Neural activation during facial emotion processing in unmedicated bipolar depression, euthymia, and mania.
BACKGROUND
Studies incorporating direct comparisons across all phases of bipolar (BP) disorder are needed to elucidate the pathophysiology of bipolar disorder. However, functional neuroimaging studies that differentiate bipolar mood states from each other and from healthy subjects are few and have yielded inconsistent findings.


METHODS
One hundred five unmedicated adults were recruited: 30 with current bipolar depression (BPD), 30 with current bipolar hypomania or mania (BPM), 15 bipolar euthymic (BPE), and 30 healthy control subjects (HC). All subjects were diagnosed with DSM-IV BP (type I or II) using a structured clinical interview. Groups were age- and gender-ratio matched. In 3T functional magnetic resonance imaging experiments, subjects completed a negative facial emotion matching task.


RESULTS
Bipolar euthymic and BPD groups exhibited increased amygdala activation compared with HCs in response to the negative faces; however, in the BPM group, this increase was not seen. Conversely, both BPE and BPM groups had increased activation in the insula relative to HCs, but in the BPD group, this effect was not seen. All three BP groups exhibited increased activation of the putamen compared with HCs. In the cortical areas, the BPM group exhibited decreased left lateral orbitofrontal cortex activation compared with both BPEs and HCs, increased dorsal anterior cingulate cortex activation compared with the BPD group, and increased dorsolateral prefrontal cortical activation compared with all other groups.


CONCLUSIONS
Both state- and trait-related abnormalities in corticolimbic activation were seen in response to the negative facial emotion processing in a large sample of unmedicated adults across BP mood states.
Mood and Emotion Disorders Across the Lifespan Center, Department of Psychiatry, Indiana University School of Medicine, Indianapolis, USA.
Leslie A
LA
Hulvershorn
Harish
H
Karne
Abigail D
AD
Gunn
Sarah L
SL
Hartwick
Yang
Y
Wang
Tom A
TA
Hummer
Amit
A
Anand
D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000503:physiopathology*; D016022:Case-Control Studies; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods / Q000523:psychology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012720:Severity of Illness Index