Psychosis and cortico-cortical connectivity

Student thesis: Doctoral ThesisDoctor of Clinical Psychology


While psychotic disorders are thought to involve a disruption of cortico-cortical and cortico-subcortical connections, it is unclear whether this is a correlate of the disorder itself or is related to risk factors for the disorder. In this PhD thesis, I examined the integrity of cortical connections, the pattern of cortical morphology in two unique MRI datasets that have been collected over the last five years: one from a large sample of twins with and without schizophrenia, and another from a cohort of subjects with prodromal signs of psychosis, scanned before and after the onset of the disorder. The main hypothesis of this work is that abnormal cortical connectivity will be evident in subjects at risk of psychosis, but to a lesser degree than in patients with psychosis. Diffusion Tensor Imaging (DTI) and T1-weighted images were acquired for both samples. DTI is a brain imaging technique that aims to reconstruct white matter connections between cortical areas and assess their microstructure. T1-weighted imaging enables the examination of cortical shape changes that may result from abnormal connections. I applied to MRI data of both samples a voxel-brain morphometry analysis to DTI data, probabilistic tractography and a method for the assessment of cortical morphology. The principal result of my analysis confirmed the main hypothesis of this study. Further work revealed that abnormal connections are evident before the onset of psychosis and that these abnormalities may underlie the risk of developing psychosis.
Date of Award2013
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorGareth Barker (Supervisor) & Philip McGuire (Supervisor)

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