Psychiatry - Research Publications

Permanent URI for this collection

http://hdl.handle.net/11343/232

Filters

2012 - 2019 2
2
Reset filters

Settings
Statistics
Citations
Author: Davey, Christopher × Author: Fornito, Alexander × Author: Harrison, Benjamin × End date: 2019 × Start date: 2012 ×

Search Results

Now showing 1 - 2 of 2
  • Item
    Thumbnail Image
    Neurodevelopmental correlates of the emerging adult self
    Davey, CG ; Fornito, AD ; Pujol, J ; Breakspear, M ; Schmaal, L ; Harrison, BJ (ELSEVIER SCI LTD, 2019-04)
    The self-concept - the set of beliefs that a person has about themselves - shows significant development from adolescence to early adulthood, in parallel with brain development over the same period. We sought to investigate how age-related changes in self-appraisal processes corresponded with brain network segregation and integration in healthy adolescents and young adults. We scanned 88 participants (46 female), aged from 15 to 25 years, as they performed a self-appraisal task. We first examined their patterns of activation to self-appraisal, and replicated prior reports of reduced dorsomedial prefrontal cortex activation with older age, with similar reductions in precuneus, right anterior insula/operculum, and a region extending from thalamus to striatum. We used independent component analysis to identify distinct anterior and posterior components of the default mode network (DMN), which were associated with the self-appraisal and rest-fixation parts of the task, respectively. Increasing age was associated with reduced functional connectivity between the two components. Finally, analyses of task-evoked interactions between pairs of nodes within the DMN identified a subnetwork that demonstrated reduced connectivity with increasing age. Decreased network integration within the DMN appears to be an important higher-order maturational process supporting the emerging adult self.
  • Item
    No Preview Available
    Brain functional connectivity during induced sadness in patients with obsessive-compulsive disorder
    Fontenelle, LF ; Harrison, BJ ; Pujol, J ; Davey, CG ; Fornito, A ; Bora, E ; Pantelis, C ; Yuecel, M (CMA-CANADIAN MEDICAL ASSOC, 2012-07)
    BACKGROUND: Obsessive-compulsive disorder (OCD) is associated with a range of emotional abnormalities linked to its defining symptoms, comorbid illnesses and cognitive deficits. The aim of this preliminary study was to examine functional changes in the brain that are associated with experimentally induced sad mood in patients with OCD compared with healthy controls in a frontolimbic circuit relevant to both OCD and mood regulation. METHODS: Participants underwent a validated sad mood induction procedure during functional magnetic resonance imaging. Analyses focused on mapping changes in the functional connectivity of the subgenual anterior cingulate cortex (ACC) within and between the 2 groups in response to successfully induced sadness. RESULTS: We enrolled 11 patients with OCD and 10 age-, sex- and IQ-matched controls in our study. Unlike controls, patients with OCD did not demonstrate predicted increases in functional connectivity between the subgenual ACC and other frontal regions during mood induction. Instead, patients demonstrated heightened connectivity between the subgenual ACC and ventral caudate/nucleus accumbens region and the hypothalamus. LIMITATIONS: Our study included a small, partially medicated patient cohort that precluded our ability to investigate sex or drug effects, evaluate behavioural differences between the groups and perform a whole-brain analysis. CONCLUSION: The ventral striatum and ventral frontal cortex were distinctly and differentially modulated in their connectivity with the subgenual ACC during the experience of sad mood in patients with OCD. These results suggest that, in patients with OCD, induced sadness appears to have provoked a primary subcortical component of the hypothesized "OCD circuit," which may offer insights into why OCD symptoms tend to develop and worsen during disturbed emotional states.