title: Alexithymia and reduced white matter integrity in schizophrenia: a diffusion tensor imaging study on impaired emotional self-awareness.
abstract: Alexithymia is characterized by deficits in emotional self-awareness. A number of previous studies have revealed impaired emotional self-awareness in schizophrenia. Although the pathology of schizophrenia is thought to involve disrupted white matter integrity, its relationship with alexithymia remains unclear. The present study investigated associations between alexithymia and white matter integrity, to seek the neural basis of impaired emotional self-awareness in schizophrenia. Forty-four patients with schizophrenia and 44 age-, gender- and predicted IQ level-matched healthy controls underwent diffusion-weighted imaging. Alexithymia was assessed using the 20-item Toronto Alexithymia Scale (TAS-20). We applied tract-based spatial statistics to investigate the correlation between the TAS-20 total score and white matter fractional anisotropy (FA). TAS-20 scores were significantly higher in patients than in controls. In the patient group only, FA was negatively correlated with the TAS-20 total score in the corpus callosum, mostly the left part of the superior and inferior longitudinal fasciculi, the inferior occipito-frontal fasciculus, the anterior and posterior thalamic radiation, and the precuneus white matter. These results suggest that schizophrenia is associated with alexithymia, and that reduced white matter integrity within these regions constitutes an important pathology underlying impaired self-emotional awareness in schizophrenia.
authors.affiliation: Department of Psychiatry, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kubota
authors.forename: Jun
authors.initials: J
authors.lastname: Miyata
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sasamoto
authors.forename: Ryosaku
authors.initials: R
authors.lastname: Kawada
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Nobukatsu
authors.initials: N
authors.lastname: Sawamoto
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Takahashi
authors.forename: Toshiya
authors.initials: T
authors.lastname: Murai
mesh_terms: D000328:Adult; D000342:Affective Symptoms / Q000209:etiology / Q000523:psychology*; D000704:Analysis of Variance; D016880:Anisotropy; D001364:Awareness; D001931:Brain Mapping; D016000:Cluster Analysis; D003337:Corpus Callosum / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications / Q000473:pathology*; D013223:Statistics as Topic; D055815:Young Adult