title: Resting State Brain Network Disturbances Related to Hypomania and Depression in Medication-Free Bipolar Disorder.
abstract: Research on resting functional brain networks in bipolar disorder (BP) has been unable to differentiate between disturbances related to mania or depression, which is necessary to understand the mechanisms leading to each state. Past research has also been unable to elucidate the impact of BP-related network disturbances on the organizational properties of the brain (eg, communication efficiency). Thus, the present work sought to isolate network disturbances related to BP, fractionate these into components associated with manic and depressive symptoms, and characterize the impact of disturbances on network function. Graph theory was used to analyze resting functional magnetic resonance imaging data from 60 medication-free patients meeting the criteria for BP and either a current hypomanic (n=30) or depressed (n=30) episode and 30 closely age/sex-matched healthy controls. Correction for multiple comparisons was carried out. Compared with controls, BP patients evidenced hyperconnectivity in a network involving right amygdala. Fractionation revealed that (hypo)manic symptoms were associated with hyperconnectivity in an overlapping network and disruptions in the brain's 'small-world' network organization. Depressive symptoms predicted hyperconnectivity in a network involving orbitofrontal cortex along with a less resilient global network organization. Findings provide deeper insight into the differential pathophysiological processes associated with hypomania and depression, along with the particular impact these differential processes have on network function.
authors.affiliation: Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, USA.|Neuroimaging Research for Veterans Center, VA Boston Healthcare System, Boston, MA, USA.
authors.forename: Jeffrey M
authors.identifier: 0000-0001-8348-7157
authors.initials: JM
authors.lastname: Spielberg
authors.affiliation: Imaging Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Erik B
authors.initials: EB
authors.lastname: Beall
authors.affiliation: Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Hulvershorn
authors.affiliation: Center for Behavioral Health, Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Murat
authors.initials: M
authors.lastname: Altinay
authors.affiliation: Center for Behavioral Health, Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Harish
authors.initials: H
authors.lastname: Karne
authors.affiliation: Center for Behavioral Health, Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Anand
mesh_terms: D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000150:complications* / Q000000981:diagnostic imaging; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D003863:Depression / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009434:Neural Pathways / Q000473:pathology; D010100:Oxygen / Q000097:blood; D011569:Psychiatric Status Rating Scales; D012146:Rest; D055815:Young Adult
chemical_list: D010100:Oxygen