficits, conduct disorder (CD) and autism spectrum disorder (ASD). Moreover, in CD and ASD, emotion processing deficits are detectable early in life. These include reduced attention to the eye region during facial emotion processing and high prevalence rates of co-occurring callous unemotional (CU) traits. Focusing on these as potential transdiagnostic factors for emotion processing deficits might help to gain deeper knowledge on the shared and disorder specific deficits.
The main aim of this thesis is to explore the potential transdiagnostic contribution of atypical eye gaze and co-occurring CU traits at the behavioral and neural level for emotion processing impairments often described in youth with CD and youth with ASD. The second aim was to investigate whether heart rate variability (HRV) influences generic self-regulation or specifically emotion regulation abilities and underlying neural structures in youth with CD compared with typically developing peers (TD). For this, we analyzed gaze behavior during an implicit facial emotion processing paradigm and functional Magnetic Resonance Imaging (MRI). Then, the impact of CU traits on empathy abilities were investigated using psychometric measures of empathy and structural imaging data. Finally, we analyzed the association between baseline HRV indices and task performance during an emotional go/no-go paradigm using data from the multicentered FemNAT-CD project.
The findings of the first study suggest that while reduced eye gaze and differences in brain activation may be disorder specific, atypical gaze patterns may be transdiagnostic. In the second study, CU traits have shown both transdiagnostic and disorder specific influences which may partially depend on the disorder, the type of emotion processing and the neural correlate investigated. Thus, gaze behavior and CU traits, although expressed in a disorder specific way, are shown in CD and ASD and impact emotion processing in both disorders. The third study suggests that HRV may be an indicator for potential self-regulation deficits in youth with CD and TD.
In sum, this thesis provides evidence for a transdiagnostic and disorder-specific impact of early indicators atypical emotion processing. More studies are needed to explore and compare the underlying mechanisms of atypical gaze patterns and subdimensions of CU traits in disorders with emotion processing deficits. This may help to better understand the disorder specific focus of impairment and to develop tailored treatment options.