Functional imaging of emotional memory in bipolar disorder and schizophrenia.
OBJECTIVE
Although in current diagnostic criteria there exists a distinction between bipolar disorder and schizophrenia, many patients manifest features of both disorders, and it is unclear which aspects, if any, confer diagnostic specificity. In the present study, we investigate whether there are differences in medial temporal lobe (MTL) activation in bipolar disorder and schizophrenia. We also investigate associations between activation levels and symptom severity across the disorders.


METHODS
Functional magnetic resonance imaging scans were conducted on 14 healthy controls, 14 patients with bipolar disorder, and 15 patients with schizophrenia undergoing an emotional memory paradigm.


RESULTS
All groups demonstrated the expected pattern of behavioural responses during encoding and retrieval, and there were no significant group differences in performance. Robust MTL activation was seen in all three groups during viewing of emotional scenes, which correlated significantly with recognition memory for emotional stimuli. The bipolar group demonstrated relatively greater increases in activation for emotional versus neutral scenes in the left hippocampus than both controls and patients with schizophrenia. There was a significant positive correlation between mania scores and activation in the anterior cingulate, and a significant negative correlation between depression scores and activation in the dorsolateral prefrontal cortex.


CONCLUSIONS
These results provide evidence that there are distinct patterns of activation in the MTL during an emotional memory task in bipolar disorder and schizophrenia. They also demonstrate that different mood states are associated with different neurobiological responses to emotion across the patient groups.
Whalley
Heather C
HC
Division of Psychiatry, School of Molecular and Clinical Medicine, University of Edinburgh, Edinburgh, Scotland, UK. hwhalley@staffmail.ed.ac.uk
McKirdy
James
J
Romaniuk
Liana
L
Sussmann
Jessika
J
Johnstone
Eve C
EC
Wan
Hong I
HI
McIntosh
Andrew M
AM
Lawrie
Stephen M
SM
Hall
Jeremy
J
D000328:Adult; D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000473:pathology* / Q000503:physiopathology; D001931:Brain Mapping; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013223:Statistics as Topic; D013702:Temporal Lobe / Q000098:blood supply*
D010100:Oxygen