title: Predictive value of premorbid IQ, negative symptoms, and age for cognitive and social functions in Japanese patients with schizophrenia: A study using the Japanese version of the Brief Assessment of Cognition in Schizophrenia.
abstract: Enduring cognitive impairment in patients with schizophrenia represents a global health burden. The Japanese-language version of the Brief Assessment of Cognition in Schizophrenia (BACS) and the Japanese Adult Reading Test were administered to 288 patients with chronic schizophrenia and 308 unrelated healthy control subjects. The Japanese version of self-reported Social Functioning Scale (SFS) was administered to a subpopulation of 157 patients with schizophrenia. In patients with schizophrenia, premorbid IQ and age were significantly related to most of the BACS subdomains, composite score, and intra-individual variability of BACS subdomains, whereas negative symptoms were significantly related to all BACS indices. Dosages of the first-generation antipsychotics had a significant negative impact on Tower of London task and intra-individual variability of BACS subdomains. The relationship of symbol coding with age was significantly lower in patients than in healthy control subjects. Multiple regression analysis revealed that negative symptoms were significantly negatively related to the total SFS scale, whereas better performance of token motor task was associated with higher total SFS. The present study revealed the role of premorbid IQ, age, and negative symptoms in predicting cognitive performance, and the significant correlation of negative symptoms and token motor task with social function in patients with schizophrenia.
authors.affiliation: Department of Biological Psychiatry and Neuroscience, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan. Electronic address: kazufuak@dokkyomed.ac.jp.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Akiyama
authors.affiliation: Department of Biological Psychiatry and Neuroscience, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan; Department of Psychiatry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saito
authors.affiliation: Department of Biological Psychiatry and Neuroscience, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, 600 North Wolfe Street/Meyer 3-146, Baltimore, MD 21287, USA.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Saito
authors.affiliation: Department of Psychiatry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ozeki
authors.affiliation: Department of Psychiatry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Psychiatry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Fujii
authors.affiliation: Seiseido Kohseikai, Mori Hospital, 419 Iidamachi, Utsunomiya, Tochigi 3210347, Japan.
authors.forename: Gyo
authors.initials: G
authors.lastname: Honda
authors.affiliation: Department of Psychiatry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi 3210293, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Shimoda
mesh_terms: D000328:Adult; D000367:Age Factors; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology*; D066107:Social Skills