Altered white matter microstructure in adolescents with major depression: a preliminary study.
OBJECTIVE
Major depressive disorder (MDD) occurs frequently in adolescents, but the neurobiology of depression in youth is poorly understood. Structural neuroimaging studies in both adult and pediatric populations have implicated frontolimbic neural networks in the pathophysiology of MDD. Diffusion tensor imaging (DTI), which measures white matter (WM) microstructure, is a promising tool for examining neural connections and how they may be abnormal in MDD.


METHODS
We used two separate approaches to analyze DTI data in adolescents with MDD (n = 14) compared with healthy volunteers (n = 14).


RESULTS
The first, hypothesis-driven approach was to use probabilistic tractography to delineate tracts arising from the subgenual anterior cingulate cortex (ACC). Adolescents with MDD demonstrated lower fractional anisotropy (FA) in the WM tract connecting subgenual ACC to amygdala in the right hemisphere. The second, exploratory approach was to conduct a voxelwise comparison of FA. This analysis revealed 10 clusters where adolescents with MDD had significantly lower (uncorrected) FA than the healthy group within WM tracts including right and left uncinate and supragenual cingulum.


CONCLUSIONS
These preliminary data support the hypothesis that altered WM microstructure in frontolimbic neural pathways may contribute to the pathophysiology of MDD in adolescents.
Cullen
Kathryn R
KR
Department of Psychiatry, University of Minnesota Medical School, University of Minnesota, Center for Magnetic Resonance Research, Minneapolis, MN 55454, USA. rega0026@umn.edu
Klimes-Dougan
Bonnie
B
Muetzel
Ryan
R
Mueller
Bryon A
BA
Camchong
Jazmin
J
Houri
Alaa
A
Kurma
Sanjiv
S
Lim
Kelvin O
KO
D000293:Adolescent; D000679:Amygdala / Q000473:pathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology*; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000473:pathology* / Q000523:psychology; D038524:Diffusion Magnetic Resonance Imaging; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000473:pathology / Q000523:psychology; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009434:Neural Pathways / Q000473:pathology; D012016:Reference Values