No neuropathologic evidence for an increased frequency of Alzheimer's disease among elderly schizophrenics.
BACKGROUND
There is currently controversy as to the frequency of Alzheimer's disease (AD) in elderly persons with schizophrenia. Several studies have reported an increased frequency of AD in elderly schizophrenics, whereas others have found no increase. This issue is important because it has been hypothesized that medications used to treat schizophrenia may exacerbate AD histopathology.


METHODS
We examined autopsy cases from a state psychiatric hospital and a Veterans Affairs medical center. Charts were reviewed on 166 subjects to determine if the history warranted a DSM-IV diagnosis of schizophrenia. All subjects had complete gross and microscopic neuropathologic evaluations, which were reviewed for evidence of Alzheimer's disease.


RESULTS
Retrospective chart review identified 51 subjects over the age of 55 who met DSM-IV criteria for schizophrenia (mean age = 71.7 years, SD = 8.6, range 56-95 years). Of these 51, only I met neuropathologic criteria for AD, a frequency of 2%.


CONCLUSIONS
The frequency of subjects meeting neuropathologic criteria for Alzheimer's disease in our sample of schizophrenics was equal to or less than that found in the general population. Because institutionalized populations may contain an excess of elderly schizophrenic patients with severe behavioral pathologies, which may in turn reflect the presence of neurodegenerative processes such as Alzheimer's disease, our results may actually overestimate the frequency of Alzheimer's in the entire schizophrenic population. The frequency of Alzheimer's disease in the elderly with schizophrenia may be less than that in the general population.
Murphy
G M
GM
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, California 94305-5485, USA.
Lim
K O
KO
Wieneke
M
M
Ellis
W G
WG
Forno
L S
LS
Hoff
A L
AL
Nordahl
T
T
D000368:Aged / Q000523:psychology*; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000473:pathology / Q000523:psychology; D001921:Brain / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000453:epidemiology* / Q000473:pathology