title: Resting-state theta band connectivity and graph analysis in generalized social anxiety disorder.
abstract: Functional magnetic resonance imaging (fMRI) resting-state studies show generalized social anxiety disorder (gSAD) is associated with disturbances in networks involved in emotion regulation, emotion processing, and perceptual functions, suggesting a network framework is integral to elucidating the pathophysiology of gSAD. However, fMRI does not measure the fast dynamic interconnections of functional networks. Therefore, we examined whole-brain functional connectomics with electroencephalogram (EEG) during resting-state.
  
  
  
  Resting-state EEG data was recorded for 32 patients with gSAD and 32 demographically-matched healthy controls (HC). Sensor-level connectivity analysis was applied on EEG data by using Weighted Phase Lag Index (WPLI) and graph analysis based on WPLI was used to determine clustering coefficient and characteristic path length to estimate local integration and global segregation of networks.
  
  
  
  WPLI results showed increased oscillatory midline coherence in the theta frequency band indicating higher connectivity in the gSAD relative to HC group during rest. Additionally, WPLI values positively correlated with state anxiety levels within the gSAD group but not the HC group. Our graph theory based connectomics analysis demonstrated increased clustering coefficient and decreased characteristic path length in theta-based whole brain functional organization in subjects with gSAD compared to HC.
  
  
  
  Theta-dependent interconnectivity was associated with state anxiety in gSAD and an increase in information processing efficiency in gSAD (compared to controls). Results may represent enhanced baseline self-focused attention, which is consistent with cognitive models of gSAD and fMRI studies implicating emotion dysregulation and disturbances in task negative networks (e.g., default mode network) in gSAD.
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States.
authors.forename: Mengqi
authors.initials: M
authors.lastname: Xing
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States.
authors.forename: Reza
authors.initials: R
authors.lastname: Tadayonnejad
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States.
authors.forename: Annmarie
authors.initials: A
authors.lastname: MacNamara
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States.
authors.forename: Olusola
authors.initials: O
authors.lastname: Ajilore
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States.
authors.forename: Julia
authors.initials: J
authors.lastname: DiGangi
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States; Department of Psychology, University of Illinois at Chicago, Chicago, IL, United States; Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States; Mental Health Service Line, Jesse Brown VA Medical Center, Chicago, IL, United States.
authors.forename: K Luan
authors.initials: KL
authors.lastname: Phan
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States; Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States.
authors.forename: Alex
authors.initials: A
authors.lastname: Leow
authors.affiliation: Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States; Department of Psychology, University of Illinois at Chicago, Chicago, IL, United States.
authors.forename: Heide
authors.initials: H
authors.lastname: Klumpp
mesh_terms: D000328:Adult; D063132:Connectome / Q000379:methods*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D000072861:Phobia, Social / Q000503:physiopathology*; D013826:Theta Rhythm / Q000502:physiology*; D055815:Young Adult
keywords: Connectomics; EEG; Graph theory; Major depressive disorder; Social anxiety disorders