Subcortical and ventral prefrontal cortical neural responses to facial expressions distinguish patients with bipolar disorder and major depression.
BACKGROUND
Bipolar disorder (BD) is characterised by abnormalities in mood and emotional processing, but the neural correlates of these, their relationship to depressive symptoms, and the similarities with deficits in major depressive disorder (MDD) remain unclear. We compared responses within subcortical and prefrontal cortical regions to emotionally salient material in patients with BP and MDD using functional magnetic resonance imaging.


METHODS
We measured neural responses to mild and intense expressions of fear, happiness, and sadness in euthymic and depressed BD patients, healthy control subjects, and depressed MDD patients.


RESULTS
Bipolar disorder patients demonstrated increased subcortical (ventral striatal, thalamic, hippocampal) and ventral prefrontal cortical responses particularly to mild and intense fear, mild happy, and mild sad expressions. Healthy control subjects demonstrated increased subcortical responses to intense happy and mild fear, and increased dorsal prefrontal cortical responses to intense sad expressions. Overall, MDD patients showed diminished neural responses to all emotional expressions except mild sadness. Depression severity correlated positively with hippocampal response to mild sadness in both patient groups.


CONCLUSIONS
Compared with healthy controls and MDD patients, BD patients demonstrated increased subcortical and ventral prefrontal cortical responses to both positive and negative emotional expressions.
Lawrence
Natalia S
NS
Section of Neuroscience and Emotion, Institute of Psychiatry, London, United Kingdom.
Williams
Andrew M
AM
Surguladze
Simon
S
Giampietro
Vincent
V
Brammer
Michael J
MJ
Andrew
Christopher
C
Frangou
Sophia
S
Ecker
Christine
C
Phillips
Mary L
ML
D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology*; D004522:Educational Status; D004644:Emotions / Q000502:physiology; D005149:Facial Expression; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000503:physiopathology*