title: Common and Dissociable Dysfunction of the Reward System in Bipolar and Unipolar Depression.
abstract: Unipolar and bipolar depressive episodes have a similar clinical presentation that suggests common dysfunction of the brain's reward system. Here, we evaluated the relationship of both dimensional depression severity and diagnostic category to reward system function in both bipolar and unipolar depression. In total, 89 adults were included, including 27 with bipolar depression, 25 with unipolar depression, and 37 healthy comparison subjects. Subjects completed both a monetary reward task and a resting-state acquisition during 3T BOLD fMRI. Across disorders, depression severity was significantly associated with reduced activation for wins compared with losses in bilateral ventral striatum, anterior cingulate cortex, posterior cingulate cortex, and right anterior insula. Resting-state connectivity within this reward network was also diminished in proportion to depression severity, most notably connectivity strength in the left ventral striatum. In addition, there were categorical differences between patient groups: resting-state connectivity at multiple reward network nodes was higher in bipolar than in unipolar depression. Reduced reward system task activation and resting-state connectivity therefore appear to be a brain phenotype that is dimensionally related to depression severity in both bipolar and unipolar depression. In contrast, categorical differences in reward system resting connectivity between unipolar and bipolar depression may reflect differential risk of mania. Reward system dysfunction thus represents a common brain mechanism with relevance that spans categories of psychiatric diagnosis.
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Theodore D
authors.initials: TD
authors.lastname: Satterthwaite
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Kable
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Lillie
authors.initials: L
authors.lastname: Vandekar
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Natalie
authors.initials: N
authors.lastname: Katchmar
authors.affiliation: Department of Electrical, Systems, and Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Danielle S
authors.initials: DS
authors.lastname: Bassett
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Claudia F
authors.initials: CF
authors.lastname: Baldassano
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Kosha
authors.initials: K
authors.lastname: Ruparel
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Elliott
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Yvette I
authors.initials: YI
authors.lastname: Sheline
authors.affiliation: 1] Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA [2] Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Ruben C
authors.initials: RC
authors.lastname: Gur
authors.affiliation: 1] Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA [2] Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Raquel E
authors.initials: RE
authors.lastname: Gur
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Christos
authors.initials: C
authors.lastname: Davatzikos
authors.affiliation: National Institutes of Mental Health Emotion and Development Branch, Bethesda, MD, USA.
authors.forename: Ellen
authors.initials: E
authors.lastname: Leibenluft
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Thase
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Wolf
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000150:complications* / Q000473:pathology; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D003863:Depression / Q000145:classification / Q000150:complications* / Q000473:pathology; D004213:Dissociative Disorders / Q000209:etiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011569:Psychiatric Status Rating Scales; D012146:Rest; D012201:Reward
chemical_list: D010100:Oxygen