Modulation of a human memory circuit by subsyndromal depression in late life: a functional magnetic resonance imaging study.
OBJECTIVE
Functional deactivation of the posteromedial cortex (PMC) seems to be a physiologic process underlying normal memory. The authors examined whether older subjects with subsyndromal depressive symptoms show impaired PMC deactivation.


METHODS
Subjects underwent 4T functional magnetic resonance imaging scan while performing a novel and familiar face-name associative encoding task. The Beck-II Depression Inventory (BDI) was used to self-rate depression symptoms. A novel-minus-familiar encoding contrast was built into a simple regression model showing brain activation magnitudes that covaried with BDI score. A region-of-interest mask was applied to isolate the PMC and other midline structures of the default-mode network.


METHODS
The study was conducted at a university-based medical center.


METHODS
Participants included 62 nondemented subjects aged 55-85, with and without mild memory deficits. BDI scores ranged from 0 to 17.


RESULTS
Analysis revealed a distinct PMC cluster confined to the dorsal posterior cingulate cortex (BA 31) whose activity correlated significantly with BDI score. A multiple regression model further showed that BDI score, as well as a history of depression and current use of antidepressants, had a significant effect on cluster variance, while age, education, gender, and mini-mental state exam scores did not.


CONCLUSIONS
Our findings raise the hypothesis that subsyndromal depressive symptoms in late life may impair physiological PMC deactivation in the dorsal posterior cingulate cortex. A prospective study of a full spectrum of depressed patients may be warranted.
Woo
Shoshana L
SL
Department of Psychiatry, Center for Study of Aging and School of Medicine, Duke University Medical Center, Duke University, Durham, NC 27710-3808, USA.
Prince
Steven E
SE
Petrella
Jeffrey R
JR
Hellegers
Caroline
C
Doraiswamy
P Murali
PM
D000368:Aged; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000503:physiopathology; D003863:Depression / Q000503:physiopathology*; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology; D008569:Memory Disorders / Q000503:physiopathology*; D008875:Middle Aged; D009424:Nervous System Physiological Phenomena; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012647:Self-Assessment
Radiology. 2006 Jul;240(1):177-86
16684919
J Psychiatr Res. 1975 Nov;12(3):189-98
1202204
Radiology. 2007 Oct;245(1):224-35
17885190
Am J Geriatr Psychiatry. 2007 Jul;15(7):604-10
17586784
Neuroimage. 2003 Jul;19(3):1233-9
12880848
Biol Psychiatry. 2007 Dec 1;62(11):1236-43
17601497
Biol Psychiatry. 2007 Sep 1;62(5):429-37
17210143
Int J Geriatr Psychiatry. 2008 Aug;23(8):773-81
18200611
Neurology. 1984 Jul;34(7):939-44
6610841
J Cogn Neurosci. 2003 Apr 1;15(3):394-408
12729491
Neurology. 1993 Nov;43(11):2412-4
8232972
PLoS One. 2007 Oct 31;2(10):e1104
17971867
Proc Natl Acad Sci U S A. 2001 Jan 16;98(2):676-82
11209064
Hum Brain Mapp. 1996;4(1):58-73
20408186
Arch Gen Psychiatry. 2006 May;63(5):530-8
16651510
Am J Geriatr Psychiatry. 2007 Jul;15(7):594-603
17353296
Arch Gen Psychiatry. 2005 Apr;62(4):397-408
15809407
Proc Natl Acad Sci U S A. 2003 Nov 25;100(24):14504-9
14608034