title: Similar age-related decline in cortical activity over frontotemporal regions in schizophrenia: a multichannel near-infrared spectroscopy study.
abstract: OBJECTIVE
  Although recent studies have demonstrated that patients with schizophrenia and healthy controls did not differ in the speed of age-related decline in cortical thickness and performances on cognitive tests, hemodynamic changes assessed by functional neuroimaging remain unclear. This study investigated age effects on regional brain cortical activity to determine whether there is similar age-related decline in cortical activity as those observed in cortical thickness and cognitive test performance.
  
  
  METHODS
  A total of 109 patients with schizophrenia (age range: 16-59 y) and 106 healthy controls (age range: 16-59 y) underwent near-infrared spectroscopy (NIRS) while performing a verbal fluency test (VFT). Group comparison of cortical activity was examined using 2-tailed t tests, adopting the false discovery rate method. The relationship between age and cortical activity was investigated using correlational and multiple regression analyses, adjusting for potential confounding variables. A 2-way ANOVA was conducted to investigate differences in the age effects between diagnostic groups.
  
  
  RESULTS
  The patient group exhibited significantly decreased cortical activity in several regions of the frontotemporal cortices. However, slopes of age-dependent decreases in cortical activity were similar between patients and healthy individuals at the bilateral frontotemporal regions.
  
  
  CONCLUSIONS
  Our study showed no significant between-group differences in the age-related decline in cortical activity, as measured by NIRS, over the frontotemporal regions during a VFT. The results of our study may indicate a decrease in cortical activity in a relatively limited period around illness onset rather than continuously progressing over the course of the illness.
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Department of Psychiatry, Taichung Veterans General Hospital, Taichung City, Taiwan;
authors.forename: Po-Han
authors.initials: PH
authors.lastname: Chou
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Division for Counseling and Support, Office for Mental Health Support, University of Tokyo, Bunkyo-ku, Tokyo, Japan;
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Koike
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan;
authors.forename: Yukika
authors.initials: Y
authors.lastname: Nishimura
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan;
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Satomura
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan;
authors.forename: Akihide
authors.initials: A
authors.lastname: Kinoshita
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK.
authors.forename: Ryu
authors.initials: R
authors.lastname: Takizawa
authors.affiliation: Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan; kasaik-tky@umin.net.
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Kasai
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology*; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000503:physiopathology*; D059907:Functional Neuroimaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*; D019265:Spectroscopy, Near-Infrared; D013702:Temporal Lobe / Q000098:blood supply / Q000503:physiopathology*; D055815:Young Adult
keywords: NIRS; age effect; near infrared spectroscopy; schizophrenia