Se. Starkstein et al., A SPECT STUDY OF DEPRESSION IN ALZHEIMERS-DISEASE, Neuropsychiatry, neuropsychology, and behavioral neurology, 8(1), 1995, pp. 38-43
While dysthymia and major depression are frequent findings among patie
nts with Alzheimer's disease (AD) the mechanism of these affective dis
orders in AD is not well known. We examined the presence of significan
t regional cerebral blood flow (rCBF) correlates of dysthymia and majo
r depression in a consecutive series of patients with AD. Ten AD patie
nts with major depression, 18 AD patients with dysthymia, 21 AD patien
ts with no depression, and 10 normal controls were studied with 99m-Tc
HMPAO-single photon emission tomography (SPECT). AD patients with majo
r depression showed a significantly lower rCBF in the left temporal su
perior and parietal regions as compared to nondepressed AD patients. A
D patients with major depression had a significantly lower rCBF over t
he left hemisphere (mainly involving the frontal dorsal, temporal, and
parietal cortices), and the right temporal cortex and basal ganglia a
s compared to AD patients with dysthymia. On the other hand, no signif
icant rCBF differences were found between AD patients with dysthymia a
nd no depression. While major depression in AD may result from metabol
ic deficits in specific brain regions, dysthymia may have a different
mechanism.