White matter abnormalities in bipolar disorder and schizophrenia detected using diffusion tensor magnetic resonance imaging.
OBJECTIVE
Strong qualitative and quantitative evidence exists of white matter abnormalities in both schizophrenia and bipolar disorder (BD). Diffusion tensor imaging (DTI) studies suggest altered connectivity in both disorders. We aim to address the diagnostic specificity of white matter abnormalities in these disorders.


METHODS
DTI was used to assess white matter integrity in clinically stable patients with familial BD (n = 42) and familial schizophrenia (n = 28), and in controls (n = 38). Differences in fractional anisotropy (FA) were measured using voxel-based morphometry and automated region of interest analysis.


RESULTS
Reduced FA was found in the anterior limb of the internal capsule (ALIC), anterior thalamic radiation (ATR), and in the region of the uncinate fasciculus in patients with BD and those with schizophrenia compared with controls. A direct comparison between patient groups found no significant differences in these regions. None of the findings were associated with psychotropic medication.


CONCLUSIONS
Reduced integrity of the ALIC, uncinate fasciculus, and ATR regions is common to both schizophrenia and BD. These results imply an overlap in white matter pathology, possibly relating to risk factors common to both disorders.
Sussmann
Jessika E
JE
Division of Psychiatry, University of Edinburgh, Royal Edinburgh Hospital, Edinburgh, UK. jess.sussmann@ed.ac.uk
Lymer
G Katherine S
GK
McKirdy
James
J
Moorhead
T William J
TW
Muñoz Maniega
Susana
S
Job
Dominic
D
Hall
Jeremy
J
Bastin
Mark E
ME
Johnstone
Eve C
EC
Lawrie
Stephen M
SM
McIntosh
Andrew M
AM
D000328:Adult; D016880:Anisotropy; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000473:pathology; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000175:diagnosis* / Q000473:pathology