title: Insight and white matter fractional anisotropy in first-episode schizophrenia.
abstract: Impaired insight is a hallmark feature of schizophrenia. Structural studies implicate predominantly prefrontal, cingulate, cuneus/precuneus, and inferior temporal brain regions. The cortical midline structures (CMS) are also implicated in functional studies primarily through self-reflective processing tasks. However, few studies have explored the relationship between white matter tracts and insight in schizophrenia, and none in first-episode schizophrenia (FES). Here, we examined for fractional anisotropy (FA) differences in 89 minimally treated FES patients and 98 matched controls, and identified those FA differences associated with impaired clinical insight in patients. We found widespread FA reduction in FES patients compared to controls. Poorer insight in patients was predicted by lower FA values in a number of white matter tracts with a predilection for tracts associated with cortical midline structures (fronto-occipital, cingulate, cingulate hippocampus, uncinate, anterior corona radiata), and more severe depressive symptoms. The association between FA abnormalities and insight was most robust for the awareness of symptoms and illness awareness domains. Our study implicates a network of tracts involved in impaired insight in schizophrenia with a predilection for the CMS. This study is a first step in delineating the white matter tracts involved in insight impairment in schizophrenia prior to chronicity.
authors.affiliation: Stellenbosch University, Faculty of Medicine and Health Sciences, Psychiatry, PO Box 19063, Tygerberg, Cape Town ZA 7505, South Africa. Electronic address: laila@sun.ac.za.
authors.forename: Laila
authors.initials: L
authors.lastname: Asmal
authors.affiliation: Stellenbosch University, Faculty of Medicine and Health Sciences, Psychiatry, PO Box 19063, Tygerberg, Cape Town ZA 7505, South Africa.
authors.forename: Stefan
authors.initials: S
authors.lastname: du Plessis
authors.affiliation: Departments of Developmental and Experimental Psychology, Utrecht University, Utrecht, The Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Vink
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, Cape Town ZA 8001, South Africa.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Fouche
authors.affiliation: Stellenbosch University, Faculty of Medicine and Health Sciences, Psychiatry, PO Box 19063, Tygerberg, Cape Town ZA 7505, South Africa.
authors.forename: Bonginkosi
authors.initials: B
authors.lastname: Chiliza
authors.affiliation: Stellenbosch University, Faculty of Medicine and Health Sciences, Psychiatry, PO Box 19063, Tygerberg, Cape Town ZA 7505, South Africa.
authors.forename: Robin
authors.initials: R
authors.lastname: Emsley
mesh_terms: D000293:Adolescent; D000328:Adult; D016880:Anisotropy; D003863:Depression / Q000000981:diagnostic imaging / Q000209:etiology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications / Q000000981:diagnostic imaging*; D012565:Schizophrenic Psychology; D066127:White Matter / Q000000981:diagnostic imaging*; D055815:Young Adult