title: Decreased resting-state brain activity complexity in schizophrenia characterized by both increased regularity and randomness.
abstract: Schizophrenia is characterized by heterogeneous pathophysiology. Using multiscale entropy (MSE) analysis, which enables capturing complex dynamics of time series, we characterized MSE patterns of blood-oxygen-level-dependent (BOLD) signals across different time scales and determined whether BOLD activity in patients with schizophrenia exhibits increased complexity (increased entropy in all time scales), decreased complexity toward regularity (decreased entropy in all time scales), or decreased complexity toward uncorrelated randomness (high entropy in short time scales followed by decayed entropy as the time scale increases). We recruited 105 patients with schizophrenia with an age of onset between 18 and 35 years and 210 age- and sex-matched healthy volunteers. Results showed that MSE of BOLD signals in patients with schizophrenia exhibited two routes of decreased BOLD complexity toward either regular or random patterns. Reduced BOLD complexity toward regular patterns was observed in the cerebellum and temporal, middle, and superior frontal regions, and reduced BOLD complexity toward randomness was observed extensively in the inferior frontal, occipital, and postcentral cortices as well as in the insula and middle cingulum. Furthermore, we determined that the two types of complexity change were associated differently with psychopathology; specifically, the regular type of BOLD complexity change was associated with positive symptoms of schizophrenia, whereas the randomness type of BOLD complexity was associated with negative symptoms of the illness. These results collectively suggested that resting-state dynamics in schizophrenia exhibit two routes of pathologic change toward regular or random patterns, which contribute to the differences in syndrome domains of psychosis in patients with schizophrenia.
authors: Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan; Division of Psychiatry, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Center for Dynamical Biomarkers and Translational Medicine, National Central University, Chungli, Taiwan; Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, Massachusetts.
authors: Albert C
authors: AC
authors: Yang
authors: Chen-Jee
authors: CJ
authors: Hong
authors: Yin-Jay
authors: YJ
authors: Liou
authors: Kai-Lin
authors: KL
authors: Huang
authors: Chu-Chung
authors: CC
authors: Huang
authors: Mu-En
authors: ME
authors: Liu
authors: Men-Tzung
authors: MT
authors: Lo
authors: Norden E
authors: NE
authors: Huang
authors: Chung-Kang
authors: CK
authors: Peng
authors: Ching-Po
authors: CP
authors: Lin
authors: Shih-Jen
authors: SJ
authors: Tsai
mesh_terms: D000328:Adult; D017668:Age of Onset; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012146:Rest; D012559:Schizophrenia / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: complexity; multiscale entropy; randomness; regularity; schizophrenia