Macromolecular white matter abnormalities in geriatric depression: a magnetization transfer imaging study.
OBJECTIVE
Geriatric depression consists of complex and heterogeneous behaviors unlikely to be caused by a single brain lesion. However, abnormalities in specific brain structures and their interconnections may confer vulnerability to the development of late-life depression. The objective of this study was to identify subtle white matter abnormalities in late-life depression.


METHODS
The authors used magnetization transfer ratio (MTR) imaging, a technique that is thought primarily to reflect myelin integrity, to examine the hypothesis that individuals with late-life depression would exhibit white matter abnormalities in frontostriatal and limbic regions.


METHODS
The study was conducted in a university-based, geriatric psychiatry clinic.


METHODS
Fifty-five older patients with major depression and 24 elderly comparison subjects were assessed.


METHODS
Voxel-based analysis of MTR data were conducted with a general linear model using age as a covariate.


RESULTS
Relative to comparison subjects, patients demonstrated lower MTR in multiple left hemisphere frontostriatal and limbic regions, including white matter lateral to the lentiform nuclei, dorsolateral and dorsomedial prefrontal, dorsal anterior cingulate, subcallosal, periamygdalar, insular, and posterior cingulate regions. Depressed patients had lower MTR in additional left hemisphere locales including the thalamus, splenium of the corpus callosum, inferior parietal, precuneus, and middle occipital white matter regions.


CONCLUSIONS
These findings suggest that geriatric depression may be characterized by reduced myelin integrity in specific aspects of frontostriatal and limbic networks, and complement diffusion tensor studies of geriatric depression that indicate decreased organization of white matter fibers in specific frontal and temporal regions.
Gunning-Dixon
Faith M
FM
Institute of Geriatric Psychiatry and the Department of Psychiatry, Weill Medical College of Cornell University, White Plains, NY, USA. fgd2002@med.cornell.edu
Hoptman
Matthew J
MJ
Lim
Kelvin O
KO
Murphy
Christopher F
CF
Klimstra
Sibel
S
Latoussakis
Vassilios
V
Majcher-Tascio
Magdalena
M
Hrabe
Jan
J
Ardekani
Babak A
BA
Alexopoulos
George S
GS
D000368:Aged; D001921:Brain / Q000033:anatomy & histology / Q000473:pathology*; D003863:Depression / Q000473:pathology*; D003866:Depressive Disorder / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012016:Reference Values