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Longitudinal follow-up of 22q11.2 Deletion Syndrome: a study of individuals at high risk of schizophrenia

Chawner, Samuel 2015. Longitudinal follow-up of 22q11.2 Deletion Syndrome: a study of individuals at high risk of schizophrenia. PhD Thesis, Cardiff University.
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22q11.2 Deletion Syndrome (22q11.2DS) is one of the strongest known risk factors for schizophrenia. The syndrome provides a rare opportunity to prospectively examine development that precedes schizophrenia. 22q11.2DS is also associated with a range of psychiatric disorders and cognitive deficits. The overall aim of this thesis is to examine the neuropsychiatric phenotype of 22q11.2DS through a developmental lens. This thesis uses data from Cardiff University’s ECHO (Experiences of CHildren with cOpy number variants) study which includes a longitudinal cohort of children with 22q11.2DS. Development in 22q11.2DS is contrasted to that of the unaffected siblings of children with 22q11.2DS. First psychopathology is examined longitudinally across early adolescence in 22q11.2DS. Children with 22q11.2DS have a significant burden of psychopathology across early adolescence, including attention-deficit/hyperactivity disorder (ADHD), anxiety disorders and autism spectrum disorder (ASD). There is a striking increase in the prevalence of psychotic experiences and a decrease in ADHD prevalence. The ASD phenotype is examined further using a diagnostic interview of developmental history. ASD and subthreshold phenomenology is found to be highly prevalent in the early development of children with 22q11.2DS. Next cognitive development in 22q11.2DS is considered and contrasted to that in unaffected siblings. Cognitive deficits across a range of domains are present in 22q11.2DS. Cognitive development in 22q11.2DS is found to be similar to that reported in children who later develop idiopathic schizophrenia. This is followed by an exploration of the relations between psychopathology and cognitive development in 22q11.2DS. Cognitive development is found to predict the emergence of psychotic experiences and the persistence of ADHD in 22q11.2DS. This thesis extends what is known about the development of the neuropsychiatric phenotype in 22q11.2DS. Furthermore, findings give an insight into the developmental pathways associated with a high risk of developing schizophrenia.

Item Type: Thesis (PhD)
Date Type: Completion
Status: Unpublished
Schools: Medicine
Subjects: R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
Funders: Medical Research Council
Date of First Compliant Deposit: 30 March 2016
Last Modified: 14 Apr 2022 09:38

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