Major depressive disorder and white matter abnormalities: a diffusion tensor imaging study with tract-based spatial statistics.
BACKGROUND
A few diffusion tensor imaging (DTI) studies have shown abnormalities in areas of white matter tracts involved in mood regulation in geriatric depressive patients, using a region-of-interest technique. A voxel-based morphometry DTI study of young depressive patients reported similar results. In this study, we explored the structure of the white matter of the whole brain with DTI in middle-aged major depressive disorder (MDD) patients, using novel tract-based spatial statistics.


METHODS
Sixteen MDD patients and 20 controls underwent DTI. An automated tract-based spatial method (TBSS) was used to analyze the scans.


RESULTS
Compared with controls, the MDD patients showed a trend for lower values of fractional anisotropy (FA) in the left sagittal stratum, and suggestive decreased FA in the right cingulate cortex and posterior body of corpus callosum. Regressing out the duration and severity of disorder in the model did not change the finding in the sagittal stratum, but dissipated the decrease of FA in latter regions.


CONCLUSIONS
Possibly by reason of a relatively small study sample for a TBSS, the results are suggestive, and should be replicated in further studies.


CONCLUSIONS
A novel observer-independent DTI method showed decreased FA in the middle-aged MDD patients in white matter regions that have previously connected to the emotional regulation. Lower FA might imply underlying structural abnormalities that contribute to the dysfunction detected in the limbic-cortical network of depressive patients.
Kieseppä
Tuula
T
Department of Mental Health and Alcohol Research, National Public Heath Institute, Finland. tuula.kieseppa@ktl.fi
Eerola
Mervi
M
Mäntylä
Riitta
R
Neuvonen
Tuomas
T
Poutanen
Veli-Pekka
VP
Luoma
Katariina
K
Tuulio-Henriksson
Annamari
A
Jylhä
Pekka
P
Mantere
Outi
O
Melartin
Tarja
T
Rytsälä
Heikki
H
Vuorilehto
Maria
M
Isometsä
Erkki
E
D000328:Adult; D016880:Anisotropy; D001921:Brain / Q000033:anatomy & histology* / Q000503:physiopathology*; D003337:Corpus Callosum / Q000033:anatomy & histology / Q000503:physiopathology; D003865:Major Depressive Disorder / Q000453:epidemiology* / Q000503:physiopathology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006179:Gyrus Cinguli / Q000033:anatomy & histology / Q000503:physiopathology; D006801:Humans; D008032:Limbic System / Q000033:anatomy & histology / Q000503:physiopathology; D008297:Male; D009415:Nerve Net / Q000033:anatomy & histology / Q000503:physiopathology