Divergent relationship of depression severity to social reward responses among patients with bipolar versus unipolar depression.
Neuroimaging studies of mood disorders demonstrate abnormalities in brain regions implicated in reward processing. However, there is a paucity of research investigating how social rewards affect reward circuit activity in these disorders. Here, we evaluated the relationship of both diagnostic category and dimensional depression severity to reward system function in bipolar and unipolar depression. In total, 86 adults were included, including 24 patients with bipolar depression, 24 patients with unipolar depression, and 38 healthy comparison subjects. Participants completed a social reward task during 3T BOLD fMRI. On average, diagnostic groups did not differ in activation to social reward. However, greater depression severity significantly correlated with reduced bilateral ventral striatum activation to social reward in the bipolar depressed group, but not the unipolar depressed group. In addition, decreased left orbitofrontal cortical activation correlated with more severe symptoms in bipolar depression, but not unipolar depression. These differential dimensional effects resulted in a significant voxelwise group by depression severity interaction. Taken together, these results provide initial evidence that deficits in social reward processing are differentially related to depression severity in the two disorders.
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: anup@mail.med.upenn.edu.
Anup
A
Sharma
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Theodore D
TD
Satterthwaite
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Lillie
L
Vandekar
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Natalie
N
Katchmar
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Aylin
A
Daldal
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Kosha
K
Ruparel
Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Mark A
MA
Elliott
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Claudia
C
Baldassano
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Michael E
ME
Thase
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Raquel E
RE
Gur
Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Joseph W
JW
Kable
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Daniel H
DH
Wolf
D000328:Adult; D001714:Bipolar Disorder / Q000503:physiopathology*; D003865:Major Depressive Disorder / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012201:Reward; D012938:Social Perception; D066328:Ventral Striatum / Q000503:physiopathology*
Magnetic resonance imaging; Mood disorders; Neuroimaging