Deviations in neural activity and network integration underpinning the co-occurrence of emotion dysregulation and attention-deficit/hyperactivity disorder: Analyses of fMRI task activations and functional brain network topology

The aim of this thesis was to improve our understanding of the relationship between Attention-deficit/hyperactivity disorder (ADHD) and emotion dysregulation and the underlying neural activity. Three research articles examine specific aspects of the relationship between ADHD and emotion dysregulation, namely the perception of emotional stimuli, the association between functional brain topology and emotion dysregulation in different ADHD presentations, and emotion dysregulation-related neurobiological and phenotypical predictors of the course of ADHD. All three articles are based on functional magnetic resonance imaging (fMRI) data. Individuals with ADHD exhibited aberrant amygdala reactivity and ventromedial prefrontal cortex coupling in the perception and processing of emotional face stimuli. Moreover, functional network topology of the right insula was shown to affect emotion dysregulation in ADHD and emotion dysregulation and integration of emotion-related brain networks were shown to affect intraindividual change in ADHD severity throughout late adolescence. In Summary, the thesis provides evidence that neural activity and functional connectivity between brain structures affecting emotion may be related to the co-occurrence of emotion dysregulation and ADHD. ADHD and the common co-occurring emotional problems should not be attributed to single, isolated systems, e.g., for executive functions and cognitive control. The neurobiological roots appear to be complex and heterogeneous, involving the interplay of different brain networks that are at least partly emotion-related