Neural activation during encoding of emotional faces in pediatric bipolar disorder.
OBJECTIVE
Neurobiological understanding of bipolar disorder (BD) is limited by a paucity of functional magnetic resonance imaging (fMRI) research examining correlates of psychological processes. To begin to address these limitations, the current study tests the hypothesis that pediatric BD (PBD) subjects exhibit altered neural activation during encoding of emotional faces compared to typically developing controls.


METHODS
Pediatric BD subjects (n=23; mean age=14.2+/-3.1 years) and controls (n=22; mean age=14.7+/-2.3 years) were matched on age, gender, and IQ. In this event-related fMRI study, subjects were scanned while viewing emotional faces and given a surprise recognition memory test 30 min postscan. Our main outcome measure was between-group differences in neural activation during successful versus unsuccessful face encoding.


RESULTS
Pediatric BD youth exhibited reduced memory for emotional faces, relative to healthy comparisons, particularly on fearful faces. Event-related fMRI analyses controlling for this behavioral difference showed that PBD subjects, compared to controls, had increased neural activation in the striatum and anterior cingulate cortex when successfully encoding happy faces and in the orbitofrontal cortex when successfully encoding angry faces. There were no between-group differences in neural activation during fearful face encoding.


CONCLUSIONS
Our results extend what is known about memory and face emotion processing impairments in PBD subjects by showing increased fronto-striatal activation during encoding of emotional faces. Further work is required to determine the impact of mood state, medication, and comorbid illnesses on these findings.
Dickstein
Daniel P
DP
Division of Intramural Research Program, National Institute of Mental Health, Pediatrics and Developmental Neuropsychiatry Branch, Bethesda, MD 20892-2670, USA. dicksted@mail.nih.gov
Rich
Brendan A
BA
Roberson-Nay
Roxann
R
Berghorst
Lisa
L
Vinton
Deborah
D
Pine
Daniel S
DS
Leibenluft
Ellen
E
D000293:Adolescent; D000367:Age Factors; D000786:Anger / Q000502:physiology; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000523:psychology; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D003342:Corpus Striatum / Q000502:physiology; D004644:Emotions / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D005149:Facial Expression; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006179:Gyrus Cinguli / Q000502:physiology; D006240:Happiness; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008568:Memory / Q000502:physiology; D009483:Neuropsychological Tests; D021641:Recognition, Psychology / Q000502:physiology; D014796:Visual Perception / Q000502:physiology