Progressive gray matter loss in patients with bipolar disorder.
BACKGROUND
Structural brain abnormalities of the medial temporal lobe have been found in people with bipolar disorder (BPD). It is not known whether these abnormalities progress over the course of the illness or how they relate to neuropsychologic functioning. We sought to address these uncertainties in a prospective cohort study of people with bipolar I disorder.


METHODS
Twenty patients with bipolar I disorder and 21 control subjects were recruited from the community. Participants were group matched for age, sex, and premorbid IQ. Longitudinal change in gray matter density was assessed using magnetic resonance imaging and evaluated using the technique of tensor-based morphometry with SPM2 software. Changes in gray and white matter density were estimated and compared with changes in cognitive function and clinical outcome.


RESULTS
Patients with BPD showed a larger decline in hippocampal, fusiform, and cerebellar gray matter density over 4 years than control subjects. No significant changes in white matter density were found. Reductions in temporal lobe gray matter correlated with decline in intellectual function and with the number of intervening mood episodes over the follow-up period.


CONCLUSIONS
Patients with BPD lose hippocampal, fusiform and cerebellar gray matter at an accelerated rate compared with healthy control subjects. This tissue loss is associated with deterioration in cognitive function and illness course.
Moorhead
T William J
TW
Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, United Kingdom.
McKirdy
James
J
Sussmann
Jessika E D
JE
Hall
Jeremy
J
Lawrie
Stephen M
SM
Johnstone
Eve C
EC
McIntosh
Andrew M
AM
D000328:Adult; D001714:Bipolar Disorder / Q000473:pathology*; D016022:Case-Control Studies; D002531:Cerebellum / Q000033:anatomy & histology / Q000473:pathology*; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000033:anatomy & histology / Q000473:pathology*; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D009929:Organ Size; D012016:Reference Values