title: Diffusion tensor imaging tractography of the fornix and belief confidence in first-episode psychosis.
abstract: Previous studies have demonstrated that patients with psychosis are more confident in beliefs and judgments compared to healthy participants and psychiatric controls with major depression. A recent study conducted by our research group has provided evidence for hippocampal pathology in association with overconfidence in a first-episode psychosis sample. The fornix is the primary efferent neural pathway of the hippocampus and may also play a role in self-certainty pathophysiology. The current investigation applied diffusion tensor imaging tractography to a first-episode psychosis sample to explore whether integrity of the fornix is associated with self-certainty. High resolution structural magnetic resonance and diffusion tensor images were obtained in 44 people with a first-episode psychosis. Diffusion tensor imaging tractography was used to estimate fractional anisotrophy (FA), a measure of white matter integrity, in the fornix. Confidence in beliefs and judgments was measured with the self-certainty subscale of the Beck Cognitive Insight Scale (BCIS). The analysis showed that self-certainty significantly correlated to FA values in the right fornix but was nonsignificant for the left fornix. The findings indicate anatomical dysconnectivity of the right fornix in correlation with BCIS-rated self-certainty in our first-episode psychosis sample. When considered with our previously published self-certainty-hippocampus result in a first-episode psychosis sample, overlapping with that of this study, the results indicate a concurrence of volumetric reductions in hippocampus and fornix pathology in correlation with self-certainty.
authors.affiliation: Brain Imaging Group, Douglas Mental Health University Institute, Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: Buchy
authors.forename: David
authors.initials: D
authors.lastname: Luck
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Czechowska
authors.forename: Ashok
authors.initials: A
authors.lastname: Malla
authors.forename: Ridha
authors.initials: R
authors.lastname: Joober
authors.forename: Martin
authors.initials: M
authors.lastname: Lepage
mesh_terms: D000293:Adolescent; D000328:Adult; D003469:Culture; D056324:Diffusion Tensor Imaging; D005260:Female; D020712:Fornix, Brain / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007600:Judgment; D008297:Male; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000150:complications / Q000473:pathology* / Q000523:psychology*; D015203:Reproducibility of Results; D055815:Young Adult