|Hye Sook Lee1;Il Han Choo1;Dong Young Lee1,2;Jee Wook Kim1;Eun Hyun Seo2;Shin Gyeom Kim3;Shin Young Park4;Ji Hye Shin1;Ki Woong Kim5; and Jong Inn Woo1,2;
1;Departments of Neuropsychiatry and
2;Interdisciplinary Program for Cognitive Science, College of Medicine, Seoul National University, Seoul,
3;Department of Neuropsychiatry, College of Medicine, Soonchunhyang University, Bucheon Hospital, Bucheon,
4;Department of Neuropsychiatry, Daerim St. Mary's Hospital, Seoul,
5;Department of Neuropsychiatry, College of Medicine, Seoul National University, Bundang Hospital, Seongnam, Korea
Objective : Depression is a very common symptom in people with mild cognitive
impairment (MCI), a preclinical stage of Alzheimer's disease (AD), and in those
with clinically evident AD. Moreover, MCI individuals with depression show a
higher conversion rate to clinical AD than those without depression. This study
aimed to elucidate the functional neuroanatomical substrate of depression in
Methods : Thirty-six patients were recruited from a University Hospital-based
cohort; 18 of these subjects had MCI with depression (MCI_D); the remaining 18
subjects were age- and gender-matched, and had MCI with no depression (MCI_ND).
For comparison, 16 cognitively normal (CN) elderly individuals were also
included. All subjects underwent Fluorodeoxyglucose Positron Emission Tomography
(FDG-PET) scanning and regional cerebral glucose metabolism was compared among
the three groups by a voxel-based method. The relationship between severity of
depression, as measured by Hamilton Rating Scale for Depression (HRSD) scores,
and glucose metabolism was also investigated.
Results : MCI_D showed lower glucose metabolism in the right superior frontal
gyrus than MCI_ND. There was a significant negative correlation between HRSD
score and glucose metabolism at the same frontal region for overall MCI
subjects. When compared with CN, both MCI_D and MCI_ND showed decreased glucose
metabolism in the precuneus, while MCI_D had, in addition, reduced metabolism in
other diffuse brain regions.
Conclusion : Given previous observations on depression in AD, our results
suggest that functional disruption of the frontal region, known to be associated
with primary or other secondary depression, underlies depression in preclinical
AD as well as clinically evident AD.
Mild cognitive impairment;Depression;Frontal;Fluorodeoxyglucose Positron Emission Tomography.