Exploring associations between neuroimaging, neurodevelopment, and emotional reactivity in individuals with or without congenital heart disease
Children with complex congenital heart disease (CHD) experience a range of stressful early life events and are at increased risk of adverse neurodevelopmental and mental health outcomes across life. This thesis, comprising four studies, examines neuroimaging, neurodevelopment, and emotional reactivity associated with complex CHD. Study 1 (Chapter 5), published in the Journal of the American College of Cardiology in 2023, is a systematic, state-of-the-art review of evidence on associations between neuroimaging findings and neurodevelopmental and psychiatric outcomes among individuals with dextro-transposition of great arteries (d-TGA) or single-ventricle CHD. While findings were mixed across studies, brain volumes and microstructural and functional brain changes appear linked to neurocognitive outcomes, including infant motor, language, and cognitive development, and adolescent and adult attention and executive functioning. Four papers investigated psychiatric outcomes; none found associations with neuroimaging data. Study 2 (Chapter 7) was a cross-sectional functional magnetic resonance imaging (fMRI) study with children and adolescents with d-TGA (n=34) and a non-CHD comparison group (n=27). In typical development, children (but not adolescents) exhibit decreases in amygdala reactivity to caregiver cues. This phenomenon is thought to represent a ‘parental buffering' effect. In Study 2, children with d-TGA showed increased amygdala reactivity when viewing images of their caregiver. These preliminary results suggest early medical adversity may influence developing emotional neural circuitry. Understanding how early life stress may alter typical developmental and neurobiological processes is critical to informing early neuroprotective and infant mental health strategies. In Study 3 (Chapter 8), recently accepted for publication in the Journal of Psychiatric Research, a new set of 124 emotionally salient medical images, called MEDIC, was developed to support investigation of the etiology and psychophysiology of medical traumatic stress. A demographically-diverse sample of 300 adults in the United States rated MEDIC images depicting medical stimuli on one of two dimensions: emotional arousal (i.e., how strongly an evoked emotion is felt) or affective valence (i.e., how positive or negative the evoked emotion is). The MEDIC Image Set demonstrated a) elicit a range of emotional arousal and valence ratings, b) have excellent inter-rater reliability, c) have moderate test-retest reliability, and d) have good face validity. This will enable researchers to provide context-specific and emotionally-salient stimuli to individuals when studying medical traumatic stress. Moving from use with adults to children, in Study 4 (Chapter 9) the MEDIC Image Set was validated with children aged 6-17 years (n=150), in order to support research intopediatric traumatic stress. In children, MEDIC was found to (a) elicit a wide spectrum of arousal and valence ratings, (b) have good inter-rater reliability and face validity, and (c) generate affective responses that are highly correlated with adult ratings. Children with chronic illness (n=24) gave higher arousal ratings to medical images (p<.01), suggesting higher emotional reactivity to medical stimuli. This positions future studies to better address medical related adversities in groups like those with CHD. Overall, this thesis identified and addressed important knowledge gaps, highlighting associations between neuroimaging, neurodevelopment, and emotional reactivity in individuals with complex CHD. Evidence for alterations in emotion circuitry in children and adolescents with d-TGA as well as increases in emotional reactivity in individuals with other chronic illnesses was found. Important next steps include replicating and extending these findings with larger patient samples and testing strategies to support neurodevelopmental and emotional outcomes in children and adolescents with complex CHD by buffering stress and supporting child-caregiver relationships.
Phillips, Katelyn ; https://orcid.org/0000-0003-2968-7929
congenital heart disease, early life stress, functional magnetic resonance imaging, amygdala reactivity, emotional reactivity, anzsrc-for: 320101 Cardiology (incl. cardiovascular diseases), anzsrc-for: 52 PSYCHOLOGY
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