Brain Structure and Mental Health in Typically Developing Youth and Those with Prenatal Alcohol Exposure and Postnatal Adversities
Date
2019-08-14
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Abstract
Mental health problems are linked to brain structural changes, primarily in the limbic system and prefrontal cortex, and commonly emerge in adolescence. Although progress has been made in understanding mental health disorders, there are still gaps in mental health research in pediatric typically-developing cohorts. Research clarifying the underlying mental health-related biomarkers aids in recognition and treatment of mental health problems and builds a foundation for studying other populations, such as those with neurodevelopmental disorders. Prenatal alcohol exposure (PAE) can broadly impact development, including brain structure and mental health. Nearly all individuals with PAE suffer from comorbid mental health disorders, yet little is known about altered brain structure and mental health in youth with PAE. To assess brain structure, structural magnetic resonance imaging (MRI) was used, specifically T1-weighted and diffusion-weighted imaging to measure anatomical volumes and properties of white matter, respectively. Internalizing and externalizing behaviours, negative behaviours directed either internally or externally, respectively, were used to assess symptoms relevant to mental health. In a typical-development cohort, lower mean diffusivity (MD) and higher fractional anisotropy (FA) measures in the cingulum and uncinate were the main underlying biomarkers for internalizing and externalizing behaviours. In the PAE study, youth with PAE showed significantly reduced volumes of the anterior cingulate cortex, superior frontal gyrus, and reduced FA in the cingulum and uncinate compared to controls. Youth with PAE and additional postnatal exposures exhibited similar brain structure to controls (i.e. volumes, FA and MD values), except in MD of the fornix. Both groups with PAE (with or without postnatal exposure) demonstrated higher externalizing behaviours than controls. Between group differences in mental health-brain structure relationships were found in both limbic gray and white matter. Together this research informs brain structure and mental health relationships in two important groups. With an understanding of typical development, a better understanding of the altered trajectories in PAE can be evaluated, and by having a more robust characterization of youth with PAE, improved services and interventions can be provided.
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MRI, DTI, Prenatal Alcohol Exposure, Adolescence, Childhood
Citation
Andre, Q. (2019). Brain Structure and Mental Health in Typically Developing Youth and Those with Prenatal Alcohol Exposure and Postnatal Adversities (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.