title: Relationships between exploratory eye movement dysfunction and clinical symptoms in schizophrenia.
abstract: OBJECTIVE
  Many psychophysiological tests have been widely researched in the search for a biological marker of schizophrenia. The exploratory eye movement (EEM) test involves the monitoring of eye movements while subjects freely view geometric figures. Suzuki et al. (2009) performed discriminant analysis between schizophrenia and non-schizophrenia subjects using EEM test data; consequently, clinically diagnosed schizophrenia patients were identified as having schizophrenia with high probability (73.3%). The aim of the present study was to investigate the characteristics of schizophrenia patients who were identified as having schizophrenia on EEM discriminant analysis (SPDSE) or schizophrenia patients who were identified as not having schizophrenia on EEM discriminant analysis (SPDNSE).
  
  
  METHODS
  The data for the 251 schizophrenia subjects used in the previous discriminant-analytic study were analyzed, and the demographic or symptomatic characteristics of SPDSE and SPDNSE were investigated. As for the symptomatic features, a factor analysis of the Brief Psychiatric Rating Scale (BPRS) rating from the schizophrenia subjects was carried out.
  
  
  RESULTS
  Five factors were found for schizophrenia symptoms: excitement/hostility; negative symptoms; depression/anxiety; positive symptoms; and disorganization. SPDSE had significantly higher factor scores for excitement/hostility, negative symptoms and disorganization than SPDNSE. Furthermore, the BPRS total score for the SPDSE was significantly higher than that for the SPDNSE.
  
  
  CONCLUSIONS
  SPDSE may be a disease subtype of schizophrenia with severe symptoms related to excitement/hostility, negative symptoms and disorganization, and EEM parameters may detect this subtype. Therefore, the EEM test may be one of the contributors to the simplification of the heterogeneity of schizophrenia.
authors.affiliation: Department of Psychiatry, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Suzuki
authors.forename: Sakae
authors.initials: S
authors.lastname: Takahashi
authors.forename: Eisuke
authors.initials: E
authors.lastname: Matsushima
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tsunoda
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kurachi
authors.forename: Takashi
authors.initials: T
authors.lastname: Okada
authors.forename: Takuji
authors.initials: T
authors.lastname: Hayashi
authors.forename: Yohei
authors.initials: Y
authors.lastname: Ishii
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Morita
authors.forename: Hisao
authors.initials: H
authors.lastname: Maeda
authors.forename: Seiji
authors.initials: S
authors.lastname: Katayama
authors.forename: Tatsui
authors.initials: T
authors.lastname: Otsuka
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hirayasu
authors.forename: Mizuho
authors.initials: M
authors.lastname: Sekine
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okubo
authors.forename: Mai
authors.initials: M
authors.lastname: Motoshita
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ohta
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Takuya
authors.initials: T
authors.lastname: Kojima
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003627:Data Interpretation, Statistical; D005106:Exploratory Behavior / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D015835:Ocular Motility Disorders / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000145:classification / Q000150:complications; D012565:Schizophrenic Psychology
chemical_list: D014150:Antipsychotic Agents